Spoilers (With Power!?)

With spoilers fuiiy deployed flyby cruise speed Krackerjac requires 1/3 up-elevator maintain constant altitude YOUR SENIOR FALCON downwind leg landing pattern go half-throttle cruise turn onto crosswind leg onto final arrive almost over fence 75-ft altitude still cruise power Can get onto short landing strip Yesif have spoil ers Can abort spoilers out Easily Can land anywhere no matter high far out ease time theoretical article Answers won trenches un adorned report problem seemingly quickly answered turned intriguing adventure kept opening fascinating Lightly-loaded RC planes great relaxed fun fly ing can landing prob lem refuse stop flying engine idling Bills solution use spoilers powered planes increases overall drag also effective wing loading Tests showed amazingly pilotfriendly U Bill Winter doors subject aircraft has flown fre quently over two seasons perhaps dozen qualified pilots asked critical constructive suggestions led refinements effective flying tech mques obvious questions will asked beginning spoilers flaps Answers evolved throughout text problem occurred enlarged 1963 Max 15-powered Krackerjac few seconds after picture left taken Steve opened spoilers half way some elevatorcompensation aligned plane parallel ground held attitude until touching down spotaboutin line antenna position 60 Model Aviation Using overkill spoilers early tests Steve Kaluf executes full-spoiler descent several hundred feet upwlthoutcom pensating elevator control As shot taken just closed spoilers rounded out nose slightly high Dive speed visibly far less normal dive acceleration dive took place thisside ofthefarsoccergoalunderelbow published American Modeler Jetco kit short-coupled 54-in-span cabin model semi-symmetrical air foil forward spar flat-bottomed aftlike new Goldberg designs took 6-ft 2-ni span 1 3-in chord K&B 40 scale up dimensions double whereas wing area increases square So ended up 69 sq ft wing 7-lb 6-oz plane resulting wing loading approximately 17 oz per sq ft problem light loading size plane high L/D approaches Wing loading comparisons accurate identical areas involved size variations have dis tortion wide-angle lens Scale Effect Reynolds Number thing facts life nevertheless lets just go simple things agree upon Little air planes flit bigger plane better flies No pundit has drawn curve spots comparable wing loadings against variations area direct observa tion 17-oz loading compares about 15 Falcon 56 35 10-ft Quarter Scale ship small plane might barely take off overkill power -scale-figure load ing would vicious snapper Youll need fill-in have perceptual problems Eaglet virtually automatic close-in approaches possible small planes far out base legs its small size demands intense concentra tion big Krackeijac easy see long finals novices prob lem accurately relating altitude dis tance clear obstacles small field Bigger better sense Although ship did float bob simply did sink fast enough Unless held precariously nose-high sink overshot everything like Sailplane its first fast taxi run came off ground Wthrottle maintained fast rate suitable angle climb test pilot required four approach attempts first flight small field its sixth test flight noted buoyancy downwind leg broke 360 near idle soared monstrous altitude site being visited 560-ft grass runway Cutting idle bone approach accidentally cut power shutoff trim still ran far-end weeds Obvi ously flaps necessary So spoil ersand power mode first spoilers considered flaps would require major rework wing mechanisms quick-fix spoiler modification grew tempting fun chal lenge reason believe spoilers could employed throughout power range merely precise control sink approaches Incidentally test plane does concentric outsides inverts nicely During 195 Os spent five years Norm Rosenstock pursuit RC duration record early escape ment versions automatic on-board rewind ability all-day capability SPOILER DIMENSIONS RELATIVE TO WING 8 RELATIVE TO FIG2 TEST MODIFICATION FIG II 7I VERTICAL 0UBLE WEB JNDER THE LG OUTER TUBE ] /32 SPOiLER HORN [Z SPOILER OPEN AUXILIARY SF ADDED LEADING -EDGE NG / / / INNER TUBING THESE PORTIONS OF TUBING ATTACH TO FRAME AILER SPOILER T E STIFFENER ON BOTTOM TO AVOID F IA7Xp0 E LOC HMIRROR ~I/I6 PLY = 1111L HOLE INRIE Ii "RIB 3/32x I-I/B RIB POSITION -HOLE IN WING BOTTOM TOP SPANWISE BOT-rOM AT 45POSITIONABLE SERVO PRIOR LOCATED AIL- SERVO HAD TO BE I8x 3/8 SPOILER PLATFORM WORKED AROUND SPOILER T E HORN BRACE FIG 2 February 1986 61 NOTE BROKEN LINES SHOWOPENING SPOILER THAT AUTHOR ISj USING IT AVOIDS ANY SPECIAL TECHNIQUES AND IS TOTALLY3QO TO 45 SAFE FOR INEXPERIENCEDIOPEN FLIERS 7-1/4 SPAN SEMI-SPAN OF 6 WING EVERSING NG ON PORT T WOULD NEED TED HERE AAGE SERVO MOUNT HORN AT 1/2 SPOILER SPAN ---4 AAAJA/A/vv\AAr ARRANGE FLEX PUSHROD TO SUIT TOP VIEW RANDOM PROJECTION vvVJyVvAsVVA~ 30 MAX 150ATTACH POINTS TOP 8 50BOTTOM FOR FLEX RODS ONE TO EACH SPOILER USE LL LINKS OR SERVO SECTION ON\HORN AFT CENTER LINEOF SPARAILERON SERVO AFT SUGGESTED SPOILER RANGE EVOLVED FROM TESTS ON FIG 2 BUT USING ONE CENTER SECTION SERVO TYPICAL FLAT BOTTOM SPOILER HINGE LINE IS AT PRECISE HIGHPOINT OF AIRFOIL FIG 3 things like dirt filter always conspired around 2 hours dash hopes early escapement versions employed spoilers altitude control power no throttle being available Fuel 09 15 diesels 6 7-ft spans respectively 32 82 liquid ounces normal K&B 35 burned 3 oz un doctored K&B 100 per hour cruis ing Incidentally 1 1-lb-gross sevenfooter will thermal discovered 1 x ler hinged its leading edge produced mid-flap-like moderate descent steady smooth-responding like airliner Cmal no tip-stall tendency Virtually no force required open 900 close spoilers single strand loop -in rubber running half-span SN escapement center section sufficient vac uum would suck spoiler up bang extended drag pounded shut equal authority retracted tried same spoiler/area combo Veco 19 Gramps rudder-only ship MAN spoilers shown produced two angles climbsteep steeper full bore steeper descent glide Popped out will during appmach spoilers extremely effective accurate landings Let Original wide-chord spoilers shown closed Krackerjacs 74-inspan 3in-chord wing Transparent covering showsthe quickfix installation two Ace Bantam servos mounted ribs ideai setup wouid centerilne servo appropriate iinkage Spoiier travei iimits centering set crudetesting arrangement viatheAce Siiver7 Tx Right Spoiiersopen position No1 Fig 2 ianding becomes matter increasing approach angie lose altitude using eievator normai until touching down Left original wide spoilers position No 2 Fig 2 pictured aborts go-rounds smooth solid opened position No3 plane could atlil abort up point landing commitment though requiring considerable power Right wide-chord spoilers opened fully position No 5 plane couid barely maintain altitude full power heavy up-elevator handful experienced pilot Furthertests proved though ships recoverywas smooth quick upon spoiler retraction 62 Model Aviation Significantly retracting spoilers did cause ballooningsink rate just returned normal spoilers forgotten like flaps too Senior Telemaster often see cracked flaps make pussycat approaches full flap planes may pitch up power added stay level rare pitch downrequiring corrective elevator depending high- low- midwing configurations have seen guys pour coal full flaps Telemaster surprise 1O-ft-dia loops right off ground roughly h-down flaps can generate additional lift drag slowing down slow up nicely l down still building gobs liftand full-down late final add great air braking Flaps great properly flown Spoilers never add lift kill lift over much greater portion wing spoilers span itself Provided spoilers too large degrees exposure easily trim-compensated appropriate back-stick degree back-stick after throttling back approach produces spectrum sink rates flight paths direct spot full spoiler no elevator compensation dive-like attitude airspeed build-up far less anticipated suggesting presence high amount drag reduction lift produces lower L/D machine spoilers have own braking drag first visualized number fixed spoiler positions used flap channel Silver 7 select progressive degrees exposure see Fig 2 Five open posi tions available Fig 2 also details two-servo fix already-completed Krackeijac Actually standard servo should located centerline during construction type mechanism cables torque rods pushrods bellcranks would suitable quick fix adjust ments possible outside al though bottom hatches wing could arranged depended end-throw centering adjustments transmit ter eliminate occasional servo buzzing shut position eventual result spoiler size movement Fig 1 Variable proportional positions could maintained simple open shut quite satisfactory See sidebar Doug Pratt continued field testing another two seasons finalized best spoiler size angle open decided make some tests larger full-open spoilers produced steep dive idle tuck-under full elevator could recover