NO OCR TEXT NO OCR TEXT juel per ipervil pnoso D inS au beHest compartment circie giving spiral dral-ilke handling w degrees last thre scribed detail b Keeping mind portional W/S ank C.u around tracked Stf ems lango ailerons result slmple uncoupled coi ited d illustr lw/b ran ailplanes Frc adral angl us dihedra rolled photos wer gher values ty 10 some luces greater spr quiva1ent dihedr of the effective ng force n yaw angle ir greater r yaw angles ig compti Part slues EDA rai Extreme values up 20 th spiral mt C1 b flight Since loading dvn 05 Rho goes down nother way airspeed2 prop wis an find ratio yaw angle required gles yaw obtained/yav proportio lw/b X ED order achieve sp aircraft yaw angle equal greater quired eoi balance neutral yaw obtained greater out circle unless put held yaw obtain will roll tighter tive varying top ru Anything increas obtained yaw req spiral stability formula crux c1 contains three Lets take detailed ratio vert tothe wp liiir E s 51mph ar momen atween FIgure 2 circular flight path tends force wing outboard yaw angle vertical stabilizer lines itself up airflow becomes quite clear illustration yaw angle sensitive both circle radius vertical stabilizer moment arm length late angle attack high angle tack gives high C1 vice versa Rho air density slugs per cubic foot about 0002377 sea level An increase C1 reduces spiral stability increasing C1 increases yaw ob tained given bank angle due reduced circle radius yaw required increased because both V2 term r reduced inverse proportion C1 general Gliders thermal best near maximum C1 just shy stall higher lift coefficients give less spiral stabil ity leads interesting effect de scribed later article Typical thermaling values C1 RC Sailpianes range 06 10 Thicker higher camber sections will high end range Typical Free Flight C1s range low 04 high 14 low values would found smaller models low-camber wings high est values would found larger thin high-camber wings such A2 class Towline Gliders Observations interesting three variables significantly affect spiral stability has important implica tions Wing loading does matter can ballast model affecting spiral stability Aspect ratio does matter long skinny wings short squat ones have about same impact spiral stabil ity Note though long wing requires long fuselage Size does matter can scale design up down spiral sta bility will retained same lift coeffi cient Circle radius bank angle matter plane stable bank angle stable bank angles assuming no change C1 Computations tested out spiral stabil ity relationship trusty computer spreadsheet described Dihedral series spreadsheet divides wing 20 spanwise segments allows fly various bank angles wing load ings dihedral angles schemes lift coef ficients yaw angles output value net roll moment given configuration fiddle dihedral angle yaw angle until roll moment zero did series configurations results showed plane spirally sta ble EDA x l/b 7 greater sake brevity lets define new variable 55 equal EDA x lw/b S stands spiral stability convenience relationship three variables plotted Figures 3 4 plots enable find third vari able already know other two have existing airplane EDA lw/b already known plots will show maximum lift coefficient plane will spirally stable example using Figure 3 can find plane 15 degrees EDA 04 lw/b will stable lift coefficient 105 less Figure 4 could used well reading plot difficult since must interpolate between lines designing plane scratch may want examine trade-off between tail boom length dihedral angle Pre sumably have already chosen wing section have estimate cir cling lift coefficient example say designing floater RC Sailplane expected thermal lift coeffi cient 10 Figure 4 permits direct exam ination boom/dihedral trade-off Fol lowing along C1 ine find could have 02 lw/b 27 de grees dihedral Wow Thats lot dihe dral plane will highiy sensitive rudder trim 04 l/b 145 degrees dihedral like 08 lw/b 75 degrees dihedral long tail boom low roll rate due low dihe dral anglesee Part Two Dihe dral series Because simplifying assumptions described below plots conserva tive Depending mostly size vertical stabilizer can back off some dihedral angle tail boom length can increase lift coefficient although just much tricky say Testing typical Two-Meter RC Sailplane found 43 approximately min imum value SS testing later Variables ignored insignificant some important variables have ig nored order boil problem down September 1990 103 35 30 25 MINIMUM20 EQUIVALENT DIHEDRAL ANGLE DEG15 10 5 0 fundamentals Most important extra outboard yaw due differential wing drag As plane circles outboard wing flying faster creates drag produces outboard yawing moment opposed vertical stabilizer der stabilizer generate opposing lift plane must yaw further outboard Large stabilizers can generate required lift small yaw angles small verticals can require much greater yaw angles 35 30 25 MINIMUM EQUIVALENT DIHEDRAL ANGLE DEG extra outboard yaw angle increases spiral stability increasing tendency plane roll out circle Free Flight models typically use small verticals consequent increase spiral stabil ity can quite great contrast RC Sailplanes typically have large vertical stabiliz ers track well produce little change spiral stability graphs ignore ef fect entirely since indicate spiral stabil ity achieved very large stabiliz Lv/b 2 era Smaller stabilizers give spiral sta bility Fuselage interference effects also ig nored since fuselages Gliders very small compared wings large fuselages Scale Free Flight models however have important ef fect spiral stability As generalization high-mounted wings large fuselages have dihedral lowmounted wings behave hnd less Also generous amount fuselage side area front center-of-gravity desta bilizes plane yaw increasing spiral stability same way reducing size vertical stabilizer does ef fects difficult quantify _____yond scope article Pendulum side-force effects ig nored because minor RC _____Sailplanes Side area above center-ofgravityor conversely low center-of1 21 3 1 4gravity relative side areaacts crease yaw-roll couple same way does increased dihedral Gas Free Flight models take advantage effect tall wing pylons heavy low-thrust engines effect still minor models typical wing dihedral need dihedral its efficient increase wing dihedral extend fuselage wing pylon Much smaller increases wetted area result last effect increases spiral sta bility ignored circling entire Glider coming down same rate inboard wing moves slowly gives inboard wing greater angle tack increasing spiral stability effect minor airplanes good glide ra tios significant very draggy models its extreme form becomes stall-spin maneuver inboard ______wing stalled outboard wing con tinues fly large simplifying assump ________________tions produce conservative results SS greater 57 airplane almost cer tain stable near 57 stability probable depending primarily size vertical stabilizer SS doesnt get close 57 craft almost sure unstable Testing spiral stability RC Sail planes given airplane configuration ___________ dihedral tail boom-to-span ratio fixed Thus airplane has maxi mum lift coefficient minimum speed spirally stable Normally want Glider stable up near its maximum lift coefficient easy test flying straight slowly come back pitch trim lever until plane seems sinking its minimum rate let plane fly hands-off model contin ues straight almost straight spirally stable begins circle its Dont surprised plane proves lack spiral stability common RC SailContinued page 106 r 20 15 10 5 0 10 44 02030405 VERTICAL TAIL MOMENT ARM TO WINGSPAN RATIO Lv/b Figure 4 chart shows minimum wing dihedral angle diminishes tail boom lengthened design lift coefficient reduced can very useful during pro cess designing since permits dIrect trade tall boom length reduced dihedral 0708 104 Model Aviation U4 0506070809111 DESIGN LIFT cOEFFICIENT ci Figure 3 Th minimum wing dihedral angie must greater plans higher lift coeffi cients shorter taii booms plot shows minimum equivalent dihedral angie guarantees spiral stability f range lift coefficients tail-boom-to-wIngspan ratios ivlb its cisc useful evaluating maximum stable im coefficient existing designs Southern Radio ControlLons fl/C Service Naples FLPhoenix NY 813 775-1554315 695-2448 s&D WC ServiceiI&J ElectronicsRivergote Hobby Center San Jose CAHowell MlGoodleftsville TN 408 281-1549517 546-2644615 859-3455 Authorized IVC Service Fallbrook CA 619 728-0440 Radio South Pensacola FL 904478-6745 Iraft Midwest IMI Northoille Ml 313 348-0095 Woiiitz PJC Jackoonoille FL 904 771-0613 DuMond C Service Carroliton TX 214 242-4682 Ocean County WC Service Toms River NJ 201 505-9477 planes seem marginal regard determine pitch trim setting plane becomes stable adjust slightly higher speed repeat experi ment Repeat cycle increasing speed slightly time until airplane no longer rolls circle speed model stable difference between speed optimum mini mum sink speed will indicate far off airplane much dihedral tail boom must increased Keep mind lift coefficient proportional speed squared model becomes stable twice optimum speed dihe dral tail boom off factor four Its best conduct experiments still morning late evening air Also sure model free asymnoetrical warps wing isnt heavier other performed experiment Two-Meter RC Sailplane Tutor airplane has simple V-dihedral two-piece wing bent piano wire joiner flown three different dihedral angles substituting three different joiners illus trated pictures model trimmed fly approximately minimum sink rate airspeed estimated C1 09 allowed fly hands-off dihedral angle 15 degrees airplane tracked well speeds would fly straight very nearly indefinitely very low speeds did tend wiggle turbulence bit really needs bigger ver tical stabilizer give margin Dutch roll 12 degrees dihedral plane ap peared verge circling min imum sink speed wandered over sky never actually settled circle higher speeds tracked true judged plane just spirally stable con figuration 57 degrees dihedral model definitely unstable Over period about 15 seconds would roll left right circle stabilize about 20 degrees bank angle Pulling back pitch trim simply increased bank angle trimmed plane estimated C1 04 interthermal cruise speed released straight flight continued fly straight Calculating spiral stability Tutor 12 degrees dihedral according formula get 12 x 0324 43 Alternatively low dihedral angle higher speed SS roughly 57 x 0324 46which fairly close 43 con sidering imprecise nature C1 esti mates Note values somewhat less ideal 57 derived earlier article probably because extra outboard yaw resulting differ ential wing drag Other methods obtaining spiral stabil ity Free Flight models use sorts meth ods enhance spiral stability Chief among Continued page 191 106 Model Aviation RCD r AIVfefl1SAJtVB~e1 QOflt ileltewwe we6 w0eCtB ggl iA%~6 ~JI ai99~ 6 Owe60 IA owAte bO SSao 06606 L400* 6gA6I icipating RCD Sticker Stations 9SR Products Sacramento CA 918 362-1962 FOR ORDERS ONLYLJL CODs 1 -8OO6337556ILLJJJWELCOME IN ALABAMA 347 3525 COLLECT TOP QUALITY FUEL FOR EXPERT OR BEGINNER NO RE-CLAIMED ALCOHOL O METHANE ONLY IS USED Designed tested give top performance both 2-cycle 4-cycle engines ringed Except engines requiring low lubricant content CONTAINS NEW TRULY SPACE AGE ADDITIVE developed outer apace vacuum new additive attaches internal metal parts engine will reduce friction much 80/o reduces heat wear absolute minimum WE HAVE 3 LUBRICANT BLENDS ALL SYNTHETIC OR SYNTHETIC BLEND CASTOR castor new high purity much cleaner burning castor ALL OUR FUELS CONTAIN ANTI-FOAMERS PREVENTERS WEAR ADDITIVES fuel developed priced tor individual club direct sales market dealer Inquiries invited Order gallon up MIx OK 4 gallon cases up ALL FUEL EXCEPT 54 GALLON DRUMS SHIPPED FREIGHT PRE-PAID Only continental USA TD 3 GalTo 23ITo63To 127 GIjAndIFreight l l24 Gal al12S al Drum 5% ..1095750700.650 . .. 57518500 120/o 5 .050. 900 7528000 250/o 5. 1400 0127547500 500/o 02200 ..21 502075780 00 Manufactured MACH-7 PO Box 1201 Enterprise Alabama 36330 houses relics displays both World Wars HMS Belfast moored Lon dons Thames River newest exhibit Cabinet War Rooms recently restored World War II condition under ground emergency headquarters Prime Minister Winston Churchill Taken together installations tell story two enormous wars raged around Englandparticularly skies over now-peaceful settings like Duxford Airfield Spiral/Beron-Rawdon Continued page 106 asymmetrical wing twist known washin washout Normally inboard wing washed twisted inci dence outboard wing washed out approximately equivalent yawing dihedraled wing outboard rudder trim should enhance spiral stability dont know Free Flight difference between approximately equivalent exactly same can important Another Free Flight method ballast inboard wing tip apply outboard rud der trim tip weight produces con stant inboard rolling moment rudder yields outboard yaw-roll couple very sensitive airspeed As model slows down tip weight rolls plane circle plane rolls up bowl effect increases airspeed rud September 1990 191 Bill Eff go * says OnlyPlans Pettern5 Sets give assorted designs yos west hove eslected best cleesic designs eli time choose hoer patterns soch part art important exclusive feature Ducted Fans Navy F4D-i Skyray 1 h soale ength 40ff wing span lg h RIO eotlbte Landing Gear RODF229gB 1 seats ength 32t$ wing span lbs wie RIO 3-0 sir R/O 5 RK725 lens ROOMgfgg One-Third Scale Piper TPacer PA-22 11R31g wing span sq wing area 20 30 old engines 4-5 oh RIO so 12 lb. SluR onersll length RO3g3029gb 1/3Piper Cub 1-3 Scale hR wing span ength 2005 sq wIng area4 oh RIO 030 old engines R030202996 Quarter Scale WWI SE-IA 001 wing span sq wing ares 5 70 tu 22 engines 0005-7 6 SPAD CXIII s70/wingsyons2l20sqin winguteos t3to3t engines Capable flynt-it captures thn imagination RCOS-g 6 FOKKER DR-i TRIPLANE 72 oring span C 1772 pa wing area 70 tot 00 engines OCOS0 82496 SOPWITH CAMEL F1 04 wing span 21 60 pa wing area ftlbs wls R/O wood ft balse construction over OPuq ft drawings 0005t 1 6 00wingspans2225sqivw cane 114 Scale Fokker 0-ViII 00 25 cid onoine 3-h ch OCOSO 0 Golden Age 114 Scale Curtiss Hawk P 1 00length04tfwingspan 2260uq 5 wing areas 1323 engines h 0/C RCOS-t 4 6 114 Scale CurtigaFalcon 03lnngthsltdwitgnpan3100 sqmnwmvg areaedchR/CRCOS-13g20961J 1/6 Scale Cessna AW 0twinospansgO0sqinwingarea 25to go ongirres channel 0/C RC6S-f $1496 roe ill Scale Purn Mogt 73Ifwingtpans4d0sinarno Pot 2040 engines annel 0/C RC0S-3 6 5111 stOnes Fouodlng Merebar AMA OPPO Hell Fewer Privon ore fur vurnyloto pbne sub asuorubly ft derajind parts huts PLEASE ADD 0200 tsr shipping Inrelllng tubal Now 1990 Pros Oats brovhxro refundablo Ion yvu h order WE TECHNICAL SERVICES RO 1 Box 2900 Santa Rosa Beach FL 32459 der becomes powerful balancing tip weight method stable circle direction still relies di hedral produce yaw-roll couple also relies bowl effect increase air speed increased bank angle Dihedral tail boom length pitch stability will still have strong effects spiral stability such model quick look Figure 3 will show low-dihedral airplanes such typical $599 o \C39\ Nut use Electric Starters Made 6061 Aluminum strong enough allow over tightening weighs under 1 oz 1 diameter 1t/t long 114 radius nose minimum AMA requirement 5/32 Torq Hole 3/4 thread depth can use thinnest props 11 thread sizes fit engines market Send us order & well mail out tast MADE IN THE USA B C PRODUCTS 111 N Starkweather Pam pa Texas 79065 1-800-441-4365 US & Canada aileron-controlled RC Sailplanes havent shadow hope being spirally stable reasonable lift coefficients example plane 30 degrees dihedral lift coefficient 07 must have tail boom 13 times long wingspan type models spiral stability can achieved artificial mechanisms example would produce artificial yaw-roll couple means yaw sensor hooked up run ailerons rate D103210/32 DOSBO5-8mm D123212/32 D06106-1mm 107107-1mm D08108-1mm D81258-125mm D101210-125mm D14281/4-28 151625/1624 38243/8-24 VISA MASTERCARD MONEY ORDERS ACCEPTED DEALER INQUIRES WELCOME ENYA 15 5-8mm SS2O SS45 1/4-28 19 to 80 7-1mm 120 8-1mm FOX 19 45 1/4-28 60 to 120 5/16-24 HB ALL SIZES 1/4-28 HP 40 6-1mm 120 5/16-24 others 1/4-28 IRVING ALL 1/4-28 K&B 19 611/428 OS 10 5-8mm 15 12/32 20 6-1mm 21 50 1/4-28 60 120 5/16-24 108 3/8-24 ROSSI ALL 8-125mm SUPERTIGER 11 to 15 5-8mm 19 to 60 1/4-28 61 to 90 5/16-24 2000 6000 10-125mm SATIO3Oto60 6-1mm 65 to90 71mm 120 to 270 8-125mm WEBRA 28 61 1/4-28 80 90 8-125mm MALONEY 100 3/8-24 .THESUPERIORGLOWPLUGSFO GO FASTFLYERSAREBACKII Puts sting engine Unique flat-wound spiral coil element high temperature glass-to-metal seal add up faster ignition increased RPM 1 /2A GloBee plugs designed exclusively 049/051 Cox engines - Ask new GB-5RX Speed Plug GB-SR Racing Plug GB-5P Spert Plug local dealer today unavailable locally write call Twinn-K collect pricing delivery information FREE GloBee Catalog MAKE THE GLOBEE / INDY CONNECTION Twinn-K Inc 10296 W Washington St Indianapolis IN 46231 Telephone 317-839-6579 FAX 317-839-8928 192 Model Aviation aileron deflection function yaw angle sufficient spiral stability could achieved Another method would employ direct mechanical link between yaw vanes aileronsthough youd probably have watchmaker get work Intro ducing yaw-roll couple will make roll axis sensitive deviations yaw axis particular attention will have paid rudder coordination during transi tional maneuvers Another possibility flat-wing air planes would incorporate rate gyro scope gyro could sense yaw rate drive ailerons roll out As plane rolled circle its bank angle yaw rate increase ailerons deflect roll plane out circle response yaw rate may provide spiral stability chance however phase diffi culties between yaw rate roll accelera tion would develop causing disruptive yawroll oscillations similar Dutch roll successful experiment thought worth trying last fix wifes large slow aileron Sailplane Tango plane originally flown zero dihe dral major pain thermal due lack spiral stability Increasing EDA two degrees made noticeable improve ment still great challenge thermal efficiently slowly installed Futabas simple least expen sive rate-sensitive gyroscope model FP G134 ballast box plane unit consists two components gyro box electronics box gyro stalled in-line between receiver aileron servo Tango uses separate rudder servo connected ai leron output receiver Y connector couples rudder ailerons control adverse yaw However rudder servo still hooked direcfly receiver unaffected gyro gyro installation illustrated pictures electronics box has little knob actu ally screw adjusts effect gyro aileron servo zero 100% 0% gyro has no ef Continued page 194 /9 ilttilt --MIt Ii tPJOflC OU QOtVT FLf WELL I1iVfRi 1I ISLiRINO%11 St 1IC m JJJ0 QUADRA RT 1 NEODESHA KS 66757 316325-2821 DEALERS CALL SEND $100 FOR COMPLETE CATALOG fect higher settings gyro input mixes pilots input control ai lerons higher setting the gyro has say about would appear 100% setting maximum con trol input gyro nearly equals maxi mum input pilots stick gyro box installed senses yaw rate reversing switch electronics box set give right aileron left yaw rate vice versa word about rate gyros may helpful contrast regular gyros sense change orientationin degrees instancerate gyros sense rate change orienta tion say degrees per second cant tell way pointing way fast turning bottom line gizmo works adjustment about 50% sensitivity plane flies extremely well model actually flies straight indefinitely straightens out circles slowly itself has feel circle good-performing polyhedral ship retains immediate roll response aileron-controlled craft No adverse effects noted flying model through entire envelope Some better fliers Soaring Union Los Angeles have flown plane gyro responses ranging enthusiastic acceptance grudging admis sion did indeed seem nice am excited about development means sorts low-dihedral aileron AJKUMUIJbL iIANT SHARK ARC PRE-BUILT G SHARK S21495 SEE YOUR HOBBY DEALER FIRST SEND STAMPED #10 ENVELOPE FOR INFO KINGS WAY RIG HOBBY SUPPLY 5559 RICHMOND HOUSTON TX 77056 DEALERS ONLY 1-800-621-7783 194 Model Aviation AT LAST An Effect ye H gh Tech Engine Cleaner R/G Engines Removes Burned-On Fuel Residue Encrusted Carbon anteed ONLY $695 CA residents add 725% lax Clean Engines-Run Cooler-Last Longer Send Check Money OrderTo AIRBORNE HOBBIES 3764 30TH ST SAN DIEGO CA 92104 619543-9703 DEALERS INQUIRES WELCOME tIN SUPERTANKS & SUPERMUFFLERS ZINGER WOOD PROPS GIANT SCALE R/C PLANS C #No663 Pea Patch $900 RC Sportster spans 60 uses 40150 4-stroke power Two plan shts No 664 Stuka Stunt $500 CL V2A Stunter semiscale spans 37 No 665 Conscientious Objector $575 FF Mulvihill Rubber competition plane spans 501/2 flat No 193 StIletto CL Stunt nindel McDonald winner 1976 1980 1982 FAt Wodd Champs $ 375 No 262Craahmaater- Ct Crash-pruof trainer two tizet1 5130 35/40 powor$125 No 3101930 Fleet Biplane AC Sport Scale 35140 4-clronnel Wingspan 56 e Ten streets6625 No 314Drake II AC Ken Witards flying boat 3-channel 15-power Fly 1mm land mmovabln gear . No 326Taylor Cub AC Don Srnlfs Schoolyard-Scale 049s 2-3 channel Spoon 50 in$350 No 332Zephyr AC Sinaf 2-channel glider hand-launch tow thermal slope soaring6200 No 386Laaer 200 AC Sport Scale replica champineship Aerehafic tiler Uses 40 power 4-5 channel Two sheets$1075 No 4471/2A Miwa America AC Old-Tuner WA Texaco model 049 glow 2-channels$650 No 4604-40 AC Shoelder-wiog sport filer 4-cycle 40-nine engine 4 channelo$650 No 465Blue Max II AC Fun-fly sportster 40-size engines spans 52 Lightweight stonctere$700 No 533Cewana C-37 AC Schoolyard Scale ni tamoos 3& plane 009/10 power 2-ch opans 42Va in6500 No 539Slmitar Slow4dotlon 15 AC Tailless flying wing 15 engines spans 98 ones 3-ch AC$350 No 569Elactroatreak AC Electric aembatic plane spans 44 ones 05 motorS550 No 572TR-260 AC Sport Scale Aerohalic plane 4-strulre 65/66 power spans 66 in61100 No 576Serendlpityt ndoor 025 record-holder spans 17/ in$325 No 578Scinwelzer 1-26B AC Quarter-ucale Sailplane spans 125 Two plan sheets61475 No 581Gee Bee Moefel Y AC Golden Age Racer spans 72 1A scale 60 power Thwe plus sheets61175 No 586Snapdragon AC Fun-fly/sponster 25/30 engines spans 45 In6698 No 588Marlah AC Slope-Soaring Sailplane spans 41 uses 2 AC channels6425 No593Taytorcralt AC Sport Scale llghtplane builds us standard 2-placer clipped-wing air show stenter Spans either 70 50 35/40 two-stmfre 45/48 four-ntmhe engine Two plan sheets no dncomentatmn$1000 No586Coronet 150 RC-Assint Old-liner enlarged 15914k spans 72 uses 40-size 4-sImlreI 30-size 2-tube6850 No601NIcicel AC Sportster WA engine 3 AC channels Spans 44 in$500 No 603Sparrow Hawk P30 FF Competitfon rebber-power plane woo 87 Nuts Spans 30 in$225 No607Curtlaw Seegull AC Glout Scale biplane spant 50 uses Oeadra/Zeuoah power Three plan sheets dec62498 No mTapeewing AC WA Pylon Racer spans 29 Plan plan use ports template about$698 No 610Protobype AC Sport biplane spans 48 uses 45/2-cycle 85/4-cycle power$650 No 619KeIth RIder R4 FF Scale Goldan Age racer rebber power spans 18 in6300 No 620GImlet 60 AC Spert/Pattem plate spans 60 iii 45/50 enguw 2 sheets61100 No 623Henderwom Longater AC Quarter-Scale 1933 fhwer spans 90h 4-strube 45/46 engine 3 plan sht no dec$1698 No624KelaIrer Laric AC Quarter-scale hontehuit spans 69 69198 4-Otmlre power 2 plait sheets dec61100 No 626Sweepee AC Spoil/Pattem canards foiward-sweyl wing spans 64 uses 48 power 2 plan sheets61300 No628Prime Cut AC SportlAerotsatic plane spuss 90 uses Quadra 35/40-sine power Two plus sheets61300 No 630OrIginal Ply Baby AC Old-Thiter spans 72 uses 19125 2-cycle 484-cycle power 2 plan sheets61150 No 635The Gambler FF Indoor Sestoeran rebber-power cable plane spans 15% in6200 No 836Keytwo AC Tn-geared low-wing sportsler 29125 power spans 44 in$575 No637A6 Shrike FF Compefitine plane AMA Clauses 5 15/23 power spans 60 in$675 No 638Owl Racer CL WA Scale Racer 049 power spans 20 6225 No 839SIcyvoIt AC Tn-geared Electric aerubatic sportoter 05/15 power spans 50 in6850 No 640Bird Prey CL AMA Fast Combat plane 36 power spans 5334 in$550 No 641UI Ole Reliable AC Old-tinter spoil filer spans 50% WA engines$575 No 642BIpe 89 CL Partlat plus updates deflofis 48 nersbon 3Scc power Spans 2234 in6225 No643Noctule IIB FF Baflulte flying wing CO2 power spoon 30 in$325 No 644Beliance ColumbIa AC Schoolyard Scale 2 AC channels WA engine Wingspan 46 m$575 No 645Lalrd Solution Cl Ponfile Scale biplane spans 36 25/35 pewer6575 No 646WInter Hawk FF Robber-power Coupe dHleer cempefiflon plane spans 47 in6375 No647Cox Speeded CL Semincale biplane WA enne spans 24 in6300 No646Cufllwa OC-2 FF Sculls Outdoor Gas Ftying Scale biplane uses electric power spans 24 HiLine lohnr-6 motor$325 No640Thlngemabob AC/CL Mutfimede trainer 25 gas 05 electric power spans 51 in$475 No 65047/66 RC Special AC Aembafic sport plane 48 power spans 61 3 plan sheetsS1075 No 651Conwortlum AC Husri-Lanoch HI-Start Coder spans 60 in6050 No652Oar Ptedenmaeea AC Lute-wing spoil plane 29125 power npons 55 -$675 No 663Aventl CL Profile Sport Scale canard hisliner twin DOgs spans 38 in$575 No 654Tamiecag AC Trainer/spottster styled Ibe F14 spaus 66 45/61 power Four plan sheets$1525 No 6S5Aetroalar FF AMA Class A/B Gas plane spans 67 uses 3 25/350cc power$800 No 856XP13C CL Profile 15 Carrier plane spans 277A in6550 No657Super Squire AC Trainer 35/48 2-stonbe 53 4-strobe power spans 9834 in6750 No 658SIturiken Streak CL Trainer uses 2-line Moonline control spans 17 WA power$225 No659Boom Box FF Walefleld Rubber competitine plane spans 54 in6400 No 660Volkaplene AC Electric-powered sportster 05 motor spans S6 2 plan shts6925 No661Embey-Omatlc FF Embryo Enderance mbber-power plane spans 20 in6200 No662Boxklte CL Scale antique caned pusher biplane spans 42 2 plan shtsS1100 0 Os 0 o C%J 0 gC Co tous Q 0 05 no 6E 050 o - Co FJ t- tog5 0 C 0 - 0 - ID 05 005 0 c us n 00 0 00 us Co-s 0 0 E-d 00 cs 0 2 0 I U0 E N STREET 0CITY - Circle numbers plans wish order best handling please include re quests payment some other service withyourplans order 193262310314326332386447 460465533539569572576578 581586588593598601603607 609610619620623624626628 630635636637638639640641 642643644645646647648649 650651652653654655656657 658659660661662663664665 Plan price includes first class postage US delivery Air Mail over 300 miles orders non-US address lease add $258 Air Mail osta e handlin Ian Make Check money order payable US funds drawn US bank Model Aviation AMA 1810 Samuel Morse Reston VA 22090 Please allow 3 6 weeks delivery Please print CarefullyEnclosed $ _______________________ ___________________________________________ AMA No _______________ airplanes can practical pleasurable fly may also mean ultimate dura tion cross-country RC Sailplane now large flat-wing variable-camber aileroncontrolled configuration instead sim pler fixed-camber rudder elevator ar rangement caution have course tried sys tem 100% sensitivity setting plane does interesting 1-Hz flat yaw oscil lation about plus minus 15 degrees ascribe adverse yaw coupling gyro model remained flyable no harm done might want come up optimum setting instead starting working way down Summary conclusions Spiral stability measure tendency airplane spiral straight circling flight Its primarily function Equiv alent Dihedral Angle EDA tail boom-towingspan ratio lIb wing lift coeffi cient C1 significant secondary variable yaw stability plane function fuselage proportions ver tical stabilizer size Airplanes strong yaw stability spirally stable EDA X lw/b C1 greater equal about 57 Air planes modest yaw stability will sta ble somewhat lower values relation ship illustrated Figures 3 4 An experimental procedure de scribed determining degree spiral stability RC Sailplanes test TwoMeter Sailplane showed good agreement theory control dihedral angle tail boom proportion lift coefficient primary means achieving spiral stability other methods can used Free Flight mod els typically incorporate asymmetrical trim balance arrangement effec tive oaly circle direction mechanical means well successful has tested article incor porates yaw rate gyro drive aile rons As practical inexpensive way provide spiral stability aileron-con trolled Sailplanes exciting devel opment Next month Part Two will describe effect circling flight spiral stability pitch trim yaw angle Southwest PC Flying Year round flight school Five day course $350 Learn fLy planes Send SASE conlete info 2818 CaroLina NE Albuquerque NM 87110 505 881-3799 196 Model Aviation IMPORTED DIESELS A-MAuroraDCEDMVVSMBia*nya PAWTaplln Standard R/C.0864S Acre & MarIne VlntegeAperg Comfiest Seed $100 Informatlo CARLSON ENGINE IMPORTS 314 East Marcomi Phoenix AZ 85022 _________________________________________ ZIP _______________________________
Edition: Model Aviation - 1990/09
Page Numbers: 100, 101, 102, 103, 104, 106, 191, 192, 194, 196
NO OCR TEXT NO OCR TEXT juel per ipervil pnoso D inS au beHest compartment circie giving spiral dral-ilke handling w degrees last thre scribed detail b Keeping mind portional W/S ank C.u around tracked Stf ems lango ailerons result slmple uncoupled coi ited d illustr lw/b ran ailplanes Frc adral angl us dihedra rolled photos wer gher values ty 10 some luces greater spr quiva1ent dihedr of the effective ng force n yaw angle ir greater r yaw angles ig compti Part slues EDA rai Extreme values up 20 th spiral mt C1 b flight Since loading dvn 05 Rho goes down nother way airspeed2 prop wis an find ratio yaw angle required gles yaw obtained/yav proportio lw/b X ED order achieve sp aircraft yaw angle equal greater quired eoi balance neutral yaw obtained greater out circle unless put held yaw obtain will roll tighter tive varying top ru Anything increas obtained yaw req spiral stability formula crux c1 contains three Lets take detailed ratio vert tothe wp liiir E s 51mph ar momen atween FIgure 2 circular flight path tends force wing outboard yaw angle vertical stabilizer lines itself up airflow becomes quite clear illustration yaw angle sensitive both circle radius vertical stabilizer moment arm length late angle attack high angle tack gives high C1 vice versa Rho air density slugs per cubic foot about 0002377 sea level An increase C1 reduces spiral stability increasing C1 increases yaw ob tained given bank angle due reduced circle radius yaw required increased because both V2 term r reduced inverse proportion C1 general Gliders thermal best near maximum C1 just shy stall higher lift coefficients give less spiral stabil ity leads interesting effect de scribed later article Typical thermaling values C1 RC Sailpianes range 06 10 Thicker higher camber sections will high end range Typical Free Flight C1s range low 04 high 14 low values would found smaller models low-camber wings high est values would found larger thin high-camber wings such A2 class Towline Gliders Observations interesting three variables significantly affect spiral stability has important implica tions Wing loading does matter can ballast model affecting spiral stability Aspect ratio does matter long skinny wings short squat ones have about same impact spiral stabil ity Note though long wing requires long fuselage Size does matter can scale design up down spiral sta bility will retained same lift coeffi cient Circle radius bank angle matter plane stable bank angle stable bank angles assuming no change C1 Computations tested out spiral stabil ity relationship trusty computer spreadsheet described Dihedral series spreadsheet divides wing 20 spanwise segments allows fly various bank angles wing load ings dihedral angles schemes lift coef ficients yaw angles output value net roll moment given configuration fiddle dihedral angle yaw angle until roll moment zero did series configurations results showed plane spirally sta ble EDA x l/b 7 greater sake brevity lets define new variable 55 equal EDA x lw/b S stands spiral stability convenience relationship three variables plotted Figures 3 4 plots enable find third vari able already know other two have existing airplane EDA lw/b already known plots will show maximum lift coefficient plane will spirally stable example using Figure 3 can find plane 15 degrees EDA 04 lw/b will stable lift coefficient 105 less Figure 4 could used well reading plot difficult since must interpolate between lines designing plane scratch may want examine trade-off between tail boom length dihedral angle Pre sumably have already chosen wing section have estimate cir cling lift coefficient example say designing floater RC Sailplane expected thermal lift coeffi cient 10 Figure 4 permits direct exam ination boom/dihedral trade-off Fol lowing along C1 ine find could have 02 lw/b 27 de grees dihedral Wow Thats lot dihe dral plane will highiy sensitive rudder trim 04 l/b 145 degrees dihedral like 08 lw/b 75 degrees dihedral long tail boom low roll rate due low dihe dral anglesee Part Two Dihe dral series Because simplifying assumptions described below plots conserva tive Depending mostly size vertical stabilizer can back off some dihedral angle tail boom length can increase lift coefficient although just much tricky say Testing typical Two-Meter RC Sailplane found 43 approximately min imum value SS testing later Variables ignored insignificant some important variables have ig nored order boil problem down September 1990 103 35 30 25 MINIMUM20 EQUIVALENT DIHEDRAL ANGLE DEG15 10 5 0 fundamentals Most important extra outboard yaw due differential wing drag As plane circles outboard wing flying faster creates drag produces outboard yawing moment opposed vertical stabilizer der stabilizer generate opposing lift plane must yaw further outboard Large stabilizers can generate required lift small yaw angles small verticals can require much greater yaw angles 35 30 25 MINIMUM EQUIVALENT DIHEDRAL ANGLE DEG extra outboard yaw angle increases spiral stability increasing tendency plane roll out circle Free Flight models typically use small verticals consequent increase spiral stabil ity can quite great contrast RC Sailplanes typically have large vertical stabiliz ers track well produce little change spiral stability graphs ignore ef fect entirely since indicate spiral stabil ity achieved very large stabiliz Lv/b 2 era Smaller stabilizers give spiral sta bility Fuselage interference effects also ig nored since fuselages Gliders very small compared wings large fuselages Scale Free Flight models however have important ef fect spiral stability As generalization high-mounted wings large fuselages have dihedral lowmounted wings behave hnd less Also generous amount fuselage side area front center-of-gravity desta bilizes plane yaw increasing spiral stability same way reducing size vertical stabilizer does ef fects difficult quantify _____yond scope article Pendulum side-force effects ig nored because minor RC _____Sailplanes Side area above center-ofgravityor conversely low center-of1 21 3 1 4gravity relative side areaacts crease yaw-roll couple same way does increased dihedral Gas Free Flight models take advantage effect tall wing pylons heavy low-thrust engines effect still minor models typical wing dihedral need dihedral its efficient increase wing dihedral extend fuselage wing pylon Much smaller increases wetted area result last effect increases spiral sta bility ignored circling entire Glider coming down same rate inboard wing moves slowly gives inboard wing greater angle tack increasing spiral stability effect minor airplanes good glide ra tios significant very draggy models its extreme form becomes stall-spin maneuver inboard ______wing stalled outboard wing con tinues fly large simplifying assump ________________tions produce conservative results SS greater 57 airplane almost cer tain stable near 57 stability probable depending primarily size vertical stabilizer SS doesnt get close 57 craft almost sure unstable Testing spiral stability RC Sail planes given airplane configuration ___________ dihedral tail boom-to-span ratio fixed Thus airplane has maxi mum lift coefficient minimum speed spirally stable Normally want Glider stable up near its maximum lift coefficient easy test flying straight slowly come back pitch trim lever until plane seems sinking its minimum rate let plane fly hands-off model contin ues straight almost straight spirally stable begins circle its Dont surprised plane proves lack spiral stability common RC SailContinued page 106 r 20 15 10 5 0 10 44 02030405 VERTICAL TAIL MOMENT ARM TO WINGSPAN RATIO Lv/b Figure 4 chart shows minimum wing dihedral angle diminishes tail boom lengthened design lift coefficient reduced can very useful during pro cess designing since permits dIrect trade tall boom length reduced dihedral 0708 104 Model Aviation U4 0506070809111 DESIGN LIFT cOEFFICIENT ci Figure 3 Th minimum wing dihedral angie must greater plans higher lift coeffi cients shorter taii booms plot shows minimum equivalent dihedral angie guarantees spiral stability f range lift coefficients tail-boom-to-wIngspan ratios ivlb its cisc useful evaluating maximum stable im coefficient existing designs Southern Radio ControlLons fl/C Service Naples FLPhoenix NY 813 775-1554315 695-2448 s&D WC ServiceiI&J ElectronicsRivergote Hobby Center San Jose CAHowell MlGoodleftsville TN 408 281-1549517 546-2644615 859-3455 Authorized IVC Service Fallbrook CA 619 728-0440 Radio South Pensacola FL 904478-6745 Iraft Midwest IMI Northoille Ml 313 348-0095 Woiiitz PJC Jackoonoille FL 904 771-0613 DuMond C Service Carroliton TX 214 242-4682 Ocean County WC Service Toms River NJ 201 505-9477 planes seem marginal regard determine pitch trim setting plane becomes stable adjust slightly higher speed repeat experi ment Repeat cycle increasing speed slightly time until airplane no longer rolls circle speed model stable difference between speed optimum mini mum sink speed will indicate far off airplane much dihedral tail boom must increased Keep mind lift coefficient proportional speed squared model becomes stable twice optimum speed dihe dral tail boom off factor four Its best conduct experiments still morning late evening air Also sure model free asymnoetrical warps wing isnt heavier other performed experiment Two-Meter RC Sailplane Tutor airplane has simple V-dihedral two-piece wing bent piano wire joiner flown three different dihedral angles substituting three different joiners illus trated pictures model trimmed fly approximately minimum sink rate airspeed estimated C1 09 allowed fly hands-off dihedral angle 15 degrees airplane tracked well speeds would fly straight very nearly indefinitely very low speeds did tend wiggle turbulence bit really needs bigger ver tical stabilizer give margin Dutch roll 12 degrees dihedral plane ap peared verge circling min imum sink speed wandered over sky never actually settled circle higher speeds tracked true judged plane just spirally stable con figuration 57 degrees dihedral model definitely unstable Over period about 15 seconds would roll left right circle stabilize about 20 degrees bank angle Pulling back pitch trim simply increased bank angle trimmed plane estimated C1 04 interthermal cruise speed released straight flight continued fly straight Calculating spiral stability Tutor 12 degrees dihedral according formula get 12 x 0324 43 Alternatively low dihedral angle higher speed SS roughly 57 x 0324 46which fairly close 43 con sidering imprecise nature C1 esti mates Note values somewhat less ideal 57 derived earlier article probably because extra outboard yaw resulting differ ential wing drag Other methods obtaining spiral stabil ity Free Flight models use sorts meth ods enhance spiral stability Chief among Continued page 191 106 Model Aviation RCD r AIVfefl1SAJtVB~e1 QOflt ileltewwe we6 w0eCtB ggl iA%~6 ~JI ai99~ 6 Owe60 IA owAte bO SSao 06606 L400* 6gA6I icipating RCD Sticker Stations 9SR Products Sacramento CA 918 362-1962 FOR ORDERS ONLYLJL CODs 1 -8OO6337556ILLJJJWELCOME IN ALABAMA 347 3525 COLLECT TOP QUALITY FUEL FOR EXPERT OR BEGINNER NO RE-CLAIMED ALCOHOL O METHANE ONLY IS USED Designed tested give top performance both 2-cycle 4-cycle engines ringed Except engines requiring low lubricant content CONTAINS NEW TRULY SPACE AGE ADDITIVE developed outer apace vacuum new additive attaches internal metal parts engine will reduce friction much 80/o reduces heat wear absolute minimum WE HAVE 3 LUBRICANT BLENDS ALL SYNTHETIC OR SYNTHETIC BLEND CASTOR castor new high purity much cleaner burning castor ALL OUR FUELS CONTAIN ANTI-FOAMERS PREVENTERS WEAR ADDITIVES fuel developed priced tor individual club direct sales market dealer Inquiries invited Order gallon up MIx OK 4 gallon cases up ALL FUEL EXCEPT 54 GALLON DRUMS SHIPPED FREIGHT PRE-PAID Only continental USA TD 3 GalTo 23ITo63To 127 GIjAndIFreight l l24 Gal al12S al Drum 5% ..1095750700.650 . .. 57518500 120/o 5 .050. 900 7528000 250/o 5. 1400 0127547500 500/o 02200 ..21 502075780 00 Manufactured MACH-7 PO Box 1201 Enterprise Alabama 36330 houses relics displays both World Wars HMS Belfast moored Lon dons Thames River newest exhibit Cabinet War Rooms recently restored World War II condition under ground emergency headquarters Prime Minister Winston Churchill Taken together installations tell story two enormous wars raged around Englandparticularly skies over now-peaceful settings like Duxford Airfield Spiral/Beron-Rawdon Continued page 106 asymmetrical wing twist known washin washout Normally inboard wing washed twisted inci dence outboard wing washed out approximately equivalent yawing dihedraled wing outboard rudder trim should enhance spiral stability dont know Free Flight difference between approximately equivalent exactly same can important Another Free Flight method ballast inboard wing tip apply outboard rud der trim tip weight produces con stant inboard rolling moment rudder yields outboard yaw-roll couple very sensitive airspeed As model slows down tip weight rolls plane circle plane rolls up bowl effect increases airspeed rud September 1990 191 Bill Eff go * says OnlyPlans Pettern5 Sets give assorted designs yos west hove eslected best cleesic designs eli time choose hoer patterns soch part art important exclusive feature Ducted Fans Navy F4D-i Skyray 1 h soale ength 40ff wing span lg h RIO eotlbte Landing Gear RODF229gB 1 seats ength 32t$ wing span lbs wie RIO 3-0 sir R/O 5 RK725 lens ROOMgfgg One-Third Scale Piper TPacer PA-22 11R31g wing span sq wing area 20 30 old engines 4-5 oh RIO so 12 lb. SluR onersll length RO3g3029gb 1/3Piper Cub 1-3 Scale hR wing span ength 2005 sq wIng area4 oh RIO 030 old engines R030202996 Quarter Scale WWI SE-IA 001 wing span sq wing ares 5 70 tu 22 engines 0005-7 6 SPAD CXIII s70/wingsyons2l20sqin winguteos t3to3t engines Capable flynt-it captures thn imagination RCOS-g 6 FOKKER DR-i TRIPLANE 72 oring span C 1772 pa wing area 70 tot 00 engines OCOS0 82496 SOPWITH CAMEL F1 04 wing span 21 60 pa wing area ftlbs wls R/O wood ft balse construction over OPuq ft drawings 0005t 1 6 00wingspans2225sqivw cane 114 Scale Fokker 0-ViII 00 25 cid onoine 3-h ch OCOSO 0 Golden Age 114 Scale Curtiss Hawk P 1 00length04tfwingspan 2260uq 5 wing areas 1323 engines h 0/C RCOS-t 4 6 114 Scale CurtigaFalcon 03lnngthsltdwitgnpan3100 sqmnwmvg areaedchR/CRCOS-13g20961J 1/6 Scale Cessna AW 0twinospansgO0sqinwingarea 25to go ongirres channel 0/C RC6S-f $1496 roe ill Scale Purn Mogt 73Ifwingtpans4d0sinarno Pot 2040 engines annel 0/C RC0S-3 6 5111 stOnes Fouodlng Merebar AMA OPPO Hell Fewer Privon ore fur vurnyloto pbne sub asuorubly ft derajind parts huts PLEASE ADD 0200 tsr shipping Inrelllng tubal Now 1990 Pros Oats brovhxro refundablo Ion yvu h order WE TECHNICAL SERVICES RO 1 Box 2900 Santa Rosa Beach FL 32459 der becomes powerful balancing tip weight method stable circle direction still relies di hedral produce yaw-roll couple also relies bowl effect increase air speed increased bank angle Dihedral tail boom length pitch stability will still have strong effects spiral stability such model quick look Figure 3 will show low-dihedral airplanes such typical $599 o \C39\ Nut use Electric Starters Made 6061 Aluminum strong enough allow over tightening weighs under 1 oz 1 diameter 1t/t long 114 radius nose minimum AMA requirement 5/32 Torq Hole 3/4 thread depth can use thinnest props 11 thread sizes fit engines market Send us order & well mail out tast MADE IN THE USA B C PRODUCTS 111 N Starkweather Pam pa Texas 79065 1-800-441-4365 US & Canada aileron-controlled RC Sailplanes havent shadow hope being spirally stable reasonable lift coefficients example plane 30 degrees dihedral lift coefficient 07 must have tail boom 13 times long wingspan type models spiral stability can achieved artificial mechanisms example would produce artificial yaw-roll couple means yaw sensor hooked up run ailerons rate D103210/32 DOSBO5-8mm D123212/32 D06106-1mm 107107-1mm D08108-1mm D81258-125mm D101210-125mm D14281/4-28 151625/1624 38243/8-24 VISA MASTERCARD MONEY ORDERS ACCEPTED DEALER INQUIRES WELCOME ENYA 15 5-8mm SS2O SS45 1/4-28 19 to 80 7-1mm 120 8-1mm FOX 19 45 1/4-28 60 to 120 5/16-24 HB ALL SIZES 1/4-28 HP 40 6-1mm 120 5/16-24 others 1/4-28 IRVING ALL 1/4-28 K&B 19 611/428 OS 10 5-8mm 15 12/32 20 6-1mm 21 50 1/4-28 60 120 5/16-24 108 3/8-24 ROSSI ALL 8-125mm SUPERTIGER 11 to 15 5-8mm 19 to 60 1/4-28 61 to 90 5/16-24 2000 6000 10-125mm SATIO3Oto60 6-1mm 65 to90 71mm 120 to 270 8-125mm WEBRA 28 61 1/4-28 80 90 8-125mm MALONEY 100 3/8-24 .THESUPERIORGLOWPLUGSFO GO FASTFLYERSAREBACKII Puts sting engine Unique flat-wound spiral coil element high temperature glass-to-metal seal add up faster ignition increased RPM 1 /2A GloBee plugs designed exclusively 049/051 Cox engines - Ask new GB-5RX Speed Plug GB-SR Racing Plug GB-5P Spert Plug local dealer today unavailable locally write call Twinn-K collect pricing delivery information FREE GloBee Catalog MAKE THE GLOBEE / INDY CONNECTION Twinn-K Inc 10296 W Washington St Indianapolis IN 46231 Telephone 317-839-6579 FAX 317-839-8928 192 Model Aviation aileron deflection function yaw angle sufficient spiral stability could achieved Another method would employ direct mechanical link between yaw vanes aileronsthough youd probably have watchmaker get work Intro ducing yaw-roll couple will make roll axis sensitive deviations yaw axis particular attention will have paid rudder coordination during transi tional maneuvers Another possibility flat-wing air planes would incorporate rate gyro scope gyro could sense yaw rate drive ailerons roll out As plane rolled circle its bank angle yaw rate increase ailerons deflect roll plane out circle response yaw rate may provide spiral stability chance however phase diffi culties between yaw rate roll accelera tion would develop causing disruptive yawroll oscillations similar Dutch roll successful experiment thought worth trying last fix wifes large slow aileron Sailplane Tango plane originally flown zero dihe dral major pain thermal due lack spiral stability Increasing EDA two degrees made noticeable improve ment still great challenge thermal efficiently slowly installed Futabas simple least expen sive rate-sensitive gyroscope model FP G134 ballast box plane unit consists two components gyro box electronics box gyro stalled in-line between receiver aileron servo Tango uses separate rudder servo connected ai leron output receiver Y connector couples rudder ailerons control adverse yaw However rudder servo still hooked direcfly receiver unaffected gyro gyro installation illustrated pictures electronics box has little knob actu ally screw adjusts effect gyro aileron servo zero 100% 0% gyro has no ef Continued page 194 /9 ilttilt --MIt Ii tPJOflC OU QOtVT FLf WELL I1iVfRi 1I ISLiRINO%11 St 1IC m JJJ0 QUADRA RT 1 NEODESHA KS 66757 316325-2821 DEALERS CALL SEND $100 FOR COMPLETE CATALOG fect higher settings gyro input mixes pilots input control ai lerons higher setting the gyro has say about would appear 100% setting maximum con trol input gyro nearly equals maxi mum input pilots stick gyro box installed senses yaw rate reversing switch electronics box set give right aileron left yaw rate vice versa word about rate gyros may helpful contrast regular gyros sense change orientationin degrees instancerate gyros sense rate change orienta tion say degrees per second cant tell way pointing way fast turning bottom line gizmo works adjustment about 50% sensitivity plane flies extremely well model actually flies straight indefinitely straightens out circles slowly itself has feel circle good-performing polyhedral ship retains immediate roll response aileron-controlled craft No adverse effects noted flying model through entire envelope Some better fliers Soaring Union Los Angeles have flown plane gyro responses ranging enthusiastic acceptance grudging admis sion did indeed seem nice am excited about development means sorts low-dihedral aileron AJKUMUIJbL iIANT SHARK ARC PRE-BUILT G SHARK S21495 SEE YOUR HOBBY DEALER FIRST SEND STAMPED #10 ENVELOPE FOR INFO KINGS WAY RIG HOBBY SUPPLY 5559 RICHMOND HOUSTON TX 77056 DEALERS ONLY 1-800-621-7783 194 Model Aviation AT LAST An Effect ye H gh Tech Engine Cleaner R/G Engines Removes Burned-On Fuel Residue Encrusted Carbon anteed ONLY $695 CA residents add 725% lax Clean Engines-Run Cooler-Last Longer Send Check Money OrderTo AIRBORNE HOBBIES 3764 30TH ST SAN DIEGO CA 92104 619543-9703 DEALERS INQUIRES WELCOME tIN SUPERTANKS & SUPERMUFFLERS ZINGER WOOD PROPS GIANT SCALE R/C PLANS C #No663 Pea Patch $900 RC Sportster spans 60 uses 40150 4-stroke power Two plan shts No 664 Stuka Stunt $500 CL V2A Stunter semiscale spans 37 No 665 Conscientious Objector $575 FF Mulvihill Rubber competition plane spans 501/2 flat No 193 StIletto CL Stunt nindel McDonald winner 1976 1980 1982 FAt Wodd Champs $ 375 No 262Craahmaater- Ct Crash-pruof trainer two tizet1 5130 35/40 powor$125 No 3101930 Fleet Biplane AC Sport Scale 35140 4-clronnel Wingspan 56 e Ten streets6625 No 314Drake II AC Ken Witards flying boat 3-channel 15-power Fly 1mm land mmovabln gear . No 326Taylor Cub AC Don Srnlfs Schoolyard-Scale 049s 2-3 channel Spoon 50 in$350 No 332Zephyr AC Sinaf 2-channel glider hand-launch tow thermal slope soaring6200 No 386Laaer 200 AC Sport Scale replica champineship Aerehafic tiler Uses 40 power 4-5 channel Two sheets$1075 No 4471/2A Miwa America AC Old-Tuner WA Texaco model 049 glow 2-channels$650 No 4604-40 AC Shoelder-wiog sport filer 4-cycle 40-nine engine 4 channelo$650 No 465Blue Max II AC Fun-fly sportster 40-size engines spans 52 Lightweight stonctere$700 No 533Cewana C-37 AC Schoolyard Scale ni tamoos 3& plane 009/10 power 2-ch opans 42Va in6500 No 539Slmitar Slow4dotlon 15 AC Tailless flying wing 15 engines spans 98 ones 3-ch AC$350 No 569Elactroatreak AC Electric aembatic plane spans 44 ones 05 motorS550 No 572TR-260 AC Sport Scale Aerohalic plane 4-strulre 65/66 power spans 66 in61100 No 576Serendlpityt ndoor 025 record-holder spans 17/ in$325 No 578Scinwelzer 1-26B AC Quarter-ucale Sailplane spans 125 Two plan sheets61475 No 581Gee Bee Moefel Y AC Golden Age Racer spans 72 1A scale 60 power Thwe plus sheets61175 No 586Snapdragon AC Fun-fly/sponster 25/30 engines spans 45 In6698 No 588Marlah AC Slope-Soaring Sailplane spans 41 uses 2 AC channels6425 No593Taytorcralt AC Sport Scale llghtplane builds us standard 2-placer clipped-wing air show stenter Spans either 70 50 35/40 two-stmfre 45/48 four-ntmhe engine Two plan sheets no dncomentatmn$1000 No586Coronet 150 RC-Assint Old-liner enlarged 15914k spans 72 uses 40-size 4-sImlreI 30-size 2-tube6850 No601NIcicel AC Sportster WA engine 3 AC channels Spans 44 in$500 No 603Sparrow Hawk P30 FF Competitfon rebber-power plane woo 87 Nuts Spans 30 in$225 No607Curtlaw Seegull AC Glout Scale biplane spant 50 uses Oeadra/Zeuoah power Three plan sheets dec62498 No mTapeewing AC WA Pylon Racer spans 29 Plan plan use ports template about$698 No 610Protobype AC Sport biplane spans 48 uses 45/2-cycle 85/4-cycle power$650 No 619KeIth RIder R4 FF Scale Goldan Age racer rebber power spans 18 in6300 No 620GImlet 60 AC Spert/Pattem plate spans 60 iii 45/50 enguw 2 sheets61100 No 623Henderwom Longater AC Quarter-Scale 1933 fhwer spans 90h 4-strube 45/46 engine 3 plan sht no dec$1698 No624KelaIrer Laric AC Quarter-scale hontehuit spans 69 69198 4-Otmlre power 2 plait sheets dec61100 No 626Sweepee AC Spoil/Pattem canards foiward-sweyl wing spans 64 uses 48 power 2 plan sheets61300 No628Prime Cut AC SportlAerotsatic plane spuss 90 uses Quadra 35/40-sine power Two plus sheets61300 No 630OrIginal Ply Baby AC Old-Thiter spans 72 uses 19125 2-cycle 484-cycle power 2 plan sheets61150 No 635The Gambler FF Indoor Sestoeran rebber-power cable plane spans 15% in6200 No 836Keytwo AC Tn-geared low-wing sportsler 29125 power spans 44 in$575 No637A6 Shrike FF Compefitine plane AMA Clauses 5 15/23 power spans 60 in$675 No 638Owl Racer CL WA Scale Racer 049 power spans 20 6225 No 839SIcyvoIt AC Tn-geared Electric aerubatic sportoter 05/15 power spans 50 in6850 No 640Bird Prey CL AMA Fast Combat plane 36 power spans 5334 in$550 No 641UI Ole Reliable AC Old-tinter spoil filer spans 50% WA engines$575 No 642BIpe 89 CL Partlat plus updates deflofis 48 nersbon 3Scc power Spans 2234 in6225 No643Noctule IIB FF Baflulte flying wing CO2 power spoon 30 in$325 No 644Beliance ColumbIa AC Schoolyard Scale 2 AC channels WA engine Wingspan 46 m$575 No 645Lalrd Solution Cl Ponfile Scale biplane spans 36 25/35 pewer6575 No 646WInter Hawk FF Robber-power Coupe dHleer cempefiflon plane spans 47 in6375 No647Cox Speeded CL Semincale biplane WA enne spans 24 in6300 No646Cufllwa OC-2 FF Sculls Outdoor Gas Ftying Scale biplane uses electric power spans 24 HiLine lohnr-6 motor$325 No640Thlngemabob AC/CL Mutfimede trainer 25 gas 05 electric power spans 51 in$475 No 65047/66 RC Special AC Aembafic sport plane 48 power spans 61 3 plan sheetsS1075 No 651Conwortlum AC Husri-Lanoch HI-Start Coder spans 60 in6050 No652Oar Ptedenmaeea AC Lute-wing spoil plane 29125 power npons 55 -$675 No 663Aventl CL Profile Sport Scale canard hisliner twin DOgs spans 38 in$575 No 654Tamiecag AC Trainer/spottster styled Ibe F14 spaus 66 45/61 power Four plan sheets$1525 No 6S5Aetroalar FF AMA Class A/B Gas plane spans 67 uses 3 25/350cc power$800 No 856XP13C CL Profile 15 Carrier plane spans 277A in6550 No657Super Squire AC Trainer 35/48 2-stonbe 53 4-strobe power spans 9834 in6750 No 658SIturiken Streak CL Trainer uses 2-line Moonline control spans 17 WA power$225 No659Boom Box FF Walefleld Rubber competitine plane spans 54 in6400 No 660Volkaplene AC Electric-powered sportster 05 motor spans S6 2 plan shts6925 No661Embey-Omatlc FF Embryo Enderance mbber-power plane spans 20 in6200 No662Boxklte CL Scale antique caned pusher biplane spans 42 2 plan shtsS1100 0 Os 0 o C%J 0 gC Co tous Q 0 05 no 6E 050 o - Co FJ t- tog5 0 C 0 - 0 - ID 05 005 0 c us n 00 0 00 us Co-s 0 0 E-d 00 cs 0 2 0 I U0 E N STREET 0CITY - Circle numbers plans wish order best handling please include re quests payment some other service withyourplans order 193262310314326332386447 460465533539569572576578 581586588593598601603607 609610619620623624626628 630635636637638639640641 642643644645646647648649 650651652653654655656657 658659660661662663664665 Plan price includes first class postage US delivery Air Mail over 300 miles orders non-US address lease add $258 Air Mail osta e handlin Ian Make Check money order payable US funds drawn US bank Model Aviation AMA 1810 Samuel Morse Reston VA 22090 Please allow 3 6 weeks delivery Please print CarefullyEnclosed $ _______________________ ___________________________________________ AMA No _______________ airplanes can practical pleasurable fly may also mean ultimate dura tion cross-country RC Sailplane now large flat-wing variable-camber aileroncontrolled configuration instead sim pler fixed-camber rudder elevator ar rangement caution have course tried sys tem 100% sensitivity setting plane does interesting 1-Hz flat yaw oscil lation about plus minus 15 degrees ascribe adverse yaw coupling gyro model remained flyable no harm done might want come up optimum setting instead starting working way down Summary conclusions Spiral stability measure tendency airplane spiral straight circling flight Its primarily function Equiv alent Dihedral Angle EDA tail boom-towingspan ratio lIb wing lift coeffi cient C1 significant secondary variable yaw stability plane function fuselage proportions ver tical stabilizer size Airplanes strong yaw stability spirally stable EDA X lw/b C1 greater equal about 57 Air planes modest yaw stability will sta ble somewhat lower values relation ship illustrated Figures 3 4 An experimental procedure de scribed determining degree spiral stability RC Sailplanes test TwoMeter Sailplane showed good agreement theory control dihedral angle tail boom proportion lift coefficient primary means achieving spiral stability other methods can used Free Flight mod els typically incorporate asymmetrical trim balance arrangement effec tive oaly circle direction mechanical means well successful has tested article incor porates yaw rate gyro drive aile rons As practical inexpensive way provide spiral stability aileron-con trolled Sailplanes exciting devel opment Next month Part Two will describe effect circling flight spiral stability pitch trim yaw angle Southwest PC Flying Year round flight school Five day course $350 Learn fLy planes Send SASE conlete info 2818 CaroLina NE Albuquerque NM 87110 505 881-3799 196 Model Aviation IMPORTED DIESELS A-MAuroraDCEDMVVSMBia*nya PAWTaplln Standard R/C.0864S Acre & MarIne VlntegeAperg Comfiest Seed $100 Informatlo CARLSON ENGINE IMPORTS 314 East Marcomi Phoenix AZ 85022 _________________________________________ ZIP _______________________________
Edition: Model Aviation - 1990/09
Page Numbers: 100, 101, 102, 103, 104, 106, 191, 192, 194, 196
NO OCR TEXT NO OCR TEXT juel per ipervil pnoso D inS au beHest compartment circie giving spiral dral-ilke handling w degrees last thre scribed detail b Keeping mind portional W/S ank C.u around tracked Stf ems lango ailerons result slmple uncoupled coi ited d illustr lw/b ran ailplanes Frc adral angl us dihedra rolled photos wer gher values ty 10 some luces greater spr quiva1ent dihedr of the effective ng force n yaw angle ir greater r yaw angles ig compti Part slues EDA rai Extreme values up 20 th spiral mt C1 b flight Since loading dvn 05 Rho goes down nother way airspeed2 prop wis an find ratio yaw angle required gles yaw obtained/yav proportio lw/b X ED order achieve sp aircraft yaw angle equal greater quired eoi balance neutral yaw obtained greater out circle unless put held yaw obtain will roll tighter tive varying top ru Anything increas obtained yaw req spiral stability formula crux c1 contains three Lets take detailed ratio vert tothe wp liiir E s 51mph ar momen atween FIgure 2 circular flight path tends force wing outboard yaw angle vertical stabilizer lines itself up airflow becomes quite clear illustration yaw angle sensitive both circle radius vertical stabilizer moment arm length late angle attack high angle tack gives high C1 vice versa Rho air density slugs per cubic foot about 0002377 sea level An increase C1 reduces spiral stability increasing C1 increases yaw ob tained given bank angle due reduced circle radius yaw required increased because both V2 term r reduced inverse proportion C1 general Gliders thermal best near maximum C1 just shy stall higher lift coefficients give less spiral stabil ity leads interesting effect de scribed later article Typical thermaling values C1 RC Sailpianes range 06 10 Thicker higher camber sections will high end range Typical Free Flight C1s range low 04 high 14 low values would found smaller models low-camber wings high est values would found larger thin high-camber wings such A2 class Towline Gliders Observations interesting three variables significantly affect spiral stability has important implica tions Wing loading does matter can ballast model affecting spiral stability Aspect ratio does matter long skinny wings short squat ones have about same impact spiral stabil ity Note though long wing requires long fuselage Size does matter can scale design up down spiral sta bility will retained same lift coeffi cient Circle radius bank angle matter plane stable bank angle stable bank angles assuming no change C1 Computations tested out spiral stabil ity relationship trusty computer spreadsheet described Dihedral series spreadsheet divides wing 20 spanwise segments allows fly various bank angles wing load ings dihedral angles schemes lift coef ficients yaw angles output value net roll moment given configuration fiddle dihedral angle yaw angle until roll moment zero did series configurations results showed plane spirally sta ble EDA x l/b 7 greater sake brevity lets define new variable 55 equal EDA x lw/b S stands spiral stability convenience relationship three variables plotted Figures 3 4 plots enable find third vari able already know other two have existing airplane EDA lw/b already known plots will show maximum lift coefficient plane will spirally stable example using Figure 3 can find plane 15 degrees EDA 04 lw/b will stable lift coefficient 105 less Figure 4 could used well reading plot difficult since must interpolate between lines designing plane scratch may want examine trade-off between tail boom length dihedral angle Pre sumably have already chosen wing section have estimate cir cling lift coefficient example say designing floater RC Sailplane expected thermal lift coeffi cient 10 Figure 4 permits direct exam ination boom/dihedral trade-off Fol lowing along C1 ine find could have 02 lw/b 27 de grees dihedral Wow Thats lot dihe dral plane will highiy sensitive rudder trim 04 l/b 145 degrees dihedral like 08 lw/b 75 degrees dihedral long tail boom low roll rate due low dihe dral anglesee Part Two Dihe dral series Because simplifying assumptions described below plots conserva tive Depending mostly size vertical stabilizer can back off some dihedral angle tail boom length can increase lift coefficient although just much tricky say Testing typical Two-Meter RC Sailplane found 43 approximately min imum value SS testing later Variables ignored insignificant some important variables have ig nored order boil problem down September 1990 103 35 30 25 MINIMUM20 EQUIVALENT DIHEDRAL ANGLE DEG15 10 5 0 fundamentals Most important extra outboard yaw due differential wing drag As plane circles outboard wing flying faster creates drag produces outboard yawing moment opposed vertical stabilizer der stabilizer generate opposing lift plane must yaw further outboard Large stabilizers can generate required lift small yaw angles small verticals can require much greater yaw angles 35 30 25 MINIMUM EQUIVALENT DIHEDRAL ANGLE DEG extra outboard yaw angle increases spiral stability increasing tendency plane roll out circle Free Flight models typically use small verticals consequent increase spiral stabil ity can quite great contrast RC Sailplanes typically have large vertical stabiliz ers track well produce little change spiral stability graphs ignore ef fect entirely since indicate spiral stabil ity achieved very large stabiliz Lv/b 2 era Smaller stabilizers give spiral sta bility Fuselage interference effects also ig nored since fuselages Gliders very small compared wings large fuselages Scale Free Flight models however have important ef fect spiral stability As generalization high-mounted wings large fuselages have dihedral lowmounted wings behave hnd less Also generous amount fuselage side area front center-of-gravity desta bilizes plane yaw increasing spiral stability same way reducing size vertical stabilizer does ef fects difficult quantify _____yond scope article Pendulum side-force effects ig nored because minor RC _____Sailplanes Side area above center-ofgravityor conversely low center-of1 21 3 1 4gravity relative side areaacts crease yaw-roll couple same way does increased dihedral Gas Free Flight models take advantage effect tall wing pylons heavy low-thrust engines effect still minor models typical wing dihedral need dihedral its efficient increase wing dihedral extend fuselage wing pylon Much smaller increases wetted area result last effect increases spiral sta bility ignored circling entire Glider coming down same rate inboard wing moves slowly gives inboard wing greater angle tack increasing spiral stability effect minor airplanes good glide ra tios significant very draggy models its extreme form becomes stall-spin maneuver inboard ______wing stalled outboard wing con tinues fly large simplifying assump ________________tions produce conservative results SS greater 57 airplane almost cer tain stable near 57 stability probable depending primarily size vertical stabilizer SS doesnt get close 57 craft almost sure unstable Testing spiral stability RC Sail planes given airplane configuration ___________ dihedral tail boom-to-span ratio fixed Thus airplane has maxi mum lift coefficient minimum speed spirally stable Normally want Glider stable up near its maximum lift coefficient easy test flying straight slowly come back pitch trim lever until plane seems sinking its minimum rate let plane fly hands-off model contin ues straight almost straight spirally stable begins circle its Dont surprised plane proves lack spiral stability common RC SailContinued page 106 r 20 15 10 5 0 10 44 02030405 VERTICAL TAIL MOMENT ARM TO WINGSPAN RATIO Lv/b Figure 4 chart shows minimum wing dihedral angle diminishes tail boom lengthened design lift coefficient reduced can very useful during pro cess designing since permits dIrect trade tall boom length reduced dihedral 0708 104 Model Aviation U4 0506070809111 DESIGN LIFT cOEFFICIENT ci Figure 3 Th minimum wing dihedral angie must greater plans higher lift coeffi cients shorter taii booms plot shows minimum equivalent dihedral angie guarantees spiral stability f range lift coefficients tail-boom-to-wIngspan ratios ivlb its cisc useful evaluating maximum stable im coefficient existing designs Southern Radio ControlLons fl/C Service Naples FLPhoenix NY 813 775-1554315 695-2448 s&D WC ServiceiI&J ElectronicsRivergote Hobby Center San Jose CAHowell MlGoodleftsville TN 408 281-1549517 546-2644615 859-3455 Authorized IVC Service Fallbrook CA 619 728-0440 Radio South Pensacola FL 904478-6745 Iraft Midwest IMI Northoille Ml 313 348-0095 Woiiitz PJC Jackoonoille FL 904 771-0613 DuMond C Service Carroliton TX 214 242-4682 Ocean County WC Service Toms River NJ 201 505-9477 planes seem marginal regard determine pitch trim setting plane becomes stable adjust slightly higher speed repeat experi ment Repeat cycle increasing speed slightly time until airplane no longer rolls circle speed model stable difference between speed optimum mini mum sink speed will indicate far off airplane much dihedral tail boom must increased Keep mind lift coefficient proportional speed squared model becomes stable twice optimum speed dihe dral tail boom off factor four Its best conduct experiments still morning late evening air Also sure model free asymnoetrical warps wing isnt heavier other performed experiment Two-Meter RC Sailplane Tutor airplane has simple V-dihedral two-piece wing bent piano wire joiner flown three different dihedral angles substituting three different joiners illus trated pictures model trimmed fly approximately minimum sink rate airspeed estimated C1 09 allowed fly hands-off dihedral angle 15 degrees airplane tracked well speeds would fly straight very nearly indefinitely very low speeds did tend wiggle turbulence bit really needs bigger ver tical stabilizer give margin Dutch roll 12 degrees dihedral plane ap peared verge circling min imum sink speed wandered over sky never actually settled circle higher speeds tracked true judged plane just spirally stable con figuration 57 degrees dihedral model definitely unstable Over period about 15 seconds would roll left right circle stabilize about 20 degrees bank angle Pulling back pitch trim simply increased bank angle trimmed plane estimated C1 04 interthermal cruise speed released straight flight continued fly straight Calculating spiral stability Tutor 12 degrees dihedral according formula get 12 x 0324 43 Alternatively low dihedral angle higher speed SS roughly 57 x 0324 46which fairly close 43 con sidering imprecise nature C1 esti mates Note values somewhat less ideal 57 derived earlier article probably because extra outboard yaw resulting differ ential wing drag Other methods obtaining spiral stabil ity Free Flight models use sorts meth ods enhance spiral stability Chief among Continued page 191 106 Model Aviation RCD r AIVfefl1SAJtVB~e1 QOflt ileltewwe we6 w0eCtB ggl iA%~6 ~JI ai99~ 6 Owe60 IA owAte bO SSao 06606 L400* 6gA6I icipating RCD Sticker Stations 9SR Products Sacramento CA 918 362-1962 FOR ORDERS ONLYLJL CODs 1 -8OO6337556ILLJJJWELCOME IN ALABAMA 347 3525 COLLECT TOP QUALITY FUEL FOR EXPERT OR BEGINNER NO RE-CLAIMED ALCOHOL O METHANE ONLY IS USED Designed tested give top performance both 2-cycle 4-cycle engines ringed Except engines requiring low lubricant content CONTAINS NEW TRULY SPACE AGE ADDITIVE developed outer apace vacuum new additive attaches internal metal parts engine will reduce friction much 80/o reduces heat wear absolute minimum WE HAVE 3 LUBRICANT BLENDS ALL SYNTHETIC OR SYNTHETIC BLEND CASTOR castor new high purity much cleaner burning castor ALL OUR FUELS CONTAIN ANTI-FOAMERS PREVENTERS WEAR ADDITIVES fuel developed priced tor individual club direct sales market dealer Inquiries invited Order gallon up MIx OK 4 gallon cases up ALL FUEL EXCEPT 54 GALLON DRUMS SHIPPED FREIGHT PRE-PAID Only continental USA TD 3 GalTo 23ITo63To 127 GIjAndIFreight l l24 Gal al12S al Drum 5% ..1095750700.650 . .. 57518500 120/o 5 .050. 900 7528000 250/o 5. 