dive allowed developrequiring spoiler retraction Minimum-open position moderately increased sink rate landing approach minimum-open came shorter positive abili ty land take off climb out goround using power elevator spoiler retraction several intermedi ate positions surely would found perfectand another would help ful quick altitude dissipation February 1986 63 uj I11uu u reduced 1 Subse tortms early trial-and-error experiment quently Doug Pratt isolated 30 open old 1 x 4 spoiler 1 950s plane best maximum spoiler chord increased Fig 1 7 x 1 reduced ize two remember almost 1000 squares wing positions open shut can think area theoretical ideal terms sink low- high-rate known excessive wing final arrangement soon found since normally Obviously spoilers applicable using Positions 1 2 spoiler aircraft light loadings low sink Left Bottom view two-servo spoiler setup aileron servo Atlas differential obvious too-slim pushrods length quickly beefed up telescoping tubing Wing key dowel added rubberband hold-downs tight loops lifted front wing Right After reducing spoilers 71/4 xl Bill turned Krackerjac over Doug Pratt forfield testing Spoilers now set open position No 4 Fig 2 Using spoilers just open shut made short landings flyby altitudes virtually automatic overshooting team up ex tremely useful high sink rate fast landings characterize aircraft flaps appropriate because lift can produce Flight tests First flights big spoilers Don Srull NVRC site 275-ft strip later series flown Steve Kaluf Fredericksburg VA 560-ft strip unlimited approaches third series AMAs Doug Pratt two sites Both Don Steve flew overlarge spoilers somewhat re duced spoiler chord span before Doug got fly Don requested high simulated downwind legs successive runs requested him apply progressive spoiler positions power setting between high idle cruise use either up-trim elevator corrections would note degree pitch-down position would quickly recover power elevator retracting spoilers first-open setting produced shallow descent angle probably would have hit ground maintained within roughly 750 1000 feet additional increment open-spoiler produced steeper descent angles expected full-open pro ducing approximately 450 600 Recovery sustained flight easy two less-open positions full-open max power increasingly severe upelevator needed sustain level flight recovery Dons opinion sys tem effective would inclined use up-trim slightly prior opening spoilers Good approaches landings made first two open positions approach normal earlier touch-down first position power dragglng bit required second position Anything beyond would useful paying off altitude less speed build-up elevator alone would tricky near ground left Steve Kaluf another polished pilot own devices knew would handle anything let him surprised made no comments Fi nally asked him make hopelesslyhigh approach at200 ftjust isOft shortof runwayand use full-spoiler result spectacular steep ap proach being prolonged using elevator could recovered full-up Steve nonchalantly pulled spoilers rounded out touched down smoothly before ship abreast us seemed accept sink rate angle pull spoilers complete perfect power approaches two highly-skilled pilots felt out spoiler performance envelope within minutes settled tech niques within two flights real test would Continued page 150 Left Holding slight up-elevator spoilers closed normal landing ship slightly flares before touching down normal roll-out follow Right following flight photographer moved other side flight path landing done spoilers fully exposed note neutral elevators atthe end roil-out Landing touch-down took place just lOft left plane now sits 64 Model Aviation Close-up final spoiler shows hinge segments Sullivan inner/outer rods Origi nal spoilers extended back short false top spar Extremely long approaches above normal flight altitudes made Idle spoilers being popped out instead typical throttle corrections holding some steady back-stick Spoilers ideal clean-flying large craft Fast heavy modeisthataiready haves good sink ratewould generally benefit use flaps increase lift shorten landing approach have proven extremely durable high-rpm situations TP/TPM 4 exhaust duration should creased fully accommodate super charging effect TP/TPM prac tical limit about 1800 after engine becomes peaky very hard set Changing exhaust timing involves some skilled machine work best left true engine experts An easier method replace stock sleeve pipe-timed sleeve K&B 65 frontrotor engine has about 1500 exhaust duration Its performance TP/TPM can increased substituting sleeve F-i version 1600 exhaust duration Some K&B Formula fliers may have couple piston/sleeve assemblies no longer competitive F-l due loose fit ideal replacements 65 front-rotor ver sion operated 15% nitro TP/TPM unlimited Pylon Racing K&B has performance update package 75 ducted fan engine package includes special sleeve 1800 exhaust dura tion eyebrow porting update also dispenses Perry pump carburetor sometimes gives reliabil ity problems field use abuse Some combinations OPS OS ST engines may yield similar results substitution pipe-timed sleeve Check importer Included segment article drawing several TP/TPMs available MACS Products presented give reader general idea dimen sions weights selecting TP/ TPM particular application next installment will discuss some newer performance-added silencers such Magic Muffler Wizzard V-Tech mufflers See next month Bill Hager 706 Glen Haven Dr Conroe TX 77385 responding advertisers mention read about ModelAviation TARBabyITRANSMITTER CASE Especially Turn-around thisAn inexpensive rugged molded 850 sq 120 4 cyclecase protect thst expensive -rpowered Ron Chidgey designtransmitter both two stick smooth solid performersingle stick transmitters Brown Rib templates computerleather grain aluminum trim plotted Plans construc-and locking clasp -$1895 tion hints -$1195 WING TUBE & SOCKETSNEW WING MOUNTING SET Aluminum alloy tubing plug-in wing mounting system developed Ron Chidgey s Included pair fast neat accurate stays tight Three special slip-tit phenolic sockets nylon brackets screws snd machined wing blocks build wing structure included $695 Now a size models 718 dia 2 $ 895 1 dies 2-$ 995 1a diax3-$1495 GIGator RIC Products P3713 Pompano Dr See Dealer Order Direct Pensacola FL 32514 Phone AC 904 476-8639Include $150 Per Item UPS Spoilers/Winter Continued page 64 own moment truth Any accom plished aerobatics pilot can relate experiences good test pilots medium-level sport pilots like own capabilities safe altitude could engage spoiler positions Fig 2 including overkill full-open devisedjust test purposes landing pattern especially final approach simul taneously retract spoilers apply emer gency power take off up-trim later ignored trim depended stick use back-stick properly fly plane tense moment wind clearly too risky low altitude whenever exceeded two first-open positions could safely land go-round spoilers out positions first-open position fed downwind perfect Whereas plane spoilers hard get down wanted consistency problem vanished first-open spoil er position setting could stand throughout approach final though landings aborted landings go-rounds touch-and-go After hoped very high approaches second-open position caused ship sink rapidly enough attain proper altitude point spoiler positions shown Fig 2 subsequent modified positionsrec ommendedare shown Fig 3 Establishing spoiler position well back downwind leg easy changing spoiler position later landing pattern was too easy get say position No 3 rather No2 Thats smaller final spoilers operate open shut proper technique re quires smooth elevator compensation pitch-down larger openings greater sink acquired al lowing dive develop maximum spoiler openings proved dif ficult first oversized spoilers too much think about late final dexterous pilot multi posi tions available may desirable 150 Model Aviation 049 Engines Suitable 2-4 classic its kind An agile odel really performs excellent piantorm durable and enloyable ship fly RIG contest enents Wean gal avirale line aid favorites Kit #116W Please send snn tar nor Flyline caraton $2995 Phane 7031 2139593Onalers Olstribalars malted FLYLINE MODELS INC PO Box 2136 Fairfax VirgInia 22031 conclusion would better off using retract channel spoiler size exposure used Doug Pratt Merely flipping retract switch open closed cinch what first second position multiposition flap control desirable proper amount open-spoiler would first have established use retract switch could play easily bumping off will like full-size sailplane its final using much elevator trim fore applying larger first-test spoilers bothersome Slight up-trim safe approach full up-trim Fig 2 setup Krackerjac behaved strange manner plane seemed hanging sinking same timea crazy sight surprised plane landed re sounding whomp accidentally bumped spoiler lever could have happened using isolated retract switch Strong open-spoiler positions using elevators retracted cor rect landing approach height attained fine plots like young Kaluf dont have mental lapses sluggish reac tions new different situations Used correctly correct spoiler size power useful tool so-so pilots plane revolts against short approaches dont think would use Kadet just possibly Falcon 56 34 x 4 in case WANNA RACE N RTH AST AREA LNJ BEGINNER RACES 0-500 * FORM-i Instructions b Programs Information Contact NORTH EAST PYLON RACING ORGANIZATION 119 DEAN AVE FRANKLIN MASS 02038 Tel 617 528 4043 203 673 -2000 Deluxe Kit coming January details other Zimbabwe Model Products kits call write Full color deluxe catalog -$100 f/- ZIMPRO MARKETING PO BOX 3076 OAK RIDGE TENNESSEE 37830 Tel 615 482-6188 clean light probably Senior Falcon 1 x 5 6 guess has considerable area low wing loading Probably measure whether spoil ers will benefit cleanness weight machine foot altitude lost equates large num ber feet over ground would use r Johnnie Casburn s Super Lucky Fly H Super Lucky Fly II 45 65 List 995Special. 