1400 0127547500 500/o 02200 ..21 502075780 00 Manufactured MACH-7 PO Box 1201 Enterprise Alabama 36330 houses relics displays both World Wars HMS Belfast moored Lon dons Thames River newest exhibit Cabinet War Rooms recently restored World War II condition under ground emergency headquarters Prime Minister Winston Churchill Taken together installations tell story two enormous wars raged around Englandparticularly skies over now-peaceful settings like Duxford Airfield Spiral/Beron-Rawdon Continued page 106 asymmetrical wing twist known washin washout Normally inboard wing washed twisted inci dence outboard wing washed out approximately equivalent yawing dihedraled wing outboard rudder trim should enhance spiral stability dont know Free Flight difference between approximately equivalent exactly same can important Another Free Flight method ballast inboard wing tip apply outboard rud der trim tip weight produces con stant inboard rolling moment rudder yields outboard yaw-roll couple very sensitive airspeed As model slows down tip weight rolls plane circle plane rolls up bowl effect increases airspeed rud September 1990 191 Bill Eff go * says OnlyPlans Pettern5 Sets give assorted designs yos west hove eslected best cleesic designs eli time choose hoer patterns soch part art important exclusive feature Ducted Fans Navy F4D-i Skyray 1 h soale ength 40ff wing span lg h RIO eotlbte Landing Gear RODF229gB 1 seats ength 32t$ wing span lbs wie RIO 3-0 sir R/O 5 RK725 lens ROOMgfgg One-Third Scale Piper TPacer PA-22 11R31g wing span sq wing area 20 30 old engines 4-5 oh RIO so 12 lb. SluR onersll length RO3g3029gb 1/3Piper Cub 1-3 Scale hR wing span ength 2005 sq wIng area4 oh RIO 030 old engines R030202996 Quarter Scale WWI SE-IA 001 wing span sq wing ares 5 70 tu 22 engines 0005-7 6 SPAD CXIII s70/wingsyons2l20sqin winguteos t3to3t engines Capable flynt-it captures thn imagination RCOS-g 6 FOKKER DR-i TRIPLANE 72 oring span C 1772 pa wing area 70 tot 00 engines OCOS0 82496 SOPWITH CAMEL F1 04 wing span 21 60 pa wing area ftlbs wls R/O wood ft balse construction over OPuq ft drawings 0005t 1 6 00wingspans2225sqivw cane 114 Scale Fokker 0-ViII 00 25 cid onoine 3-h ch OCOSO 0 Golden Age 114 Scale Curtiss Hawk P 1 00length04tfwingspan 2260uq 5 wing areas 1323 engines h 0/C RCOS-t 4 6 114 Scale CurtigaFalcon 03lnngthsltdwitgnpan3100 sqmnwmvg areaedchR/CRCOS-13g20961J 1/6 Scale Cessna AW 0twinospansgO0sqinwingarea 25to go ongirres channel 0/C RC6S-f $1496 roe ill Scale Purn Mogt 73Ifwingtpans4d0sinarno Pot 2040 engines annel 0/C RC0S-3 6 5111 stOnes Fouodlng Merebar AMA OPPO Hell Fewer Privon ore fur vurnyloto pbne sub asuorubly ft derajind parts huts PLEASE ADD 0200 tsr shipping Inrelllng tubal Now 1990 Pros Oats brovhxro refundablo Ion yvu h order WE TECHNICAL SERVICES RO 1 Box 2900 Santa Rosa Beach FL 32459 der becomes powerful balancing tip weight method stable circle direction still relies di hedral produce yaw-roll couple also relies bowl effect increase air speed increased bank angle Dihedral tail boom length pitch stability will still have strong effects spiral stability such model quick look Figure 3 will show low-dihedral airplanes such typical $599 o \C39\ Nut use Electric Starters Made 6061 Aluminum strong enough allow over tightening weighs under 1 oz 1 diameter 1t/t long 114 radius nose minimum AMA requirement 5/32 Torq Hole 3/4 thread depth can use thinnest props 11 thread sizes fit engines market Send us order & well mail out tast MADE IN THE USA B C PRODUCTS 111 N Starkweather Pam pa Texas 79065 1-800-441-4365 US & Canada aileron-controlled RC Sailplanes havent shadow hope being spirally stable reasonable lift coefficients example plane 30 degrees dihedral lift coefficient 07 must have tail boom 13 times long wingspan type models spiral stability can achieved artificial mechanisms example would produce artificial yaw-roll couple means yaw sensor hooked up run ailerons rate D103210/32 DOSBO5-8mm D123212/32 D06106-1mm 107107-1mm D08108-1mm D81258-125mm D101210-125mm D14281/4-28 151625/1624 38243/8-24 VISA MASTERCARD MONEY ORDERS ACCEPTED DEALER INQUIRES WELCOME ENYA 15 5-8mm SS2O SS45 1/4-28 19 to 80 7-1mm 120 8-1mm FOX 19 45 1/4-28 60 to 120 5/16-24 HB ALL SIZES 1/4-28 HP 40 6-1mm 120 5/16-24 others 1/4-28 IRVING ALL 1/4-28 K&B 19 611/428 OS 10 5-8mm 15 12/32 20 6-1mm 21 50 1/4-28 60 120 5/16-24 108 3/8-24 ROSSI ALL 8-125mm SUPERTIGER 11 to 15 5-8mm 19 to 60 1/4-28 61 to 90 5/16-24 2000 6000 10-125mm SATIO3Oto60 6-1mm 65 to90 71mm 120 to 270 8-125mm WEBRA 28 61 1/4-28 80 90 8-125mm MALONEY 100 3/8-24 .THESUPERIORGLOWPLUGSFO GO FASTFLYERSAREBACKII Puts sting engine Unique flat-wound spiral coil element high temperature glass-to-metal seal add up faster ignition increased RPM 1 /2A GloBee plugs designed exclusively 049/051 Cox engines - Ask new GB-5RX Speed Plug GB-SR Racing Plug GB-5P Spert Plug local dealer today unavailable locally write call Twinn-K collect pricing delivery information FREE GloBee Catalog MAKE THE GLOBEE / INDY CONNECTION Twinn-K Inc 10296 W Washington St Indianapolis IN 46231 Telephone 317-839-6579 FAX 317-839-8928 192 Model Aviation aileron deflection function yaw angle sufficient spiral stability could achieved Another method would employ direct mechanical link between yaw vanes aileronsthough youd probably have watchmaker get work Intro ducing yaw-roll couple will make roll axis sensitive deviations yaw axis particular attention will have paid rudder coordination during transi tional maneuvers Another possibility flat-wing air planes would incorporate rate gyro scope gyro could sense yaw rate drive ailerons roll out As plane rolled circle its bank angle yaw rate increase ailerons deflect roll plane out circle response yaw rate may provide spiral stability chance however phase diffi culties between yaw rate roll accelera tion would develop causing disruptive yawroll oscillations similar Dutch roll successful experiment thought worth trying last fix wifes large slow aileron Sailplane Tango plane originally flown zero dihe dral major pain thermal due lack spiral stability Increasing EDA two degrees made noticeable improve ment still great challenge thermal efficiently slowly installed Futabas simple least expen sive rate-sensitive gyroscope model FP G134 ballast box plane unit consists two components gyro box electronics box gyro stalled in-line between receiver aileron servo Tango uses separate rudder servo connected ai leron output receiver Y connector couples rudder ailerons control adverse yaw However rudder servo still hooked direcfly receiver unaffected gyro gyro installation illustrated pictures electronics box has little knob actu ally screw adjusts effect gyro aileron servo zero 100% 0% gyro has no ef Continued page 194 /9 ilttilt --MIt Ii tPJOflC OU QOtVT FLf WELL I1iVfRi 1I ISLiRINO%11 St 1IC m JJJ0 QUADRA RT 1 NEODESHA KS 66757 316325-2821 DEALERS CALL SEND $100 FOR COMPLETE CATALOG fect higher settings gyro input mixes pilots input control ai lerons higher setting the gyro has say about would appear 100% setting maximum con trol input gyro nearly equals maxi mum input pilots stick gyro box installed senses yaw rate reversing switch electronics box set give right aileron left yaw rate vice versa word about rate gyros may helpful contrast regular gyros sense change orientationin degrees instancerate gyros sense rate change orienta tion say degrees per second cant tell way pointing way fast turning bottom line gizmo works adjustment about 50% sensitivity plane flies extremely well model actually flies straight indefinitely straightens out circles slowly itself has feel circle good-performing polyhedral ship retains immediate roll response aileron-controlled craft No adverse effects noted flying model through entire envelope Some better fliers Soaring Union Los Angeles have flown plane gyro responses ranging enthusiastic acceptance grudging admis sion did indeed seem nice am excited about development means sorts low-dihedral aileron AJKUMUIJbL iIANT SHARK ARC PRE-BUILT G SHARK S21495 SEE YOUR HOBBY DEALER FIRST SEND STAMPED #10 ENVELOPE FOR INFO KINGS WAY RIG HOBBY SUPPLY 5559 RICHMOND HOUSTON TX 77056 DEALERS ONLY 1-800-621-7783 194 Model Aviation AT LAST An Effect ye H gh Tech Engine Cleaner R/G Engines Removes Burned-On Fuel Residue Encrusted Carbon anteed ONLY $695 CA residents add 725% lax Clean Engines-Run Cooler-Last Longer Send Check Money OrderTo AIRBORNE HOBBIES 3764 30TH ST SAN DIEGO CA 92104 619543-9703 DEALERS INQUIRES WELCOME tIN SUPERTANKS & SUPERMUFFLERS ZINGER WOOD PROPS GIANT SCALE R/C PLANS C #No663 Pea Patch $900 RC Sportster spans 60 uses 40150 4-stroke power Two plan shts No 664 Stuka Stunt $500 CL V2A Stunter semiscale spans 37 No 665 Conscientious Objector $575 FF Mulvihill Rubber competition plane spans 501/2 flat No 193 StIletto CL Stunt nindel McDonald winner 1976 1980 1982 FAt Wodd Champs $ 375 No 262Craahmaater- Ct Crash-pruof trainer two tizet1 5130 35/40 powor$125 No 3101930 Fleet Biplane AC Sport Scale 35140 4-clronnel Wingspan 56 e Ten streets6625 No 314Drake II AC Ken Witards flying boat 3-channel 15-power Fly 1mm land mmovabln gear . No 326Taylor Cub AC Don Srnlfs Schoolyard-Scale 049s 2-3 channel Spoon 50 in$350 No 332Zephyr AC Sinaf 2-channel glider hand-launch tow thermal slope soaring6200 No 386Laaer 200 AC Sport Scale replica champineship Aerehafic tiler Uses 40 power 4-5 channel Two sheets$1075 No 4471/2A Miwa America AC Old-Tuner WA Texaco model 049 glow 2-channels$650 No 4604-40 AC Shoelder-wiog sport filer 4-cycle 40-nine engine 4 channelo$650 No 465Blue Max II AC Fun-fly sportster 40-size engines spans 52 Lightweight stonctere$700 No 533Cewana C-37 AC Schoolyard Scale ni tamoos 3& plane 009/10 power 2-ch opans 42Va in6500 No 539Slmitar Slow4dotlon 15 AC Tailless flying wing 15 engines spans 98 ones 3-ch AC$350 No 569Elactroatreak AC Electric aembatic plane spans 44 ones 05 motorS550 No 572TR-260 AC Sport Scale Aerohalic plane 4-strulre 65/66 power spans 66 in61100 No 576Serendlpityt ndoor 025 record-holder spans 17/ in$325 No 578Scinwelzer 1-26B AC Quarter-ucale Sailplane spans 125 Two plan sheets61475 No 581Gee Bee Moefel Y AC Golden Age Racer spans 72 1A scale 60 power Thwe plus sheets61175 No 586Snapdragon AC Fun-fly/sponster 25/30 engines spans 45 In6698 No 588Marlah AC Slope-Soaring Sailplane spans 41 uses 2 AC channels6425 No593Taytorcralt AC Sport Scale llghtplane builds us standard 2-placer clipped-wing air show stenter Spans either 70 50 35/40 two-stmfre 45/48 four-ntmhe engine Two plan sheets no dncomentatmn$1000 No586Coronet 150 RC-Assint Old-liner enlarged 15914k spans 72 uses 40-size 4-sImlreI 30-size 2-tube6850 No601NIcicel AC Sportster WA engine 3 AC channels Spans 44 in$500 No 603Sparrow Hawk P30 FF Competitfon rebber-power plane woo 87 Nuts Spans 30 in$225 No607Curtlaw Seegull AC Glout Scale biplane spant 50 uses Oeadra/Zeuoah power Three plan sheets dec62498 No mTapeewing AC WA Pylon Racer spans 29 Plan plan use ports template about$698 No 610Protobype AC Sport biplane spans 48 uses 45/2-cycle 85/4-cycle power$650 No 619KeIth RIder R4 FF Scale Goldan Age racer rebber power spans 18 in6300 No 620GImlet 60 AC Spert/Pattem plate spans 60 iii 45/50 enguw 2 sheets61100 No 623Henderwom Longater AC Quarter-Scale 1933 fhwer spans 90h 4-strube 45/46 engine 3 plan sht no dec$1698 No624KelaIrer Laric AC Quarter-scale hontehuit spans 69 69198 4-Otmlre power 2 plait sheets dec61100 No 626Sweepee AC Spoil/Pattem canards foiward-sweyl wing spans 64 uses 48 power 2 plan sheets61300 No628Prime Cut AC SportlAerotsatic plane spuss 90 uses Quadra 35/40-sine power Two plus sheets61300 No 630OrIginal Ply Baby AC Old-Thiter spans 72 uses 19125 2-cycle 484-cycle power 2 plan sheets61150 No 635The Gambler FF Indoor Sestoeran rebber-power cable plane spans 15% in6200 No 836Keytwo AC Tn-geared low-wing sportsler 29125 power spans 44 in$575 No637A6 Shrike FF Compefitine plane AMA Clauses 5 15/23 power spans 60 in$675 No 638Owl Racer CL WA Scale Racer 049 power spans 20 6225 No 839SIcyvoIt AC Tn-geared Electric aerubatic sportoter 05/15 power spans 50 in6850 No 640Bird Prey CL AMA Fast Combat plane 36 power spans 5334 in$550 No 641UI Ole Reliable AC Old-tinter spoil filer spans 50% WA engines$575 No 642BIpe 89 CL Partlat plus updates deflofis 48 nersbon 3Scc power Spans 2234 in6225 No643Noctule IIB FF Baflulte flying wing CO2 power spoon 30 in$325 No 644Beliance ColumbIa AC Schoolyard Scale 2 AC channels WA engine Wingspan 46 m$575 No 645Lalrd Solution Cl Ponfile Scale biplane spans 36 25/35 pewer6575 No 646WInter Hawk FF Robber-power Coupe dHleer cempefiflon plane spans 47 in6375 No647Cox Speeded CL Semincale biplane WA enne spans 24 in6300 No646Cufllwa OC-2 FF Sculls Outdoor Gas Ftying Scale biplane uses electric power spans 24 HiLine lohnr-6 motor$325 No640Thlngemabob AC/CL Mutfimede trainer 25 gas 05 electric power spans 51 in$475 No 65047/66 RC Special AC Aembafic sport plane 48 power spans 61 3 plan sheetsS1075 No 651Conwortlum AC Husri-Lanoch HI-Start Coder spans 60 in6050 No652Oar Ptedenmaeea AC Lute-wing spoil plane 29125 power npons 55 -$675 No 663Aventl CL Profile Sport Scale canard hisliner twin DOgs spans 38 in$575 No 654Tamiecag AC Trainer/spottster styled Ibe F14 spaus 66 45/61 power Four plan sheets$1525 No 6S5Aetroalar FF AMA Class A/B Gas plane spans 67 uses 3 25/350cc power$800 No 856XP13C CL Profile 15 Carrier plane spans 277A in6550 No657Super Squire AC Trainer 35/48 2-stonbe 53 4-strobe power spans 9834 in6750 No 658SIturiken Streak CL Trainer uses 2-line Moonline control spans 17 WA power$225 No659Boom Box FF Walefleld Rubber competitine plane spans 54 in6400 No 660Volkaplene AC Electric-powered sportster 05 motor spans S6 2 plan shts6925 No661Embey-Omatlc FF Embryo Enderance mbber-power plane spans 20 in6200 No662Boxklte CL Scale antique caned pusher biplane spans 42 2 plan shtsS1100 0 Os 0 o C%J 0 gC Co tous Q 0 05 no 6E 050 o - Co FJ t- tog5 0 C 0 - 0 - ID 05 005 0 c us n 00 0 00 us Co-s 0 0 E-d 00 cs 0 2 0 I U0 E N STREET 0CITY - Circle numbers plans wish order best handling please include re quests payment some other service withyourplans order 193262310314326332386447 460465533539569572576578 581586588593598601603607 609610619620623624626628 630635636637638639640641 642643644645646647648649 650651652653654655656657 658659660661662663664665 Plan price includes first class postage US delivery Air Mail over 300 miles orders non-US address lease add $258 Air Mail osta e handlin Ian Make Check money order payable US funds drawn US bank Model Aviation AMA 1810 Samuel Morse Reston VA 22090 Please allow 3 6 weeks delivery Please print CarefullyEnclosed $ _______________________ ___________________________________________ AMA No _______________ airplanes can practical pleasurable fly may also mean ultimate dura tion cross-country RC Sailplane now large flat-wing variable-camber aileroncontrolled configuration instead sim pler fixed-camber rudder elevator ar rangement caution have course tried sys tem 100% sensitivity setting plane does interesting 1-Hz flat yaw oscil lation about plus minus 15 degrees ascribe adverse yaw coupling gyro model remained flyable no harm done might want come up optimum setting instead starting working way down Summary conclusions Spiral stability measure tendency airplane spiral straight circling flight Its primarily function Equiv alent Dihedral Angle EDA tail boom-towingspan ratio lIb wing lift coeffi cient C1 significant secondary variable yaw stability plane function fuselage proportions ver tical stabilizer size Airplanes strong yaw stability spirally stable EDA X lw/b C1 greater equal about 57 Air planes modest yaw stability will sta ble somewhat lower values relation ship illustrated Figures 3 4 An experimental procedure de scribed determining degree spiral stability RC Sailplanes test TwoMeter Sailplane showed good agreement theory control dihedral angle tail boom proportion lift coefficient primary means achieving spiral stability other methods can used Free Flight mod els typically incorporate asymmetrical trim balance arrangement effec tive oaly circle direction mechanical means well successful has tested article incor porates yaw rate gyro drive aile rons As practical inexpensive way provide spiral stability aileron-con trolled Sailplanes exciting devel opment Next month Part Two will describe effect circling flight spiral stability pitch trim yaw angle Southwest PC Flying Year round flight school Five day course $350 Learn fLy planes Send SASE conlete info 2818 CaroLina NE Albuquerque NM 87110 505 881-3799 196 Model Aviation IMPORTED DIESELS A-MAuroraDCEDMVVSMBia*nya PAWTaplln Standard R/C.0864S Acre & MarIne VlntegeAperg Comfiest Seed $100 Informatlo CARLSON ENGINE IMPORTS 314 East Marcomi Phoenix AZ 85022 _________________________________________ ZIP _______________________________
Edition: Model Aviation - 1990/09
Page Numbers: 100, 101, 102, 103, 104, 106, 191, 192, 194, 196
NO OCR TEXT NO OCR TEXT juel per ipervil pnoso D inS au beHest compartment circie giving spiral dral-ilke handling w degrees last thre scribed detail b Keeping mind portional W/S ank C.u around tracked Stf ems lango ailerons result slmple uncoupled coi ited d illustr lw/b ran ailplanes Frc adral angl us dihedra rolled photos wer gher values ty 10 some luces greater spr quiva1ent dihedr of the effective ng force n yaw angle ir greater r yaw angles ig compti Part slues EDA rai Extreme values up 20 th spiral mt C1 b flight Since loading dvn 05 Rho goes down nother way airspeed2 prop wis an find ratio yaw angle required gles yaw obtained/yav proportio lw/b X ED order achieve sp aircraft yaw angle equal greater quired eoi balance neutral yaw obtained greater out circle unless put held yaw obtain will roll tighter tive varying top ru Anything increas obtained yaw req spiral stability formula crux c1 contains three Lets take detailed ratio vert tothe wp liiir E s 51mph ar momen atween FIgure 2 circular flight path tends force wing outboard yaw angle vertical stabilizer lines itself up airflow becomes quite clear illustration yaw angle sensitive both circle radius vertical stabilizer moment arm length late angle attack high angle tack gives high C1 vice versa Rho air density slugs per cubic foot about 0002377 sea level An increase C1 reduces spiral stability increasing C1 increases yaw ob tained given bank angle due reduced circle radius yaw required increased because both V2 term r reduced inverse proportion C1 general Gliders thermal best near maximum C1 just shy stall higher lift coefficients give less spiral stabil ity leads interesting effect de scribed later article Typical thermaling values C1 RC Sailpianes range 06 10 Thicker higher camber sections will high end range Typical Free Flight C1s range low 04 high 14 low values would found smaller models low-camber wings high est values would found larger thin high-camber wings such A2 class Towline Gliders Observations interesting three variables significantly affect spiral stability has important implica tions Wing loading does matter can ballast model affecting spiral stability Aspect ratio does matter long skinny wings short squat ones have about same impact spiral stabil ity Note though long wing requires long fuselage Size does matter can scale design up down spiral sta bility will retained same lift coeffi cient Circle radius bank angle matter plane stable bank angle stable bank angles assuming no change C1 Computations tested out spiral stabil ity relationship trusty computer spreadsheet described Dihedral series spreadsheet divides wing 20 spanwise segments allows fly various bank angles wing load ings dihedral angles schemes lift coef ficients yaw angles output value net roll moment given configuration fiddle dihedral angle yaw angle until roll moment zero did series configurations results showed plane spirally sta ble EDA x l/b 7 greater sake brevity lets define new variable 55 equal EDA x lw/b S stands spiral stability convenience relationship three variables plotted Figures 3 4 plots enable find third vari able already know other two have existing airplane EDA lw/b already known plots will show maximum lift coefficient plane will spirally stable example using Figure 3 can find plane 15 degrees EDA 04 lw/b will stable lift coefficient 105 less Figure 4 could used well reading plot difficult since must interpolate between lines designing plane scratch may want examine trade-off between tail boom length dihedral angle Pre sumably have already chosen wing section have estimate cir cling lift coefficient example say designing floater RC Sailplane expected thermal lift coeffi cient 10 Figure 4 permits direct exam ination boom/dihedral trade-off Fol lowing along C1 ine find could have 02 lw/b 27 de grees dihedral Wow Thats lot dihe dral plane will highiy sensitive rudder trim 04 l/b 145 degrees dihedral like 08 lw/b 75 degrees dihedral long tail boom low roll rate due low dihe dral anglesee Part Two Dihe dral series Because simplifying assumptions described below plots conserva tive Depending mostly size vertical stabilizer can back off some dihedral angle tail boom length can increase lift coefficient although just much tricky say Testing typical Two-Meter RC Sailplane found 43 approximately min imum value SS testing later Variables ignored insignificant some important variables have ig nored order boil problem down September 1990 103 35 30 25 MINIMUM20 EQUIVALENT DIHEDRAL ANGLE DEG15 10 5 0 fundamentals Most important extra outboard yaw due differential wing drag As plane circles outboard wing flying faster creates drag produces outboard yawing moment opposed vertical stabilizer der stabilizer generate opposing lift plane must yaw further outboard Large stabilizers can generate required lift small yaw angles small verticals can require much greater yaw angles 35 30 25 MINIMUM EQUIVALENT DIHEDRAL ANGLE DEG extra outboard yaw angle increases spiral stability increasing tendency plane roll out circle Free Flight models typically use small verticals consequent increase spiral stabil ity can quite great contrast RC Sailplanes typically have large vertical stabiliz ers track well produce little change spiral stability graphs ignore ef fect entirely since indicate spiral stabil ity achieved very large stabiliz Lv/b 2 era Smaller stabilizers give spiral sta bility Fuselage interference effects also ig nored since fuselages Gliders very small compared wings large fuselages Scale Free Flight models however have important ef fect spiral stability As generalization high-mounted wings large fuselages have dihedral lowmounted wings behave hnd less Also generous amount fuselage side area front center-of-gravity desta bilizes plane yaw increasing spiral stability same way reducing size vertical stabilizer does ef fects difficult quantify _____yond scope article Pendulum side-force effects ig nored because minor RC _____Sailplanes Side area above center-ofgravityor conversely low center-of1 21 3 1 4gravity relative side areaacts crease yaw-roll couple same way does increased dihedral Gas Free Flight models take advantage effect tall wing pylons heavy low-thrust engines effect still minor models typical wing dihedral need dihedral its efficient increase wing dihedral extend fuselage wing pylon Much smaller increases wetted area result last effect increases spiral sta bility ignored circling entire Glider coming down same rate inboard wing moves slowly gives inboard wing greater angle tack increasing spiral stability effect minor airplanes good glide ra tios significant very draggy models its extreme form becomes stall-spin maneuver inboard ______wing stalled outboard wing con tinues fly large simplifying assump ________________tions produce conservative results SS greater 57 airplane almost cer tain stable near 57 stability probable depending primarily size vertical stabilizer SS doesnt get close 57 craft almost sure unstable Testing spiral stability RC Sail planes given airplane configuration ___________ dihedral tail boom-to-span ratio fixed Thus airplane has maxi mum lift coefficient minimum speed spirally stable Normally want Glider stable up near its maximum lift coefficient easy test flying straight slowly come back pitch trim lever until plane seems sinking its minimum rate let plane fly hands-off model contin ues straight almost straight spirally stable begins circle its Dont surprised plane proves lack spiral stability common RC SailContinued page 106 r 20 15 10 5 0 10 44 02030405 VERTICAL TAIL MOMENT ARM TO WINGSPAN RATIO Lv/b Figure 4 chart shows minimum wing dihedral angle diminishes tail boom lengthened design lift coefficient reduced can very useful during pro cess designing since permits dIrect trade tall boom length reduced dihedral 0708 104 Model Aviation U4 0506070809111 DESIGN LIFT cOEFFICIENT ci Figure 3 Th minimum wing dihedral angie must greater plans higher lift coeffi cients shorter taii booms plot shows minimum equivalent dihedral angie guarantees spiral stability f range lift coefficients tail-boom-to-wIngspan ratios ivlb its cisc useful evaluating maximum stable im coefficient existing designs Southern Radio ControlLons fl/C Service Naples FLPhoenix NY 813 775-1554315 695-2448 s&D WC ServiceiI&J ElectronicsRivergote Hobby Center San Jose CAHowell MlGoodleftsville TN 408 281-1549517 546-2644615 859-3455 Authorized IVC Service Fallbrook CA 619 728-0440 Radio South Pensacola FL 904478-6745 Iraft Midwest IMI Northoille Ml 313 348-0095 Woiiitz PJC Jackoonoille FL 904 771-0613 DuMond C Service Carroliton TX 214 242-4682 Ocean County WC Service Toms River NJ 201 505-9477 planes seem marginal regard determine pitch trim setting plane becomes stable adjust slightly higher speed repeat experi ment Repeat cycle increasing speed slightly time until airplane no longer rolls circle speed model stable difference between speed optimum mini mum sink speed will indicate far off airplane much dihedral tail boom must increased Keep mind lift coefficient proportional speed squared model becomes stable twice optimum speed dihe dral tail boom off factor four Its best conduct experiments still morning late evening air Also sure model free asymnoetrical warps wing isnt heavier other performed experiment Two-Meter RC Sailplane Tutor airplane has simple V-dihedral two-piece wing bent piano wire joiner flown three different dihedral angles substituting three different joiners illus trated pictures model trimmed fly approximately minimum sink rate airspeed estimated C1 09 allowed fly hands-off dihedral angle 15 degrees airplane tracked well speeds would fly straight very nearly indefinitely very low speeds did tend wiggle turbulence bit really needs bigger ver tical stabilizer give margin Dutch roll 12 degrees dihedral plane ap peared verge circling min imum sink speed wandered over sky never actually settled circle higher speeds tracked true judged plane just spirally stable con figuration 57 degrees dihedral model definitely unstable Over period about 15 seconds would roll left right circle stabilize about 20 degrees bank angle Pulling back pitch trim simply increased bank angle trimmed plane estimated C1 04 interthermal cruise speed released straight flight continued fly straight Calculating spiral stability Tutor 12 degrees dihedral according formula get 12 x 0324 43 Alternatively low dihedral angle higher speed SS roughly 57 x 0324 46which fairly close 43 con sidering imprecise nature C1 esti mates Note values somewhat less ideal 57 derived earlier article probably because extra outboard yaw resulting differ ential wing drag Other methods obtaining spiral stabil ity Free Flight models use sorts meth ods enhance spiral stability Chief among Continued page 191 106 Model Aviation RCD r AIVfefl1SAJtVB~e1 QOflt ileltewwe we6 w0eCtB ggl iA%~6 ~JI ai99~ 6 Owe60 IA owAte bO SSao 06606 L400* 6gA6I icipating RCD Sticker Stations 9SR Products Sacramento CA 918 362-1962 FOR ORDERS ONLYLJL CODs 1 -8OO6337556ILLJJJWELCOME IN ALABAMA 347 3525 COLLECT TOP QUALITY FUEL FOR EXPERT OR BEGINNER NO RE-CLAIMED ALCOHOL O METHANE ONLY IS USED Designed tested give top performance both 2-cycle 4-cycle engines ringed Except engines requiring low lubricant content CONTAINS NEW TRULY SPACE AGE ADDITIVE developed outer apace vacuum new additive attaches internal metal parts engine will reduce friction much 80/o reduces heat wear absolute minimum WE HAVE 3 LUBRICANT BLENDS ALL SYNTHETIC OR SYNTHETIC BLEND CASTOR castor new high purity much cleaner burning castor ALL OUR FUELS CONTAIN ANTI-FOAMERS PREVENTERS WEAR ADDITIVES fuel developed priced tor individual club direct sales market dealer Inquiries invited Order gallon up MIx OK 4 gallon cases up ALL FUEL EXCEPT 54 GALLON DRUMS SHIPPED FREIGHT PRE-PAID Only continental USA TD 3 GalTo 23ITo63To 127 GIjAndIFreight l l24 Gal al12S al Drum 5% ..1095750700.650 . .. 57518500 120/o 5 .050. 900 7528000 250/o 5. 1400 0127547500 500/o 02200 ..21 502075780 00 Manufactured MACH-7 PO Box 1201 Enterprise Alabama 36330 houses relics displays both World Wars HMS Belfast moored Lon dons Thames River newest exhibit Cabinet War Rooms recently restored World War II condition under ground emergency headquarters Prime Minister Winston Churchill Taken together installations tell story two enormous wars raged around Englandparticularly skies over now-peaceful settings like Duxford Airfield Spiral/Beron-Rawdon Continued page 106 asymmetrical wing twist known washin washout Normally inboard wing washed twisted inci dence outboard wing washed out approximately equivalent yawing dihedraled wing outboard rudder trim should enhance spiral stability dont know Free Flight difference between approximately equivalent exactly same can important Another Free Flight method ballast inboard wing tip apply outboard rud der trim tip weight produces con stant inboard rolling moment rudder yields outboard yaw-roll couple very sensitive airspeed As model slows down tip weight rolls plane circle plane rolls up bowl effect increases airspeed rud September 1990 191 Bill Eff go * says OnlyPlans Pettern5 Sets give assorted designs yos west hove eslected best cleesic designs eli time choose hoer patterns soch part art important exclusive feature Ducted Fans Navy F4D-i Skyray 1 h soale ength 40ff wing span lg h RIO eotlbte Landing Gear RODF229gB 1 seats ength 32t$ wing span lbs wie RIO 3-0 sir R/O 5 RK725 lens ROOMgfgg One-Third Scale Piper TPacer PA-22 11R31g wing span sq wing area 20 30 old engines 4-5 oh RIO so 12 lb. SluR onersll length RO3g3029gb 1/3Piper Cub 1-3 Scale hR wing span ength 2005 sq wIng area4 oh RIO 030 old engines R030202996 Quarter Scale WWI SE-IA 001 wing span sq wing ares 5 70 tu 22 engines 0005-7 6 SPAD CXIII s70/wingsyons2l20sqin winguteos t3to3t engines Capable flynt-it captures thn imagination RCOS-g 6 FOKKER DR-i TRIPLANE 72 oring span C 1772 pa wing area 70 tot 00 engines OCOS0 82496 SOPWITH CAMEL F1 04 wing span 21 60 pa wing area ftlbs wls R/O wood ft balse construction over OPuq ft drawings 0005t 1 6 00wingspans2225sqivw cane 114 Scale Fokker 0-ViII 00 25 cid onoine 3-h ch OCOSO 0 Golden Age 114 Scale Curtiss Hawk P 1 00length04tfwingspan 2260uq 5 wing areas 1323 engines h 0/C RCOS-t 4 6 114 Scale CurtigaFalcon 03lnngthsltdwitgnpan3100 sqmnwmvg areaedchR/CRCOS-13g20961J 1/6 Scale Cessna AW 0twinospansgO0sqinwingarea 25to go ongirres channel 0/C RC6S-f $1496 roe ill Scale Purn Mogt 73Ifwingtpans4d0sinarno Pot 2040 engines annel 0/C RC0S-3 6 5111 stOnes Fouodlng Merebar AMA OPPO Hell Fewer Privon ore fur vurnyloto pbne sub asuorubly ft derajind parts huts PLEASE ADD 0200 tsr shipping Inrelllng tubal Now 1990 Pros Oats brovhxro refundablo Ion yvu h order WE TECHNICAL SERVICES RO 1 Box 2900 Santa Rosa Beach FL 32459 der becomes powerful balancing tip weight method stable circle direction still relies di hedral produce yaw-roll couple also relies bowl effect increase air speed increased bank angle Dihedral tail boom length pitch stability will still have strong effects spiral stability such model quick look Figure 3 will show low-dihedral airplanes such typical $599 o \C39\ Nut use Electric Starters Made 6061 Aluminum strong enough allow over tightening weighs under 1 oz 1 diameter 1t/t long 114 radius nose minimum AMA requirement 5/32 Torq Hole 3/4 thread depth can use thinnest props 11 thread sizes fit engines market Send us order & well mail out tast MADE IN THE USA B C PRODUCTS 111 N Starkweather Pam pa Texas 79065 1-800-441-4365 US & Canada aileron-controlled RC Sailplanes havent shadow hope being spirally stable reasonable lift coefficients example plane 30 degrees dihedral lift coefficient 07 must have tail boom 13 times long wingspan type models spiral stability can achieved artificial mechanisms example would produce artificial yaw-roll couple means yaw sensor hooked up run ailerons rate D103210/32 DOSBO5-8mm D123212/32 D06106-1mm 107107-1mm D08108-1mm D81258-125mm D101210-125mm D14281/4-28 151625/1624 38243/8-24 VISA MASTERCARD MONEY ORDERS ACCEPTED DEALER INQUIRES WELCOME ENYA 15 5-8mm SS2O SS45 1/4-28 19 to 80 7-1mm 120 8-1mm FOX 19 45 1/4-28 60 to 120 5/16-24 HB ALL SIZES 1/4-28 HP 40 6-1mm 120 5/16-24 others 1/4-28 IRVING ALL 1/4-28 K&B 19 611/428 OS 10 5-8mm 15 12/32 20 6-1mm 21 50 1/4-28 60 120 5/16-24 108 3/8-24 ROSSI ALL 8-125mm SUPERTIGER 11 to 15 5-8mm 19 to 60 1/4-28 61 to 90 5/16-24 2000 6000 10-125mm SATIO3Oto60 6-1mm 65 to90 71mm 120 to 270 8-125mm WEBRA 28 61 1/4-28 80 90 8-125mm MALONEY 100 3/8-24 .THESUPERIORGLOWPLUGSFO GO FASTFLYERSAREBACKII Puts sting engine Unique flat-wound spiral coil element high temperature glass-to-metal seal add up faster ignition increased RPM 1 /2A GloBee plugs designed exclusively 049/051 Cox engines - Ask new GB-5RX Speed Plug GB-SR Racing Plug GB-5P Spert Plug local dealer today unavailable locally write call Twinn-K collect pricing delivery information FREE GloBee Catalog MAKE THE GLOBEE / INDY CONNECTION Twinn-K Inc 10296 W Washington St Indianapolis IN 46231 Telephone 317-839-6579 FAX 317-839-8928 192 Model Aviation aileron deflection function yaw angle sufficient spiral stability could achieved Another method would employ direct mechanical link between yaw vanes aileronsthough youd probably have watchmaker get work Intro ducing yaw-roll couple will make roll axis sensitive deviations yaw axis particular attention will have paid rudder coordination during transi tional maneuvers Another possibility flat-wing air planes would incorporate rate gyro scope gyro could sense yaw rate drive ailerons roll out As plane rolled circle its bank angle yaw rate increase ailerons deflect roll plane out circle response yaw rate may provide spiral stability chance however phase diffi culties between yaw rate roll accelera tion would develop causing disruptive yawroll oscillations similar Dutch roll successful experiment thought worth trying last fix wifes large slow aileron Sailplane Tango plane originally flown zero dihe dral major pain thermal due lack spiral stability Increasing EDA two degrees made noticeable improve ment still great challenge thermal efficiently slowly installed Futabas simple least expen sive rate-sensitive gyroscope model FP G134 ballast box plane unit consists two components gyro box electronics box gyro stalled in-line between receiver aileron servo Tango uses separate rudder servo connected ai leron output receiver Y connector couples rudder ailerons control adverse yaw However rudder servo still hooked direcfly receiver unaffected gyro gyro installation illustrated pictures electronics box has little knob actu ally screw adjusts effect gyro aileron servo zero 100% 0% gyro has no ef Continued page 194 /9 ilttilt --MIt Ii tPJOflC OU QOtVT FLf WELL I1iVfRi 1I ISLiRINO%11 St 1IC m JJJ0 QUADRA RT 1 NEODESHA KS 66757 316325-2821 DEALERS CALL SEND $100 FOR COMPLETE CATALOG fect higher settings gyro input mixes pilots input control ai lerons higher setting the gyro has say about would appear 100% setting maximum con trol input gyro nearly equals maxi mum input pilots stick gyro box installed senses yaw rate reversing switch electronics box set give right aileron left yaw rate vice versa word about rate gyros may helpful contrast regular gyros sense change orientationin degrees instancerate gyros sense rate change orienta tion say degrees per second cant tell way pointing way fast turning bottom line gizmo works adjustment about 50% sensitivity plane flies extremely well model actually flies straight indefinitely straightens out circles slowly itself has feel circle good-performing polyhedral ship retains immediate roll response aileron-controlled craft No adverse effects noted flying model through entire envelope Some better fliers Soaring Union Los Angeles have flown plane gyro responses ranging enthusiastic acceptance grudging admis sion did indeed seem nice am excited about development means sorts low-dihedral aileron AJKUMUIJbL iIANT SHARK ARC PRE-BUILT G SHARK S21495 SEE YOUR HOBBY DEALER FIRST SEND STAMPED #10 ENVELOPE FOR INFO KINGS WAY RIG HOBBY SUPPLY 5559 RICHMOND HOUSTON TX 77056 DEALERS ONLY 1-800-621-7783 194 Model Aviation AT LAST An Effect ye H gh Tech Engine Cleaner R/G Engines Removes Burned-On Fuel Residue Encrusted Carbon anteed ONLY $695 CA residents add 725% lax Clean Engines-Run Cooler-Last Longer Send Check Money OrderTo AIRBORNE HOBBIES 3764 30TH ST SAN DIEGO CA 92104 619543-9703 DEALERS INQUIRES WELCOME tIN SUPERTANKS & SUPERMUFFLERS ZINGER WOOD PROPS GIANT SCALE R/C PLANS C #No663 Pea Patch $900 RC Sportster spans 60 uses 40150 4-stroke power Two plan shts No 664 Stuka Stunt $500 CL V2A Stunter semiscale spans 37 No 665 Conscientious Objector $575 FF Mulvihill Rubber competition plane spans 501/2 flat No 193 StIletto CL Stunt nindel McDonald winner 1976 1980 1982 FAt Wodd Champs $ 375 No 262Craahmaater- Ct Crash-pruof trainer two tizet1 5130 35/40 powor$125 No 3101930 Fleet Biplane AC Sport Scale 35140 4-clronnel Wingspan 56 e Ten streets6625 No 314Drake II AC Ken Witards flying boat 3-channel 15-power Fly 1mm land mmovabln gear . No 326Taylor Cub AC Don Srnlfs Schoolyard-Scale 049s 2-3 channel Spoon 50 in$350 No 332Zephyr AC Sinaf 2-channel glider hand-launch tow thermal slope soaring6200 No 386Laaer 200 AC Sport Scale replica champineship Aerehafic tiler Uses 40 power 4-5 channel Two sheets$1075 No 4471/2A Miwa America AC Old-Tuner WA Texaco model 049 glow 2-channels$650 No 4604-40 AC Shoelder-wiog sport filer 4-cycle 40-nine engine 4 channelo$650 No 465Blue Max II AC Fun-fly sportster 40-size engines spans 52 Lightweight stonctere$700 No 533Cewana C-37 AC Schoolyard Scale ni tamoos 3& plane 009/10 power 2-ch opans 42Va in6500 No 539Slmitar Slow4dotlon 15 AC Tailless flying wing 15 engines spans 98 ones 3-ch AC$350 No 569Elactroatreak AC Electric aembatic plane spans 44 ones 05 motorS550 No 572TR-260 AC Sport Scale Aerohalic plane 4-strulre 65/66 power spans 66 in61100 No 576Serendlpityt ndoor 025 record-holder spans 17/ in$325 No 578Scinwelzer 1-26B AC Quarter-ucale Sailplane spans 125 Two plan sheets61475 No 581Gee Bee Moefel Y AC Golden Age Racer spans 72 1A scale 60 power Thwe plus sheets61175 No 586Snapdragon AC Fun-fly/sponster 25/30 engines spans 45 In6698 No 588Marlah AC Slope-Soaring Sailplane spans 41 uses 2 AC channels6425 No593Taytorcralt AC Sport Scale llghtplane builds us standard 2-placer clipped-wing air show stenter Spans either 70 50 35/40 two-stmfre 45/48 four-ntmhe engine Two plan sheets no dncomentatmn$1000 No586Coronet 150 RC-Assint Old-liner enlarged 15914k spans 72 uses 40-size 4-sImlreI 30-size 2-tube6850 No601NIcicel AC Sportster WA engine 3 AC channels Spans 44 in$500 No 603Sparrow Hawk P30 FF Competitfon rebber-power plane woo 87 Nuts Spans 30 in$225 No607Curtlaw Seegull AC Glout Scale biplane spant 50 uses Oeadra/Zeuoah power Three plan sheets dec62498 No mTapeewing AC WA Pylon Racer spans 29 Plan plan use ports template about$698 No 610Protobype AC Sport biplane spans 48 uses 45/2-cycle 85/4-cycle power$650 No 619KeIth RIder R4 FF Scale Goldan Age racer rebber power spans 18 in6300 No 620GImlet 60 AC Spert/Pattem plate spans 60 iii 45/50 enguw 2 sheets61100 No 623Henderwom Longater AC Quarter-Scale 1933 fhwer spans 90h 4-strube 45/46 engine 3 plan sht no dec$1698 No624KelaIrer Laric AC Quarter-scale hontehuit spans 69 69198 4-Otmlre power 2 plait sheets dec61100 No 626Sweepee AC Spoil/Pattem canards foiward-sweyl wing spans 64 uses 48 power 2 plan sheets61300 No628Prime Cut AC SportlAerotsatic plane spuss 90 uses Quadra 35/40-sine power Two plus sheets61300 No 630OrIginal Ply Baby AC Old-Thiter spans 72 uses 19125 2-cycle 484-cycle power 2 plan sheets61150 No 635The Gambler FF Indoor Sestoeran rebber-power cable plane spans 15% in6200 No 836Keytwo AC Tn-geared low-wing sportsler 29125 power spans 44 in$575 No637A6 Shrike FF Compefitine plane AMA Clauses 5 15/23 power spans 60 in$675 No 638Owl Racer CL WA Scale Racer 049 power spans 20 6225 No 839SIcyvoIt AC Tn-geared Electric aerubatic sportoter 05/15 power spans 50 in6850 No 640Bird Prey CL AMA Fast Combat plane 36 power spans 5334 in$550 No 641UI Ole Reliable AC Old-tinter spoil filer spans 50% WA engines$575 No 642BIpe 89 CL Partlat plus updates deflofis 48 nersbon 3Scc power Spans 2234 in6225 No643Noctule IIB FF Baflulte flying wing CO2 power spoon 30 in$325 No 644Beliance ColumbIa AC Schoolyard Scale 2 AC channels WA engine Wingspan 46 m$575 No 645Lalrd Solution Cl Ponfile Scale biplane spans 36 25/35 pewer6575 No 646WInter Hawk FF Robber-power Coupe dHleer cempefiflon plane spans 47 in6375 No647Cox Speeded CL Semincale biplane WA enne spans 24 in6300 No646Cufllwa OC-2 FF Sculls Outdoor Gas Ftying Scale biplane uses electric power spans 24 HiLine lohnr-6 motor$325 No640Thlngemabob AC/CL Mutfimede trainer 25 gas 05 electric power spans 51 in$475 No 65047/66 RC Special AC Aembafic sport plane 48 power spans 61 3 plan sheetsS1075 No 651Conwortlum AC Husri-Lanoch HI-Start Coder spans 60 in6050 No652Oar Ptedenmaeea AC Lute-wing spoil plane 29125 power npons 55 -$675 No 663Aventl CL Profile Sport Scale canard hisliner twin DOgs spans 38 in$575 No 654Tamiecag AC Trainer/spottster styled Ibe F14 spaus 66 45/61 power Four plan sheets$1525 No 6S5Aetroalar FF AMA Class A/B Gas plane spans 67 uses 3 25/350cc power$800 No 856XP13C CL Profile 15 Carrier plane spans 277A in6550 No657Super Squire AC Trainer 35/48 2-stonbe 53 4-strobe power spans 9834 in6750 No 658SIturiken Streak CL Trainer uses 2-line Moonline control spans 17 WA power$225 No659Boom Box FF Walefleld Rubber competitine plane spans 54 in6400 No 660Volkaplene AC Electric-powered sportster 05 motor spans S6 2 plan shts6925 No661Embey-Omatlc FF Embryo Enderance mbber-power plane spans 20 in6200 No662Boxklte CL Scale antique caned pusher biplane spans 42 2 plan shtsS1100 0 Os 0 o C%J 0 gC Co tous Q 0 05 no 6E 050 o - Co FJ t- tog5 0 C 0 - 0 - ID 05 005 0 c us n 00 0 00 us Co-s 0 0 E-d 00 cs 0 2 0 I U0 E N STREET 0CITY - Circle numbers plans wish order best handling please include re quests payment some other service withyourplans order 193262310314326332386447 460465533539569572576578 581586588593598601603607 609610619620623624626628 630635636637638639640641 642643644645646647648649 650651652653654655656657 658659660661662663664665 Plan price includes first class postage US delivery Air Mail over 300 miles orders non-US address lease add $258 Air Mail osta e handlin Ian Make Check money order payable US funds drawn US bank Model Aviation AMA 1810 Samuel Morse Reston VA 22090 Please allow 3 6 weeks delivery Please print CarefullyEnclosed $ _______________________ ___________________________________________ AMA No _______________ airplanes can practical pleasurable fly may also mean ultimate dura tion cross-country RC Sailplane now large flat-wing variable-camber aileroncontrolled configuration instead sim pler fixed-camber rudder elevator ar rangement caution have course tried sys tem 100% sensitivity setting plane does interesting 1-Hz flat yaw oscil lation about plus minus 15 degrees ascribe adverse yaw coupling gyro model remained flyable no harm done might want come up optimum setting instead starting working way down Summary conclusions Spiral stability measure tendency airplane spiral straight circling flight Its primarily function Equiv alent Dihedral Angle EDA tail boom-towingspan ratio lIb wing lift coeffi cient C1 significant secondary variable yaw stability plane function fuselage proportions ver tical stabilizer size Airplanes strong yaw stability spirally stable EDA X lw/b C1 greater equal about 57 Air planes modest yaw stability will sta ble somewhat lower values relation ship illustrated Figures 3 4 An experimental procedure de scribed determining degree spiral stability RC Sailplanes test TwoMeter Sailplane showed good agreement theory control dihedral angle tail boom proportion lift coefficient primary means achieving spiral stability other methods can used Free Flight mod els typically incorporate asymmetrical trim balance arrangement effec tive oaly circle direction mechanical means well successful has tested article incor porates yaw rate gyro drive aile rons As practical inexpensive way provide spiral stability aileron-con trolled Sailplanes exciting devel opment Next month Part Two will describe effect circling flight spiral stability pitch trim yaw angle Southwest PC Flying Year round flight school Five day course $350 Learn fLy planes Send SASE conlete info 2818 CaroLina NE Albuquerque NM 87110 505 881-3799 196 Model Aviation IMPORTED DIESELS A-MAuroraDCEDMVVSMBia*nya PAWTaplln Standard R/C.0864S Acre & MarIne VlntegeAperg Comfiest Seed $100 Informatlo CARLSON ENGINE IMPORTS 314 East Marcomi Phoenix AZ 85022 _________________________________________ ZIP _______________________________
Edition: Model Aviation - 1990/09
Page Numbers: 100, 101, 102, 103, 104, 106, 191, 192, 194, 196
NO OCR TEXT NO OCR TEXT juel per ipervil pnoso D inS au beHest compartment circie giving spiral dral-ilke handling w degrees last thre scribed detail b Keeping mind portional W/S ank C.u around tracked Stf ems lango ailerons result slmple uncoupled coi ited d illustr lw/b ran ailplanes Frc adral angl us dihedra rolled photos wer gher values ty 10 some luces greater spr quiva1ent dihedr of the effective ng force n yaw angle ir greater r yaw angles ig compti Part slues EDA rai Extreme values up 20 th spiral mt C1 b flight Since loading dvn 05 Rho goes down nother way airspeed2 prop wis an find ratio yaw angle required gles yaw obtained/yav proportio lw/b X ED order achieve sp aircraft yaw angle equal greater quired eoi balance neutral yaw obtained greater out circle unless put held yaw obtain will roll tighter tive varying top ru Anything increas obtained yaw req spiral stability formula crux c1 contains three Lets take detailed ratio vert tothe wp liiir E s 51mph ar momen atween FIgure 2 circular flight path tends force wing outboard yaw angle vertical stabilizer lines itself up airflow becomes quite clear illustration yaw angle sensitive both circle radius vertical stabilizer moment arm length late angle attack high angle tack gives high C1 vice versa Rho air density slugs per cubic foot about 0002377 sea level An increase C1 reduces spiral stability increasing C1 increases yaw ob tained given bank angle due reduced circle radius yaw required increased because both V2 term r reduced inverse proportion C1 general Gliders thermal best near maximum C1 just shy stall higher lift coefficients give less spiral stabil ity leads interesting effect de scribed later article Typical thermaling values C1 RC Sailpianes range 06 10 Thicker higher camber sections will high end range Typical Free Flight C1s range low 04 high 14 low values would found smaller models low-camber wings high est values would found larger thin high-camber wings such A2 class Towline Gliders Observations interesting three variables significantly affect spiral stability has important implica tions Wing loading does matter can ballast model affecting spiral stability Aspect ratio does matter long skinny wings short squat ones have about same impact spiral stabil ity Note though long wing requires long fuselage Size does matter can scale design up down spiral sta bility will retained same lift coeffi cient Circle radius bank angle matter plane stable bank angle stable bank angles assuming no change C1 Computations tested out spiral stabil ity relationship trusty computer spreadsheet described Dihedral series spreadsheet divides wing 20 spanwise segments allows fly various bank angles wing load ings dihedral angles schemes lift coef ficients yaw angles output value net roll moment given configuration fiddle dihedral angle yaw angle until roll moment zero did series configurations results showed plane spirally sta ble EDA x l/b 7 greater sake brevity lets define new variable 55 equal EDA x lw/b S stands spiral stability convenience relationship three variables plotted Figures 3 4 plots enable find third vari able already know other two have existing airplane EDA lw/b already known plots will show maximum lift coefficient plane will spirally stable example using Figure 3 can find plane 15 degrees EDA 04 lw/b will stable lift coefficient 105 less Figure 4 could used well reading plot difficult since must interpolate between lines designing plane scratch may want examine trade-off between tail boom length dihedral angle Pre sumably have already chosen wing section have estimate cir cling lift coefficient example say designing floater RC Sailplane expected thermal lift coeffi cient 10 Figure 4 permits direct exam ination boom/dihedral trade-off Fol lowing along C1 ine find could have 02 lw/b 27 de grees dihedral Wow Thats lot dihe dral plane will highiy sensitive rudder trim 04 l/b 145 degrees dihedral like 08 lw/b 75 degrees dihedral long tail boom low roll rate due low dihe dral anglesee Part Two Dihe dral series Because simplifying assumptions described below plots conserva tive Depending mostly size vertical stabilizer can back off some dihedral angle tail boom length can increase lift coefficient although just much tricky say Testing typical Two-Meter RC Sailplane found 43 approximately min imum value SS testing later Variables ignored insignificant some important variables have ig nored order boil problem down September 1990 103 35 30 25 MINIMUM20 EQUIVALENT DIHEDRAL ANGLE DEG15 10 5 0 fundamentals Most important extra outboard yaw due differential wing drag As plane circles outboard wing flying faster creates drag produces outboard yawing moment opposed vertical stabilizer der stabilizer generate opposing lift plane must yaw further outboard Large stabilizers can generate required lift small yaw angles small verticals can require much greater yaw angles 35 30 25 MINIMUM EQUIVALENT DIHEDRAL ANGLE DEG extra outboard yaw angle increases spiral stability increasing tendency plane roll out circle Free Flight models typically use small verticals consequent increase spiral stabil ity can quite great contrast RC Sailplanes typically have large vertical stabiliz ers track well produce little change spiral stability graphs ignore ef fect entirely since indicate spiral stabil ity achieved very large stabiliz Lv/b 2 era Smaller stabilizers give spiral sta bility Fuselage interference effects also ig nored since fuselages Gliders very small compared wings large fuselages Scale Free Flight models however have important ef fect spiral stability As generalization high-mounted wings large fuselages have dihedral lowmounted wings behave hnd less Also generous amount fuselage side area front center-of-gravity desta bilizes plane yaw increasing spiral stability same way reducing size vertical stabilizer does ef fects difficult quantify _____yond scope article Pendulum side-force effects ig nored because minor RC _____Sailplanes Side area above center-ofgravityor conversely low center-of1 21 3 1 4gravity relative side areaacts crease yaw-roll couple same way does increased dihedral Gas Free Flight models take advantage effect tall wing pylons heavy low-thrust engines effect still minor models typical wing dihedral need dihedral its efficient increase wing dihedral extend fuselage wing pylon Much smaller increases wetted area result last effect increases spiral sta bility ignored circling entire Glider coming down same rate inboard wing moves slowly gives inboard wing greater angle tack increasing spiral stability effect minor airplanes good glide ra tios significant very draggy models its extreme form becomes stall-spin maneuver inboard ______wing stalled outboard wing con tinues fly large simplifying assump ________________tions produce conservative results SS greater 57 airplane almost cer tain stable near 57 stability probable depending primarily size vertical stabilizer SS doesnt get close 57 craft almost sure unstable Testing spiral stability RC Sail planes given airplane configuration ___________ dihedral tail boom-to-span ratio fixed Thus airplane has maxi mum lift coefficient minimum speed spirally stable Normally want Glider stable up near its maximum lift coefficient easy test flying straight slowly come back pitch trim lever until plane seems sinking its minimum rate let plane fly hands-off model contin ues straight almost straight spirally stable begins circle its Dont surprised plane proves lack spiral stability common RC SailContinued page 106 r 20 15 10 5 0 10 44 02030405 VERTICAL TAIL MOMENT ARM TO WINGSPAN RATIO Lv/b Figure 4 chart shows minimum wing dihedral angle diminishes tail boom lengthened design lift coefficient reduced can very useful during pro cess designing since permits dIrect trade tall boom length reduced dihedral 0708 104 Model Aviation U4 0506070809111 DESIGN LIFT cOEFFICIENT ci Figure 3 Th minimum wing dihedral angie must greater plans higher lift coeffi cients shorter taii booms plot shows minimum equivalent dihedral angie guarantees spiral stability f range lift coefficients tail-boom-to-wIngspan ratios ivlb its cisc useful evaluating maximum stable im coefficient existing designs Southern Radio ControlLons fl/C Service Naples FLPhoenix NY 813 775-1554315 695-2448 s&D WC ServiceiI&J ElectronicsRivergote Hobby Center San Jose CAHowell MlGoodleftsville TN 408 281-1549517 546-2644615 859-3455 Authorized IVC Service Fallbrook CA 619 728-0440 Radio South Pensacola FL 904478-6745 Iraft Midwest IMI Northoille Ml 313 348-0095 Woiiitz PJC Jackoonoille FL 904 771-0613 DuMond C Service Carroliton TX 214 242-4682 Ocean County WC Service Toms River NJ 201 505-9477 planes seem marginal regard determine pitch trim setting plane becomes stable adjust slightly higher speed repeat experi ment Repeat cycle increasing speed slightly time until airplane no longer rolls circle speed model stable difference between speed optimum mini mum sink speed will indicate far off airplane much dihedral tail boom must increased Keep mind lift coefficient proportional speed squared model becomes stable twice optimum speed dihe dral tail boom off factor four Its best conduct experiments still morning late evening air Also sure model free asymnoetrical warps wing isnt heavier other performed experiment Two-Meter RC Sailplane Tutor airplane has simple V-dihedral two-piece wing bent piano wire joiner flown three different dihedral angles substituting three different joiners illus trated pictures model trimmed fly approximately minimum sink rate airspeed estimated C1 09 allowed fly hands-off dihedral angle 15 degrees airplane tracked well speeds would fly straight very nearly indefinitely very low speeds did tend wiggle turbulence bit really needs bigger ver tical stabilizer give margin Dutch roll 12 degrees dihedral plane ap peared verge circling min imum sink speed wandered over sky never actually settled circle higher speeds tracked true judged plane just spirally stable con figuration 57 degrees dihedral model definitely unstable Over period about 15 seconds would roll left right circle stabilize about 20 degrees bank angle Pulling back pitch trim simply increased bank angle trimmed plane estimated C1 04 interthermal cruise speed released straight flight continued fly straight Calculating spiral stability Tutor 12 degrees dihedral according formula get 12 x 0324 43 Alternatively low dihedral angle higher speed SS roughly 57 x 0324 46which fairly close 43 con sidering imprecise nature C1 esti mates Note values somewhat less ideal 57 derived earlier article probably because extra outboard yaw resulting differ ential wing drag Other methods obtaining spiral stabil ity Free Flight models use sorts meth ods enhance spiral stability Chief among Continued page 191 106 Model Aviation RCD r AIVfefl1SAJtVB~e1 QOflt ileltewwe we6 w0eCtB ggl iA%~6 ~JI ai99~ 6 Owe60 IA owAte bO SSao 06606 L400* 6gA6I icipating RCD Sticker Stations 9SR Products Sacramento CA 918 362-1962 FOR ORDERS ONLYLJL CODs 1 -8OO6337556ILLJJJWELCOME IN ALABAMA 347 3525 COLLECT TOP QUALITY FUEL FOR EXPERT OR BEGINNER NO RE-CLAIMED ALCOHOL O METHANE ONLY IS USED Designed tested give top performance both 2-cycle 4-cycle engines ringed Except engines requiring low lubricant content CONTAINS NEW TRULY SPACE AGE ADDITIVE developed outer apace vacuum new additive attaches internal metal parts engine will reduce friction much 80/o reduces heat wear absolute minimum WE HAVE 3 LUBRICANT BLENDS ALL SYNTHETIC OR SYNTHETIC BLEND CASTOR castor new high purity much cleaner burning castor ALL OUR FUELS CONTAIN ANTI-FOAMERS PREVENTERS WEAR ADDITIVES fuel developed priced tor individual club direct sales market dealer Inquiries invited Order gallon up MIx OK 4 gallon cases up ALL FUEL EXCEPT 54 GALLON DRUMS SHIPPED FREIGHT PRE-PAID Only continental USA TD 3 GalTo 23ITo63To 127 GIjAndIFreight l l24 Gal al12S al Drum 5% ..1095750700.650 . .. 57518500 120/o 5 .050. 900 7528000 250/o 5. 1400 0127547500 500/o 02200 ..21 502075780 00 Manufactured MACH-7 PO Box 1201 Enterprise Alabama 36330 houses relics displays both World Wars HMS Belfast moored Lon dons Thames River newest exhibit Cabinet War Rooms recently restored World War II condition under ground emergency headquarters Prime Minister Winston Churchill Taken together installations tell story two enormous wars raged around Englandparticularly skies over now-peaceful settings like Duxford Airfield Spiral/Beron-Rawdon Continued page 106 asymmetrical wing twist known washin washout Normally inboard wing washed twisted inci dence outboard wing washed out approximately equivalent yawing dihedraled wing outboard rudder trim should enhance spiral stability dont know Free Flight difference between approximately equivalent exactly same can important Another Free Flight method ballast inboard wing tip apply outboard rud der trim tip weight produces con stant inboard rolling moment rudder yields outboard yaw-roll couple very sensitive airspeed As model slows down tip weight rolls plane circle plane rolls up bowl effect increases airspeed rud September 1990 191 Bill Eff go * says OnlyPlans Pettern5 Sets give assorted designs yos west hove eslected best cleesic designs eli time choose hoer patterns soch part art important exclusive feature Ducted Fans Navy F4D-i Skyray 1 h soale ength 40ff wing span lg h RIO eotlbte Landing Gear RODF229gB 1 seats ength 32t$ wing span lbs wie RIO 3-0 sir R/O 5 RK725 lens ROOMgfgg One-Third Scale Piper TPacer PA-22 11R31g wing span sq wing area 20 30 old engines 4-5 oh RIO so 12 lb. SluR onersll length RO3g3029gb 1/3Piper Cub 1-3 Scale hR wing span ength 2005 sq wIng area4 oh RIO 030 old engines R030202996 Quarter Scale WWI SE-IA 001 wing span sq wing ares 5 70 tu 22 engines 0005-7 6 SPAD CXIII s70/wingsyons2l20sqin winguteos t3to3t engines Capable flynt-it captures thn imagination RCOS-g 6 FOKKER DR-i TRIPLANE 72 oring span C 1772 pa wing area 70 tot 00 engines OCOS0 82496 SOPWITH CAMEL F1 04 wing span 21 60 pa wing area ftlbs wls R/O wood ft balse construction over OPuq ft drawings 0005t 1 6 00wingspans2225sqivw cane 114 Scale Fokker 0-ViII 00 25 cid onoine 3-h ch OCOSO 0 Golden Age 114 Scale Curtiss Hawk P 1 00length04tfwingspan 2260uq 5 wing areas 1323 engines h 0/C RCOS-t 4 6 114 Scale CurtigaFalcon 03lnngthsltdwitgnpan3100 sqmnwmvg areaedchR/CRCOS-13g20961J 1/6 Scale Cessna AW 0twinospansgO0sqinwingarea 25to go ongirres channel 0/C RC6S-f $1496 roe ill Scale Purn Mogt 73Ifwingtpans4d0sinarno Pot 2040 engines annel 0/C RC0S-3 6 5111 stOnes Fouodlng Merebar AMA OPPO Hell Fewer Privon ore fur vurnyloto pbne sub asuorubly ft derajind parts huts PLEASE ADD 0200 tsr shipping Inrelllng tubal Now 1990 Pros Oats brovhxro refundablo Ion yvu h order WE TECHNICAL SERVICES RO 1 Box 2900 Santa Rosa Beach FL 32459 der becomes powerful balancing tip weight method stable circle direction still relies di hedral produce yaw-roll couple also relies bowl effect increase air speed increased bank angle Dihedral tail boom length pitch stability will still have strong effects spiral stability such model quick look Figure 3 will show low-dihedral airplanes such typical $599 o \C39\ Nut use Electric Starters Made 6061 Aluminum strong enough allow over tightening weighs under 1 oz 1 diameter 1t/t long 114 radius nose minimum AMA requirement 5/32 Torq Hole 3/4 thread depth can use thinnest props 11 thread sizes fit engines market Send us order & well mail out tast MADE IN THE USA B C PRODUCTS 111 N Starkweather Pam pa Texas 79065 1-800-441-4365 US & Canada aileron-controlled RC Sailplanes havent shadow hope being spirally stable reasonable lift coefficients example plane 30 degrees dihedral lift coefficient 07 must have tail boom 13 times long wingspan type models spiral stability can achieved artificial mechanisms example would produce artificial yaw-roll couple means yaw sensor hooked up run ailerons rate D103210/32 DOSBO5-8mm D123212/32 D06106-1mm 107107-1mm D08108-1mm D81258-125mm D101210-125mm D14281/4-28 151625/1624 38243/8-24 VISA MASTERCARD MONEY ORDERS ACCEPTED DEALER INQUIRES WELCOME ENYA 15 5-8mm SS2O SS45 1/4-28 19 to 80 7-1mm 120 8-1mm FOX 19 45 1/4-28 60 to 120 5/16-24 HB ALL SIZES 1/4-28 HP 40 6-1mm 120 5/16-24 others 1/4-28 IRVING ALL 1/4-28 K&B 19 611/428 OS 10 5-8mm 15 12/32 20 6-1mm 21 50 1/4-28 60 120 5/16-24 108 3/8-24 ROSSI ALL 8-125mm SUPERTIGER 11 to 15 5-8mm 19 to 60 1/4-28 61 to 90 5/16-24 2000 6000 10-125mm SATIO3Oto60 6-1mm 65 to90 71mm 120 to 270 8-125mm WEBRA 28 61 1/4-28 80 90 8-125mm MALONEY 100 3/8-24 .THESUPERIORGLOWPLUGSFO GO FASTFLYERSAREBACKII Puts sting engine Unique flat-wound spiral coil element high temperature glass-to-metal seal add up faster ignition increased RPM 1 /2A GloBee plugs designed exclusively 049/051 Cox engines - Ask new GB-5RX Speed Plug GB-SR Racing Plug GB-5P Spert Plug local dealer today unavailable locally write call Twinn-K collect pricing delivery information FREE GloBee Catalog MAKE THE GLOBEE / INDY CONNECTION Twinn-K Inc 10296 W Washington St Indianapolis IN 46231 Telephone 317-839-6579 FAX 317-839-8928 192 Model Aviation aileron deflection function yaw angle sufficient spiral stability could achieved Another method would employ direct mechanical link between yaw vanes aileronsthough youd probably have watchmaker get work Intro ducing yaw-roll couple will make roll axis sensitive deviations yaw axis particular attention will have paid rudder coordination during transi tional maneuvers Another possibility flat-wing air planes would incorporate rate gyro scope gyro could sense yaw rate drive ailerons roll out As plane rolled circle its bank angle yaw rate increase ailerons deflect roll plane out circle response yaw rate may provide spiral stability chance however phase diffi culties between yaw rate roll accelera tion would develop causing disruptive yawroll oscillations similar Dutch roll successful experiment thought worth trying last fix wifes large slow aileron Sailplane Tango plane originally flown zero dihe dral major pain thermal due lack spiral stability Increasing EDA two degrees made noticeable improve ment still great challenge thermal efficiently slowly installed Futabas simple least expen sive rate-sensitive gyroscope model FP G134 ballast box plane unit consists two components gyro box electronics box gyro stalled in-line between receiver aileron servo Tango uses separate rudder servo connected ai leron output receiver Y connector couples rudder ailerons control adverse yaw However rudder servo still hooked direcfly receiver unaffected gyro gyro installation illustrated pictures electronics box has little knob actu ally screw adjusts effect gyro aileron servo zero 100% 0% gyro has no ef Continued page 194 /9 ilttilt --MIt Ii tPJOflC OU QOtVT FLf WELL I1iVfRi 1I ISLiRINO%11 St 1IC m JJJ0 QUADRA RT 1 NEODESHA KS 66757 316325-2821 DEALERS CALL SEND $100 FOR COMPLETE CATALOG fect higher settings gyro input mixes pilots input control ai lerons higher setting the gyro has say about would appear 100% setting maximum con trol input gyro nearly equals maxi mum input pilots stick gyro box installed senses yaw rate reversing switch electronics box set give right aileron left yaw rate vice versa word about rate gyros may helpful contrast regular gyros sense change orientationin degrees instancerate gyros sense rate change orienta tion say degrees per second cant tell way pointing way fast turning bottom line gizmo works adjustment about 50% sensitivity plane flies extremely well model actually flies straight indefinitely straightens out circles slowly itself has feel circle good-performing polyhedral ship retains immediate roll response aileron-controlled craft No adverse effects noted flying model through entire envelope Some better fliers Soaring Union Los Angeles have flown plane gyro responses ranging enthusiastic acceptance grudging admis sion did indeed seem nice am excited about development means sorts low-dihedral aileron AJKUMUIJbL iIANT SHARK ARC PRE-BUILT G SHARK S21495 SEE YOUR HOBBY DEALER FIRST SEND STAMPED #10 ENVELOPE FOR INFO KINGS WAY RIG HOBBY SUPPLY 5559 RICHMOND HOUSTON TX 77056 DEALERS ONLY 1-800-621-7783 194 Model Aviation AT LAST An Effect ye H gh Tech Engine Cleaner R/G Engines Removes Burned-On Fuel Residue Encrusted Carbon anteed ONLY $695 CA residents add 725% lax Clean Engines-Run Cooler-Last Longer Send Check Money OrderTo AIRBORNE HOBBIES 3764 30TH ST SAN DIEGO CA 92104 619543-9703 DEALERS INQUIRES WELCOME tIN SUPERTANKS & SUPERMUFFLERS ZINGER WOOD PROPS GIANT SCALE R/C PLANS C #No663 Pea Patch $900 RC Sportster spans 60 uses 40150 4-stroke power Two plan shts No 664 Stuka Stunt $500 CL V2A Stunter semiscale spans 37 No 665 Conscientious Objector $575 FF Mulvihill Rubber competition plane spans 501/2 flat No 193 StIletto CL Stunt nindel McDonald winner 1976 1980 1982 FAt Wodd Champs $ 375 No 262Craahmaater- Ct Crash-pruof trainer two tizet1 5130 35/40 powor$125 No 3101930 Fleet Biplane AC Sport Scale 35140 4-clronnel Wingspan 56 e Ten streets6625 No 314Drake II AC Ken Witards flying boat 3-channel 15-power Fly 1mm land mmovabln gear . No 326Taylor Cub AC Don Srnlfs Schoolyard-Scale 049s 2-3 channel Spoon 50 in$350 No 332Zephyr AC Sinaf 2-channel glider hand-launch tow thermal slope soaring6200 No 386Laaer 200 AC Sport Scale replica champineship Aerehafic tiler Uses 40 power 4-5 channel Two sheets$1075 No 4471/2A Miwa America AC Old-Tuner WA Texaco model 049 glow 2-channels$650 No 4604-40 AC Shoelder-wiog sport filer 4-cycle 40-nine engine 4 channelo$650 No 465Blue Max II AC Fun-fly sportster 40-size engines spans 52 Lightweight stonctere$700 No 533Cewana C-37 AC Schoolyard Scale ni tamoos 3& plane 009/10 power 2-ch opans 42Va in6500 No 539Slmitar Slow4dotlon 15 AC Tailless flying wing 15 engines spans 98 ones 3-ch AC$350 No 569Elactroatreak AC Electric aembatic plane spans 44 ones 05 motorS550 No 572TR-260 AC Sport Scale Aerohalic plane 4-strulre 65/66 power spans 66 in61100 No 576Serendlpityt ndoor 025 record-holder spans 17/ in$325 No 578Scinwelzer 1-26B AC Quarter-ucale Sailplane spans 125 Two plan sheets61475 No 581Gee Bee Moefel Y AC Golden Age Racer spans 72 1A scale 60 power Thwe plus sheets61175 No 586Snapdragon AC Fun-fly/sponster 25/30 engines spans 45 In6698 No 588Marlah AC Slope-Soaring Sailplane spans 41 uses 2 AC channels6425 No593Taytorcralt AC Sport Scale llghtplane builds us standard 2-placer clipped-wing air show stenter Spans either 70 50 35/40 two-stmfre 45/48 four-ntmhe engine Two plan sheets no dncomentatmn$1000 No586Coronet 150 RC-Assint Old-liner enlarged 15914k spans 72 uses 40-size 4-sImlreI 30-size 2-tube6850 No601NIcicel AC Sportster WA engine 3 AC channels Spans 44 in$500 No 603Sparrow Hawk P30 FF Competitfon rebber-power plane woo 87 Nuts Spans 30 in$225 No607Curtlaw Seegull AC Glout Scale biplane spant 50 uses Oeadra/Zeuoah power Three plan sheets dec62498 No mTapeewing AC WA Pylon Racer spans 29 Plan plan use ports template about$698 No 610Protobype AC Sport biplane spans 48 uses 45/2-cycle 85/4-cycle power$650 No 619KeIth RIder R4 FF Scale Goldan Age racer rebber power spans 18 in6300 No 620GImlet 60 AC Spert/Pattem plate spans 60 iii 45/50 enguw 2 sheets61100 No 623Henderwom Longater AC Quarter-Scale 1933 fhwer spans 90h 4-strube 45/46 engine 3 plan sht no dec$1698 No624KelaIrer Laric AC Quarter-scale hontehuit spans 69 69198 4-Otmlre power 2 plait sheets dec61100 No 626Sweepee AC Spoil/Pattem canards foiward-sweyl wing spans 64 uses 48 power 2 plan sheets61300 No628Prime Cut AC SportlAerotsatic plane spuss 90 uses Quadra 35/40-sine power Two plus sheets61300 No 630OrIginal Ply Baby AC Old-Thiter spans 72 uses 19125 2-cycle 484-cycle power 2 plan sheets61150 No 635The Gambler FF Indoor Sestoeran rebber-power cable plane spans 15% in6200 No 836Keytwo AC Tn-geared low-wing sportsler 29125 power spans 44 in$575 No637A6 Shrike FF Compefitine plane AMA Clauses 5 15/23 power spans 60 in$675 No 638Owl Racer CL WA Scale Racer 049 power spans 20 6225 No 839SIcyvoIt AC Tn-geared Electric aerubatic sportoter 05/15 power spans 50 in6850 No 640Bird Prey CL AMA Fast Combat plane 36 power spans 5334 in$550 No 641UI Ole Reliable AC Old-tinter spoil filer spans 50% WA engines$575 No 642BIpe 89 CL Partlat plus updates deflofis 48 nersbon 3Scc power Spans 2234 in6225 No643Noctule IIB FF Baflulte flying wing CO2 power spoon 30 in$325 No 644Beliance ColumbIa AC Schoolyard Scale 2 AC channels WA engine Wingspan 46 m$575 No 645Lalrd Solution Cl Ponfile Scale biplane spans 36 25/35 pewer6575 No 646WInter Hawk FF Robber-power Coupe dHleer cempefiflon plane spans 47 in6375 No647Cox Speeded CL Semincale biplane WA enne spans 24 in6300 No646Cufllwa OC-2 FF Sculls Outdoor Gas Ftying Scale biplane uses electric power spans 24 HiLine lohnr-6 motor$325 No640Thlngemabob AC/CL Mutfimede trainer 25 gas 05 electric power spans 51 in$475 No 65047/66 RC Special AC Aembafic sport plane 48 power spans 61 3 plan sheetsS1075 No 651Conwortlum AC Husri-Lanoch HI-Start Coder spans 60 in6050 No652Oar Ptedenmaeea AC Lute-wing spoil plane 29125 power npons 55 -$675 No 663Aventl CL Profile Sport Scale canard hisliner twin DOgs spans 38 in$575 No 654Tamiecag AC Trainer/spottster styled Ibe F14 spaus 66 45/61 power Four plan sheets$1525 No 6S5Aetroalar FF AMA Class A/B Gas plane spans 67 uses 3 25/350cc power$800 No 856XP13C CL Profile 15 Carrier plane spans 277A in6550 No657Super Squire AC Trainer 35/48 2-stonbe 53 4-strobe power spans 9834 in6750 No 658SIturiken Streak CL Trainer uses 2-line Moonline control spans 17 WA power$225 No659Boom Box FF Walefleld Rubber competitine plane spans 54 in6400 No 660Volkaplene AC Electric-powered sportster 05 motor spans S6 2 plan shts6925 No661Embey-Omatlc FF Embryo Enderance mbber-power plane spans 20 in6200 No662Boxklte CL Scale antique caned pusher biplane spans 42 2 plan shtsS1100 0 Os 0 o C%J 0 gC Co tous Q 0 05 no 6E 050 o - Co FJ t- tog5 0 C 0 - 0 - ID 05 005 0 c us n 00 0 00 us Co-s 0 0 E-d 00 cs 0 2 0 I U0 E N STREET 0CITY - Circle numbers plans wish order best handling please include re quests payment some other service withyourplans order 193262310314326332386447 460465533539569572576578 581586588593598601603607 609610619620623624626628 630635636637638639640641 642643644645646647648649 650651652653654655656657 658659660661662663664665 Plan price includes first class postage US delivery Air Mail over 300 miles orders non-US address lease add $258 Air Mail osta e handlin Ian Make Check money order payable US funds drawn US bank Model Aviation AMA 1810 Samuel Morse Reston VA 22090 Please allow 3 6 weeks delivery Please print CarefullyEnclosed $ _______________________ ___________________________________________ AMA No _______________ airplanes can practical pleasurable fly may also mean ultimate dura tion cross-country RC Sailplane now large flat-wing variable-camber aileroncontrolled configuration instead sim pler fixed-camber rudder elevator ar rangement caution have course tried sys tem 100% sensitivity setting plane does interesting 1-Hz flat yaw oscil lation about plus minus 15 degrees ascribe adverse yaw coupling gyro model remained flyable no harm done might want come up optimum setting instead starting working way down Summary conclusions Spiral stability measure tendency airplane spiral straight circling flight Its primarily function Equiv alent Dihedral Angle EDA tail boom-towingspan ratio lIb wing lift coeffi cient C1 significant secondary variable yaw stability plane function fuselage proportions ver tical stabilizer size Airplanes strong yaw stability spirally stable EDA X lw/b C1 greater equal about 57 Air planes modest yaw stability will sta ble somewhat lower values relation ship illustrated Figures 3 4 An experimental procedure de scribed determining degree spiral stability RC Sailplanes test TwoMeter Sailplane showed good agreement theory control dihedral angle tail boom proportion lift coefficient primary means achieving spiral stability other methods can used Free Flight mod els typically incorporate asymmetrical trim balance arrangement effec tive oaly circle direction mechanical means well successful has tested article incor porates yaw rate gyro drive aile rons As practical inexpensive way provide spiral stability aileron-con trolled Sailplanes exciting devel opment Next month Part Two will describe effect circling flight spiral stability pitch trim yaw angle Southwest PC Flying Year round flight school Five day course $350 Learn fLy planes Send SASE conlete info 2818 CaroLina NE Albuquerque NM 87110 505 881-3799 196 Model Aviation IMPORTED DIESELS A-MAuroraDCEDMVVSMBia*nya PAWTaplln Standard R/C.0864S Acre & MarIne VlntegeAperg Comfiest Seed $100 Informatlo CARLSON ENGINE IMPORTS 314 East Marcomi Phoenix AZ 85022 _________________________________________ ZIP _______________________________
Edition: Model Aviation - 1990/09