59495 Little Super Lucky Fly II 35 45 LIST. $11995SPECIAL 95 Prices Subject Change Without Notice L smaller spoilers and/or small-open posi tions smaller ships close normal loadings large spoilers large bigger planes having lightness cleanness results persistance fly dont want 34 x 4-in spoiler opened 600 would ideal 6-ft Old-Timer both low power glide planes such spoiler would ideal limiting climb rate strong thermals resorting escape maneuvers could hang go soaring opening closing spoilers will months have passed since foregoing written Doug Pratt has old model now powered Enya 46 four-stroke has briefed technique Approaches like shooting ducks rain barrel strange indeed come cruising up almost fence ridiculously high sink short landing As far landings concerned spoilers make perfect STOL high up distance Ready-Built fuselage Pre-finished wing ready join Wing covered 1/64 plywood Easy build Easy fly Excellent Plans Lots Hardware Accessories Jahnnie Casburn Manufacturing Co 5715-SE E Rosadale Fort Worth TX 76112 Day 817/451-7537 t 817/572-145 February 1 986151 1985 USA National Champion Ivan Kristensen An enlarged telephoto shot hence fuzziness Krackerjacs landing attitude full spoilers about 113 up-elevator Touch-down occurred right after snapshot sink rate about same forward speedgentle impact never stressing gear Spoilers turned plane wanted glide forever great short-field performance drawbacks flaps photos Tom Schmitt author FOR SERIOUS MODELERS ONLY New PistonlRod Reset Tool * & Piston Holder Set Now can easily extend life Cox 020 049/051 09 engine Whether youre free-flight control-line 1/2-A pylon racing time ball-socket area piston can become too loose continued high RPM output new tool Cox Hobbies piston/rod reset tool set designed support piston no chance damage crucial piston crown area properly re-set ball socket will insure continued top performance winning ston/cylinder combination case hardened CL Scale/Boss Continued page 66 cut what follows should taken official interpretation current rules rather own view light questions asked Official interpretations and/or approval rules sole responsibility AMA Scale Contest Board answer first question far could determine Yes Bauer did receive multi-engine points model described CL FAI Scale rules case multi-engine option scored 0-10 points multiplied coef ficient K factor seven total option score next two questions somewhat related discussed such review CL Scale rules indicates no specific wording prohibit use different types power plants same model However am sure intent rules elec tric power added allow different forms power mixed same model suspect intent model should powered type engine/motor Scale Board time did anticipate possible problems mixing power types use straight electric power presents possible problem Precision event awarding Engine Starting bonus points posed third question above award bonus 10 points starting within minute no need toflip some models propellers electric motors used operating switch start electric motors equivalent flip ping propellers answer last two questions multi-engine models pretty clear according rules no men tion contestants need prove engines support models perfor mance nor model equipped two engines eligible 20 points under multi-engine option thoughts received multiengine option model ly additional engine received 20 points didnt model like B-36 six engines receive 100 points five additional engines quick look Scale rule 52A8 shows six 20-point options including multi-engines allowed total 120 points dicating multi-engine option cannot interpreted being worth 20 pointsregardless number engines used However idea extra points beyond 20 models two engines does have merit such rule incorporated rules might possibly encourage model ers build complex models last area concern question asks jet model piston engine its nose propeller-driven bona fide entry Scale events believe best way look ques tion consider model entry AMA Scale events nothing could find Sport Scale rules would prohibit model being entered However would imagine some downgrading model during static flight judging would order because built performing prototype Precision Scale event however quite different model might kept entry basis Unified Scale Judging Regulation 50&a effect disallows addition pro peller wasnt during static judging might other hand consider entry propeller pkce instance Im sure penalty 152 Model Aviation model will hit spot straight-in line literally anywhere Just go high idle hold altitude some back stick until final flare play spoilers out open shut instead using throttle gives stair step approach heavens accurate easy can skim weeds runways entry settle oh-so-softly Quite conversation piece FIBERGLASS COWLS 70 cowls eelpants Sig Pica Top-Flite Jemco Nosen Pilot Stafford Radlals Behrens Garmhausen W E Tech other kits plans fine-piece laminated construction handlaid fiberglass strong lightweight Send SASE price list please include names models interested parts call between 9AM9 PM EDT informal ion COD ordering hope hear 703 890-6017 bpt MA es eo 530 Goodiew VA 24095 HOBBY HAMMER *995 APPROXLENGTH7/ExtraTip INCLUDES$125 ONE STEEL AND ONE BRASS TIP Send Check Money Order M&WMODELS PO Box 6627 Huntington Beach CA 92615 Add 150 Post & Hand CA Res add 6% tea Modelers Choice GMP EPOXIES High Quality Model Construction Jr Kwik Set 6 Minute5 oz $ 595 Kwik Set 6 Minute10 oz *996 Giant Kwik Set 6 Minute16 oz $1395 Half FastlOMinutelOoz$ 895 GMP AIRCRAFT INSTRUMENTS 80in31161/4318112$ 149 40 3/4 inch $ 149 EASY OFF PULLER proper tool removing drive waaher%and flywheels * 795 Gas Model Products 8773 Russet Dr Cincinnati OH 45239 513 385-7398 motel veer deal eider died Peet Heed edd $130

With spoilers fuiiy deployed flyby cruise speed Krackerjac requires 1/3 up-elevator maintain constant altitude YOUR SENIOR FALCON downwind leg landing pattern go half-throttle cruise turn onto crosswind leg onto final arrive almost over fence 75-ft altitude still cruise power Can get onto short landing strip Yesif have spoil ers Can abort spoilers out Easily Can land anywhere no matter high far out ease time theoretical article Answers won trenches un adorned report problem seemingly quickly answered turned intriguing adventure kept opening fascinating Lightly-loaded RC planes great relaxed fun fly ing can landing prob lem refuse stop flying engine idling Bills solution use spoilers powered planes increases overall drag also effective wing loading Tests showed amazingly pilotfriendly U Bill Winter doors subject aircraft has flown fre quently over two seasons perhaps dozen qualified pilots asked critical constructive suggestions led refinements effective flying tech mques obvious questions will asked beginning spoilers flaps Answers evolved throughout text problem occurred enlarged 1963 Max 15-powered Krackerjac few seconds after picture left taken Steve opened spoilers half way some elevatorcompensation aligned plane parallel ground held attitude until touching down spotaboutin line antenna position 60 Model Aviation Using overkill spoilers early tests Steve Kaluf executes full-spoiler descent several hundred feet upwlthoutcom pensating elevator control As shot taken just closed spoilers rounded out nose slightly high Dive speed visibly far less normal dive acceleration dive took place thisside ofthefarsoccergoalunderelbow published American Modeler Jetco kit short-coupled 54-in-span cabin model semi-symmetrical air foil forward spar flat-bottomed aftlike new Goldberg designs took 6-ft 2-ni span 1 3-in chord K&B 40 scale up dimensions double whereas wing area increases square So ended up 69 sq ft wing 7-lb 6-oz plane resulting wing loading approximately 17 oz per sq ft problem light loading size plane high L/D approaches Wing loading comparisons accurate identical areas involved size variations have dis tortion wide-angle lens Scale Effect Reynolds Number thing facts life nevertheless