Page Numbers: 100, 101, 102, 103, 104, 106, 191, 192, 194, 196
NO OCR TEXT NO OCR TEXT juel per ipervil pnoso D inS au beHest compartment circie giving spiral dral-ilke handling w degrees last thre scribed detail b Keeping mind portional W/S ank C.u around tracked Stf ems lango ailerons result slmple uncoupled coi ited d illustr lw/b ran ailplanes Frc adral angl us dihedra rolled photos wer gher values ty 10 some luces greater spr quiva1ent dihedr of the effective ng force n yaw angle ir greater r yaw angles ig compti Part slues EDA rai Extreme values up 20 th spiral mt C1 b flight Since loading dvn 05 Rho goes down nother way airspeed2 prop wis an find ratio yaw angle required gles yaw obtained/yav proportio lw/b X ED order achieve sp aircraft yaw angle equal greater quired eoi balance neutral yaw obtained greater out circle unless put held yaw obtain will roll tighter tive varying top ru Anything increas obtained yaw req spiral stability formula crux c1 contains three Lets take detailed ratio vert tothe wp liiir E s 51mph ar momen atween FIgure 2 circular flight path tends force wing outboard yaw angle vertical stabilizer lines itself up airflow becomes quite clear illustration yaw angle sensitive both circle radius vertical stabilizer moment arm length late angle attack high angle tack gives high C1 vice versa Rho air density slugs per cubic foot about 0002377 sea level An increase C1 reduces spiral stability increasing C1 increases yaw ob tained given bank angle due reduced circle radius yaw required increased because both V2 term r reduced inverse proportion C1 general Gliders thermal best near maximum C1 just shy stall higher lift coefficients give less spiral stabil ity leads interesting effect de scribed later article Typical thermaling values C1 RC Sailpianes range 06 10 Thicker higher camber sections will high end range Typical Free Flight C1s range low 04 high 14 low values would found smaller models low-camber wings high est values would found larger thin high-camber wings such A2 class Towline Gliders Observations interesting three variables significantly affect spiral stability has important implica tions Wing loading does matter can ballast model affecting spiral stability Aspect ratio does matter long skinny wings short squat ones have about same impact spiral stabil ity Note though long wing requires long fuselage Size does matter can scale design up down spiral sta bility will retained same lift coeffi cient Circle radius bank angle matter plane stable bank angle stable bank angles assuming no change C1 Computations tested out spiral stabil ity relationship trusty computer spreadsheet described Dihedral series spreadsheet divides wing 20 spanwise segments allows fly various bank angles wing load ings dihedral angles schemes lift coef ficients yaw angles output value net roll moment given configuration fiddle dihedral angle yaw angle until roll moment zero did series configurations results showed plane spirally sta ble EDA x l/b 7 greater sake brevity lets define new variable 55 equal EDA x lw/b S stands spiral stability convenience relationship three variables plotted Figures 3 4 plots enable find third vari able already know other two have existing airplane EDA lw/b already known plots will show maximum lift coefficient plane will spirally stable example using Figure 3 can find plane 15 degrees EDA 04 lw/b will stable lift coefficient 105 less Figure 4 could used well reading plot difficult since must interpolate between lines designing plane scratch may want examine trade-off between tail boom length dihedral angle Pre sumably have already chosen wing section have estimate cir cling lift coefficient example say designing floater RC Sailplane expected thermal lift coeffi cient 10 Figure 4 permits direct exam ination boom/dihedral trade-off Fol lowing along C1 ine find could have 02 lw/b 27 de grees dihedral Wow Thats lot dihe dral plane will highiy sensitive rudder trim 04 l/b 145 degrees dihedral like 08 lw/b 75 degrees dihedral long tail boom low roll rate due low dihe dral anglesee Part Two Dihe dral series Because simplifying assumptions described below plots conserva tive Depending mostly size vertical stabilizer can back off some dihedral angle tail boom length can increase lift coefficient although just much tricky say Testing typical Two-Meter RC Sailplane found 43 approximately min imum value SS testing later Variables ignored insignificant some important variables have ig nored order boil problem down September 1990 103 35 30 25 MINIMUM20 EQUIVALENT DIHEDRAL ANGLE DEG15 10 5 0 fundamentals Most important extra outboard yaw due differential wing drag As plane circles outboard wing flying faster creates drag produces outboard yawing moment opposed vertical stabilizer der stabilizer generate opposing lift plane must yaw further outboard Large stabilizers can generate required lift small yaw angles small verticals can require much greater yaw angles 35 30 25 MINIMUM EQUIVALENT DIHEDRAL ANGLE DEG extra outboard yaw angle increases spiral stability increasing tendency plane roll out circle Free Flight models typically use small verticals consequent increase spiral stabil ity can quite great contrast RC Sailplanes typically have large vertical stabiliz ers track well produce little change spiral stability graphs ignore ef fect entirely since indicate spiral stabil ity achieved very large stabiliz Lv/b 2 era Smaller stabilizers give spiral sta bility Fuselage interference effects also ig nored since fuselages Gliders very small compared wings large fuselages Scale Free Flight models however have important ef fect spiral stability As generalization high-mounted wings large fuselages have dihedral lowmounted wings behave hnd less Also generous amount fuselage side area front center-of-gravity desta bilizes plane yaw increasing spiral stability same way reducing size vertical stabilizer does ef fects difficult quantify _____yond scope article Pendulum side-force effects ig nored because minor RC _____Sailplanes Side area above center-ofgravityor conversely low center-of1 21 3 1 4gravity relative side areaacts crease yaw-roll couple same way does increased dihedral Gas Free Flight models take advantage effect tall wing pylons heavy low-thrust engines effect still minor models typical wing dihedral need dihedral its efficient increase wing dihedral extend fuselage wing pylon Much smaller increases wetted area result last effect increases spiral sta bility ignored circling entire Glider coming down same rate inboard wing moves slowly gives inboard wing greater angle tack increasing spiral stability effect minor airplanes good glide ra tios significant very draggy models its extreme form becomes stall-spin maneuver inboard ______wing stalled outboard wing con tinues fly large simplifying assump ________________tions produce conservative results SS greater 57 airplane almost cer tain stable near 57 stability probable depending primarily size vertical stabilizer SS doesnt get close 57 craft almost sure unstable Testing spiral stability RC Sail planes given airplane configuration ___________ dihedral tail boom-to-span ratio fixed Thus airplane has maxi mum lift coefficient minimum speed spirally stable Normally want Glider stable up near its maximum lift coefficient easy test flying straight slowly come back pitch trim lever until plane seems sinking its minimum rate let plane fly hands-off model contin ues straight almost straight spirally stable begins circle its Dont surprised plane proves lack spiral stability common RC SailContinued page 106 r 20 15 10 5 0 10 44 02030405 VERTICAL TAIL MOMENT ARM TO WINGSPAN RATIO Lv/b Figure 4 chart shows minimum wing dihedral angle diminishes tail boom lengthened design lift coefficient reduced can very useful during pro cess designing since permits dIrect trade tall boom length reduced dihedral 0708 104 Model Aviation U4 0506070809111 DESIGN LIFT cOEFFICIENT ci Figure 3 Th minimum wing dihedral angie must greater plans higher lift coeffi cients shorter taii booms plot shows minimum equivalent dihedral angie guarantees spiral stability f range lift coefficients tail-boom-to-wIngspan ratios ivlb its cisc useful evaluating maximum stable im coefficient existing designs Southern Radio ControlLons fl/C Service Naples FLPhoenix NY 813 775-1554315 695-2448 s&D WC ServiceiI&J ElectronicsRivergote Hobby Center San Jose CAHowell MlGoodleftsville TN 408 281-1549517 546-2644615 859-3455 Authorized IVC Service Fallbrook CA 619 728-0440 Radio South Pensacola FL 904478-6745 Iraft Midwest IMI Northoille Ml 313 348-0095 Woiiitz PJC Jackoonoille FL 904 771-0613 DuMond C Service Carroliton TX 214 242-4682 Ocean County WC Service Toms River NJ 201 505-9477 planes seem marginal regard determine pitch trim setting plane becomes stable adjust slightly higher speed repeat experi ment Repeat cycle increasing speed slightly time until airplane no longer rolls circle speed model stable difference between speed optimum mini mum sink speed will indicate far off airplane much dihedral tail boom must increased Keep mind lift coefficient proportional speed squared model becomes stable twice optimum speed dihe dral tail boom off factor four Its best conduct experiments still morning late evening air Also sure model free asymnoetrical warps wing isnt heavier other performed experiment Two-Meter RC Sailplane Tutor airplane has simple V-dihedral two-piece wing bent piano wire joiner flown three different dihedral angles substituting three different joiners illus trated pictures model trimmed fly approximately minimum sink rate airspeed estimated C1 09 allowed fly hands-off dihedral angle 15 degrees airplane tracked well speeds would fly straight very nearly indefinitely very low speeds did tend wiggle turbulence bit really needs bigger ver tical stabilizer give margin Dutch roll 12 degrees dihedral plane ap peared verge circling min imum sink speed wandered over sky never actually settled circle higher speeds tracked true judged plane just spirally stable con figuration 57 degrees dihedral model definitely unstable Over period about 15 seconds would roll left right circle stabilize about 20 degrees bank angle Pulling back pitch trim simply increased bank angle trimmed plane estimated C1 04 interthermal cruise speed released straight flight continued fly straight Calculating spiral stability Tutor 12 degrees dihedral according formula get 12 x 0324 43 Alternatively low dihedral angle higher speed SS roughly 57 x 0324 46which fairly close 43 con sidering imprecise nature C1 esti mates Note values somewhat less ideal 57 derived earlier article probably because extra outboard yaw resulting differ ential wing drag Other methods obtaining spiral stabil ity Free Flight models use sorts meth ods enhance spiral stability Chief among Continued page 191 106 Model Aviation RCD r AIVfefl1SAJtVB~e1 QOflt ileltewwe we6 w0eCtB ggl iA%~6 ~JI ai99~ 6 Owe60 IA owAte bO SSao 06606 L400* 6gA6I icipating RCD Sticker Stations 9SR Products Sacramento CA 918 362-1962 FOR ORDERS ONLYLJL CODs 1 -8OO6337556ILLJJJWELCOME IN ALABAMA 347 3525 COLLECT TOP QUALITY FUEL FOR EXPERT OR BEGINNER NO RE-CLAIMED ALCOHOL O METHANE ONLY IS USED Designed tested give top performance both 2-cycle 4-cycle engines ringed Except engines requiring low lubricant content CONTAINS NEW TRULY SPACE AGE ADDITIVE developed outer apace vacuum new additive attaches internal metal parts engine will reduce friction much 80/o reduces heat wear absolute minimum WE HAVE 3 LUBRICANT BLENDS ALL SYNTHETIC OR SYNTHETIC BLEND CASTOR castor new high purity much cleaner burning castor ALL OUR FUELS CONTAIN ANTI-FOAMERS PREVENTERS WEAR ADDITIVES fuel developed priced tor individual club direct sales market dealer Inquiries invited Order gallon up MIx OK 4 gallon cases up ALL FUEL EXCEPT 54 GALLON DRUMS SHIPPED FREIGHT PRE-PAID Only continental USA TD 3 GalTo 23ITo63To 127 GIjAndIFreight l l24 Gal al12S al Drum 5% ..1095750700.650 . .. 57518500 120/o 5 .050. 900 7528000 250/o 5. 1400 0127547500 500/o 02200 ..21 502075780 00 Manufactured MACH-7 PO Box 1201 Enterprise Alabama 36330 houses relics displays both World Wars HMS Belfast moored Lon dons Thames River newest exhibit Cabinet War Rooms recently restored World War II condition under ground emergency headquarters Prime Minister Winston Churchill Taken together installations tell story two enormous wars raged around Englandparticularly skies over now-peaceful settings like Duxford Airfield Spiral/Beron-Rawdon Continued page 106 asymmetrical wing twist known washin washout Normally inboard wing washed twisted inci dence outboard wing washed out approximately equivalent yawing dihedraled wing outboard rudder trim should enhance spiral stability dont know Free Flight difference between approximately equivalent exactly same can important Another Free Flight method ballast inboard wing tip apply outboard rud der trim tip weight produces con stant inboard rolling moment rudder yields outboard yaw-roll couple very sensitive airspeed As model slows down tip weight rolls plane circle plane rolls up bowl effect increases airspeed rud September 1990 191 Bill Eff go * says OnlyPlans Pettern5 Sets give assorted designs yos west hove eslected best cleesic designs eli time choose hoer patterns soch part art important exclusive feature Ducted Fans Navy F4D-i Skyray 1 h soale ength 40ff wing span lg h RIO eotlbte Landing Gear RODF229gB 1 seats ength 32t$ wing span lbs wie RIO 3-0 sir R/O 5 RK725 lens ROOMgfgg One-Third Scale Piper TPacer PA-22 11R31g wing span sq wing area 20 30 old engines 4-5 oh RIO so 12 lb. SluR onersll length RO3g3029gb 1/3Piper Cub 1-3 Scale hR wing span ength 2005 sq wIng area4 oh RIO 030 old engines R030202996 Quarter Scale WWI SE-IA 001 wing span sq wing ares 5 70 tu 22 engines 0005-7 6 SPAD CXIII s70/wingsyons2l20sqin winguteos t3to3t engines Capable flynt-it captures thn imagination RCOS-g 6 FOKKER DR-i TRIPLANE 72 oring span C 1772 pa wing area 70 tot 00 engines OCOS0 82496 SOPWITH CAMEL F1 04 wing span 21 60 pa wing area ftlbs wls R/O wood ft balse construction over OPuq ft drawings 0005t 1 6 00wingspans2225sqivw cane 114 Scale Fokker 0-ViII 00 25 cid onoine 3-h ch OCOSO 0 Golden Age 114 Scale Curtiss Hawk P 1 00length04tfwingspan 2260uq 5 wing areas 1323 engines h 0/C RCOS-t 4 6 114 Scale CurtigaFalcon 03lnngthsltdwitgnpan3100 sqmnwmvg areaedchR/CRCOS-13g20961J 1/6 Scale Cessna AW 0twinospansgO0sqinwingarea 25to go ongirres channel 0/C RC6S-f $1496 roe ill Scale Purn Mogt 73Ifwingtpans4d0sinarno Pot 2040 engines annel 0/C RC0S-3 6 5111 stOnes Fouodlng Merebar AMA OPPO Hell Fewer Privon ore fur vurnyloto pbne sub asuorubly ft derajind parts huts PLEASE ADD 0200 tsr shipping Inrelllng tubal Now 1990 Pros Oats brovhxro refundablo Ion yvu h order WE TECHNICAL SERVICES RO 1 Box 2900 Santa Rosa Beach FL 32459 der becomes powerful balancing tip weight method stable circle direction still relies di hedral produce yaw-roll couple also relies bowl effect increase air speed increased bank angle Dihedral tail boom length pitch stability will still have strong effects spiral stability such model quick look Figure 3 will show low-dihedral airplanes such typical $599 o \C39\ Nut use Electric Starters Made 6061 Aluminum strong enough allow over tightening weighs under 1 oz 1 diameter 1t/t long 114 radius nose minimum AMA requirement 5/32 Torq Hole 3/4 thread depth can use thinnest props 11 thread sizes fit engines market Send us order & well mail out tast MADE IN THE USA B C PRODUCTS 111 N Starkweather Pam pa Texas 79065 1-800-441-4365 US & Canada aileron-controlled RC Sailplanes havent shadow hope being spirally stable reasonable lift coefficients example plane 30 degrees dihedral lift coefficient 07 must have tail boom 13 times long wingspan type models spiral stability can achieved artificial mechanisms example would produce artificial yaw-roll couple means yaw sensor hooked up run ailerons rate D103210/32 DOSBO5-8mm D123212/32 D06106-1mm 107107-1mm D08108-1mm D81258-125mm D101210-125mm D14281/4-28 151625/1624 38243/8-24 VISA MASTERCARD MONEY ORDERS ACCEPTED DEALER INQUIRES WELCOME ENYA 15 5-8mm SS2O SS45 1/4-28 19 to 80 7-1mm 120 8-1mm FOX 19 45 1/4-28 60 to 120 5/16-24 HB ALL SIZES 1/4-28 HP 40 6-1mm 120 5/16-24 others 1/4-28 IRVING ALL 1/4-28 K&B 19 611/428 OS 10 5-8mm 15 12/32 20 6-1mm 21 50 1/4-28 60 120 5/16-24 108 3/8-24 ROSSI ALL 8-125mm SUPERTIGER 11 to 15 5-8mm 19 to 60 1/4-28 61 to 90 5/16-24 2000 6000 10-125mm SATIO3Oto60 6-1mm 65 to90 71mm 120 to 270 8-125mm WEBRA 28 61 1/4-28 80 90 8-125mm MALONEY 100 3/8-24 .THESUPERIORGLOWPLUGSFO GO FASTFLYERSAREBACKII Puts sting engine Unique flat-wound spiral coil element high temperature glass-to-metal seal add up faster ignition increased RPM 1 /2A GloBee plugs designed exclusively 049/051 Cox engines - Ask new GB-5RX Speed Plug GB-SR Racing Plug GB-5P Spert Plug local dealer today unavailable locally write call Twinn-K collect pricing delivery information FREE GloBee Catalog MAKE THE GLOBEE / INDY CONNECTION Twinn-K Inc 10296 W Washington St Indianapolis IN 46231 Telephone 317-839-6579 FAX 317-839-8928 192 Model Aviation aileron deflection function yaw angle sufficient spiral stability could achieved Another method would employ direct mechanical link between yaw vanes aileronsthough youd probably have watchmaker get work Intro ducing yaw-roll couple will make roll axis sensitive deviations yaw axis particular attention will have paid rudder coordination during transi tional maneuvers Another possibility flat-wing air planes would incorporate rate gyro scope gyro could sense yaw rate drive ailerons roll out As plane rolled circle its bank angle yaw rate increase ailerons deflect roll plane out circle response yaw rate may provide spiral stability chance however phase diffi culties between yaw rate roll accelera tion would develop causing disruptive yawroll oscillations similar Dutch roll successful experiment thought worth trying last fix wifes large slow aileron Sailplane Tango plane originally flown zero dihe dral major pain thermal due lack spiral stability Increasing EDA two degrees made noticeable improve ment still great challenge thermal efficiently slowly installed Futabas simple least expen sive rate-sensitive gyroscope model FP G134 ballast box plane unit consists two components gyro box electronics box gyro stalled in-line between receiver aileron servo Tango uses separate rudder servo connected ai leron output receiver Y connector couples rudder ailerons control adverse yaw However rudder servo still hooked direcfly receiver unaffected gyro gyro installation illustrated pictures electronics box has little knob actu ally screw adjusts effect gyro aileron servo zero 100% 0% gyro has no ef Continued page 194 /9 ilttilt --MIt Ii tPJOflC OU QOtVT FLf WELL I1iVfRi 1I ISLiRINO%11 St 1IC m JJJ0 QUADRA RT 1 NEODESHA KS 66757 316325-2821 DEALERS CALL SEND $100 FOR COMPLETE CATALOG fect higher settings gyro input mixes pilots input control ai lerons higher setting the gyro has say about would appear 100% setting maximum con trol input gyro nearly equals maxi mum input pilots stick gyro box installed senses yaw rate reversing switch electronics box set give right aileron left yaw rate vice versa word about rate gyros may helpful contrast regular gyros sense change orientationin degrees instancerate gyros sense rate change orienta tion say degrees per second cant tell way pointing way fast turning bottom line gizmo works adjustment about 50% sensitivity plane flies extremely well model actually flies straight indefinitely straightens out circles slowly itself has feel circle good-performing polyhedral ship retains immediate roll response aileron-controlled craft No adverse effects noted flying model through entire envelope Some better fliers Soaring Union Los Angeles have flown plane gyro responses ranging enthusiastic acceptance grudging admis sion did indeed seem nice am excited about development means sorts low-dihedral aileron AJKUMUIJbL iIANT SHARK ARC PRE-BUILT G SHARK S21495 SEE YOUR HOBBY DEALER FIRST SEND STAMPED #10 ENVELOPE FOR INFO KINGS WAY RIG HOBBY SUPPLY 5559 RICHMOND HOUSTON TX 77056 DEALERS ONLY 1-800-621-7783 194 Model Aviation AT LAST An Effect ye H gh Tech Engine Cleaner R/G Engines Removes Burned-On Fuel Residue Encrusted Carbon anteed ONLY $695 CA residents add 725% lax Clean Engines-Run Cooler-Last Longer Send Check Money OrderTo AIRBORNE HOBBIES 3764 30TH ST SAN DIEGO CA 92104 619543-9703 DEALERS INQUIRES WELCOME tIN SUPERTANKS & SUPERMUFFLERS ZINGER WOOD PROPS GIANT SCALE R/C PLANS C #No663 Pea Patch $900 RC Sportster spans 60 uses 40150 4-stroke power Two plan shts No 664 Stuka Stunt $500 CL V2A Stunter semiscale spans 37 No 665 Conscientious Objector $575 FF Mulvihill Rubber competition plane spans 501/2 flat No 193 StIletto CL Stunt nindel McDonald winner 1976 1980 1982 FAt Wodd Champs $ 375 No 262Craahmaater- Ct Crash-pruof trainer two tizet1 5130 35/40 powor$125 No 3101930 Fleet Biplane AC Sport Scale 35140 4-clronnel Wingspan 56 e Ten streets6625 No 314Drake II AC Ken Witards flying boat 3-channel 15-power Fly 1mm land mmovabln gear . No 326Taylor Cub AC Don Srnlfs Schoolyard-Scale 049s 2-3 channel Spoon 50 in$350 No 332Zephyr AC Sinaf 2-channel glider hand-launch tow thermal slope soaring6200 No 386Laaer 200 AC Sport Scale replica champineship Aerehafic tiler Uses 40 power 4-5 channel Two sheets$1075 No 4471/2A Miwa America AC Old-Tuner WA Texaco model 049 glow 2-channels$650 No 4604-40 AC Shoelder-wiog sport filer 4-cycle 40-nine engine 4 channelo$650 No 465Blue Max II AC Fun-fly sportster 40-size engines spans 52 Lightweight stonctere$700 No 533Cewana C-37 AC Schoolyard Scale ni tamoos 3& plane 009/10 power 2-ch opans 42Va in6500 No 539Slmitar Slow4dotlon 15 AC Tailless flying wing 15 engines spans 98 ones 3-ch AC$350 No 569Elactroatreak AC Electric aembatic plane spans 44 ones 05 motorS550 No 572TR-260 AC Sport Scale Aerohalic plane 4-strulre 65/66 power spans 66 in61100 No 576Serendlpityt ndoor 025 record-holder spans 17/ in$325 No 578Scinwelzer 1-26B AC Quarter-ucale Sailplane spans 125 Two plan sheets61475 No 581Gee Bee Moefel Y AC Golden Age Racer spans 72 1A scale 60 power Thwe plus sheets61175 No 586Snapdragon AC Fun-fly/sponster 25/30 engines spans 45 In6698 No 588Marlah AC Slope-Soaring Sailplane spans 41 uses 2 AC channels6425 No593Taytorcralt AC Sport Scale llghtplane builds us standard 2-placer clipped-wing air show stenter Spans either 70 50 35/40 two-stmfre 45/48 four-ntmhe engine Two plan sheets no dncomentatmn$1000 No586Coronet 150 RC-Assint Old-liner enlarged 15914k spans 72 uses 40-size 4-sImlreI 30-size 2-tube6850 No601NIcicel AC Sportster WA engine 3 AC channels Spans 44 in$500 No 603Sparrow Hawk P30 FF Competitfon rebber-power plane woo 87 Nuts Spans 30 in$225 No607Curtlaw Seegull AC Glout Scale biplane spant 50 uses Oeadra/Zeuoah power Three plan sheets dec62498 No mTapeewing AC WA Pylon Racer spans 29 Plan plan use ports template about$698 No 610Protobype AC Sport biplane spans 48 uses 45/2-cycle 85/4-cycle power$650 No 619KeIth RIder R4 FF Scale Goldan Age racer rebber power spans 18 in6300 No 620GImlet 60 AC Spert/Pattem plate spans 60 iii 45/50 enguw 2 sheets61100 No 623Henderwom Longater AC Quarter-Scale 1933 fhwer spans 90h 4-strube 45/46 engine 3 plan sht no dec$1698 No624KelaIrer Laric AC Quarter-scale hontehuit spans 69 69198 4-Otmlre power 2 plait sheets dec61100 No 626Sweepee AC Spoil/Pattem canards foiward-sweyl wing spans 64 uses 48 power 2 plan sheets61300 No628Prime Cut AC SportlAerotsatic plane spuss 90 uses Quadra 35/40-sine power Two plus sheets61300 No 630OrIginal Ply Baby AC Old-Thiter spans 72 uses 19125 2-cycle 484-cycle power 2 plan sheets61150 No 635The Gambler FF Indoor Sestoeran rebber-power cable plane spans 15% in6200 No 836Keytwo AC Tn-geared low-wing sportsler 29125 power spans 44 in$575 No637A6 Shrike FF Compefitine plane AMA Clauses 5 15/23 power spans 60 in$675 No 638Owl Racer CL WA Scale Racer 049 power spans 20 6225 No 839SIcyvoIt AC Tn-geared Electric aerubatic sportoter 05/15 power spans 50 in6850 No 640Bird Prey CL AMA Fast Combat plane 36 power spans 5334 in$550 No 641UI Ole Reliable AC Old-tinter spoil filer spans 50% WA engines$575 No 642BIpe 89 CL Partlat plus updates deflofis 48 nersbon 3Scc power Spans 2234 in6225 No643Noctule IIB FF Baflulte flying wing CO2 power spoon 30 in$325 No 644Beliance ColumbIa AC Schoolyard Scale 2 AC channels WA engine Wingspan 46 m$575 No 645Lalrd Solution Cl Ponfile Scale biplane spans 36 25/35 pewer6575 No 646WInter Hawk FF Robber-power Coupe dHleer cempefiflon plane spans 47 in6375 No647Cox Speeded CL Semincale biplane WA enne spans 24 in6300 No646Cufllwa OC-2 FF Sculls Outdoor Gas Ftying Scale biplane uses electric power spans 24 HiLine lohnr-6 motor$325 No640Thlngemabob AC/CL Mutfimede trainer 25 gas 05 electric power spans 51 in$475 No 65047/66 RC Special AC Aembafic sport plane 48 power spans 61 3 plan sheetsS1075 No 651Conwortlum AC Husri-Lanoch HI-Start Coder spans 60 in6050 No652Oar Ptedenmaeea AC Lute-wing spoil plane 29125 power npons 55 -$675 No 663Aventl CL Profile Sport Scale canard hisliner twin DOgs spans 38 in$575 No 654Tamiecag AC Trainer/spottster styled Ibe F14 spaus 66 45/61 power Four plan sheets$1525 No 6S5Aetroalar FF AMA Class A/B Gas plane spans 67 uses 3 25/350cc power$800 No 856XP13C CL Profile 15 Carrier plane spans 277A in6550 No657Super Squire AC Trainer 35/48 2-stonbe 53 4-strobe power spans 9834 in6750 No 658SIturiken Streak CL Trainer uses 2-line Moonline control spans 17 WA power$225 No659Boom Box FF Walefleld Rubber competitine plane spans 54 in6400 No 660Volkaplene AC Electric-powered sportster 05 motor spans S6 2 plan shts6925 No661Embey-Omatlc FF Embryo Enderance mbber-power plane spans 20 in6200 No662Boxklte CL Scale antique caned pusher biplane spans 42 2 plan shtsS1100 0 Os 0 o C%J 0 gC Co tous Q 0 05 no 6E 050 o - Co FJ t- tog5 0 C 0 - 0 - ID 05 005 0 c us n 00 0 00 us Co-s 0 0 E-d 00 cs 0 2 0 I U0 E N STREET 0CITY - Circle numbers plans wish order best handling please include re quests payment some other service withyourplans order 193262310314326332386447 460465533539569572576578 581586588593598601603607 609610619620623624626628 630635636637638639640641 642643644645646647648649 650651652653654655656657 658659660661662663664665 Plan price includes first class postage US delivery Air Mail over 300 miles orders non-US address lease add $258 Air Mail osta e handlin Ian Make Check money order payable US funds drawn US bank Model Aviation AMA 1810 Samuel Morse Reston VA 22090 Please allow 3 6 weeks delivery Please print CarefullyEnclosed $ _______________________ ___________________________________________ AMA No _______________ airplanes can practical pleasurable fly may also mean ultimate dura tion cross-country RC Sailplane now large flat-wing variable-camber aileroncontrolled configuration instead sim pler fixed-camber rudder elevator ar rangement caution have course tried sys tem 100% sensitivity setting plane does interesting 1-Hz flat yaw oscil lation about plus minus 15 degrees ascribe adverse yaw coupling gyro model remained flyable no harm done might want come up optimum setting instead starting working way down Summary conclusions Spiral stability measure tendency airplane spiral straight circling flight Its primarily function Equiv alent Dihedral Angle EDA tail boom-towingspan ratio lIb wing lift coeffi cient C1 significant secondary variable yaw stability plane function fuselage proportions ver tical stabilizer size Airplanes strong yaw stability spirally stable EDA X lw/b C1 greater equal about 57 Air planes modest yaw stability will sta ble somewhat lower values relation ship illustrated Figures 3 4 An experimental procedure de scribed determining degree spiral stability RC Sailplanes test TwoMeter Sailplane showed good agreement theory control dihedral angle tail boom proportion lift coefficient primary means achieving spiral stability other methods can used Free Flight mod els typically incorporate asymmetrical trim balance arrangement effec tive oaly circle direction mechanical means well successful has tested article incor porates yaw rate gyro drive aile rons As practical inexpensive way provide spiral stability aileron-con trolled Sailplanes exciting devel opment Next month Part Two will describe effect circling flight spiral stability pitch trim yaw angle Southwest PC Flying Year round flight school Five day course $350 Learn fLy planes Send SASE conlete info 2818 CaroLina NE Albuquerque NM 87110 505 881-3799 196 Model Aviation IMPORTED DIESELS A-MAuroraDCEDMVVSMBia*nya PAWTaplln Standard R/C.0864S Acre & MarIne VlntegeAperg Comfiest Seed $100 Informatlo CARLSON ENGINE IMPORTS 314 East Marcomi Phoenix AZ 85022 _________________________________________ ZIP _______________________________
Edition: Model Aviation - 1990/09
Page Numbers: 100, 101, 102, 103, 104, 106, 191, 192, 194, 196
NO OCR TEXT NO OCR TEXT juel per ipervil pnoso D inS au beHest compartment circie giving spiral dral-ilke handling w degrees last thre scribed detail b Keeping mind portional W/S ank C.u around tracked Stf ems lango ailerons result slmple uncoupled coi ited d illustr lw/b ran ailplanes Frc adral angl us dihedra rolled photos wer gher values ty 10 some luces greater spr quiva1ent dihedr of the effective ng force n yaw angle ir greater r yaw angles ig compti Part slues EDA rai Extreme values up 20 th spiral mt C1 b flight Since loading dvn 05 Rho goes down nother way airspeed2 prop wis an find ratio yaw angle required gles yaw obtained/yav proportio lw/b X ED order achieve sp aircraft yaw angle equal greater quired eoi balance neutral yaw obtained greater out circle unless put held yaw obtain will roll tighter tive varying top ru Anything increas obtained yaw req spiral stability formula crux c1 contains three Lets take detailed ratio vert tothe wp liiir E s 51mph ar momen atween FIgure 2 circular flight path tends force wing outboard yaw angle vertical stabilizer lines itself up airflow becomes quite clear illustration yaw angle sensitive both circle radius vertical stabilizer moment arm length late angle attack high angle tack gives high C1 vice versa Rho air density slugs per cubic foot about 0002377 sea level An increase C1 reduces spiral stability increasing C1 increases yaw ob tained given bank angle due reduced circle radius yaw required increased because both V2 term r reduced inverse proportion C1 general Gliders thermal best near maximum C1 just shy stall higher lift coefficients give less spiral stabil ity leads interesting effect de scribed later article Typical thermaling values C1 RC Sailpianes range 06 10 Thicker higher camber sections will high end range Typical Free Flight C1s range low 04 high 14 low values would found smaller models low-camber wings high est values would found larger thin high-camber wings such A2 class Towline Gliders Observations interesting three variables significantly affect spiral stability has important implica tions Wing loading does matter can ballast model affecting spiral stability Aspect ratio does matter long skinny wings short squat ones have about same impact spiral stabil ity Note though long wing requires long fuselage Size does matter can scale design up down spiral sta bility will retained same lift coeffi cient Circle radius bank angle matter plane stable bank angle stable bank angles assuming no change C1 Computations tested out spiral stabil ity relationship trusty computer spreadsheet described Dihedral series spreadsheet divides wing 20 spanwise segments allows fly various bank angles wing load ings dihedral angles schemes lift coef ficients yaw angles output value net roll moment given configuration fiddle dihedral angle yaw angle until roll moment zero did series configurations results showed plane spirally sta ble EDA x l/b 7 greater sake brevity lets define new variable 55 equal EDA x lw/b S stands spiral stability convenience relationship three variables plotted Figures 3 4 plots enable find third vari able already know other two have existing airplane EDA lw/b already known plots will show maximum lift coefficient plane will spirally stable example using Figure 3 can find plane 15 degrees EDA 04 lw/b will stable lift coefficient 105 less Figure 4 could used well reading plot difficult since must interpolate between lines designing plane scratch may want examine trade-off between tail boom length dihedral angle Pre sumably have already chosen wing section have estimate cir cling lift coefficient example say designing floater RC Sailplane expected thermal lift coeffi cient 10 Figure 4 permits direct exam ination boom/dihedral trade-off Fol lowing along C1 ine find could have 02 lw/b 27 de grees dihedral Wow Thats lot dihe dral plane will highiy sensitive rudder trim 04 l/b 145 degrees dihedral like 08 lw/b 75 degrees dihedral long tail boom low roll rate due low dihe dral anglesee Part Two Dihe dral series Because simplifying assumptions described below plots conserva tive Depending mostly size vertical stabilizer can back off some dihedral angle tail boom length can increase lift coefficient although just much tricky say Testing typical Two-Meter RC Sailplane found 43 approximately min imum value SS testing later Variables ignored insignificant some important variables have ig nored order boil problem down September 1990 103 35 30 25 MINIMUM20 EQUIVALENT DIHEDRAL ANGLE DEG15 10 5 0 fundamentals Most important extra outboard yaw due differential wing drag As plane circles outboard wing flying faster creates drag produces outboard yawing moment opposed vertical stabilizer der stabilizer generate opposing lift plane must yaw further outboard Large stabilizers can generate required lift small yaw angles small verticals can require much greater yaw angles 35 30 25 MINIMUM EQUIVALENT DIHEDRAL ANGLE DEG extra outboard yaw angle increases spiral stability increasing tendency plane roll out circle Free Flight models typically use small verticals consequent increase spiral stabil ity can quite great contrast RC Sailplanes typically have large vertical stabiliz ers track well produce little change spiral stability graphs ignore ef fect entirely since indicate spiral stabil ity achieved very large stabiliz Lv/b 2 era Smaller stabilizers give spiral sta bility Fuselage interference effects also ig nored since fuselages Gliders very small compared wings large fuselages Scale Free Flight models however have important ef fect spiral stability As generalization high-mounted wings large fuselages have dihedral lowmounted wings behave hnd less Also generous amount fuselage side area front center-of-gravity desta bilizes plane yaw increasing spiral stability same way reducing size vertical stabilizer does ef fects difficult quantify _____yond scope article Pendulum side-force effects ig nored because minor RC _____Sailplanes Side area above center-ofgravityor conversely low center-of1 21 3 1 4gravity relative side areaacts crease yaw-roll couple same way does increased dihedral Gas Free Flight models take advantage effect tall wing pylons heavy low-thrust engines effect still minor models typical wing dihedral need dihedral its efficient increase wing dihedral extend fuselage wing pylon Much smaller increases wetted area result last effect increases spiral sta bility ignored circling entire Glider coming down same rate inboard wing moves slowly gives inboard wing greater angle tack increasing spiral stability effect minor airplanes good glide ra tios significant very draggy models its extreme form becomes stall-spin maneuver inboard ______wing stalled outboard wing con tinues fly large simplifying assump ________________tions produce conservative results SS greater 57 airplane almost cer tain stable near 57 stability probable depending primarily size vertical stabilizer SS doesnt get close 57 craft almost sure unstable Testing spiral stability RC Sail planes given airplane configuration ___________ dihedral tail boom-to-span ratio fixed Thus airplane has maxi mum lift coefficient minimum speed spirally stable Normally want Glider stable up near its maximum lift coefficient easy test flying straight slowly come back pitch trim lever until plane seems sinking its minimum rate let plane fly hands-off model contin ues straight almost straight spirally stable begins circle its Dont surprised plane proves lack spiral stability common RC SailContinued page 106 r 20 15 10 5 0 10 44 02030405 VERTICAL TAIL MOMENT ARM TO WINGSPAN RATIO Lv/b Figure 4 chart shows minimum wing dihedral angle diminishes tail boom lengthened design lift coefficient reduced can very useful during pro cess designing since permits dIrect trade tall boom length reduced dihedral 0708 104 Model Aviation U4 0506070809111 DESIGN LIFT cOEFFICIENT ci Figure 3 Th minimum wing dihedral angie must greater plans higher lift coeffi cients shorter taii booms plot shows minimum equivalent dihedral angie guarantees spiral stability f range lift coefficients tail-boom-to-wIngspan ratios ivlb its cisc useful evaluating maximum stable im coefficient existing designs Southern Radio ControlLons fl/C Service Naples FLPhoenix NY 813 775-1554315 695-2448 s&D WC ServiceiI&J ElectronicsRivergote Hobby Center San Jose CAHowell MlGoodleftsville TN 408 281-1549517 546-2644615 859-3455 Authorized IVC Service Fallbrook CA 619 728-0440 Radio South Pensacola FL 904478-6745 Iraft Midwest IMI Northoille Ml 313 348-0095 Woiiitz PJC Jackoonoille FL 904 771-0613 DuMond C Service Carroliton TX 214 242-4682 Ocean County WC Service Toms River NJ 201 505-9477 planes seem marginal regard determine pitch trim setting plane becomes stable adjust slightly higher speed repeat experi ment Repeat cycle increasing speed slightly time until airplane no longer rolls circle speed model stable difference between speed optimum mini mum sink speed will indicate far off airplane much dihedral tail boom must increased Keep mind lift coefficient proportional speed squared model becomes stable twice optimum speed dihe dral tail boom off factor four Its best conduct experiments still morning late evening air Also sure model free asymnoetrical warps wing isnt heavier other performed experiment Two-Meter RC Sailplane Tutor airplane has simple V-dihedral two-piece wing bent piano wire joiner flown three different dihedral angles substituting three different joiners illus trated pictures model trimmed fly approximately minimum sink rate airspeed estimated C1 09 allowed fly hands-off dihedral angle 15 degrees airplane tracked well speeds would fly straight very nearly indefinitely very low speeds did tend wiggle turbulence bit really needs bigger ver tical stabilizer give margin Dutch roll 12 degrees dihedral plane ap peared verge circling min imum sink speed wandered over sky never actually settled circle higher speeds tracked true judged plane just spirally stable con figuration 57 degrees dihedral model definitely unstable Over period about 15 seconds would roll left right circle stabilize about 20 degrees bank angle Pulling back pitch trim simply increased bank angle trimmed plane estimated C1 04 interthermal cruise speed released straight flight continued fly straight Calculating spiral stability Tutor 12 degrees dihedral according formula get 12 x 0324 43 Alternatively low dihedral angle higher speed SS roughly 57 x 0324 46which fairly close 43 con sidering imprecise nature C1 esti mates Note values somewhat less ideal 57 derived earlier article probably because extra outboard yaw resulting differ ential wing drag Other methods obtaining spiral stabil ity Free Flight models use sorts meth ods enhance spiral stability Chief among Continued page 191 106 Model Aviation RCD r AIVfefl1SAJtVB~e1 QOflt ileltewwe we6 w0eCtB ggl iA%~6 ~JI ai99~ 6 Owe60 IA owAte bO SSao 06606 L400* 6gA6I icipating RCD Sticker Stations 9SR Products Sacramento CA 918 362-1962 FOR ORDERS ONLYLJL CODs 1 -8OO6337556ILLJJJWELCOME IN ALABAMA 347 3525 COLLECT TOP QUALITY FUEL FOR EXPERT OR BEGINNER NO RE-CLAIMED ALCOHOL O METHANE ONLY IS USED Designed tested give top performance both 2-cycle 4-cycle engines ringed Except engines requiring low lubricant content CONTAINS NEW TRULY SPACE AGE ADDITIVE developed outer apace vacuum new additive attaches internal metal parts engine will reduce friction much 80/o reduces heat wear absolute minimum WE HAVE 3 LUBRICANT BLENDS ALL SYNTHETIC OR SYNTHETIC BLEND CASTOR castor new high purity much cleaner burning castor ALL OUR FUELS CONTAIN ANTI-FOAMERS PREVENTERS WEAR ADDITIVES fuel developed priced tor individual club direct sales market dealer Inquiries invited Order gallon up MIx OK 4 gallon cases up ALL FUEL EXCEPT 54 GALLON DRUMS SHIPPED FREIGHT PRE-PAID Only continental USA TD 3 GalTo 23ITo63To 127 GIjAndIFreight l l24 Gal al12S al Drum 5% ..1095750700.650 . .. 