lets just go simple things agree upon Little air planes flit bigger plane better flies No pundit has drawn curve spots comparable wing loadings against variations area direct observa tion 17-oz loading compares about 15 Falcon 56 35 10-ft Quarter Scale ship small plane might barely take off overkill power -scale-figure load ing would vicious snapper Youll need fill-in have perceptual problems Eaglet virtually automatic close-in approaches possible small planes far out base legs its small size demands intense concentra tion big Krackeijac easy see long finals novices prob lem accurately relating altitude dis tance clear obstacles small field Bigger better sense Although ship did float bob simply did sink fast enough Unless held precariously nose-high sink overshot everything like Sailplane its first fast taxi run came off ground Wthrottle maintained fast rate suitable angle climb test pilot required four approach attempts first flight small field its sixth test flight noted buoyancy downwind leg broke 360 near idle soared monstrous altitude site being visited 560-ft grass runway Cutting idle bone approach accidentally cut power shutoff trim still ran far-end weeds Obvi ously flaps necessary So spoil ersand power mode first spoilers considered flaps would require major rework wing mechanisms quick-fix spoiler modification grew tempting fun chal lenge reason believe spoilers could employed throughout power range merely precise control sink approaches Incidentally test plane does concentric outsides inverts nicely During 195 Os spent five years Norm Rosenstock pursuit RC duration record early escape ment versions automatic on-board rewind ability all-day capability SPOILER DIMENSIONS RELATIVE TO WING 8 RELATIVE TO FIG2 TEST MODIFICATION FIG II 7I VERTICAL 0UBLE WEB JNDER THE LG OUTER TUBE ] /32 SPOiLER HORN [Z SPOILER OPEN AUXILIARY SF ADDED LEADING -EDGE NG / / / INNER TUBING THESE PORTIONS OF TUBING ATTACH TO FRAME AILER SPOILER T E STIFFENER ON BOTTOM TO AVOID F IA7Xp0 E LOC HMIRROR ~I/I6 PLY = 1111L HOLE INRIE Ii "RIB 3/32x I-I/B RIB POSITION -HOLE IN WING BOTTOM TOP SPANWISE BOT-rOM AT 45POSITIONABLE SERVO PRIOR LOCATED AIL- SERVO HAD TO BE I8x 3/8 SPOILER PLATFORM WORKED AROUND SPOILER T E HORN BRACE FIG 2 February 1986 61 NOTE BROKEN LINES SHOWOPENING SPOILER THAT AUTHOR ISj USING IT AVOIDS ANY SPECIAL TECHNIQUES AND IS TOTALLY3QO TO 45 SAFE FOR INEXPERIENCEDIOPEN FLIERS 7-1/4 SPAN SEMI-SPAN OF 6 WING EVERSING NG ON PORT T WOULD NEED TED HERE AAGE SERVO MOUNT HORN AT 1/2 SPOILER SPAN ---4 AAAJA/A/vv\AAr ARRANGE FLEX PUSHROD TO SUIT TOP VIEW RANDOM PROJECTION vvVJyVvAsVVA~ 30 MAX 150ATTACH POINTS TOP 8 50BOTTOM FOR FLEX RODS ONE TO EACH SPOILER USE LL LINKS OR SERVO SECTION ON\HORN AFT CENTER LINEOF SPARAILERON SERVO AFT SUGGESTED SPOILER RANGE EVOLVED FROM TESTS ON FIG 2 BUT USING ONE CENTER SECTION SERVO TYPICAL FLAT BOTTOM SPOILER HINGE LINE IS AT PRECISE HIGHPOINT OF AIRFOIL FIG 3 things like dirt filter always conspired around 2 hours dash hopes early escapement versions employed spoilers altitude control power no throttle being available Fuel 09 15 diesels 6 7-ft spans respectively 32 82 liquid ounces normal K&B 35 burned 3 oz un doctored K&B 100 per hour cruis ing Incidentally 1 1-lb-gross sevenfooter will thermal discovered 1 x ler hinged its leading edge produced mid-flap-like moderate descent steady smooth-responding like airliner Cmal no tip-stall tendency Virtually no force required open 900 close spoilers single strand loop -in rubber running half-span SN escapement center section sufficient vac uum would suck spoiler up bang extended drag pounded shut equal authority retracted tried same spoiler/area combo Veco 19 Gramps rudder-only ship MAN spoilers shown produced two angles climbsteep steeper full bore steeper descent glide Popped out will during appmach spoilers extremely effective accurate landings Let Original wide-chord spoilers shown closed Krackerjacs 74-inspan 3in-chord wing Transparent covering showsthe quickfix installation two Ace Bantam servos mounted ribs ideai setup wouid centerilne servo appropriate iinkage Spoiier travei iimits centering set crudetesting arrangement viatheAce Siiver7 Tx Right Spoiiersopen position No1 Fig 2 ianding becomes matter increasing approach angie lose altitude using eievator normai until touching down Left original wide spoilers position No 2 Fig 2 pictured aborts go-rounds smooth solid opened position No3 plane could atlil abort up point landing commitment though requiring considerable power Right wide-chord spoilers opened fully position No 5 plane couid barely maintain altitude full power heavy up-elevator handful experienced pilot Furthertests proved though ships recoverywas smooth quick upon spoiler retraction 62 Model Aviation Significantly retracting spoilers did cause ballooningsink rate just returned normal spoilers forgotten like flaps too Senior Telemaster often see cracked flaps make pussycat approaches full flap planes may pitch up power added stay level rare pitch downrequiring corrective elevator depending high- low- midwing configurations have seen guys pour coal full flaps Telemaster surprise 1O-ft-dia loops right off ground roughly h-down flaps can generate additional lift drag slowing down slow up nicely l down still building gobs liftand full-down late final add great air braking Flaps great properly flown Spoilers never add lift kill lift over much greater portion wing spoilers span itself Provided spoilers too large degrees exposure easily trim-compensated appropriate back-stick degree back-stick after throttling back approach produces spectrum sink rates flight paths direct spot full spoiler no elevator compensation dive-like attitude airspeed build-up far less anticipated suggesting presence high amount drag reduction lift produces lower L/D machine spoilers have own braking drag first visualized number fixed spoiler positions used flap channel Silver 7 select progressive degrees exposure see Fig 2 Five open posi tions available Fig 2 also details two-servo fix already-completed Krackeijac Actually standard servo should located centerline during construction type mechanism cables torque rods pushrods bellcranks would suitable quick fix adjust ments possible outside al though bottom hatches wing could arranged depended end-throw centering adjustments transmit ter eliminate occasional servo buzzing shut position eventual result spoiler size movement Fig 1 Variable proportional positions could maintained simple open shut quite satisfactory See sidebar Doug Pratt continued field testing another two seasons finalized best spoiler size angle open decided make some tests larger full-open spoilers produced steep dive idle tuck-under full elevator could recover dive allowed developrequiring spoiler retraction Minimum-open position moderately increased sink rate landing approach minimum-open came shorter positive abili ty land take off climb out goround using power elevator spoiler retraction several intermedi ate positions surely would found perfectand another would help ful quick altitude dissipation February 1986 63 uj I11uu u reduced 1 Subse tortms early trial-and-error experiment quently Doug Pratt isolated 30 open old 1 x 4 spoiler 1 950s plane best maximum spoiler chord increased Fig 1 7 x 1 reduced ize two remember almost 1000 squares wing positions open shut can think area theoretical ideal terms sink low- high-rate known excessive wing final arrangement soon found since normally Obviously spoilers applicable using Positions 1 2 spoiler aircraft light loadings low sink Left Bottom view two-servo spoiler setup aileron servo Atlas differential obvious too-slim pushrods length quickly beefed up telescoping tubing Wing key dowel added rubberband hold-downs tight loops lifted front wing Right After reducing spoilers 71/4 xl Bill turned Krackerjac over Doug Pratt forfield testing Spoilers now set open position No 4 Fig 2 Using spoilers just open shut made short landings flyby altitudes virtually automatic overshooting team up ex tremely useful high sink rate fast landings characterize aircraft flaps appropriate because lift can produce Flight tests First flights big spoilers Don Srull NVRC site 275-ft strip later series flown Steve Kaluf Fredericksburg VA 560-ft strip unlimited approaches third series AMAs Doug Pratt two sites Both Don Steve flew overlarge spoilers somewhat re duced spoiler chord span before Doug got fly Don requested high simulated downwind legs successive runs requested him apply progressive spoiler positions power setting between high idle cruise use either up-trim elevator corrections would note degree pitch-down position would quickly recover power elevator retracting spoilers first-open setting produced shallow descent angle probably would have hit ground maintained within roughly 750 1000 feet additional increment open-spoiler produced steeper descent angles expected full-open pro ducing approximately 450 600 Recovery sustained flight easy two less-open positions full-open max power increasingly severe upelevator needed sustain level flight recovery Dons opinion sys tem effective would inclined use up-trim slightly prior opening spoilers Good approaches landings made first two open positions approach normal earlier touch-down first position power dragglng bit required second position Anything beyond would useful paying off altitude less speed build-up elevator alone would tricky near ground left Steve Kaluf another polished pilot own devices knew would handle anything let him surprised made no comments Fi nally asked him make hopelesslyhigh approach at200 ftjust isOft shortof runwayand use full-spoiler result spectacular steep ap proach being prolonged using elevator could recovered full-up Steve nonchalantly pulled spoilers rounded out touched down smoothly before ship abreast us seemed accept sink rate angle pull spoilers complete perfect power approaches two highly-skilled pilots felt out spoiler performance envelope within minutes settled tech niques within two flights real test would Continued page 150 Left Holding slight up-elevator spoilers closed normal landing ship slightly flares before touching down normal roll-out follow Right following flight photographer moved other side flight path landing done spoilers fully exposed note neutral elevators atthe end roil-out Landing touch-down took place just lOft left plane now sits 64 Model Aviation Close-up final spoiler shows hinge segments Sullivan inner/outer rods Origi nal spoilers extended back short false top spar Extremely long approaches above normal flight altitudes made Idle spoilers being popped out instead typical throttle corrections holding some steady back-stick Spoilers ideal clean-flying large craft Fast heavy modeisthataiready haves good sink ratewould generally benefit use flaps increase lift shorten landing approach have proven extremely durable high-rpm situations TP/TPM 4 exhaust duration should creased fully accommodate super charging effect TP/TPM prac tical limit about 1800 after engine becomes peaky very hard set Changing exhaust timing involves some skilled machine work best left true engine experts An easier method replace stock sleeve pipe-timed sleeve K&B 65 frontrotor engine has about 1500 exhaust duration Its performance TP/TPM can increased substituting sleeve F-i version 1600 exhaust duration Some K&B Formula fliers may have couple piston/sleeve assemblies no longer competitive F-l due loose fit ideal replacements 65 front-rotor ver sion operated 15% nitro TP/TPM unlimited Pylon Racing K&B has performance update package 75 ducted fan engine package includes special sleeve 1800 exhaust dura tion eyebrow porting update also dispenses Perry pump carburetor sometimes gives reliabil ity problems field use abuse Some combinations OPS OS ST engines may yield similar results substitution pipe-timed sleeve Check importer Included segment article drawing several TP/TPMs available MACS Products presented give reader general idea dimen sions weights selecting TP/ TPM particular application next installment will discuss some newer performance-added silencers such Magic Muffler Wizzard V-Tech mufflers See next month Bill Hager 706 Glen Haven Dr Conroe TX 77385 responding advertisers mention read about ModelAviation TARBabyITRANSMITTER CASE Especially Turn-around thisAn inexpensive rugged molded 850 sq 120 4 cyclecase protect thst expensive -rpowered Ron Chidgey designtransmitter both two stick smooth solid performersingle stick transmitters Brown Rib templates computerleather grain aluminum trim plotted Plans construc-and locking clasp -$1895 tion hints -$1195 WING TUBE & SOCKETSNEW WING MOUNTING SET Aluminum alloy tubing plug-in wing mounting system developed Ron Chidgey s Included pair fast neat accurate stays tight Three special slip-tit phenolic sockets nylon brackets screws snd machined wing blocks build wing structure included $695 Now a size models 718 dia 2 $ 895 1 dies 2-$ 995 1a diax3-$1495 GIGator RIC Products P3713 Pompano Dr See Dealer Order Direct Pensacola FL 32514 Phone AC 904 476-8639Include $150 Per Item UPS Spoilers/Winter Continued page 64 own moment truth Any accom plished aerobatics pilot can relate experiences good test pilots medium-level sport pilots like own capabilities safe altitude could engage spoiler positions Fig 2 including overkill full-open devisedjust test purposes landing pattern especially final approach simul taneously retract spoilers apply emer gency power take off up-trim later ignored trim depended stick use back-stick properly fly plane tense moment wind clearly too risky low altitude whenever exceeded two first-open positions could safely land go-round spoilers out positions first-open position fed downwind perfect Whereas plane spoilers hard get down wanted consistency problem vanished first-open spoil er position setting could stand throughout approach final though landings aborted landings go-rounds touch-and-go After hoped very high approaches second-open position caused ship sink rapidly enough attain proper altitude point spoiler positions shown Fig 2 subsequent modified positionsrec ommendedare shown Fig 3 Establishing spoiler position well back downwind leg easy changing spoiler position later landing pattern was too easy get say position No 3 rather No2 Thats smaller final spoilers operate open shut proper technique re quires smooth elevator compensation pitch-down larger openings greater sink acquired al lowing dive develop maximum spoiler openings proved dif ficult first oversized spoilers too much think about late final dexterous pilot multi posi tions available may desirable 150 Model Aviation 049 Engines Suitable 2-4 classic its kind An agile odel really performs excellent piantorm durable and enloyable ship fly RIG contest enents Wean gal avirale line aid favorites Kit #116W Please send snn tar nor Flyline caraton $2995 Phane 7031 2139593Onalers Olstribalars malted FLYLINE MODELS INC PO Box 2136 Fairfax VirgInia 22031 conclusion would better off using retract channel spoiler size exposure used Doug Pratt Merely flipping retract switch open closed cinch what first second position multiposition flap control desirable proper amount open-spoiler would first have established use retract switch could play easily bumping off will like full-size sailplane its final using much elevator trim fore applying larger first-test spoilers bothersome Slight up-trim safe approach full up-trim Fig 2 setup Krackerjac behaved strange manner plane seemed hanging sinking same timea crazy sight surprised plane landed re sounding whomp accidentally bumped spoiler lever could have happened using isolated retract switch Strong open-spoiler positions using elevators retracted cor rect landing approach height attained fine plots like young Kaluf dont have mental lapses sluggish reac tions new different situations Used correctly correct spoiler size power useful tool so-so pilots plane revolts against short approaches dont think would use Kadet just possibly Falcon 56 34 x 4 in case WANNA RACE N RTH AST AREA LNJ BEGINNER RACES 0-500 * FORM-i Instructions b Programs Information Contact NORTH EAST PYLON RACING ORGANIZATION 119 DEAN AVE FRANKLIN MASS 02038 Tel 617 528 4043 203 673 -2000 Deluxe Kit coming January details other Zimbabwe Model Products kits call write Full color deluxe catalog -$100 f/- ZIMPRO MARKETING PO BOX 3076 OAK RIDGE TENNESSEE 37830 Tel 615 482-6188 clean light probably Senior Falcon 1 x 5 6 guess has considerable area low wing loading Probably measure whether spoil ers will benefit cleanness weight machine foot altitude lost equates large num ber feet over ground would use r Johnnie Casburn s Super Lucky Fly H Super Lucky Fly II 45 65 List 995Special. 