57518500 120/o 5 .050. 900 7528000 250/o 5. 1400 0127547500 500/o 02200 ..21 502075780 00 Manufactured MACH-7 PO Box 1201 Enterprise Alabama 36330 houses relics displays both World Wars HMS Belfast moored Lon dons Thames River newest exhibit Cabinet War Rooms recently restored World War II condition under ground emergency headquarters Prime Minister Winston Churchill Taken together installations tell story two enormous wars raged around Englandparticularly skies over now-peaceful settings like Duxford Airfield Spiral/Beron-Rawdon Continued page 106 asymmetrical wing twist known washin washout Normally inboard wing washed twisted inci dence outboard wing washed out approximately equivalent yawing dihedraled wing outboard rudder trim should enhance spiral stability dont know Free Flight difference between approximately equivalent exactly same can important Another Free Flight method ballast inboard wing tip apply outboard rud der trim tip weight produces con stant inboard rolling moment rudder yields outboard yaw-roll couple very sensitive airspeed As model slows down tip weight rolls plane circle plane rolls up bowl effect increases airspeed rud September 1990 191 Bill Eff go * says OnlyPlans Pettern5 Sets give assorted designs yos west hove eslected best cleesic designs eli time choose hoer patterns soch part art important exclusive feature Ducted Fans Navy F4D-i Skyray 1 h soale ength 40ff wing span lg h RIO eotlbte Landing Gear RODF229gB 1 seats ength 32t$ wing span lbs wie RIO 3-0 sir R/O 5 RK725 lens ROOMgfgg One-Third Scale Piper TPacer PA-22 11R31g wing span sq wing area 20 30 old engines 4-5 oh RIO so 12 lb. SluR onersll length RO3g3029gb 1/3Piper Cub 1-3 Scale hR wing span ength 2005 sq wIng area4 oh RIO 030 old engines R030202996 Quarter Scale WWI SE-IA 001 wing span sq wing ares 5 70 tu 22 engines 0005-7 6 SPAD CXIII s70/wingsyons2l20sqin winguteos t3to3t engines Capable flynt-it captures thn imagination RCOS-g 6 FOKKER DR-i TRIPLANE 72 oring span C 1772 pa wing area 70 tot 00 engines OCOS0 82496 SOPWITH CAMEL F1 04 wing span 21 60 pa wing area ftlbs wls R/O wood ft balse construction over OPuq ft drawings 0005t 1 6 00wingspans2225sqivw cane 114 Scale Fokker 0-ViII 00 25 cid onoine 3-h ch OCOSO 0 Golden Age 114 Scale Curtiss Hawk P 1 00length04tfwingspan 2260uq 5 wing areas 1323 engines h 0/C RCOS-t 4 6 114 Scale CurtigaFalcon 03lnngthsltdwitgnpan3100 sqmnwmvg areaedchR/CRCOS-13g20961J 1/6 Scale Cessna AW 0twinospansgO0sqinwingarea 25to go ongirres channel 0/C RC6S-f $1496 roe ill Scale Purn Mogt 73Ifwingtpans4d0sinarno Pot 2040 engines annel 0/C RC0S-3 6 5111 stOnes Fouodlng Merebar AMA OPPO Hell Fewer Privon ore fur vurnyloto pbne sub asuorubly ft derajind parts huts PLEASE ADD 0200 tsr shipping Inrelllng tubal Now 1990 Pros Oats brovhxro refundablo Ion yvu h order WE TECHNICAL SERVICES RO 1 Box 2900 Santa Rosa Beach FL 32459 der becomes powerful balancing tip weight method stable circle direction still relies di hedral produce yaw-roll couple also relies bowl effect increase air speed increased bank angle Dihedral tail boom length pitch stability will still have strong effects spiral stability such model quick look Figure 3 will show low-dihedral airplanes such typical $599 o \C39\ Nut use Electric Starters Made 6061 Aluminum strong enough allow over tightening weighs under 1 oz 1 diameter 1t/t long 114 radius nose minimum AMA requirement 5/32 Torq Hole 3/4 thread depth can use thinnest props 11 thread sizes fit engines market Send us order & well mail out tast MADE IN THE USA B C PRODUCTS 111 N Starkweather Pam pa Texas 79065 1-800-441-4365 US & Canada aileron-controlled RC Sailplanes havent shadow hope being spirally stable reasonable lift coefficients example plane 30 degrees dihedral lift coefficient 07 must have tail boom 13 times long wingspan type models spiral stability can achieved artificial mechanisms example would produce artificial yaw-roll couple means yaw sensor hooked up run ailerons rate D103210/32 DOSBO5-8mm D123212/32 D06106-1mm 107107-1mm D08108-1mm D81258-125mm D101210-125mm D14281/4-28 151625/1624 38243/8-24 VISA MASTERCARD MONEY ORDERS ACCEPTED DEALER INQUIRES WELCOME ENYA 15 5-8mm SS2O SS45 1/4-28 19 to 80 7-1mm 120 8-1mm FOX 19 45 1/4-28 60 to 120 5/16-24 HB ALL SIZES 1/4-28 HP 40 6-1mm 120 5/16-24 others 1/4-28 IRVING ALL 1/4-28 K&B 19 611/428 OS 10 5-8mm 15 12/32 20 6-1mm 21 50 1/4-28 60 120 5/16-24 108 3/8-24 ROSSI ALL 8-125mm SUPERTIGER 11 to 15 5-8mm 19 to 60 1/4-28 61 to 90 5/16-24 2000 6000 10-125mm SATIO3Oto60 6-1mm 65 to90 71mm 120 to 270 8-125mm WEBRA 28 61 1/4-28 80 90 8-125mm MALONEY 100 3/8-24 .THESUPERIORGLOWPLUGSFO GO FASTFLYERSAREBACKII Puts sting engine Unique flat-wound spiral coil element high temperature glass-to-metal seal add up faster ignition increased RPM 1 /2A GloBee plugs designed exclusively 049/051 Cox engines - Ask new GB-5RX Speed Plug GB-SR Racing Plug GB-5P Spert Plug local dealer today unavailable locally write call Twinn-K collect pricing delivery information FREE GloBee Catalog MAKE THE GLOBEE / INDY CONNECTION Twinn-K Inc 10296 W Washington St Indianapolis IN 46231 Telephone 317-839-6579 FAX 317-839-8928 192 Model Aviation aileron deflection function yaw angle sufficient spiral stability could achieved Another method would employ direct mechanical link between yaw vanes aileronsthough youd probably have watchmaker get work Intro ducing yaw-roll couple will make roll axis sensitive deviations yaw axis particular attention will have paid rudder coordination during transi tional maneuvers Another possibility flat-wing air planes would incorporate rate gyro scope gyro could sense yaw rate drive ailerons roll out As plane rolled circle its bank angle yaw rate increase ailerons deflect roll plane out circle response yaw rate may provide spiral stability chance however phase diffi culties between yaw rate roll accelera tion would develop causing disruptive yawroll oscillations similar Dutch roll successful experiment thought worth trying last fix wifes large slow aileron Sailplane Tango plane originally flown zero dihe dral major pain thermal due lack spiral stability Increasing EDA two degrees made noticeable improve ment still great challenge thermal efficiently slowly installed Futabas simple least expen sive rate-sensitive gyroscope model FP G134 ballast box plane unit consists two components gyro box electronics box gyro stalled in-line between receiver aileron servo Tango uses separate rudder servo connected ai leron output receiver Y connector couples rudder ailerons control adverse yaw However rudder servo still hooked direcfly receiver unaffected gyro gyro installation illustrated pictures electronics box has little knob actu ally screw adjusts effect gyro aileron servo zero 100% 0% gyro has no ef Continued page 194 /9 ilttilt --MIt Ii tPJOflC OU QOtVT FLf WELL I1iVfRi 1I ISLiRINO%11 St 1IC m JJJ0 QUADRA RT 1 NEODESHA KS 66757 316325-2821 DEALERS CALL SEND $100 FOR COMPLETE CATALOG fect higher settings gyro input mixes pilots input control ai lerons higher setting the gyro has say about would appear 100% setting maximum con trol input gyro nearly equals maxi mum input pilots stick gyro box installed senses yaw rate reversing switch electronics box set give right aileron left yaw rate vice versa word about rate gyros may helpful contrast regular gyros sense change orientationin degrees instancerate gyros sense rate change orienta tion say degrees per second cant tell way pointing way fast turning bottom line gizmo works adjustment about 50% sensitivity plane flies extremely well model actually flies straight indefinitely straightens out circles slowly itself has feel circle good-performing polyhedral ship retains immediate roll response aileron-controlled craft No adverse effects noted flying model through entire envelope Some better fliers Soaring Union Los Angeles have flown plane gyro responses ranging enthusiastic acceptance grudging admis sion did indeed seem nice am excited about development means sorts low-dihedral aileron AJKUMUIJbL iIANT SHARK ARC PRE-BUILT G SHARK S21495 SEE YOUR HOBBY DEALER FIRST SEND STAMPED #10 ENVELOPE FOR INFO KINGS WAY RIG HOBBY SUPPLY 5559 RICHMOND HOUSTON TX 77056 DEALERS ONLY 1-800-621-7783 194 Model Aviation AT LAST An Effect ye H gh Tech Engine Cleaner R/G Engines Removes Burned-On Fuel Residue Encrusted Carbon anteed ONLY $695 CA residents add 725% lax Clean Engines-Run Cooler-Last Longer Send Check Money OrderTo AIRBORNE HOBBIES 3764 30TH ST SAN DIEGO CA 92104 619543-9703 DEALERS INQUIRES WELCOME tIN SUPERTANKS & SUPERMUFFLERS ZINGER WOOD PROPS GIANT SCALE R/C PLANS C #No663 Pea Patch $900 RC Sportster spans 60 uses 40150 4-stroke power Two plan shts No 664 Stuka Stunt $500 CL V2A Stunter semiscale spans 37 No 665 Conscientious Objector $575 FF Mulvihill Rubber competition plane spans 501/2 flat No 193 StIletto CL Stunt nindel McDonald winner 1976 1980 1982 FAt Wodd Champs $ 375 No 262Craahmaater- Ct Crash-pruof trainer two tizet1 5130 35/40 powor$125 No 3101930 Fleet Biplane AC Sport Scale 35140 4-clronnel Wingspan 56 e Ten streets6625 No 314Drake II AC Ken Witards flying boat 3-channel 15-power Fly 1mm land mmovabln gear . No 326Taylor Cub AC Don Srnlfs Schoolyard-Scale 049s 2-3 channel Spoon 50 in$350 No 332Zephyr AC Sinaf 2-channel glider hand-launch tow thermal slope soaring6200 No 386Laaer 200 AC Sport Scale replica champineship Aerehafic tiler Uses 40 power 4-5 channel Two sheets$1075 No 4471/2A Miwa America AC Old-Tuner WA Texaco model 049 glow 2-channels$650 No 4604-40 AC Shoelder-wiog sport filer 4-cycle 40-nine engine 4 channelo$650 No 465Blue Max II AC Fun-fly sportster 40-size engines spans 52 Lightweight stonctere$700 No 533Cewana C-37 AC Schoolyard Scale ni tamoos 3& plane 009/10 power 2-ch opans 42Va in6500 No 539Slmitar Slow4dotlon 15 AC Tailless flying wing 15 engines spans 98 ones 3-ch AC$350 No 569Elactroatreak AC Electric aembatic plane spans 44 ones 05 motorS550 No 572TR-260 AC Sport Scale Aerohalic plane 4-strulre 65/66 power spans 66 in61100 No 576Serendlpityt ndoor 025 record-holder spans 17/ in$325 No 578Scinwelzer 1-26B AC Quarter-ucale Sailplane spans 125 Two plan sheets61475 No 581Gee Bee Moefel Y AC Golden Age Racer spans 72 1A scale 60 power Thwe plus sheets61175 No 586Snapdragon AC Fun-fly/sponster 25/30 engines spans 45 In6698 No 588Marlah AC Slope-Soaring Sailplane spans 41 uses 2 AC channels6425 No593Taytorcralt AC Sport Scale llghtplane builds us standard 2-placer clipped-wing air show stenter Spans either 70 50 35/40 two-stmfre 45/48 four-ntmhe engine Two plan sheets no dncomentatmn$1000 No586Coronet 150 RC-Assint Old-liner enlarged 15914k spans 72 uses 40-size 4-sImlreI 30-size 2-tube6850 No601NIcicel AC Sportster WA engine 3 AC channels Spans 44 in$500 No 603Sparrow Hawk P30 FF Competitfon rebber-power plane woo 87 Nuts Spans 30 in$225 No607Curtlaw Seegull AC Glout Scale biplane spant 50 uses Oeadra/Zeuoah power Three plan sheets dec62498 No mTapeewing AC WA Pylon Racer spans 29 Plan plan use ports template about$698 No 610Protobype AC Sport biplane spans 48 uses 45/2-cycle 85/4-cycle power$650 No 619KeIth RIder R4 FF Scale Goldan Age racer rebber power spans 18 in6300 No 620GImlet 60 AC Spert/Pattem plate spans 60 iii 45/50 enguw 2 sheets61100 No 623Henderwom Longater AC Quarter-Scale 1933 fhwer spans 90h 4-strube 45/46 engine 3 plan sht no dec$1698 No624KelaIrer Laric AC Quarter-scale hontehuit spans 69 69198 4-Otmlre power 2 plait sheets dec61100 No 626Sweepee AC Spoil/Pattem canards foiward-sweyl wing spans 64 uses 48 power 2 plan sheets61300 No628Prime Cut AC SportlAerotsatic plane spuss 90 uses Quadra 35/40-sine power Two plus sheets61300 No 630OrIginal Ply Baby AC Old-Thiter spans 72 uses 19125 2-cycle 484-cycle power 2 plan sheets61150 No 635The Gambler FF Indoor Sestoeran rebber-power cable plane spans 15% in6200 No 836Keytwo AC Tn-geared low-wing sportsler 29125 power spans 44 in$575 No637A6 Shrike FF Compefitine plane AMA Clauses 5 15/23 power spans 60 in$675 No 638Owl Racer CL WA Scale Racer 049 power spans 20 6225 No 839SIcyvoIt AC Tn-geared Electric aerubatic sportoter 05/15 power spans 50 in6850 No 640Bird Prey CL AMA Fast Combat plane 36 power spans 5334 in$550 No 641UI Ole Reliable AC Old-tinter spoil filer spans 50% WA engines$575 No 642BIpe 89 CL Partlat plus updates deflofis 48 nersbon 3Scc power Spans 2234 in6225 No643Noctule IIB FF Baflulte flying wing CO2 power spoon 30 in$325 No 644Beliance ColumbIa AC Schoolyard Scale 2 AC channels WA engine Wingspan 46 m$575 No 645Lalrd Solution Cl Ponfile Scale biplane spans 36 25/35 pewer6575 No 646WInter Hawk FF Robber-power Coupe dHleer cempefiflon plane spans 47 in6375 No647Cox Speeded CL Semincale biplane WA enne spans 24 in6300 No646Cufllwa OC-2 FF Sculls Outdoor Gas Ftying Scale biplane uses electric power spans 24 HiLine lohnr-6 motor$325 No640Thlngemabob AC/CL Mutfimede trainer 25 gas 05 electric power spans 51 in$475 No 65047/66 RC Special AC Aembafic sport plane 48 power spans 61 3 plan sheetsS1075 No 651Conwortlum AC Husri-Lanoch HI-Start Coder spans 60 in6050 No652Oar Ptedenmaeea AC Lute-wing spoil plane 29125 power npons 55 -$675 No 663Aventl CL Profile Sport Scale canard hisliner twin DOgs spans 38 in$575 No 654Tamiecag AC Trainer/spottster styled Ibe F14 spaus 66 45/61 power Four plan sheets$1525 No 6S5Aetroalar FF AMA Class A/B Gas plane spans 67 uses 3 25/350cc power$800 No 856XP13C CL Profile 15 Carrier plane spans 277A in6550 No657Super Squire AC Trainer 35/48 2-stonbe 53 4-strobe power spans 9834 in6750 No 658SIturiken Streak CL Trainer uses 2-line Moonline control spans 17 WA power$225 No659Boom Box FF Walefleld Rubber competitine plane spans 54 in6400 No 660Volkaplene AC Electric-powered sportster 05 motor spans S6 2 plan shts6925 No661Embey-Omatlc FF Embryo Enderance mbber-power plane spans 20 in6200 No662Boxklte CL Scale antique caned pusher biplane spans 42 2 plan shtsS1100 0 Os 0 o C%J 0 gC Co tous Q 0 05 no 6E 050 o - Co FJ t- tog5 0 C 0 - 0 - ID 05 005 0 c us n 00 0 00 us Co-s 0 0 E-d 00 cs 0 2 0 I U0 E N STREET 0CITY - Circle numbers plans wish order best handling please include re quests payment some other service withyourplans order 193262310314326332386447 460465533539569572576578 581586588593598601603607 609610619620623624626628 630635636637638639640641 642643644645646647648649 650651652653654655656657 658659660661662663664665 Plan price includes first class postage US delivery Air Mail over 300 miles orders non-US address lease add $258 Air Mail osta e handlin Ian Make Check money order payable US funds drawn US bank Model Aviation AMA 1810 Samuel Morse Reston VA 22090 Please allow 3 6 weeks delivery Please print CarefullyEnclosed $ _______________________ ___________________________________________ AMA No _______________ airplanes can practical pleasurable fly may also mean ultimate dura tion cross-country RC Sailplane now large flat-wing variable-camber aileroncontrolled configuration instead sim pler fixed-camber rudder elevator ar rangement caution have course tried sys tem 100% sensitivity setting plane does interesting 1-Hz flat yaw oscil lation about plus minus 15 degrees ascribe adverse yaw coupling gyro model remained flyable no harm done might want come up optimum setting instead starting working way down Summary conclusions Spiral stability measure tendency airplane spiral straight circling flight Its primarily function Equiv alent Dihedral Angle EDA tail boom-towingspan ratio lIb wing lift coeffi cient C1 significant secondary variable yaw stability plane function fuselage proportions ver tical stabilizer size Airplanes strong yaw stability spirally stable EDA X lw/b C1 greater equal about 57 Air planes modest yaw stability will sta ble somewhat lower values relation ship illustrated Figures 3 4 An experimental procedure de scribed determining degree spiral stability RC Sailplanes test TwoMeter Sailplane showed good agreement theory control dihedral angle tail boom proportion lift coefficient primary means achieving spiral stability other methods can used Free Flight mod els typically incorporate asymmetrical trim balance arrangement effec tive oaly circle direction mechanical means well successful has tested article incor porates yaw rate gyro drive aile rons As practical inexpensive way provide spiral stability aileron-con trolled Sailplanes exciting devel opment Next month Part Two will describe effect circling flight spiral stability pitch trim yaw angle Southwest PC Flying Year round flight school Five day course $350 Learn fLy planes Send SASE conlete info 2818 CaroLina NE Albuquerque NM 87110 505 881-3799 196 Model Aviation IMPORTED DIESELS A-MAuroraDCEDMVVSMBia*nya PAWTaplln Standard R/C.0864S Acre & MarIne VlntegeAperg Comfiest Seed $100 Informatlo CARLSON ENGINE IMPORTS 314 East Marcomi Phoenix AZ 85022 _________________________________________ ZIP _______________________________
Edition: Model Aviation - 1990/09
Page Numbers: 100, 101, 102, 103, 104, 106, 191, 192, 194, 196
NO OCR TEXT NO OCR TEXT juel per ipervil pnoso D inS au beHest compartment circie giving spiral dral-ilke handling w degrees last thre scribed detail b Keeping mind portional W/S ank C.u around tracked Stf ems lango ailerons result slmple uncoupled coi ited d illustr lw/b ran ailplanes Frc adral angl us dihedra rolled photos wer gher values ty 10 some luces greater spr quiva1ent dihedr of the effective ng force n yaw angle ir greater r yaw angles ig compti Part slues EDA rai Extreme values up 20 th spiral mt C1 b flight Since loading dvn 05 Rho goes down nother way airspeed2 prop wis an find ratio yaw angle required gles yaw obtained/yav proportio lw/b X ED order achieve sp aircraft yaw angle equal greater quired eoi balance neutral yaw obtained greater out circle unless put held yaw obtain will roll tighter tive varying top ru Anything increas obtained yaw req spiral stability formula crux c1 contains three Lets take detailed ratio vert tothe wp liiir E s 51mph ar momen atween FIgure 2 circular flight path tends force wing outboard yaw angle vertical stabilizer lines itself up airflow becomes quite clear illustration yaw angle sensitive both circle radius vertical stabilizer moment arm length late angle attack high angle tack gives high C1 vice versa Rho air density slugs per cubic foot about 0002377 sea level An increase C1 reduces spiral stability increasing C1 increases yaw ob tained given bank angle due reduced circle radius yaw required increased because both V2 term r reduced inverse proportion C1 general Gliders thermal best near maximum C1 just shy stall higher lift coefficients give less spiral stabil ity leads interesting effect de scribed later article Typical thermaling values C1 RC Sailpianes range 06 10 Thicker higher camber sections will high end range Typical Free Flight C1s range low 04 high 14 low values would found smaller models low-camber wings high est values would found larger thin high-camber wings such A2 class Towline Gliders Observations interesting three variables significantly affect spiral stability has important implica tions Wing loading does matter can ballast model affecting spiral stability Aspect ratio does matter long skinny wings short squat ones have about same impact spiral stabil ity Note though long wing requires long fuselage Size does matter can scale design up down spiral sta bility will retained same lift coeffi cient Circle radius bank angle matter plane stable bank angle stable bank angles assuming no change C1 Computations tested out spiral stabil ity relationship trusty computer spreadsheet described Dihedral series spreadsheet divides wing 20 spanwise segments allows fly various bank angles wing load ings dihedral angles schemes lift coef ficients yaw angles output value net roll moment given configuration fiddle dihedral angle yaw angle until roll moment zero did series configurations results showed plane spirally sta ble EDA x l/b 7 greater sake brevity lets define new variable 55 equal EDA x lw/b S stands spiral stability convenience relationship three variables plotted Figures 3 4 plots enable find third vari able already know other two have existing airplane EDA lw/b already known plots will show maximum lift coefficient plane will spirally stable example using Figure 3 can find plane 15 degrees EDA 04 lw/b will stable lift coefficient 105 less Figure 4 could used well reading plot difficult since must interpolate between lines designing plane scratch may want examine trade-off between tail boom length dihedral angle Pre sumably have already chosen wing section have estimate cir cling lift coefficient example say designing floater RC Sailplane expected thermal lift coeffi cient 10 Figure 4 permits direct exam ination boom/dihedral trade-off Fol lowing along C1 ine find could have 02 lw/b 27 de grees dihedral Wow Thats lot dihe dral plane will highiy sensitive rudder trim 04 l/b 145 degrees dihedral like 08 lw/b 75 degrees dihedral long tail boom low roll rate due low dihe dral anglesee Part Two Dihe dral series Because simplifying assumptions described below plots conserva tive Depending mostly size vertical stabilizer can back off some dihedral angle tail boom length can increase lift coefficient although just much tricky say Testing typical Two-Meter RC Sailplane found 43 approximately min imum value SS testing later Variables ignored insignificant some important variables have ig nored order boil problem down September 1990 103 35 30 25 MINIMUM20 EQUIVALENT DIHEDRAL ANGLE DEG15 10 5 0 fundamentals Most important extra outboard yaw due differential wing drag As plane circles outboard wing flying faster creates drag produces outboard yawing moment opposed vertical stabilizer der stabilizer generate opposing lift plane must yaw further outboard Large stabilizers can generate required lift small yaw angles small verticals can require much greater yaw angles 35 30 25 MINIMUM EQUIVALENT DIHEDRAL ANGLE DEG extra outboard yaw angle increases spiral stability increasing tendency plane roll out circle Free Flight models typically use small verticals consequent increase spiral stabil ity can quite great contrast RC Sailplanes typically have large vertical stabiliz ers track well produce little change spiral stability graphs ignore ef fect entirely since indicate spiral stabil ity achieved very large stabiliz Lv/b 2 era Smaller stabilizers give spiral sta bility Fuselage interference effects also ig nored since fuselages Gliders very small compared wings large fuselages Scale Free Flight models however have important ef fect spiral stability As generalization high-mounted wings large fuselages have dihedral lowmounted wings behave hnd less Also generous amount fuselage side area front center-of-gravity desta bilizes plane yaw increasing spiral stability same way reducing size vertical stabilizer does ef fects difficult quantify _____yond scope article Pendulum side-force effects ig nored because minor RC _____Sailplanes Side area above center-ofgravityor conversely low center-of1 21 3 1 4gravity relative side areaacts crease yaw-roll couple same way does increased dihedral Gas Free Flight models take advantage effect tall wing pylons heavy low-thrust engines effect still minor models typical wing dihedral need dihedral its efficient increase wing dihedral extend fuselage wing pylon Much smaller increases wetted area result last effect increases spiral sta bility ignored circling entire Glider coming down same rate inboard wing moves slowly gives inboard wing greater angle tack increasing spiral stability effect minor airplanes good glide ra tios significant very draggy models its extreme form becomes stall-spin maneuver inboard ______wing stalled outboard wing con tinues fly large simplifying assump ________________tions produce conservative results SS greater 57 airplane almost cer tain stable near 57 stability probable depending primarily size vertical stabilizer SS doesnt get close 57 craft almost sure unstable Testing spiral stability RC Sail planes given airplane configuration ___________ dihedral tail boom-to-span ratio fixed Thus airplane has maxi mum lift coefficient minimum speed spirally stable Normally want Glider stable up near its maximum lift coefficient easy test flying straight slowly come back pitch trim lever until plane seems sinking its minimum rate let plane fly hands-off model contin ues straight almost straight spirally stable begins circle its Dont surprised plane proves lack spiral stability common RC SailContinued page 106 r 20 15 10 5 0 10 44 02030405 VERTICAL TAIL MOMENT ARM TO WINGSPAN RATIO Lv/b Figure 4 chart shows minimum wing dihedral angle diminishes tail boom lengthened design lift coefficient reduced can very useful during pro cess designing since permits dIrect trade tall boom length reduced dihedral 0708 104 Model Aviation U4 0506070809111 DESIGN LIFT cOEFFICIENT ci Figure 3 Th minimum wing dihedral angie must greater plans higher lift coeffi cients shorter taii booms plot shows minimum equivalent dihedral angie guarantees spiral stability f range lift coefficients tail-boom-to-wIngspan ratios ivlb its cisc useful evaluating maximum stable im coefficient existing designs Southern Radio ControlLons fl/C Service Naples FLPhoenix NY 813 775-1554315 695-2448 s&D WC ServiceiI&J ElectronicsRivergote Hobby Center San Jose CAHowell MlGoodleftsville TN 408 281-1549517 546-2644615 859-3455 Authorized IVC Service Fallbrook CA 619 728-0440 Radio South Pensacola FL 904478-6745 Iraft Midwest IMI Northoille Ml 313 348-0095 Woiiitz PJC Jackoonoille FL 904 771-0613 DuMond C Service Carroliton TX 214 242-4682 Ocean County WC Service Toms River NJ 201 505-9477 planes seem marginal regard determine pitch trim setting plane becomes stable adjust slightly higher speed repeat experi ment Repeat cycle increasing speed slightly time until airplane no longer rolls circle speed model stable difference between speed optimum mini mum sink speed will indicate far off airplane much dihedral tail boom must increased Keep mind lift coefficient proportional speed squared model becomes stable twice optimum speed dihe dral tail boom off factor four Its best conduct experiments still morning late evening air Also sure model free asymnoetrical warps wing isnt heavier other performed experiment Two-Meter RC Sailplane Tutor airplane has simple V-dihedral two-piece wing bent piano wire joiner flown three different dihedral angles substituting three different joiners illus trated pictures model trimmed fly approximately minimum sink rate airspeed estimated C1 09 allowed fly hands-off dihedral angle 15 degrees airplane tracked well speeds would fly straight very nearly indefinitely very low speeds did tend wiggle turbulence bit really needs bigger ver tical stabilizer give margin Dutch roll 12 degrees dihedral plane ap peared verge circling min imum sink speed wandered over sky never actually settled circle higher speeds tracked true judged plane just spirally stable con figuration 57 degrees dihedral model definitely unstable Over period about 15 seconds would roll left right circle stabilize about 20 degrees bank angle Pulling back pitch trim simply increased bank angle trimmed plane estimated C1 04 interthermal cruise speed released straight flight continued fly straight Calculating spiral stability Tutor 12 degrees dihedral according formula get 12 x 0324 43 Alternatively low dihedral angle higher speed SS roughly 57 x 0324 46which fairly close 43 con sidering imprecise nature C1 esti mates Note values somewhat less ideal 57 derived earlier article probably because extra outboard yaw resulting differ ential wing drag Other methods obtaining spiral stabil ity Free Flight models use sorts meth ods enhance spiral stability Chief among Continued page 191 106 Model Aviation RCD r AIVfefl1SAJtVB~e1 QOflt ileltewwe we6 w0eCtB ggl iA%~6 ~JI ai99~ 6 Owe60 IA owAte bO SSao 06606 L400* 6gA6I icipating RCD Sticker Stations 9SR Products Sacramento CA 918 362-1962 FOR ORDERS ONLYLJL CODs 1 -8OO6337556ILLJJJWELCOME IN ALABAMA 347 3525 COLLECT TOP QUALITY FUEL FOR EXPERT OR BEGINNER NO RE-CLAIMED ALCOHOL O METHANE ONLY IS USED Designed tested give top performance both 2-cycle 4-cycle engines ringed Except engines requiring low lubricant content CONTAINS NEW TRULY SPACE AGE ADDITIVE developed outer apace vacuum new additive attaches internal metal parts engine will reduce friction much 80/o reduces heat wear absolute minimum WE HAVE 3 LUBRICANT BLENDS ALL SYNTHETIC OR SYNTHETIC BLEND CASTOR castor new high purity much cleaner burning castor ALL OUR FUELS CONTAIN ANTI-FOAMERS PREVENTERS WEAR ADDITIVES fuel developed priced tor individual club direct sales market dealer Inquiries invited Order gallon up MIx OK 4 gallon cases up ALL FUEL EXCEPT 54 GALLON DRUMS SHIPPED FREIGHT PRE-PAID Only continental USA TD 3 GalTo 23ITo63To 127 GIjAndIFreight l l24 Gal al12S al Drum 5% ..1095750700.650 . .. 57518500 120/o 5 .050. 900 7528000 250/o 5. 