59495 Little Super Lucky Fly II 35 45 LIST. $11995SPECIAL 95 Prices Subject Change Without Notice L smaller spoilers and/or small-open posi tions smaller ships close normal loadings large spoilers large bigger planes having lightness cleanness results persistance fly dont want 34 x 4-in spoiler opened 600 would ideal 6-ft Old-Timer both low power glide planes such spoiler would ideal limiting climb rate strong thermals resorting escape maneuvers could hang go soaring opening closing spoilers will months have passed since foregoing written Doug Pratt has old model now powered Enya 46 four-stroke has briefed technique Approaches like shooting ducks rain barrel strange indeed come cruising up almost fence ridiculously high sink short landing As far landings concerned spoilers make perfect STOL high up distance Ready-Built fuselage Pre-finished wing ready join Wing covered 1/64 plywood Easy build Easy fly Excellent Plans Lots Hardware Accessories Jahnnie Casburn Manufacturing Co 5715-SE E Rosadale Fort Worth TX 76112 Day 817/451-7537 t 817/572-145 February 1 986151 1985 USA National Champion Ivan Kristensen An enlarged telephoto shot hence fuzziness Krackerjacs landing attitude full spoilers about 113 up-elevator Touch-down occurred right after snapshot sink rate about same forward speedgentle impact never stressing gear Spoilers turned plane wanted glide forever great short-field performance drawbacks flaps photos Tom Schmitt author FOR SERIOUS MODELERS ONLY New PistonlRod Reset Tool * & Piston Holder Set Now can easily extend life Cox 020 049/051 09 engine Whether youre free-flight control-line 1/2-A pylon racing time ball-socket area piston can become too loose continued high RPM output new tool Cox Hobbies piston/rod reset tool set designed support piston no chance damage crucial piston crown area properly re-set ball socket will insure continued top performance winning ston/cylinder combination case hardened CL Scale/Boss Continued page 66 cut what follows should taken official interpretation current rules rather own view light questions asked Official interpretations and/or approval rules sole responsibility AMA Scale Contest Board answer first question far could determine Yes Bauer did receive multi-engine points model described CL FAI Scale rules case multi-engine option scored 0-10 points multiplied coef ficient K factor seven total option score next two questions somewhat related discussed such review CL Scale rules indicates no specific wording prohibit use different types power plants same model However am sure intent rules elec tric power added allow different forms power mixed same model suspect intent model should powered type engine/motor Scale Board time did anticipate possible problems mixing power types use straight electric power presents possible problem Precision event awarding Engine Starting bonus points posed third question above award bonus 10 points starting within minute no need toflip some models propellers electric motors used operating switch start electric motors equivalent flip ping propellers answer last two questions multi-engine models pretty clear according rules no men tion contestants need prove engines support models perfor mance nor model equipped two engines eligible 20 points under multi-engine option thoughts received multiengine option model ly additional engine received 20 points didnt model like B-36 six engines receive 100 points five additional engines quick look Scale rule 52A8 shows six 20-point options including multi-engines allowed total 120 points dicating multi-engine option cannot interpreted being worth 20 pointsregardless number engines used However idea extra points beyond 20 models two engines does have merit such rule incorporated rules might possibly encourage model ers build complex models last area concern question asks jet model piston engine its nose propeller-driven bona fide entry Scale events believe best way look ques tion consider model entry AMA Scale events nothing could find Sport Scale rules would prohibit model being entered However would imagine some downgrading model during static flight judging would order because built performing prototype Precision Scale event however quite different model might kept entry basis Unified Scale Judging Regulation 50&a effect disallows addition pro peller wasnt during static judging might other hand consider entry propeller pkce instance Im sure penalty 152 Model Aviation model will hit spot straight-in line literally anywhere Just go high idle hold altitude some back stick until final flare play spoilers out open shut instead using throttle gives stair step approach heavens accurate easy can skim weeds runways entry settle oh-so-softly Quite conversation piece FIBERGLASS COWLS 70 cowls eelpants Sig Pica Top-Flite Jemco Nosen Pilot Stafford Radlals Behrens Garmhausen W E Tech other kits plans fine-piece laminated construction handlaid fiberglass strong lightweight Send SASE price list please include names models interested parts call between 9AM9 PM EDT informal ion COD ordering hope hear 703 890-6017 bpt MA es eo 530 Goodiew VA 24095 HOBBY HAMMER *995 APPROXLENGTH7/ExtraTip INCLUDES$125 ONE STEEL AND ONE BRASS TIP Send Check Money Order M&WMODELS PO Box 6627 Huntington Beach CA 92615 Add 150 Post & Hand CA Res add 6% tea Modelers Choice GMP EPOXIES High Quality Model Construction Jr Kwik Set 6 Minute5 oz $ 595 Kwik Set 6 Minute10 oz *996 Giant Kwik Set 6 Minute16 oz $1395 Half FastlOMinutelOoz$ 895 GMP AIRCRAFT INSTRUMENTS 80in31161/4318112$ 149 40 3/4 inch $ 149 EASY OFF PULLER proper tool removing drive waaher%and flywheels * 795 Gas Model Products 8773 Russet Dr Cincinnati OH 45239 513 385-7398 motel veer deal eider died Peet Heed edd $130

With spoilers fuiiy deployed flyby cruise speed Krackerjac requires 1/3 up-elevator maintain constant altitude YOUR SENIOR FALCON downwind leg landing pattern go half-throttle cruise turn onto crosswind leg onto final arrive almost over fence 75-ft altitude still cruise power Can get onto short landing strip Yesif have spoil ers Can abort spoilers out Easily Can land anywhere no matter high far out ease time theoretical article Answers won trenches un adorned report problem seemingly quickly answered turned intriguing adventure kept opening fascinating Lightly-loaded RC planes great relaxed fun fly ing can landing prob lem refuse stop flying engine idling Bills solution use spoilers powered planes increases overall drag also effective wing loading Tests showed amazingly pilotfriendly U Bill Winter doors subject aircraft has flown fre quently over two seasons perhaps dozen qualified pilots asked critical constructive suggestions led refinements effective flying tech mques obvious questions will asked beginning spoilers flaps Answers evolved throughout text problem occurred enlarged 1963 Max 15-powered Krackerjac few seconds after picture left taken Steve opened spoilers half way some elevatorcompensation aligned plane parallel ground held attitude until touching down spotaboutin line antenna position 60 Model Aviation Using overkill spoilers early tests Steve Kaluf executes full-spoiler descent several hundred feet upwlthoutcom pensating elevator control As shot taken just closed spoilers rounded out nose slightly high Dive speed visibly far less normal dive acceleration dive took place thisside ofthefarsoccergoalunderelbow published American Modeler Jetco kit short-coupled 54-in-span cabin model semi-symmetrical air foil forward spar flat-bottomed aftlike new Goldberg designs took 6-ft 2-ni span 1 3-in chord K&B 40 scale up dimensions double whereas wing area increases square So ended up 69 sq ft wing 7-lb 6-oz plane resulting wing loading approximately 17 oz per sq ft problem light loading size plane high L/D approaches Wing loading comparisons accurate identical areas involved size variations have dis tortion wide-angle lens Scale Effect Reynolds Number thing facts life nevertheless lets just go simple things agree upon Little air planes flit bigger plane better flies No pundit has drawn curve spots comparable wing loadings against variations area direct observa tion 17-oz loading compares about 15 Falcon 56 35 10-ft Quarter Scale ship small plane might barely take off overkill power -scale-figure load ing would vicious snapper Youll need fill-in have perceptual problems Eaglet virtually automatic close-in approaches possible small planes far out base legs its small size demands intense concentra tion big Krackeijac easy see long finals novices prob lem accurately relating altitude dis tance clear obstacles small field Bigger better sense Although ship did float bob simply did sink fast enough Unless held precariously nose-high sink overshot everything like Sailplane its first fast taxi run came off ground Wthrottle maintained fast rate suitable angle climb test pilot required four approach attempts first flight small field its sixth test flight noted buoyancy downwind leg broke 360 near idle soared monstrous altitude site being visited 560-ft grass runway Cutting idle bone approach accidentally cut power shutoff trim still ran far-end weeds Obvi ously flaps necessary So spoil ersand power mode first spoilers considered flaps would require major rework wing mechanisms quick-fix spoiler modification grew tempting fun chal lenge reason believe spoilers could employed throughout power range merely precise control sink approaches Incidentally test plane does concentric outsides inverts nicely During 195 Os spent five years Norm Rosenstock pursuit RC duration record early escape ment versions automatic on-board rewind ability all-day capability SPOILER DIMENSIONS RELATIVE TO WING 8 RELATIVE TO FIG2 TEST MODIFICATION FIG II 7I VERTICAL 0UBLE WEB JNDER THE LG OUTER TUBE ] /32 SPOiLER HORN [Z SPOILER OPEN AUXILIARY SF ADDED LEADING -EDGE NG / / / INNER TUBING THESE PORTIONS OF TUBING ATTACH TO FRAME AILER SPOILER T E STIFFENER ON BOTTOM TO AVOID F IA7Xp0 E LOC HMIRROR ~I/I6 PLY = 1111L HOLE INRIE Ii "RIB 3/32x I-I/B RIB POSITION -HOLE IN WING BOTTOM TOP SPANWISE BOT-rOM AT 45POSITIONABLE SERVO PRIOR LOCATED AIL- SERVO HAD TO BE I8x 3/8 SPOILER PLATFORM WORKED AROUND SPOILER T E HORN BRACE FIG 2 February 1986 61 NOTE BROKEN LINES SHOWOPENING SPOILER THAT AUTHOR ISj USING IT AVOIDS ANY SPECIAL TECHNIQUES AND IS TOTALLY3QO TO 45 SAFE FOR INEXPERIENCEDIOPEN FLIERS 7-1/4 SPAN SEMI-SPAN OF 6 WING EVERSING NG ON PORT T WOULD NEED TED HERE AAGE SERVO MOUNT HORN AT 1/2 SPOILER SPAN ---4 AAAJA/A/vv\AAr ARRANGE FLEX PUSHROD TO SUIT TOP VIEW RANDOM PROJECTION vvVJyVvAsVVA~ 30 MAX 150ATTACH POINTS TOP 8 50BOTTOM FOR FLEX RODS ONE TO EACH SPOILER USE LL LINKS OR SERVO SECTION ON\HORN AFT CENTER LINEOF SPARAILERON SERVO AFT SUGGESTED SPOILER RANGE EVOLVED FROM TESTS ON FIG 2 BUT USING ONE CENTER SECTION SERVO TYPICAL FLAT BOTTOM SPOILER HINGE LINE IS AT PRECISE HIGHPOINT OF AIRFOIL FIG 3 things like dirt filter always conspired around 2 hours dash hopes early escapement versions employed spoilers altitude control power no throttle being available Fuel 09 15 diesels 6 7-ft spans respectively 32 82 liquid ounces normal K&B 35 burned 3 oz un doctored K&B 100 per hour cruis ing Incidentally 1 1-lb-gross sevenfooter will thermal discovered 1 x ler hinged its leading edge produced mid-flap-like moderate descent steady smooth-responding like airliner Cmal no tip-stall tendency Virtually no force required open 900 close spoilers single strand loop -in rubber running half-span SN escapement center section sufficient vac uum would suck spoiler up bang extended drag pounded shut equal authority retracted tried same spoiler/area combo Veco 19 Gramps rudder-only ship MAN spoilers shown produced two angles climbsteep steeper full bore steeper descent glide Popped out will during appmach spoilers extremely effective accurate landings Let Original wide-chord spoilers shown closed Krackerjacs 74-inspan 3in-chord wing Transparent covering showsthe quickfix installation two Ace Bantam servos mounted ribs ideai setup wouid centerilne servo appropriate iinkage Spoiier travei iimits centering set crudetesting arrangement viatheAce Siiver7 Tx Right Spoiiersopen position No1 Fig 2 ianding becomes matter increasing approach angie lose altitude using eievator normai until touching down Left original wide spoilers position No 2 Fig 2 pictured aborts go-rounds smooth solid opened position No3 plane could atlil abort up point landing commitment though requiring considerable power Right wide-chord spoilers opened fully position No 5 plane couid barely maintain altitude full power heavy up-elevator handful experienced pilot Furthertests proved though ships recoverywas smooth quick upon spoiler retraction 62 Model Aviation Significantly retracting spoilers did cause ballooningsink rate just returned normal spoilers forgotten like flaps too Senior Telemaster often see cracked flaps make pussycat approaches full flap planes may pitch up power added stay level rare pitch downrequiring corrective elevator depending high- low- midwing configurations have seen guys pour coal full flaps Telemaster surprise 1O-ft-dia loops right off ground roughly h-down flaps can generate additional lift drag slowing down slow up nicely l down still building gobs liftand full-down late final add great air braking Flaps great properly flown Spoilers never add lift kill lift over much greater portion wing spoilers span itself Provided spoilers too large degrees exposure easily trim-compensated appropriate back-stick degree back-stick after throttling back approach produces spectrum sink rates flight paths direct spot full spoiler no elevator compensation dive-like attitude airspeed build-up far less anticipated suggesting presence high amount drag reduction lift produces lower L/D machine spoilers have own braking drag first visualized number fixed spoiler positions used flap channel Silver 7 select progressive degrees exposure see Fig 2 Five open posi tions available Fig 2 also details two-servo fix already-completed Krackeijac Actually standard servo should located centerline during construction type mechanism cables torque rods pushrods bellcranks would suitable quick fix adjust ments possible outside al though bottom hatches wing could arranged depended end-throw centering adjustments transmit ter eliminate occasional servo buzzing shut position eventual result spoiler size movement Fig 1 Variable proportional positions could maintained simple open shut quite satisfactory See sidebar Doug Pratt continued field testing another two seasons finalized best spoiler size angle open decided make some tests larger full-open spoilers produced steep dive idle tuck-under full elevator could recover dive allowed developrequiring spoiler retraction Minimum-open position moderately increased sink rate landing approach minimum-open came shorter positive abili ty land take off climb out goround using power elevator spoiler retraction several intermedi ate positions surely would found perfectand another would help ful quick altitude dissipation February 1986 63 uj I11uu u reduced 1 Subse tortms early trial-and-error experiment quently Doug Pratt isolated 30 open old 1 x 4 spoiler 1 950s plane best maximum spoiler chord increased Fig 1 7 x 1 reduced ize two remember almost 1000 squares wing positions open shut can think area theoretical ideal terms sink low- high-rate known excessive wing final arrangement soon found since normally Obviously spoilers applicable using Positions 1 2 spoiler aircraft light loadings low sink Left Bottom view two-servo spoiler setup aileron servo Atlas differential obvious too-slim pushrods length quickly beefed up telescoping tubing Wing key dowel added rubberband hold-downs tight loops lifted front wing Right After reducing spoilers 71/4 xl Bill turned Krackerjac over Doug Pratt forfield testing Spoilers now set open position No 4 Fig 2 Using spoilers just open shut made short landings flyby altitudes virtually automatic overshooting team up ex tremely useful high sink rate fast landings characterize aircraft flaps appropriate because lift can produce Flight tests First flights big spoilers Don Srull NVRC site 275-ft strip later series flown Steve Kaluf Fredericksburg VA 560-ft strip unlimited approaches third series AMAs Doug Pratt two sites Both Don Steve flew overlarge spoilers somewhat re duced spoiler chord span before Doug got fly Don requested high simulated downwind legs successive runs requested him apply progressive spoiler positions power setting between high idle cruise use either up-trim elevator corrections would note degree pitch-down position would quickly recover power elevator retracting spoilers first-open setting produced shallow descent angle probably would have hit ground maintained within roughly 750 1000 feet additional increment open-spoiler produced steeper descent angles expected full-open pro ducing approximately 450 600 Recovery sustained flight easy two less-open positions full-open max power increasingly severe upelevator needed sustain level flight recovery Dons opinion sys tem effective would inclined use up-trim slightly prior opening spoilers Good approaches landings made first two open positions approach normal earlier touch-down first position power dragglng bit required second position Anything beyond would useful paying off altitude less speed build-up elevator alone would tricky near ground left Steve Kaluf another polished pilot own devices knew would handle anything let him surprised made no comments Fi nally asked him make hopelesslyhigh approach at200 ftjust isOft shortof runwayand use full-spoiler result spectacular steep ap proach being prolonged using elevator could recovered full-up Steve nonchalantly pulled spoilers rounded out touched down smoothly before ship abreast us seemed accept sink rate angle pull spoilers complete perfect power approaches two highly-skilled pilots felt out spoiler performance envelope within minutes settled tech niques within two flights real test would Continued page 150 Left Holding slight up-elevator spoilers closed normal landing ship slightly flares before touching down normal roll-out follow Right following flight photographer moved other side flight path landing done spoilers fully exposed note neutral elevators atthe end roil-out Landing touch-down took place just lOft left plane now sits 64 Model Aviation Close-up final spoiler shows hinge segments Sullivan inner/outer rods Origi nal spoilers extended back short false top spar Extremely long approaches above normal flight altitudes made Idle spoilers being popped out instead typical throttle corrections holding some steady back-stick Spoilers ideal clean-flying large craft Fast heavy modeisthataiready haves good sink ratewould generally benefit use flaps increase lift shorten landing approach have proven extremely durable high-rpm situations TP/TPM 4 exhaust duration should creased fully accommodate super charging effect TP/TPM prac tical limit about 1800 after engine becomes peaky very hard set Changing exhaust timing involves some skilled machine work best left true engine experts An easier method replace stock sleeve pipe-timed sleeve K&B 65 frontrotor