1400 0127547500 500/o 02200 ..21 502075780 00 Manufactured MACH-7 PO Box 1201 Enterprise Alabama 36330 houses relics displays both World Wars HMS Belfast moored Lon dons Thames River newest exhibit Cabinet War Rooms recently restored World War II condition under ground emergency headquarters Prime Minister Winston Churchill Taken together installations tell story two enormous wars raged around Englandparticularly skies over now-peaceful settings like Duxford Airfield Spiral/Beron-Rawdon Continued page 106 asymmetrical wing twist known washin washout Normally inboard wing washed twisted inci dence outboard wing washed out approximately equivalent yawing dihedraled wing outboard rudder trim should enhance spiral stability dont know Free Flight difference between approximately equivalent exactly same can important Another Free Flight method ballast inboard wing tip apply outboard rud der trim tip weight produces con stant inboard rolling moment rudder yields outboard yaw-roll couple very sensitive airspeed As model slows down tip weight rolls plane circle plane rolls up bowl effect increases airspeed rud September 1990 191 Bill Eff go * says OnlyPlans Pettern5 Sets give assorted designs yos west hove eslected best cleesic designs eli time choose hoer patterns soch part art important exclusive feature Ducted Fans Navy F4D-i Skyray 1 h soale ength 40ff wing span lg h RIO eotlbte Landing Gear RODF229gB 1 seats ength 32t$ wing span lbs wie RIO 3-0 sir R/O 5 RK725 lens ROOMgfgg One-Third Scale Piper TPacer PA-22 11R31g wing span sq wing area 20 30 old engines 4-5 oh RIO so 12 lb. SluR onersll length RO3g3029gb 1/3Piper Cub 1-3 Scale hR wing span ength 2005 sq wIng area4 oh RIO 030 old engines R030202996 Quarter Scale WWI SE-IA 001 wing span sq wing ares 5 70 tu 22 engines 0005-7 6 SPAD CXIII s70/wingsyons2l20sqin winguteos t3to3t engines Capable flynt-it captures thn imagination RCOS-g 6 FOKKER DR-i TRIPLANE 72 oring span C 1772 pa wing area 70 tot 00 engines OCOS0 82496 SOPWITH CAMEL F1 04 wing span 21 60 pa wing area ftlbs wls R/O wood ft balse construction over OPuq ft drawings 0005t 1 6 00wingspans2225sqivw cane 114 Scale Fokker 0-ViII 00 25 cid onoine 3-h ch OCOSO 0 Golden Age 114 Scale Curtiss Hawk P 1 00length04tfwingspan 2260uq 5 wing areas 1323 engines h 0/C RCOS-t 4 6 114 Scale CurtigaFalcon 03lnngthsltdwitgnpan3100 sqmnwmvg areaedchR/CRCOS-13g20961J 1/6 Scale Cessna AW 0twinospansgO0sqinwingarea 25to go ongirres channel 0/C RC6S-f $1496 roe ill Scale Purn Mogt 73Ifwingtpans4d0sinarno Pot 2040 engines annel 0/C RC0S-3 6 5111 stOnes Fouodlng Merebar AMA OPPO Hell Fewer Privon ore fur vurnyloto pbne sub asuorubly ft derajind parts huts PLEASE ADD 0200 tsr shipping Inrelllng tubal Now 1990 Pros Oats brovhxro refundablo Ion yvu h order WE TECHNICAL SERVICES RO 1 Box 2900 Santa Rosa Beach FL 32459 der becomes powerful balancing tip weight method stable circle direction still relies di hedral produce yaw-roll couple also relies bowl effect increase air speed increased bank angle Dihedral tail boom length pitch stability will still have strong effects spiral stability such model quick look Figure 3 will show low-dihedral airplanes such typical $599 o \C39\ Nut use Electric Starters Made 6061 Aluminum strong enough allow over tightening weighs under 1 oz 1 diameter 1t/t long 114 radius nose minimum AMA requirement 5/32 Torq Hole 3/4 thread depth can use thinnest props 11 thread sizes fit engines market Send us order & well mail out tast MADE IN THE USA B C PRODUCTS 111 N Starkweather Pam pa Texas 79065 1-800-441-4365 US & Canada aileron-controlled RC Sailplanes havent shadow hope being spirally stable reasonable lift coefficients example plane 30 degrees dihedral lift coefficient 07 must have tail boom 13 times long wingspan type models spiral stability can achieved artificial mechanisms example would produce artificial yaw-roll couple means yaw sensor hooked up run ailerons rate D103210/32 DOSBO5-8mm D123212/32 D06106-1mm 107107-1mm D08108-1mm D81258-125mm D101210-125mm D14281/4-28 151625/1624 38243/8-24 VISA MASTERCARD MONEY ORDERS ACCEPTED DEALER INQUIRES WELCOME ENYA 15 5-8mm SS2O SS45 1/4-28 19 to 80 7-1mm 120 8-1mm FOX 19 45 1/4-28 60 to 120 5/16-24 HB ALL SIZES 1/4-28 HP 40 6-1mm 120 5/16-24 others 1/4-28 IRVING ALL 1/4-28 K&B 19 611/428 OS 10 5-8mm 15 12/32 20 6-1mm 21 50 1/4-28 60 120 5/16-24 108 3/8-24 ROSSI ALL 8-125mm SUPERTIGER 11 to 15 5-8mm 19 to 60 1/4-28 61 to 90 5/16-24 2000 6000 10-125mm SATIO3Oto60 6-1mm 65 to90 71mm 120 to 270 8-125mm WEBRA 28 61 1/4-28 80 90 8-125mm MALONEY 100 3/8-24 .THESUPERIORGLOWPLUGSFO GO FASTFLYERSAREBACKII Puts sting engine Unique flat-wound spiral coil element high temperature glass-to-metal seal add up faster ignition increased RPM 1 /2A GloBee plugs designed exclusively 049/051 Cox engines - Ask new GB-5RX Speed Plug GB-SR Racing Plug GB-5P Spert Plug local dealer today unavailable locally write call Twinn-K collect pricing delivery information FREE GloBee Catalog MAKE THE GLOBEE / INDY CONNECTION Twinn-K Inc 10296 W Washington St Indianapolis IN 46231 Telephone 317-839-6579 FAX 317-839-8928 192 Model Aviation aileron deflection function yaw angle sufficient spiral stability could achieved Another method would employ direct mechanical link between yaw vanes aileronsthough youd probably have watchmaker get work Intro ducing yaw-roll couple will make roll axis sensitive deviations yaw axis particular attention will have paid rudder coordination during transi tional maneuvers Another possibility flat-wing air planes would incorporate rate gyro scope gyro could sense yaw rate drive ailerons roll out As plane rolled circle its bank angle yaw rate increase ailerons deflect roll plane out circle response yaw rate may provide spiral stability chance however phase diffi culties between yaw rate roll accelera tion would develop causing disruptive yawroll oscillations similar Dutch roll successful experiment thought worth trying last fix wifes large slow aileron Sailplane Tango plane originally flown zero dihe dral major pain thermal due lack spiral stability Increasing EDA two degrees made noticeable improve ment still great challenge thermal efficiently slowly installed Futabas simple least expen sive rate-sensitive gyroscope model FP G134 ballast box plane unit consists two components gyro box electronics box gyro stalled in-line between receiver aileron servo Tango uses separate rudder servo connected ai leron output receiver Y connector couples rudder ailerons control adverse yaw However rudder servo still hooked direcfly receiver unaffected gyro gyro installation illustrated pictures electronics box has little knob actu ally screw adjusts effect gyro aileron servo zero 100% 0% gyro has no ef Continued page 194 /9 ilttilt --MIt Ii tPJOflC OU QOtVT FLf WELL I1iVfRi 1I ISLiRINO%11 St 1IC m JJJ0 QUADRA RT 1 NEODESHA KS 66757 316325-2821 DEALERS CALL SEND $100 FOR COMPLETE CATALOG fect higher settings gyro input mixes pilots input control ai lerons higher setting the gyro has say about would appear 100% setting maximum con trol input gyro nearly equals maxi mum input pilots stick gyro box installed senses yaw rate reversing switch electronics box set give right aileron left yaw rate vice versa word about rate gyros may helpful contrast regular gyros sense change orientationin degrees instancerate gyros sense rate change orienta tion say degrees per second cant tell way pointing way fast turning bottom line gizmo works adjustment about 50% sensitivity plane flies extremely well model actually flies straight indefinitely straightens out circles slowly itself has feel circle good-performing polyhedral ship retains immediate roll response aileron-controlled craft No adverse effects noted flying model through entire envelope Some better fliers Soaring Union Los Angeles have flown plane gyro responses ranging enthusiastic acceptance grudging admis sion did indeed seem nice am excited about development means sorts low-dihedral aileron AJKUMUIJbL iIANT SHARK ARC PRE-BUILT G SHARK S21495 SEE YOUR HOBBY DEALER FIRST SEND STAMPED #10 ENVELOPE FOR INFO KINGS WAY RIG HOBBY SUPPLY 5559 RICHMOND HOUSTON TX 77056 DEALERS ONLY 1-800-621-7783 194 Model Aviation AT LAST An Effect ye H gh Tech Engine Cleaner R/G Engines Removes Burned-On Fuel Residue Encrusted Carbon anteed ONLY $695 CA residents add 725% lax Clean Engines-Run Cooler-Last Longer Send Check Money OrderTo AIRBORNE HOBBIES 3764 30TH ST SAN DIEGO CA 92104 619543-9703 DEALERS INQUIRES WELCOME tIN SUPERTANKS & SUPERMUFFLERS ZINGER WOOD PROPS GIANT SCALE R/C PLANS C #No663 Pea Patch $900 RC Sportster spans 60 uses 40150 4-stroke power Two plan shts No 664 Stuka Stunt $500 CL V2A Stunter semiscale spans 37 No 665 Conscientious Objector $575 FF Mulvihill Rubber competition plane spans 501/2 flat No 193 StIletto CL Stunt nindel McDonald winner 1976 1980 1982 FAt Wodd Champs $ 375 No 262Craahmaater- Ct Crash-pruof trainer two tizet1 5130 35/40 powor$125 No 3101930 Fleet Biplane AC Sport Scale 35140 4-clronnel Wingspan 56 e Ten streets6625 No 314Drake II AC Ken Witards flying boat 3-channel 15-power Fly 1mm land mmovabln gear . No 326Taylor Cub AC Don Srnlfs Schoolyard-Scale 049s 2-3 channel Spoon 50 in$350 No 332Zephyr AC Sinaf 2-channel glider hand-launch tow thermal slope soaring6200 No 386Laaer 200 AC Sport Scale replica champineship Aerehafic tiler Uses 40 power 4-5 channel Two sheets$1075 No 4471/2A Miwa America AC Old-Tuner WA Texaco model 049 glow 2-channels$650 No 4604-40 AC Shoelder-wiog sport filer 4-cycle 40-nine engine 4 channelo$650 No 465Blue Max II AC Fun-fly sportster 40-size engines spans 52 Lightweight stonctere$700 No 533Cewana C-37 AC Schoolyard Scale ni tamoos 3& plane 009/10 power 2-ch opans 42Va in6500 No 539Slmitar Slow4dotlon 15 AC Tailless flying wing 15 engines spans 98 ones 3-ch AC$350 No 569Elactroatreak AC Electric aembatic plane spans 44 ones 05 motorS550 No 572TR-260 AC Sport Scale Aerohalic plane 4-strulre 65/66 power spans 66 in61100 No 576Serendlpityt ndoor 025 record-holder spans 17/ in$325 No 578Scinwelzer 1-26B AC Quarter-ucale Sailplane spans 125 Two plan sheets61475 No 581Gee Bee Moefel Y AC Golden Age Racer spans 72 1A scale 60 power Thwe plus sheets61175 No 586Snapdragon AC Fun-fly/sponster 25/30 engines spans 45 In6698 No 588Marlah AC Slope-Soaring Sailplane spans 41 uses 2 AC channels6425 No593Taytorcralt AC Sport Scale llghtplane builds us standard 2-placer clipped-wing air show stenter Spans either 70 50 35/40 two-stmfre 45/48 four-ntmhe engine Two plan sheets no dncomentatmn$1000 No586Coronet 150 RC-Assint Old-liner enlarged 15914k spans 72 uses 40-size 4-sImlreI 30-size 2-tube6850 No601NIcicel AC Sportster WA engine 3 AC channels Spans 44 in$500 No 603Sparrow Hawk P30 FF Competitfon rebber-power plane woo 87 Nuts Spans 30 in$225 No607Curtlaw Seegull AC Glout Scale biplane spant 50 uses Oeadra/Zeuoah power Three plan sheets dec62498 No mTapeewing AC WA Pylon Racer spans 29 Plan plan use ports template about$698 No 610Protobype AC Sport biplane spans 48 uses 45/2-cycle 85/4-cycle power$650 No 619KeIth RIder R4 FF Scale Goldan Age racer rebber power spans 18 in6300 No 620GImlet 60 AC Spert/Pattem plate spans 60 iii 45/50 enguw 2 sheets61100 No 623Henderwom Longater AC Quarter-Scale 1933 fhwer spans 90h 4-strube 45/46 engine 3 plan sht no dec$1698 No624KelaIrer Laric AC Quarter-scale hontehuit spans 69 69198 4-Otmlre power 2 plait sheets dec61100 No 626Sweepee AC Spoil/Pattem canards foiward-sweyl wing spans 64 uses 48 power 2 plan sheets61300 No628Prime Cut AC SportlAerotsatic plane spuss 90 uses Quadra 35/40-sine power Two plus sheets61300 No 630OrIginal Ply Baby AC Old-Thiter spans 72 uses 19125 2-cycle 484-cycle power 2 plan sheets61150 No 635The Gambler FF Indoor Sestoeran rebber-power cable plane spans 15% in6200 No 836Keytwo AC Tn-geared low-wing sportsler 29125 power spans 44 in$575 No637A6 Shrike FF Compefitine plane AMA Clauses 5 15/23 power spans 60 in$675 No 638Owl Racer CL WA Scale Racer 049 power spans 20 6225 No 839SIcyvoIt AC Tn-geared Electric aerubatic sportoter 05/15 power spans 50 in6850 No 640Bird Prey CL AMA Fast Combat plane 36 power spans 5334 in$550 No 641UI Ole Reliable AC Old-tinter spoil filer spans 50% WA engines$575 No 642BIpe 89 CL Partlat plus updates deflofis 48 nersbon 3Scc power Spans 2234 in6225 No643Noctule IIB FF Baflulte flying wing CO2 power spoon 30 in$325 No 644Beliance ColumbIa AC Schoolyard Scale 2 AC channels WA engine Wingspan 46 m$575 No 645Lalrd Solution Cl Ponfile Scale biplane spans 36 25/35 pewer6575 No 646WInter Hawk FF Robber-power Coupe dHleer cempefiflon plane spans 47 in6375 No647Cox Speeded CL Semincale biplane WA enne spans 24 in6300 No646Cufllwa OC-2 FF Sculls Outdoor Gas Ftying Scale biplane uses electric power spans 24 HiLine lohnr-6 motor$325 No640Thlngemabob AC/CL Mutfimede trainer 25 gas 05 electric power spans 51 in$475 No 65047/66 RC Special AC Aembafic sport plane 48 power spans 61 3 plan sheetsS1075 No 651Conwortlum AC Husri-Lanoch HI-Start Coder spans 60 in6050 No652Oar Ptedenmaeea AC Lute-wing spoil plane 29125 power npons 55 -$675 No 663Aventl CL Profile Sport Scale canard hisliner twin DOgs spans 38 in$575 No 654Tamiecag AC Trainer/spottster styled Ibe F14 spaus 66 45/61 power Four plan sheets$1525 No 6S5Aetroalar FF AMA Class A/B Gas plane spans 67 uses 3 25/350cc power$800 No 856XP13C CL Profile 15 Carrier plane spans 277A in6550 No657Super Squire AC Trainer 35/48 2-stonbe 53 4-strobe power spans 9834 in6750 No 658SIturiken Streak CL Trainer uses 2-line Moonline control spans 17 WA power$225 No659Boom Box FF Walefleld Rubber competitine plane spans 54 in6400 No 660Volkaplene AC Electric-powered sportster 05 motor spans S6 2 plan shts6925 No661Embey-Omatlc FF Embryo Enderance mbber-power plane spans 20 in6200 No662Boxklte CL Scale antique caned pusher biplane spans 42 2 plan shtsS1100 0 Os 0 o C%J 0 gC Co tous Q 0 05 no 6E 050 o - Co FJ t- tog5 0 C 0 - 0 - ID 05 005 0 c us n 00 0 00 us Co-s 0 0 E-d 00 cs 0 2 0 I U0 E N STREET 0CITY - Circle numbers plans wish order best handling please include re quests payment some other service withyourplans order 193262310314326332386447 460465533539569572576578 581586588593598601603607 609610619620623624626628 630635636637638639640641 642643644645646647648649 650651652653654655656657 658659660661662663664665 Plan price includes first class postage US delivery Air Mail over 300 miles orders non-US address lease add $258 Air Mail osta e handlin Ian Make Check money order payable US funds drawn US bank Model Aviation AMA 1810 Samuel Morse Reston VA 22090 Please allow 3 6 weeks delivery Please print CarefullyEnclosed $ _______________________ ___________________________________________ AMA No _______________ airplanes can practical pleasurable fly may also mean ultimate dura tion cross-country RC Sailplane now large flat-wing variable-camber aileroncontrolled configuration instead sim pler fixed-camber rudder elevator ar rangement caution have course tried sys tem 100% sensitivity setting plane does interesting 1-Hz flat yaw oscil lation about plus minus 15 degrees ascribe adverse yaw coupling gyro model remained flyable no harm done might want come up optimum setting instead starting working way down Summary conclusions Spiral stability measure tendency airplane spiral straight circling flight Its primarily function Equiv alent Dihedral Angle EDA tail boom-towingspan ratio lIb wing lift coeffi cient C1 significant secondary variable yaw stability plane function fuselage proportions ver tical stabilizer size Airplanes strong yaw stability spirally stable EDA X lw/b C1 greater equal about 57 Air planes modest yaw stability will sta ble somewhat lower values relation ship illustrated Figures 3 4 An experimental procedure de scribed determining degree spiral stability RC Sailplanes test TwoMeter Sailplane showed good agreement theory control dihedral angle tail boom proportion lift coefficient primary means achieving spiral stability other methods can used Free Flight mod els typically incorporate asymmetrical trim balance arrangement effec tive oaly circle direction mechanical means well successful has tested article incor porates yaw rate gyro drive aile rons As practical inexpensive way provide spiral stability aileron-con trolled Sailplanes exciting devel opment Next month Part Two will describe effect circling flight spiral stability pitch trim yaw angle Southwest PC Flying Year round flight school Five day course $350 Learn fLy planes Send SASE conlete info 2818 CaroLina NE Albuquerque NM 87110 505 881-3799 196 Model Aviation IMPORTED DIESELS A-MAuroraDCEDMVVSMBia*nya PAWTaplln Standard R/C.0864S Acre & MarIne VlntegeAperg Comfiest Seed $100 Informatlo CARLSON ENGINE IMPORTS 314 East Marcomi Phoenix AZ 85022 _________________________________________ ZIP _______________________________
Edition: Model Aviation - 1990/09
Page Numbers: 100, 101, 102, 103, 104, 106, 191, 192, 194, 196
NO OCR TEXT NO OCR TEXT juel per ipervil pnoso D inS au beHest compartment circie giving spiral dral-ilke handling w degrees last thre scribed detail b Keeping mind portional W/S ank C.u around tracked Stf ems lango ailerons result slmple uncoupled coi ited d illustr lw/b ran ailplanes Frc adral angl us dihedra rolled photos wer gher values ty 10 some luces greater spr quiva1ent dihedr of the effective ng force n yaw angle ir greater r yaw angles ig compti Part slues EDA rai Extreme values up 20 th spiral mt C1 b flight Since loading dvn 05 Rho goes down nother way airspeed2 prop wis an find ratio yaw angle required gles yaw obtained/yav proportio lw/b X ED order achieve sp aircraft yaw angle equal greater quired eoi balance neutral yaw obtained greater out circle unless put held yaw obtain will roll tighter tive varying top ru Anything increas obtained yaw req spiral stability formula crux c1 contains three Lets take detailed ratio vert tothe wp liiir E s 51mph ar momen atween FIgure 2 circular flight path tends force wing outboard yaw angle vertical stabilizer lines itself up airflow becomes quite clear illustration yaw angle sensitive both circle radius vertical stabilizer moment arm length late angle attack high angle tack gives high C1 vice versa Rho air density slugs per cubic foot about 0002377 sea level An increase C1 reduces spiral stability increasing C1 increases yaw ob tained given bank angle due reduced circle radius yaw required increased because both V2 term r reduced inverse proportion C1 general Gliders thermal best near maximum C1 just shy stall higher lift coefficients give less spiral stabil ity leads interesting effect de scribed later article Typical thermaling values C1 RC Sailpianes range 06 10 Thicker higher camber sections will high end range Typical Free Flight C1s range low 04 high 14 low values would found smaller models low-camber wings high est values would found larger thin high-camber wings such A2 class Towline Gliders Observations interesting three variables significantly affect spiral stability has important implica tions Wing loading does matter can ballast model affecting spiral stability Aspect ratio does matter long skinny wings short squat ones have about same impact spiral stabil ity Note though long wing requires long fuselage Size does matter can scale design up down spiral sta bility will retained same lift coeffi cient Circle radius bank angle matter plane stable bank angle stable bank angles assuming no change C1 Computations tested out spiral stabil ity relationship trusty computer spreadsheet described Dihedral series spreadsheet divides wing 20 spanwise segments allows fly various bank angles wing load ings dihedral angles schemes lift coef ficients yaw angles output value net roll moment given configuration fiddle dihedral angle yaw angle until roll moment zero did series configurations results showed plane spirally sta ble EDA x l/b 7 greater sake brevity lets define new variable 55 equal EDA x lw/b S stands spiral stability convenience relationship three variables plotted Figures 3 4 plots enable find third vari able already know other two have existing airplane EDA lw/b already known plots will show maximum lift coefficient plane will spirally stable example using Figure 3 can find plane 15 degrees EDA 04 lw/b will stable lift coefficient 105 less Figure 4 could used well reading plot difficult since must interpolate between lines designing plane scratch may want examine trade-off between tail boom length dihedral angle Pre sumably have already chosen wing section have estimate cir cling lift coefficient example say designing floater RC Sailplane expected thermal lift coeffi cient 10 Figure 4 permits direct exam ination boom/dihedral trade-off Fol lowing along C1 ine find could have 02 lw/b 27 de grees dihedral Wow Thats lot dihe dral plane will highiy sensitive rudder trim 04 l/b 145 degrees dihedral like 08 lw/b 75 degrees dihedral long tail boom low roll rate due low dihe dral anglesee Part Two Dihe dral series Because simplifying assumptions described below plots conserva tive Depending mostly size vertical stabilizer can back off some dihedral angle tail boom length can increase lift coefficient although just much tricky say Testing typical Two-Meter RC Sailplane found 43 approximately min imum value SS testing later Variables ignored insignificant some important variables have ig nored order boil problem down September 1990 103 35 30 25 MINIMUM20 EQUIVALENT DIHEDRAL ANGLE DEG15 10 5 0 fundamentals Most important extra outboard yaw due differential wing drag As plane circles outboard wing flying faster creates drag produces outboard yawing moment opposed vertical stabilizer der stabilizer generate opposing lift plane must yaw further outboard Large stabilizers can generate required lift small yaw angles small verticals can require much greater yaw angles 35 30 25 MINIMUM EQUIVALENT DIHEDRAL ANGLE DEG extra outboard yaw angle increases spiral stability increasing tendency plane roll out circle Free Flight models typically use small verticals consequent increase spiral stabil ity can quite great contrast RC Sailplanes typically have large vertical stabiliz ers track well produce little change spiral stability graphs ignore ef fect entirely since indicate spiral stabil ity achieved very large stabiliz Lv/b 2 era Smaller stabilizers give spiral sta bility Fuselage interference effects also ig nored since fuselages Gliders very small compared wings large fuselages Scale Free Flight models however have important ef fect spiral stability As generalization high-mounted wings large fuselages have dihedral lowmounted wings behave hnd less Also generous amount fuselage side area front center-of-gravity desta bilizes plane yaw increasing spiral stability same way reducing size vertical stabilizer does ef fects difficult quantify _____yond scope article Pendulum side-force effects ig nored because minor RC _____Sailplanes Side area above center-ofgravityor conversely low center-of1 21 3 1 4gravity relative side areaacts crease yaw-roll couple same way does increased dihedral Gas Free Flight models take advantage effect tall wing pylons heavy low-thrust engines effect still minor models typical wing dihedral need dihedral its efficient increase wing dihedral extend fuselage wing pylon Much smaller increases wetted area result last effect increases spiral sta bility ignored circling entire Glider coming down same rate inboard wing moves slowly gives inboard wing greater angle tack increasing spiral stability effect minor airplanes good glide ra tios significant very draggy models its extreme form becomes stall-spin maneuver inboard ______wing stalled outboard wing con tinues fly large simplifying assump ________________tions produce conservative results SS greater 57 airplane almost cer tain stable near 57 stability probable depending primarily size vertical stabilizer SS doesnt get close 57 craft almost sure unstable Testing spiral stability RC Sail planes given airplane configuration ___________ dihedral tail boom-to-span ratio fixed Thus airplane has maxi mum lift coefficient minimum speed spirally stable Normally want Glider stable up near its maximum lift coefficient easy test flying straight slowly come back pitch trim lever until plane seems sinking its minimum rate let plane fly hands-off model contin ues straight almost straight spirally stable begins circle its Dont surprised plane proves lack spiral stability common RC SailContinued page 106 r 20 15 10 5 0 10 44 02030405 VERTICAL TAIL MOMENT ARM TO WINGSPAN RATIO Lv/b Figure 4 chart shows minimum wing dihedral angle diminishes tail boom lengthened design lift coefficient reduced can very useful during pro cess designing since permits dIrect trade tall boom length reduced dihedral 0708 104 Model Aviation U4 0506070809111 DESIGN LIFT cOEFFICIENT ci Figure 3 Th minimum wing dihedral angie must greater plans higher lift coeffi cients shorter taii booms plot shows minimum equivalent dihedral angie guarantees spiral stability f range lift coefficients tail-boom-to-wIngspan ratios ivlb its cisc useful evaluating maximum stable im coefficient existing designs Southern Radio ControlLons fl/C Service Naples FLPhoenix NY 813 775-1554315 695-2448 s&D WC ServiceiI&J ElectronicsRivergote Hobby Center San Jose CAHowell MlGoodleftsville TN 408 281-1549517 546-2644615 859-3455 Authorized IVC Service Fallbrook CA 619 728-0440 Radio South Pensacola FL 904478-6745 Iraft Midwest IMI Northoille Ml 313 348-0095 Woiiitz PJC Jackoonoille FL 904 771-0613 DuMond C Service Carroliton TX 214 242-4682 Ocean County WC Service Toms River NJ 201 505-9477 planes seem marginal regard determine pitch trim setting plane becomes stable adjust slightly higher speed repeat experi ment Repeat cycle increasing speed slightly time until airplane no longer rolls circle speed model stable difference between speed optimum mini mum sink speed will indicate far off airplane much dihedral tail boom must increased Keep mind lift coefficient proportional speed squared model becomes stable twice optimum speed dihe dral tail boom off factor four Its best conduct experiments still morning late evening air Also sure model free asymnoetrical warps wing isnt heavier other performed experiment Two-Meter RC Sailplane Tutor airplane has simple V-dihedral two-piece wing bent piano wire joiner flown three different dihedral angles substituting three different joiners illus trated pictures model trimmed fly approximately minimum sink rate airspeed estimated C1 09 allowed fly hands-off dihedral angle 15 degrees airplane tracked well speeds would fly straight very nearly indefinitely very low speeds did tend wiggle turbulence bit really needs bigger ver tical stabilizer give margin Dutch roll 12 degrees dihedral plane ap peared verge circling min imum sink speed wandered over sky never actually settled circle higher speeds tracked true judged plane just spirally stable con figuration 57 degrees dihedral model definitely unstable Over period about 15 seconds would roll left right circle stabilize about 20 degrees bank angle Pulling back pitch trim simply increased bank angle trimmed plane estimated C1 04 interthermal cruise speed released straight flight continued fly straight Calculating spiral stability Tutor 12 degrees dihedral according formula get 12 x 0324 43 Alternatively low dihedral angle higher speed SS roughly 57 x 0324 46which fairly close 43 con sidering imprecise nature C1 esti mates Note values somewhat less ideal 57 derived earlier article probably because extra outboard yaw resulting differ ential wing drag Other methods obtaining spiral stabil ity Free Flight models use sorts meth ods enhance spiral stability Chief among Continued page 191 106 Model Aviation RCD r AIVfefl1SAJtVB~e1 QOflt ileltewwe we6 w0eCtB ggl iA%~6 ~JI ai99~ 6 Owe60 IA owAte bO SSao 06606 L400* 6gA6I icipating RCD Sticker Stations 9SR Products Sacramento CA 918 362-1962 FOR ORDERS ONLYLJL CODs 1 -8OO6337556ILLJJJWELCOME IN ALABAMA 347 3525 COLLECT TOP QUALITY FUEL FOR EXPERT OR BEGINNER NO RE-CLAIMED ALCOHOL O METHANE ONLY IS USED Designed tested give top performance both 2-cycle 4-cycle engines ringed Except engines requiring low lubricant content CONTAINS NEW TRULY SPACE AGE ADDITIVE developed outer apace vacuum new additive attaches internal metal parts engine will reduce friction much 80/o reduces heat wear absolute minimum WE HAVE 3 LUBRICANT BLENDS ALL SYNTHETIC OR SYNTHETIC BLEND CASTOR castor new high purity much cleaner burning castor ALL OUR FUELS CONTAIN ANTI-FOAMERS PREVENTERS WEAR ADDITIVES fuel developed priced tor individual club direct sales market dealer Inquiries invited Order gallon up MIx OK 4 gallon cases up ALL FUEL EXCEPT 54 GALLON DRUMS SHIPPED FREIGHT PRE-PAID Only continental USA TD 3 GalTo 23ITo63To 127 GIjAndIFreight l l24 Gal al12S al Drum 5% ..1095750700.650 . .. 57518500 120/o 5 .050. 900 7528000 250/o 5. 1400 0127547500 500/o 02200 ..21 502075780 00 Manufactured MACH-7 PO Box 1201 Enterprise Alabama 36330 houses relics displays both World Wars HMS Belfast moored Lon dons Thames River newest exhibit Cabinet War Rooms recently restored World War II condition under ground emergency headquarters Prime Minister Winston Churchill Taken together installations tell story two enormous wars raged around Englandparticularly skies over now-peaceful settings like Duxford Airfield Spiral/Beron-Rawdon Continued page 106 asymmetrical wing twist known washin washout Normally inboard wing washed twisted inci dence outboard wing washed out approximately equivalent yawing dihedraled wing outboard rudder trim should enhance spiral stability dont know Free Flight difference between approximately equivalent exactly same can important Another Free Flight method ballast inboard wing tip apply outboard rud der trim tip weight produces con stant inboard rolling moment rudder yields outboard yaw-roll couple very sensitive airspeed As model slows down tip weight rolls plane circle plane rolls up bowl effect increases airspeed rud September 1990 191 Bill Eff go * says OnlyPlans Pettern5 Sets give assorted designs yos west hove eslected best cleesic designs eli time choose hoer patterns soch part art important exclusive feature Ducted Fans Navy F4D-i Skyray 1 h soale ength 40ff wing span lg h RIO eotlbte Landing Gear RODF229gB 1 seats ength 32t$ wing span lbs wie RIO 3-0 sir R/O 5 RK725 lens ROOMgfgg One-Third Scale Piper TPacer PA-22 11R31g wing span sq wing area 20 30 old engines 4-5 oh RIO so 12 lb. SluR onersll length RO3g3029gb 1/3Piper Cub 1-3 Scale hR wing span ength 2005 sq wIng area4 oh RIO 030 old engines R030202996 Quarter Scale WWI SE-IA 001 wing span sq wing ares 5 70 tu 22 engines 0005-7 6 SPAD CXIII s70/wingsyons2l20sqin winguteos t3to3t engines Capable flynt-it captures thn imagination RCOS-g 6 FOKKER DR-i TRIPLANE 72 oring span C 1772 pa wing area 70 tot 00 engines OCOS0 82496 SOPWITH CAMEL F1 04 wing span 21 60 pa wing area ftlbs wls R/O wood ft balse construction over OPuq ft drawings 0005t 1 6 00wingspans2225sqivw cane 114 Scale Fokker 0-ViII 00 25 cid onoine 3-h ch OCOSO 0 Golden Age 114 Scale Curtiss Hawk P 1 00length04tfwingspan 2260uq 5 wing areas 1323 engines h 0/C RCOS-t 4 6 114 Scale CurtigaFalcon 03lnngthsltdwitgnpan3100 sqmnwmvg areaedchR/CRCOS-13g20961J 1/6 Scale Cessna AW 0twinospansgO0sqinwingarea 25to go ongirres channel 0/C RC6S-f $1496 roe ill Scale Purn Mogt 73Ifwingtpans4d0sinarno Pot 2040 engines annel 0/C RC0S-3 6 5111 stOnes Fouodlng Merebar AMA OPPO Hell Fewer Privon ore fur vurnyloto pbne sub asuorubly ft derajind parts huts PLEASE ADD 0200 tsr shipping Inrelllng tubal Now 1990 Pros Oats brovhxro refundablo Ion yvu h order WE TECHNICAL SERVICES RO 1 Box 2900 Santa Rosa Beach FL 32459 der becomes powerful balancing tip weight method stable circle direction still relies di hedral produce yaw-roll couple also relies bowl effect increase air speed increased bank angle Dihedral tail boom length pitch stability will still have strong effects spiral stability such model quick look Figure 3 will show low-dihedral airplanes such typical $599 o \C39\ Nut use Electric Starters Made 6061 Aluminum strong enough allow over tightening weighs under 1 oz 1 diameter 1t/t long 114 radius nose minimum AMA requirement 5/32 Torq Hole 3/4 thread depth can use thinnest props 11 thread sizes fit engines market Send us order & well mail out tast MADE IN THE USA B C PRODUCTS 111 N Starkweather Pam pa Texas 79065 1-800-441-4365 US & Canada aileron-controlled RC Sailplanes havent shadow hope being spirally stable reasonable lift coefficients example plane 30 degrees dihedral lift coefficient 07 must have tail boom 13 times long wingspan type models spiral stability can achieved artificial mechanisms example would produce artificial yaw-roll couple means yaw sensor hooked up run ailerons rate D103210/32 DOSBO5-8mm D123212/32 D06106-1mm 107107-1mm D08108-1mm D81258-125mm D101210-125mm D14281/4-28 151625/1624 38243/8-24 VISA MASTERCARD MONEY ORDERS ACCEPTED DEALER INQUIRES WELCOME ENYA 15 5-8mm SS2O SS45 1/4-28 19 to 80 7-1mm 120 8-1mm FOX 19 45 1/4-28 60 to 120 5/16-24 HB ALL SIZES 1/4-28 HP 40 6-1mm 120 5/16-24 others 1/4-28 IRVING ALL 1/4-28 K&B 19 611/428 OS 10 5-8mm 15 12/32 20 6-1mm 21 50 1/4-28 60 120 5/16-24 108 3/8-24 ROSSI ALL 8-125mm SUPERTIGER 11 to 15 5-8mm 19 to 60 1/4-28 61 to 90 5/16-24 2000 6000 10-125mm SATIO3Oto60 6-1mm 65 to90 71mm 120 to 270 8-125mm WEBRA 28 61 1/4-28 80 90 8-125mm MALONEY 100 3/8-24 .THESUPERIORGLOWPLUGSFO GO FASTFLYERSAREBACKII Puts sting engine Unique flat-wound spiral coil element high temperature glass-to-metal seal add up faster ignition increased RPM 1 /2A GloBee plugs designed exclusively 049/051 Cox engines - Ask new GB-5RX Speed Plug GB-SR Racing Plug GB-5P Spert Plug local dealer today unavailable locally write call Twinn-K collect pricing delivery information FREE GloBee Catalog MAKE THE GLOBEE / INDY CONNECTION Twinn-K Inc 10296 W Washington St Indianapolis IN 46231 Telephone 317-839-6579 FAX 317-839-8928 192 Model Aviation aileron deflection function yaw angle sufficient spiral stability could achieved Another method would employ direct mechanical link between yaw vanes aileronsthough youd probably have watchmaker get work Intro ducing yaw-roll couple will make roll axis sensitive deviations yaw axis particular attention will have paid rudder coordination during transi tional maneuvers Another possibility flat-wing air planes would incorporate rate gyro scope gyro could sense yaw rate drive ailerons roll out As plane rolled circle its bank angle yaw rate increase ailerons deflect roll plane out circle response yaw rate may provide spiral stability chance however phase diffi culties between yaw rate roll accelera tion would develop causing disruptive yawroll oscillations similar Dutch roll successful experiment thought worth trying last fix wifes large slow aileron Sailplane Tango plane originally flown zero dihe dral major pain thermal due lack spiral stability Increasing EDA two degrees made noticeable improve ment still great challenge thermal efficiently slowly installed Futabas simple least expen sive rate-sensitive gyroscope model FP G134 ballast box plane unit consists two components gyro box electronics box gyro stalled in-line between receiver aileron servo Tango uses separate rudder servo connected ai leron output receiver Y connector couples rudder ailerons control adverse yaw However rudder servo still hooked direcfly receiver unaffected gyro gyro installation illustrated pictures electronics box has little knob actu ally screw adjusts effect gyro aileron servo zero 100% 0% gyro has no ef Continued page 194 /9 ilttilt --MIt Ii tPJOflC OU QOtVT FLf WELL I1iVfRi 1I ISLiRINO%11 St 1IC m JJJ0 QUADRA RT 1 NEODESHA KS 66757 316325-2821 DEALERS CALL SEND $100 FOR COMPLETE CATALOG fect higher settings gyro input mixes pilots input control ai lerons higher setting the gyro has say about would appear 100% setting maximum con trol input gyro nearly equals maxi mum input pilots stick gyro box installed senses yaw rate reversing switch electronics box set give right aileron left yaw rate vice versa word about rate gyros may helpful contrast regular gyros sense change orientationin degrees instancerate gyros sense rate change orienta tion say degrees per second cant tell way pointing way fast turning bottom line gizmo works adjustment about 50% sensitivity plane flies extremely well model actually flies straight indefinitely straightens out circles slowly itself has feel circle good-performing polyhedral ship retains immediate roll response aileron-controlled craft No adverse effects noted flying model through entire envelope Some better fliers Soaring Union Los Angeles have flown plane gyro responses ranging enthusiastic acceptance grudging admis sion did indeed seem nice am excited about development means sorts low-dihedral aileron AJKUMUIJbL iIANT SHARK ARC PRE-BUILT G SHARK S21495 SEE YOUR HOBBY DEALER FIRST SEND STAMPED #10 ENVELOPE FOR INFO KINGS WAY RIG HOBBY SUPPLY 5559 RICHMOND HOUSTON TX 77056 DEALERS ONLY 1-800-621-7783 194 Model Aviation AT LAST An Effect ye H gh Tech Engine Cleaner R/G Engines Removes Burned-On Fuel Residue Encrusted Carbon anteed ONLY $695 CA residents add 725% lax Clean Engines-Run Cooler-Last Longer Send Check Money OrderTo AIRBORNE HOBBIES 3764 30TH ST SAN DIEGO CA 92104 619543-9703 DEALERS INQUIRES WELCOME tIN SUPERTANKS & SUPERMUFFLERS ZINGER WOOD PROPS GIANT SCALE R/C PLANS C #No663 Pea Patch $900 RC Sportster spans 60 uses 40150 4-stroke power Two plan shts No 664 Stuka Stunt $500 CL V2A Stunter semiscale spans 37 No 665 Conscientious Objector $575 FF Mulvihill Rubber competition plane spans 501/2 flat No 193 StIletto CL Stunt nindel McDonald winner 1976 1980 1982 FAt Wodd Champs $ 375 No 262Craahmaater- Ct Crash-pruof trainer two tizet1 5130 35/40 powor$125 No 3101930 Fleet Biplane AC Sport Scale 35140 4-clronnel Wingspan 56 e Ten streets6625 No 314Drake II AC Ken Witards flying boat 3-channel 15-power Fly 1mm land mmovabln gear . No 326Taylor Cub AC Don Srnlfs Schoolyard-Scale 049s 2-3 channel Spoon 50 in$350 No 332Zephyr AC Sinaf 2-channel glider hand-launch tow thermal slope soaring6200 No 386Laaer 200 AC Sport Scale replica champineship Aerehafic tiler Uses 40 power 4-5 channel Two sheets$1075 No 4471/2A Miwa America AC Old-Tuner WA Texaco model 049 glow 2-channels$650 No 4604-40 AC Shoelder-wiog sport filer 4-cycle 40-nine engine 4 channelo$650 No 465Blue Max II AC Fun-fly sportster 40-size engines spans 52 Lightweight stonctere$700 No 533Cewana C-37 AC Schoolyard Scale ni tamoos 3& plane 009/10 power 2-ch opans 42Va in6500 No 539Slmitar Slow4dotlon 15 AC Tailless flying wing 15 engines spans 98 ones 3-ch AC$350 No 569Elactroatreak AC Electric aembatic plane spans 44 ones 05 motorS550 No 572TR-260 AC Sport Scale Aerohalic plane 4-strulre 65/66 power spans 66 in61100 No 576Serendlpityt ndoor 025 record-holder spans 17/ in$325 No 578Scinwelzer 1-26B AC Quarter-ucale Sailplane spans 125 Two plan sheets61475 No 581Gee Bee Moefel Y AC Golden Age Racer spans 72 1A scale 60 power Thwe plus sheets61175 No 586Snapdragon AC Fun-fly/sponster 25/30 engines spans 45 In6698 No 588Marlah AC Slope-Soaring Sailplane spans 41 uses 2 AC channels6425 No593Taytorcralt AC Sport Scale llghtplane builds us standard 2-placer clipped-wing air show stenter Spans either 70 50 35/40 two-stmfre 45/48 four-ntmhe engine Two plan sheets no dncomentatmn$1000 No586Coronet 150 RC-Assint Old-liner enlarged 15914k spans 72 uses 40-size 4-sImlreI 30-size 2-tube6850 No601NIcicel AC Sportster WA engine 3 AC channels Spans 44 in$500 No 603Sparrow Hawk P30 FF Competitfon rebber-power plane woo 87 Nuts Spans 30 in$225 No607Curtlaw Seegull AC Glout Scale biplane spant 50 uses Oeadra/Zeuoah power Three plan sheets dec62498 No mTapeewing AC WA Pylon Racer spans 29 Plan plan use ports template about$698 No 610Protobype AC Sport biplane spans 48 uses 45/2-cycle 85/4-cycle power$650 No 619KeIth RIder R4 FF Scale Goldan Age racer rebber power spans 18 in6300 No 620GImlet 60 AC Spert/Pattem plate spans 60 iii 45/50 enguw 2 sheets61100 No 623Henderwom Longater AC Quarter-Scale 1933 fhwer spans 90h 4-strube 45/46 engine 3 plan sht no dec$1698 No624KelaIrer Laric AC Quarter-scale hontehuit spans 69 69198 4-Otmlre power 2 plait sheets dec61100 No 626Sweepee AC Spoil/Pattem canards foiward-sweyl wing spans 64 uses 48 power 2 plan sheets61300 No628Prime Cut AC SportlAerotsatic plane spuss 90 uses Quadra 35/40-sine power Two plus sheets61300 No 630OrIginal Ply Baby AC Old-Thiter spans 72 uses 19125 2-cycle 484-cycle power 2 plan sheets61150 No 635The Gambler FF Indoor Sestoeran rebber-power cable plane spans 15% in6200 No 836Keytwo AC Tn-geared low-wing sportsler 29125 power spans 44 in$575 No637A6 Shrike FF Compefitine plane AMA Clauses 5 15/23 power spans 60 in$675 No 638Owl Racer CL WA Scale Racer 049 power spans 20 6225 No 839SIcyvoIt AC Tn-geared Electric aerubatic sportoter 05/15 power spans 50 in6850 No 640Bird Prey CL AMA Fast Combat plane 36 power spans 5334 in$550 No 641UI Ole Reliable AC Old-tinter spoil filer spans 50% WA engines$575 No 642BIpe 89 CL Partlat plus updates deflofis 48 nersbon 3Scc power Spans 2234 in6225 No643Noctule IIB FF Baflulte flying wing CO2 power spoon 30 in$325 No 644Beliance ColumbIa AC Schoolyard Scale 2 AC channels WA engine Wingspan 46 m$575 No 645Lalrd Solution Cl Ponfile Scale biplane spans 36 25/35 pewer6575 No 646WInter Hawk FF Robber-power Coupe dHleer cempefiflon plane spans 47 in6375 No647Cox Speeded CL Semincale biplane WA enne spans 24 in6300 No646Cufllwa OC-2 FF Sculls Outdoor Gas Ftying Scale biplane uses electric power spans 24 HiLine lohnr-6 motor$325 No640Thlngemabob AC/CL Mutfimede trainer 25 gas 05 electric power spans 51 in$475 No 65047/66 RC Special AC Aembafic sport plane 48 power spans 61 3 plan sheetsS1075 No 651Conwortlum AC Husri-Lanoch HI-Start Coder spans 60 in6050 No652Oar Ptedenmaeea AC Lute-wing spoil plane 29125 power npons 55 -$675 No 663Aventl CL Profile Sport Scale canard hisliner twin DOgs spans 38 in$575 No 654Tamiecag AC Trainer/spottster styled Ibe F14 spaus 66 45/61 power Four plan sheets$1525 No 6S5Aetroalar FF AMA Class A/B Gas plane spans 67 uses 3 25/350cc power$800 No 856XP13C CL Profile 15 Carrier plane spans 277A in6550 No657Super Squire AC Trainer 35/48 2-stonbe 53 4-strobe power spans 9834 in6750 No 658SIturiken Streak CL Trainer uses 2-line Moonline control spans 17 WA power$225 No659Boom Box FF Walefleld Rubber competitine plane spans 54 in6400 No 660Volkaplene AC Electric-powered sportster 05 motor spans S6 2 plan shts6925 No661Embey-Omatlc FF Embryo Enderance mbber-power plane spans 20 in6200 No662Boxklte CL Scale antique caned pusher biplane spans 42 2 plan shtsS1100 0 Os 0 o C%J 0 gC Co tous Q 0 05 no 6E 050 o - Co FJ t- tog5 0 C 0 - 0 - ID 05 005 0 c us n 00 0 00 us Co-s 0 0 E-d 00 cs 0 2 0 I U0 E N STREET 0CITY - Circle numbers plans wish order best handling please include re quests payment some other service withyourplans order 193262310314326332386447 460465533539569572576578 581586588593598601603607 609610619620623624626628 630635636637638639640641 642643644645646647648649 650651652653654655656657 658659660661662663664665 Plan price includes first class postage US delivery Air Mail over 300 miles orders non-US address lease add $258 Air Mail osta e handlin Ian Make Check money order payable US funds drawn US bank Model Aviation AMA 1810 Samuel Morse Reston VA 22090 Please allow 3 6 weeks delivery Please print CarefullyEnclosed $ _______________________ ___________________________________________ AMA No _______________ airplanes can practical pleasurable fly may also mean ultimate dura tion cross-country RC Sailplane now large flat-wing variable-camber aileroncontrolled configuration instead sim pler fixed-camber rudder elevator ar rangement caution have course tried sys tem 100% sensitivity setting plane does interesting 1-Hz flat yaw oscil lation about plus minus 15 degrees ascribe adverse yaw coupling gyro model remained flyable no harm done might want come up optimum setting instead starting working way down Summary conclusions Spiral stability measure tendency airplane spiral straight circling flight Its primarily function Equiv alent Dihedral Angle EDA tail boom-towingspan ratio lIb wing lift coeffi cient C1 significant secondary variable yaw stability plane function fuselage proportions ver tical stabilizer size Airplanes strong yaw stability spirally stable EDA X lw/b C1 greater equal about 57 Air planes modest yaw stability will sta ble somewhat lower values relation ship illustrated Figures 3 4 An experimental procedure de scribed determining degree spiral stability RC Sailplanes test TwoMeter Sailplane showed good agreement theory control dihedral angle tail boom proportion lift coefficient primary means achieving spiral stability other methods can used Free Flight mod els typically incorporate asymmetrical trim balance arrangement effec tive oaly circle direction mechanical means well successful has tested article incor porates yaw rate gyro drive aile rons As practical inexpensive way provide spiral stability aileron-con trolled Sailplanes exciting devel opment Next month Part Two will describe effect circling flight spiral stability pitch trim yaw angle Southwest PC Flying Year round flight school Five day course $350 Learn fLy planes Send SASE conlete info 2818 CaroLina NE Albuquerque NM 87110 505 881-3799 196 Model Aviation IMPORTED DIESELS A-MAuroraDCEDMVVSMBia*nya PAWTaplln Standard R/C.0864S Acre & MarIne VlntegeAperg Comfiest Seed $100 Informatlo CARLSON ENGINE IMPORTS 314 East Marcomi Phoenix AZ 85022 _________________________________________ ZIP _______________________________
Edition: Model Aviation - 1990/09
Page Numbers: 100, 101, 102, 103, 104, 106, 191, 192, 194, 196
NO OCR TEXT NO OCR TEXT juel per ipervil pnoso D inS au beHest compartment circie giving spiral dral-ilke handling w degrees last thre scribed detail b Keeping mind portional W/S ank C.u around tracked Stf ems lango ailerons result slmple uncoupled coi ited d illustr lw/b ran ailplanes Frc adral angl us dihedra rolled photos wer gher values ty 10 some luces greater spr quiva1ent dihedr of the effective ng force n yaw angle ir greater r yaw angles ig compti Part slues EDA rai Extreme values up 20 th spiral mt C1 b flight Since loading dvn 05 Rho goes down nother way airspeed2 prop wis an find ratio yaw angle required gles yaw obtained/yav proportio lw/b X ED order achieve sp aircraft yaw angle equal greater quired eoi balance neutral yaw obtained greater out circle unless put held yaw obtain will roll tighter tive varying top ru Anything increas obtained yaw req spiral stability formula crux c1 contains three Lets take detailed ratio vert tothe wp liiir E s 51mph ar momen atween FIgure 2 circular flight path tends force wing outboard yaw angle vertical stabilizer lines itself up airflow becomes quite clear illustration yaw angle sensitive both circle radius vertical stabilizer moment arm length late angle attack high angle tack gives high C1 vice versa Rho air density slugs per cubic foot about 0002377 sea level An increase C1 reduces spiral stability increasing C1 increases yaw ob tained given bank angle due reduced circle radius yaw required increased because both V2 term r reduced inverse proportion C1 general Gliders thermal best near maximum C1 just shy stall higher lift coefficients give less spiral stabil ity leads interesting effect de scribed later article Typical thermaling values C1 RC Sailpianes range 06 10 Thicker higher camber sections will high end range Typical Free Flight C1s range low 04 high 14 low values would found smaller models low-camber wings high est values would found larger thin high-camber wings such A2 class Towline Gliders Observations interesting three variables significantly affect spiral stability has important implica tions Wing loading does matter can ballast model affecting spiral stability Aspect ratio does matter long skinny wings short squat ones have about same impact spiral stabil ity Note though long wing requires long fuselage Size does matter can scale design up down spiral sta bility will retained same lift coeffi cient Circle radius bank angle matter plane stable bank angle stable bank angles assuming no change C1 Computations tested out spiral stabil ity relationship trusty computer spreadsheet described Dihedral series spreadsheet divides wing 20 spanwise segments allows fly various bank angles wing load ings dihedral angles schemes lift coef ficients yaw angles output value net roll moment given configuration fiddle dihedral angle yaw angle until roll moment zero did series configurations results showed plane spirally sta ble EDA x l/b 7 greater sake brevity lets define new variable 55 equal EDA x lw/b S stands spiral stability convenience relationship three variables plotted Figures 3 4 plots enable find third vari able already know other two have existing airplane EDA lw/b already known plots will show maximum lift coefficient plane will spirally stable example using Figure 3 can find plane 15 degrees EDA 04 lw/b will stable lift coefficient 105 less Figure 4 could used well reading plot difficult since must interpolate between lines designing plane scratch may want examine trade-off between tail boom length dihedral angle Pre sumably have already chosen wing section have estimate cir cling lift coefficient example say designing floater RC Sailplane expected thermal lift coeffi cient 10 Figure 4 permits direct exam ination boom/dihedral trade-off Fol lowing along C1 ine find could have 02 lw/b 27 de grees dihedral Wow Thats lot dihe dral plane will highiy sensitive rudder trim 04 l/b 145 degrees dihedral like 08 lw/b 75 degrees dihedral long tail boom low roll rate due low dihe dral anglesee Part Two Dihe dral series Because simplifying assumptions described below plots conserva tive Depending mostly size vertical stabilizer can back off some dihedral angle tail boom length can increase lift coefficient although just much tricky say Testing typical Two-Meter RC Sailplane found 43 approximately min imum value SS testing later Variables ignored insignificant some important variables have ig nored order boil problem down September 1990 103 35 30 25 MINIMUM20 EQUIVALENT DIHEDRAL ANGLE DEG15 10 5 0 fundamentals Most important extra outboard yaw due differential wing drag As plane circles outboard wing flying faster creates drag produces outboard yawing moment opposed vertical stabilizer der stabilizer generate opposing lift plane must yaw further outboard Large stabilizers can generate required lift small yaw angles small verticals can require much greater yaw angles 35 30 25 MINIMUM EQUIVALENT DIHEDRAL ANGLE DEG extra outboard yaw angle increases spiral stability increasing tendency plane roll out circle Free Flight models typically use small verticals consequent increase spiral stabil ity can quite great contrast RC Sailplanes typically have large vertical stabiliz ers track well produce little change spiral stability graphs ignore ef fect entirely since indicate spiral stabil ity achieved very large stabiliz Lv/b 2 era Smaller stabilizers give spiral sta bility Fuselage interference effects also ig nored since fuselages Gliders very small compared wings large fuselages Scale Free Flight models however have important ef fect spiral stability As generalization high-mounted wings large fuselages have dihedral lowmounted wings behave hnd less Also generous amount fuselage side area front center-of-gravity desta bilizes plane yaw increasing spiral stability same way reducing size vertical stabilizer does ef fects difficult quantify _____yond scope article Pendulum side-force effects ig nored because minor RC _____Sailplanes Side area above center-ofgravityor conversely low center-of1 21 3 1 4gravity relative side areaacts crease yaw-roll couple same way does increased dihedral Gas Free Flight models take advantage effect tall wing pylons heavy low-thrust engines effect still minor models typical wing dihedral need dihedral its efficient increase wing dihedral extend fuselage wing pylon Much smaller increases wetted area result last effect increases spiral sta bility ignored circling entire Glider coming down same rate inboard wing moves slowly gives inboard wing greater angle tack increasing spiral stability effect minor airplanes good glide ra tios significant very draggy models its extreme form becomes stall-spin maneuver inboard ______wing stalled outboard wing con tinues fly large simplifying assump ________________tions produce conservative results SS greater 57 airplane almost cer tain stable near 57 stability probable depending primarily size vertical stabilizer SS doesnt get close 57 craft almost sure unstable Testing spiral stability RC Sail planes given airplane configuration ___________ dihedral tail boom-to-span ratio fixed Thus airplane has maxi mum lift coefficient minimum speed spirally stable Normally want Glider stable up near its maximum lift coefficient easy test flying straight slowly come back pitch trim lever until plane seems sinking its minimum rate let plane fly hands-off model contin ues straight almost straight spirally stable begins circle its Dont surprised plane proves lack spiral stability common RC SailContinued page 106 r 20 15 10 5 0 10 44 02030405 VERTICAL TAIL MOMENT ARM TO WINGSPAN RATIO Lv/b Figure 4 chart shows minimum wing dihedral angle diminishes tail boom lengthened design lift coefficient reduced can very useful during pro cess designing since permits dIrect trade tall boom length reduced dihedral 0708 104 Model Aviation U4 0506070809111 DESIGN LIFT cOEFFICIENT ci Figure 3 Th minimum wing dihedral angie must greater plans higher lift coeffi cients shorter taii booms plot shows minimum equivalent dihedral angie guarantees spiral stability f range lift coefficients tail-boom-to-wIngspan ratios ivlb its cisc useful evaluating maximum stable im coefficient existing designs Southern Radio ControlLons fl/C Service Naples FLPhoenix NY 813 775-1554315 695-2448 s&D WC ServiceiI&J ElectronicsRivergote Hobby Center San Jose CAHowell MlGoodleftsville TN 408 281-1549517 546-2644615 859-3455 Authorized IVC Service Fallbrook CA 619 728-0440 Radio South Pensacola FL 904478-6745 Iraft Midwest IMI Northoille Ml 313 348-0095 Woiiitz PJC Jackoonoille FL 904 771-0613 DuMond C Service Carroliton TX 214 242-4682 Ocean County WC Service Toms River NJ 201 505-9477 planes seem marginal regard determine pitch trim setting plane becomes stable adjust slightly higher speed repeat experi ment Repeat cycle increasing speed slightly time until airplane no longer rolls circle speed model stable difference between speed optimum mini mum sink speed will indicate far off airplane much dihedral tail boom must increased Keep mind lift coefficient proportional speed squared model becomes stable twice optimum speed dihe dral tail boom off factor four Its best conduct experiments still morning late evening air Also sure model free asymnoetrical warps wing isnt heavier other performed experiment Two-Meter RC Sailplane Tutor airplane has simple V-dihedral two-piece wing bent piano wire joiner flown three different dihedral angles substituting three different joiners illus trated pictures model trimmed fly approximately minimum sink rate airspeed estimated C1 09 allowed fly hands-off dihedral angle 15 degrees airplane tracked well speeds would fly straight very nearly indefinitely very low speeds did tend wiggle turbulence bit really needs bigger ver tical stabilizer give margin Dutch roll 12 degrees dihedral plane ap peared verge circling min imum sink speed wandered over sky never actually settled circle higher speeds tracked true judged plane just spirally stable con figuration 57 degrees dihedral model definitely unstable Over period about 15 seconds would roll left right circle stabilize about 20 degrees bank angle Pulling back pitch trim simply increased bank angle trimmed plane estimated C1 04 interthermal cruise speed released straight flight continued fly straight Calculating spiral stability Tutor 12 degrees dihedral according formula get 12 x 0324 43 Alternatively low dihedral angle higher speed SS roughly 57 x 0324 46which fairly close 43 con sidering imprecise nature C1 esti mates Note values somewhat less ideal 57 derived earlier article probably because extra outboard yaw resulting differ ential wing drag Other methods obtaining spiral stabil ity Free Flight models use sorts meth ods enhance spiral stability Chief among Continued page 191 106 Model Aviation RCD r AIVfefl1SAJtVB~e1 QOflt ileltewwe we6 w0eCtB ggl iA%~6 ~JI ai99~ 6 Owe60 IA owAte bO SSao 06606 L400* 6gA6I icipating RCD Sticker Stations 9SR Products Sacramento CA 918 362-1962 FOR ORDERS ONLYLJL CODs 1 -8OO6337556ILLJJJWELCOME IN ALABAMA 347 3525 COLLECT TOP QUALITY FUEL FOR EXPERT OR BEGINNER NO RE-CLAIMED ALCOHOL O METHANE ONLY IS USED Designed tested give top performance both 2-cycle 4-cycle engines ringed Except engines requiring low lubricant content CONTAINS NEW TRULY SPACE AGE ADDITIVE developed outer apace vacuum new additive attaches internal metal parts engine will reduce friction much 80/o reduces heat wear absolute minimum WE HAVE 3 LUBRICANT BLENDS ALL SYNTHETIC OR SYNTHETIC BLEND CASTOR castor new high purity much cleaner burning castor ALL OUR FUELS CONTAIN ANTI-FOAMERS PREVENTERS WEAR ADDITIVES fuel developed priced tor individual club direct sales market dealer Inquiries invited Order gallon up MIx OK 4 gallon cases up ALL FUEL EXCEPT 54 GALLON DRUMS SHIPPED FREIGHT PRE-PAID Only continental USA TD 3 GalTo 23ITo63To 127 GIjAndIFreight l l24 Gal al12S al Drum 5% ..1095750700.650 . .. 57518500 120/o 5 .050. 900 7528000 250/o 5. 1400 0127547500 500/o 02200 ..21 502075780 00 Manufactured MACH-7 PO Box 1201 Enterprise Alabama 36330 houses relics displays both World Wars HMS Belfast moored Lon dons Thames River newest exhibit Cabinet War Rooms recently restored World War II condition under ground emergency headquarters Prime Minister Winston Churchill Taken together installations tell story two enormous wars raged around Englandparticularly skies over now-peaceful settings like Duxford Airfield Spiral/Beron-Rawdon Continued page 106 asymmetrical wing twist known washin washout Normally inboard wing washed twisted inci dence outboard wing washed out approximately equivalent yawing dihedraled wing outboard rudder trim should enhance spiral stability dont know Free Flight difference between approximately equivalent exactly same can important Another Free Flight method ballast inboard wing tip apply outboard rud der trim tip weight produces con stant inboard rolling moment rudder yields outboard yaw-roll couple very sensitive airspeed As model slows down tip weight rolls plane circle plane rolls up bowl effect increases airspeed rud September 1990 191 Bill Eff go * says OnlyPlans Pettern5 Sets give assorted designs yos west hove eslected best cleesic designs eli time choose hoer patterns soch part art important exclusive feature Ducted Fans Navy F4D-i Skyray 1 h soale ength 40ff wing span lg h RIO eotlbte Landing Gear RODF229gB 1 seats ength 32t$ wing span lbs wie RIO 3-0 sir R/O 5 RK725 lens ROOMgfgg One-Third Scale Piper TPacer PA-22 11R31g wing span sq wing area 20 30 old engines 4-5 oh RIO so 12 lb. SluR onersll length RO3g3029gb 1/3Piper Cub 1-3 Scale hR wing span ength 2005 sq wIng area4 oh RIO 030 old engines R030202996 Quarter Scale WWI SE-IA 001 wing span sq wing ares 5 70 tu 22 engines 0005-7 6 SPAD CXIII s70/wingsyons2l20sqin winguteos t3to3t engines Capable flynt-it captures thn imagination RCOS-g 6 FOKKER DR-i TRIPLANE 72 oring span C 1772 pa wing area 70 tot 00 engines OCOS0 82496 SOPWITH CAMEL F1 04 wing span 21 60 pa wing area ftlbs wls R/O wood ft balse construction over OPuq ft drawings 0005t 1 6 00wingspans2225sqivw cane 114 Scale Fokker 0-ViII 00 25 cid onoine 3-h ch OCOSO 0 Golden Age 114 Scale Curtiss Hawk P 1 00length04tfwingspan 2260uq 5 wing areas 1323 engines h 0/C RCOS-t 4 6 114 Scale CurtigaFalcon 03lnngthsltdwitgnpan3100 sqmnwmvg areaedchR/CRCOS-13g20961J 1/6 Scale Cessna AW 0twinospansgO0sqinwingarea 25to go ongirres channel 0/C RC6S-f $1496 roe ill Scale Purn Mogt 73Ifwingtpans4d0sinarno Pot 2040 engines annel 0/C RC0S-3 6 5111 stOnes Fouodlng Merebar AMA OPPO Hell Fewer Privon ore fur vurnyloto pbne sub asuorubly ft derajind parts huts PLEASE ADD 0200 tsr shipping Inrelllng tubal Now 1990 Pros Oats brovhxro refundablo Ion yvu h order WE TECHNICAL SERVICES RO 1 Box 2900 Santa Rosa Beach FL 32459 der becomes powerful balancing tip weight method stable circle direction still relies di hedral produce yaw-roll couple also relies bowl effect increase air speed increased bank angle Dihedral tail boom length pitch stability will still have strong effects spiral stability such model quick look Figure 3 will show low-dihedral airplanes such typical $599 o \C39\ Nut use Electric Starters Made 6061 Aluminum strong enough allow over tightening weighs under 1 oz 1 diameter 1t/t long 114 radius nose minimum AMA requirement 5/32 Torq Hole 3/4 thread depth can use thinnest props 11 thread sizes fit engines market Send us order & well mail out tast MADE IN THE USA B C PRODUCTS 111 N Starkweather Pam pa Texas 79065 1-800-441-4365 US & Canada aileron-controlled RC Sailplanes havent shadow hope being spirally stable reasonable lift coefficients example plane 30 degrees dihedral lift coefficient 07 must have tail boom 13 times long wingspan type models spiral stability can achieved artificial mechanisms example would produce artificial yaw-roll couple means yaw sensor hooked up run ailerons rate D103210/32 DOSBO5-8mm D123212/32 D06106-1mm 107107-1mm D08108-1mm D81258-125mm D101210-125mm D14281/4-28 151625/1624 38243/8-24 VISA MASTERCARD MONEY ORDERS ACCEPTED DEALER INQUIRES WELCOME ENYA 15 5-8mm SS2O SS45 1/4-28 19 to 80 7-1mm 120 8-1mm FOX 19 45 1/4-28 60 to 120 5/16-24 HB ALL SIZES 1/4-28 HP 40 6-1mm 120 5/16-24 others 1/4-28 IRVING ALL 1/4-28 K&B 19 611/428 OS 10 5-8mm 15 12/32 20 6-1mm 21 50 1/4-28 60 120 5/16-24 108 3/8-24 ROSSI ALL 8-125mm SUPERTIGER 11 to 15 5-8mm 19 to 60 1/4-28 61 to 90 5/16-24 2000 6000 10-125mm SATIO3Oto60 6-1mm 65 to90 71mm 120 to 270 8-125mm WEBRA 28 61 1/4-28 80 90 8-125mm MALONEY 100 3/8-24 .THESUPERIORGLOWPLUGSFO GO FASTFLYERSAREBACKII Puts sting engine Unique flat-wound spiral coil element high temperature glass-to-metal seal add up faster ignition increased RPM 1 /2A GloBee plugs designed exclusively 049/051 Cox engines - Ask new GB-5RX Speed Plug GB-SR Racing Plug GB-5P Spert Plug local dealer today unavailable locally write call Twinn-K collect pricing delivery information FREE GloBee Catalog MAKE THE GLOBEE / INDY CONNECTION Twinn-K Inc 10296 W Washington St Indianapolis IN 46231 Telephone 317-839-6579 FAX 317-839-8928 192 Model Aviation aileron deflection function yaw angle sufficient spiral stability could achieved Another method would employ direct mechanical link between yaw vanes aileronsthough youd probably have watchmaker get work Intro ducing yaw-roll couple will make roll axis sensitive deviations yaw axis particular attention will have paid rudder coordination during transi tional maneuvers Another possibility flat-wing air planes would incorporate rate gyro scope gyro could sense yaw rate drive ailerons roll out As plane rolled circle its bank angle yaw rate increase ailerons deflect roll plane out circle response yaw rate may provide spiral stability chance however phase diffi culties between yaw rate roll accelera tion would develop causing disruptive yawroll oscillations similar Dutch roll successful experiment thought worth trying last fix wifes large slow aileron Sailplane Tango plane originally flown zero dihe dral major pain thermal due lack spiral stability Increasing EDA two degrees made noticeable improve ment still great challenge thermal efficiently slowly installed Futabas simple least expen sive rate-sensitive gyroscope model FP G134 ballast box plane unit consists two components gyro box electronics box gyro stalled in-line between receiver aileron servo Tango uses separate rudder servo connected ai leron output receiver Y connector couples rudder ailerons control adverse yaw However rudder servo still hooked direcfly receiver unaffected gyro gyro installation illustrated pictures electronics box has little knob actu ally screw adjusts effect gyro aileron servo zero 100% 0% gyro has no ef Continued page 194 /9 ilttilt --MIt Ii tPJOflC OU QOtVT FLf WELL I1iVfRi 1I ISLiRINO%11 St 1IC m JJJ0 QUADRA RT 1 NEODESHA KS 66757 316325-2821 DEALERS CALL SEND $100 FOR COMPLETE CATALOG fect higher settings gyro input mixes pilots input control ai lerons higher setting the gyro has say about would appear 100% setting maximum con trol input gyro nearly equals maxi mum input pilots stick gyro box installed senses yaw rate reversing switch electronics box set give right aileron left yaw rate vice versa word about rate gyros may helpful contrast regular gyros sense change orientationin degrees instancerate gyros sense rate change orienta tion say degrees per second cant tell way pointing way fast turning bottom line gizmo works adjustment about 50% sensitivity plane flies extremely well model actually flies straight indefinitely straightens out circles slowly itself has feel circle good-performing polyhedral ship retains immediate roll response aileron-controlled craft No adverse effects noted flying model through entire envelope Some better fliers Soaring Union Los Angeles have flown plane gyro responses ranging enthusiastic acceptance grudging admis sion did indeed seem nice am excited about development means sorts low-dihedral aileron AJKUMUIJbL iIANT SHARK ARC PRE-BUILT G SHARK S21495 SEE YOUR HOBBY DEALER FIRST SEND STAMPED #10 ENVELOPE FOR INFO KINGS WAY RIG HOBBY SUPPLY 5559 RICHMOND HOUSTON TX 77056 DEALERS ONLY 1-800-621-7783 194 Model Aviation AT LAST An Effect ye H gh Tech Engine Cleaner R/G Engines Removes Burned-On Fuel Residue Encrusted Carbon anteed ONLY $695 CA residents add 725% lax Clean Engines-Run Cooler-Last Longer Send Check Money OrderTo AIRBORNE HOBBIES 3764 30TH ST SAN DIEGO CA 92104 619543-9703 DEALERS INQUIRES WELCOME tIN SUPERTANKS & SUPERMUFFLERS ZINGER WOOD PROPS GIANT SCALE R/C PLANS C #No663 Pea Patch $900 RC Sportster spans 60 uses 40150 4-stroke power Two plan shts No 664 Stuka Stunt $500 CL V2A Stunter semiscale spans 37 No 665 Conscientious Objector $575 FF Mulvihill Rubber competition plane spans 501/2 flat No 193 StIletto CL Stunt nindel McDonald winner 1976 1980 1982 FAt Wodd Champs $ 375 No 262Craahmaater- Ct Crash-pruof trainer two tizet1 5130 35/40 powor$125 No 3101930 Fleet Biplane AC Sport Scale 35140 4-clronnel Wingspan 56 e Ten streets6625 No 314Drake II AC Ken Witards flying boat 3-channel 15-power Fly 1mm land mmovabln gear . No 326Taylor Cub AC Don Srnlfs Schoolyard-Scale 049s 2-3 channel Spoon 50 in$350 No 332Zephyr AC Sinaf 2-channel glider hand-launch tow thermal slope soaring6200 No 386Laaer 200 AC Sport Scale replica champineship Aerehafic tiler Uses 40 power 4-5 channel Two sheets$1075 No 4471/2A Miwa America AC Old-Tuner WA Texaco model 049 glow 2-channels$650 No 4604-40 AC Shoelder-wiog sport filer 4-cycle 40-nine engine 4 channelo$650 No 465Blue Max II AC Fun-fly sportster 40-size engines spans 52 Lightweight stonctere$700 No 533Cewana C-37 AC Schoolyard Scale ni tamoos 3& plane 009/10 power 2-ch opans 42Va in6500 No 539Slmitar Slow4dotlon 15 AC Tailless flying wing 15 engines spans 98 ones 3-ch AC$350 No 569Elactroatreak AC Electric aembatic plane spans 44 ones 05 motorS550 No 572TR-260 AC Sport Scale Aerohalic plane 4-strulre 65/66 power spans 66 in61100 No 576Serendlpityt ndoor 025 record-holder spans 17/ in$325 No 578Scinwelzer 1-26B AC Quarter-ucale Sailplane spans 125 Two plan sheets61475 No 581Gee Bee Moefel Y AC Golden Age Racer spans 72 1A scale 60 power Thwe plus sheets61175 No 586Snapdragon AC Fun-fly/sponster 25/30 engines spans 45 In6698 No 588Marlah AC Slope-Soaring Sailplane spans 41 uses 2 AC channels6425 No593Taytorcralt AC Sport Scale llghtplane builds us standard 2-placer clipped-wing air show stenter Spans either 70 50 35/40 two-stmfre 45/48 four-ntmhe engine Two plan sheets no dncomentatmn$1000 No586Coronet 150 RC-Assint Old-liner enlarged 15914k spans 72 uses 40-size 4-sImlreI 30-size 2-tube6850 No601NIcicel AC Sportster WA engine 3 AC channels Spans 44 in$500 No 603Sparrow Hawk P30 FF Competitfon rebber-power plane woo 87 Nuts Spans 30 in$225 No607Curtlaw Seegull AC Glout Scale biplane spant 50 uses Oeadra/Zeuoah power Three plan sheets dec62498 No mTapeewing AC WA Pylon Racer spans 29 Plan plan use ports template about$698 No 610Protobype AC Sport biplane spans 48 uses 45/2-cycle 85/4-cycle power$650 No 619KeIth RIder R4 FF Scale Goldan Age racer rebber power spans 18 in6300 No 620GImlet 60 AC Spert/Pattem plate spans 60 iii 45/50 enguw 2 sheets61100 No 623Henderwom Longater AC Quarter-Scale 1933 fhwer spans 90h 4-strube 45/46 engine 3 plan sht no dec$1698 No624KelaIrer Laric AC Quarter-scale hontehuit spans 69 69198 4-Otmlre power 2 plait sheets dec61100 No 626Sweepee AC Spoil/Pattem canards foiward-sweyl wing spans 64 uses 48 power 2 plan sheets61300 No628Prime Cut AC SportlAerotsatic plane spuss 90 uses Quadra 35/40-sine power Two plus sheets61300 No 630OrIginal Ply Baby AC Old-Thiter spans 72 uses 19125 2-cycle 484-cycle power 2 plan sheets61150 No 635The Gambler FF Indoor Sestoeran rebber-power cable plane spans 15% in6200 No 836Keytwo AC Tn-geared low-wing sportsler 29125 power spans 44 in$575 No637A6 Shrike FF Compefitine plane AMA Clauses 5 15/23 power spans 60 in$675 No 638Owl Racer CL WA Scale Racer 049 power spans 20 6225 No 839SIcyvoIt AC Tn-geared Electric aerubatic sportoter 05/15 power spans 50 in6850 No 640Bird Prey CL AMA Fast Combat plane 36 power spans 5334 in$550 No 641UI Ole Reliable AC Old-tinter spoil filer spans 50% WA engines$575 No 642BIpe 89 CL Partlat plus updates deflofis 48 nersbon 3Scc power Spans 2234 in6225 No643Noctule IIB FF Baflulte flying wing CO2 power spoon 30 in$325 No 644Beliance ColumbIa AC Schoolyard Scale 2 AC channels WA engine Wingspan 46 m$575 No 645Lalrd Solution Cl Ponfile Scale biplane spans 36 25/35 pewer6575 No 646WInter Hawk FF Robber-power Coupe dHleer cempefiflon plane spans 47 in6375 No647Cox Speeded CL Semincale biplane WA enne spans 24 in6300 No646Cufllwa OC-2 FF Sculls Outdoor Gas Ftying Scale biplane uses electric power spans 24 HiLine lohnr-6 motor$325 No640Thlngemabob AC/CL Mutfimede trainer 25 gas 05 electric power spans 51 in$475 No 65047/66 RC Special AC Aembafic sport plane 48 power spans 61 3 plan sheetsS1075 No 651Conwortlum AC Husri-Lanoch HI-Start Coder spans 60 in6050 No652Oar Ptedenmaeea AC Lute-wing spoil plane 29125 power npons 55 -$675 No 663Aventl CL Profile Sport Scale canard hisliner twin DOgs spans 38 in$575 No 654Tamiecag AC Trainer/spottster styled Ibe F14 spaus 66 45/61 power Four plan sheets$1525 No 6S5Aetroalar FF AMA Class A/B Gas plane spans 67 uses 3 25/350cc power$800 No 856XP13C CL Profile 15 Carrier plane spans 277A in6550 No657Super Squire AC Trainer 35/48 2-stonbe 53 4-strobe power spans 9834 in6750 No 658SIturiken Streak CL Trainer uses 2-line Moonline control spans 17 WA power$225 No659Boom Box FF Walefleld Rubber competitine plane spans 54 in6400 No 660Volkaplene AC Electric-powered sportster 05 motor spans S6 2 plan shts6925 No661Embey-Omatlc FF Embryo Enderance mbber-power plane spans 20 in6200 No662Boxklte CL Scale antique caned pusher biplane spans 42 2 plan shtsS1100 0 Os 0 o C%J 0 gC Co tous Q 0 05 no 6E 050 o - Co FJ t- tog5 0 C 0 - 0 - ID 05 005 0 c us n 00 0 00 us Co-s 0 0 E-d 00 cs 0 2 0 I U0 E N STREET 0CITY - Circle numbers plans wish order best handling please include re quests payment some other service withyourplans order 193262310314326332386447 460465533539569572576578 581586588593598601603607 609610619620623624626628 630635636637638639640641 642643644645646647648649 650651652653654655656657 658659660661662663664665 Plan price includes first class postage US delivery Air Mail over 300 miles orders non-US address lease add $258 Air Mail osta e handlin Ian Make Check money order payable US funds drawn US bank Model Aviation AMA 1810 Samuel Morse Reston VA 22090 Please allow 3 6 weeks delivery Please print CarefullyEnclosed $ _______________________ ___________________________________________ AMA No _______________ airplanes can practical pleasurable fly may also mean ultimate dura tion cross-country RC Sailplane now large flat-wing variable-camber aileroncontrolled configuration instead sim pler fixed-camber rudder elevator ar rangement caution have course tried sys tem 100% sensitivity setting plane does interesting 1-Hz flat yaw oscil lation about plus minus 15 degrees ascribe adverse yaw coupling gyro model remained flyable no harm done might want come up optimum setting instead starting working way down Summary conclusions Spiral stability measure tendency airplane spiral straight circling flight Its primarily function Equiv alent Dihedral Angle EDA tail boom-towingspan ratio lIb wing lift coeffi cient C1 significant secondary variable yaw stability plane function fuselage proportions ver tical stabilizer size Airplanes strong yaw stability spirally stable EDA X lw/b C1 greater equal about 57 Air planes modest yaw stability will sta ble somewhat lower values relation ship illustrated Figures 3 4 An experimental procedure de scribed determining degree spiral stability RC Sailplanes test TwoMeter Sailplane showed good agreement theory control dihedral angle tail boom proportion lift coefficient primary means achieving spiral stability other methods can used Free Flight mod els typically incorporate asymmetrical trim balance arrangement effec tive oaly circle direction mechanical means well successful has tested article incor porates yaw rate gyro drive aile rons As practical inexpensive way provide spiral stability aileron-con trolled Sailplanes exciting devel opment Next month Part Two will describe effect circling flight spiral stability pitch trim yaw angle Southwest PC Flying Year round flight school Five day course $350 Learn fLy planes Send SASE conlete info 2818 CaroLina NE Albuquerque NM 87110 505 881-3799 196 Model Aviation IMPORTED DIESELS A-MAuroraDCEDMVVSMBia*nya PAWTaplln Standard R/C.0864S Acre & MarIne VlntegeAperg Comfiest Seed $100 Informatlo CARLSON ENGINE IMPORTS 314 East Marcomi Phoenix AZ 85022 _________________________________________ ZIP _______________________________