engine has about 1500 exhaust duration Its performance TP/TPM can increased substituting sleeve F-i version 1600 exhaust duration Some K&B Formula fliers may have couple piston/sleeve assemblies no longer competitive F-l due loose fit ideal replacements 65 front-rotor ver sion operated 15% nitro TP/TPM unlimited Pylon Racing K&B has performance update package 75 ducted fan engine package includes special sleeve 1800 exhaust dura tion eyebrow porting update also dispenses Perry pump carburetor sometimes gives reliabil ity problems field use abuse Some combinations OPS OS ST engines may yield similar results substitution pipe-timed sleeve Check importer Included segment article drawing several TP/TPMs available MACS Products presented give reader general idea dimen sions weights selecting TP/ TPM particular application next installment will discuss some newer performance-added silencers such Magic Muffler Wizzard V-Tech mufflers See next month Bill Hager 706 Glen Haven Dr Conroe TX 77385 responding advertisers mention read about ModelAviation TARBabyITRANSMITTER CASE Especially Turn-around thisAn inexpensive rugged molded 850 sq 120 4 cyclecase protect thst expensive -rpowered Ron Chidgey designtransmitter both two stick smooth solid performersingle stick transmitters Brown Rib templates computerleather grain aluminum trim plotted Plans construc-and locking clasp -$1895 tion hints -$1195 WING TUBE & SOCKETSNEW WING MOUNTING SET Aluminum alloy tubing plug-in wing mounting system developed Ron Chidgey s Included pair fast neat accurate stays tight Three special slip-tit phenolic sockets nylon brackets screws snd machined wing blocks build wing structure included $695 Now a size models 718 dia 2 $ 895 1 dies 2-$ 995 1a diax3-$1495 GIGator RIC Products P3713 Pompano Dr See Dealer Order Direct Pensacola FL 32514 Phone AC 904 476-8639Include $150 Per Item UPS Spoilers/Winter Continued page 64 own moment truth Any accom plished aerobatics pilot can relate experiences good test pilots medium-level sport pilots like own capabilities safe altitude could engage spoiler positions Fig 2 including overkill full-open devisedjust test purposes landing pattern especially final approach simul taneously retract spoilers apply emer gency power take off up-trim later ignored trim depended stick use back-stick properly fly plane tense moment wind clearly too risky low altitude whenever exceeded two first-open positions could safely land go-round spoilers out positions first-open position fed downwind perfect Whereas plane spoilers hard get down wanted consistency problem vanished first-open spoil er position setting could stand throughout approach final though landings aborted landings go-rounds touch-and-go After hoped very high approaches second-open position caused ship sink rapidly enough attain proper altitude point spoiler positions shown Fig 2 subsequent modified positionsrec ommendedare shown Fig 3 Establishing spoiler position well back downwind leg easy changing spoiler position later landing pattern was too easy get say position No 3 rather No2 Thats smaller final spoilers operate open shut proper technique re quires smooth elevator compensation pitch-down larger openings greater sink acquired al lowing dive develop maximum spoiler openings proved dif ficult first oversized spoilers too much think about late final dexterous pilot multi posi tions available may desirable 150 Model Aviation 049 Engines Suitable 2-4 classic its kind An agile odel really performs excellent piantorm durable and enloyable ship fly RIG contest enents Wean gal avirale line aid favorites Kit #116W Please send snn tar nor Flyline caraton $2995 Phane 7031 2139593Onalers Olstribalars malted FLYLINE MODELS INC PO Box 2136 Fairfax VirgInia 22031 conclusion would better off using retract channel spoiler size exposure used Doug Pratt Merely flipping retract switch open closed cinch what first second position multiposition flap control desirable proper amount open-spoiler would first have established use retract switch could play easily bumping off will like full-size sailplane its final using much elevator trim fore applying larger first-test spoilers bothersome Slight up-trim safe approach full up-trim Fig 2 setup Krackerjac behaved strange manner plane seemed hanging sinking same timea crazy sight surprised plane landed re sounding whomp accidentally bumped spoiler lever could have happened using isolated retract switch Strong open-spoiler positions using elevators retracted cor rect landing approach height attained fine plots like young Kaluf dont have mental lapses sluggish reac tions new different situations Used correctly correct spoiler size power useful tool so-so pilots plane revolts against short approaches dont think would use Kadet just possibly Falcon 56 34 x 4 in case WANNA RACE N RTH AST AREA LNJ BEGINNER RACES 0-500 * FORM-i Instructions b Programs Information Contact NORTH EAST PYLON RACING ORGANIZATION 119 DEAN AVE FRANKLIN MASS 02038 Tel 617 528 4043 203 673 -2000 Deluxe Kit coming January details other Zimbabwe Model Products kits call write Full color deluxe catalog -$100 f/- ZIMPRO MARKETING PO BOX 3076 OAK RIDGE TENNESSEE 37830 Tel 615 482-6188 clean light probably Senior Falcon 1 x 5 6 guess has considerable area low wing loading Probably measure whether spoil ers will benefit cleanness weight machine foot altitude lost equates large num ber feet over ground would use r Johnnie Casburn s Super Lucky Fly H Super Lucky Fly II 45 65 List 995Special. 59495 Little Super Lucky Fly II 35 45 LIST. $11995SPECIAL 95 Prices Subject Change Without Notice L smaller spoilers and/or small-open posi tions smaller ships close normal loadings large spoilers large bigger planes having lightness cleanness results persistance fly dont want 34 x 4-in spoiler opened 600 would ideal 6-ft Old-Timer both low power glide planes such spoiler would ideal limiting climb rate strong thermals resorting escape maneuvers could hang go soaring opening closing spoilers will months have passed since foregoing written Doug Pratt has old model now powered Enya 46 four-stroke has briefed technique Approaches like shooting ducks rain barrel strange indeed come cruising up almost fence ridiculously high sink short landing As far landings concerned spoilers make perfect STOL high up distance Ready-Built fuselage Pre-finished wing ready join Wing covered 1/64 plywood Easy build Easy fly Excellent Plans Lots Hardware Accessories Jahnnie Casburn Manufacturing Co 5715-SE E Rosadale Fort Worth TX 76112 Day 817/451-7537 t 817/572-145 February 1 986151 1985 USA National Champion Ivan Kristensen An enlarged telephoto shot hence fuzziness Krackerjacs landing attitude full spoilers about 113 up-elevator Touch-down occurred right after snapshot sink rate about same forward speedgentle impact never stressing gear Spoilers turned plane wanted glide forever great short-field performance drawbacks flaps photos Tom Schmitt author FOR SERIOUS MODELERS ONLY New PistonlRod Reset Tool * & Piston Holder Set Now can easily extend life Cox 020 049/051 09 engine Whether youre free-flight control-line 1/2-A pylon racing time ball-socket area piston can become too loose continued high RPM output new tool Cox Hobbies piston/rod reset tool set designed support piston no chance damage crucial piston crown area properly re-set ball socket will insure continued top performance winning ston/cylinder combination case hardened CL Scale/Boss Continued page 66 cut what follows should taken official interpretation current rules rather own view light questions asked Official interpretations and/or approval rules sole responsibility AMA Scale Contest Board answer first question far could determine Yes Bauer did receive multi-engine points model described CL FAI Scale rules case multi-engine option scored 0-10 points multiplied coef ficient K factor seven total option score next two questions somewhat related discussed such review CL Scale rules indicates no specific wording prohibit use different types power plants same model However am sure intent rules elec tric power added allow different forms power mixed same model suspect intent model should powered type engine/motor Scale Board time did anticipate possible problems mixing power types use straight electric power presents possible problem Precision event awarding Engine Starting bonus points posed third question above award bonus 10 points starting within minute no need toflip some models propellers electric motors used operating switch start electric motors equivalent flip ping propellers answer last two questions multi-engine models pretty clear according rules no men tion contestants need prove engines support models perfor mance nor model equipped two engines eligible 20 points under multi-engine option thoughts received multiengine option model ly additional engine received 20 points didnt model like B-36 six engines receive 100 points five additional engines quick look Scale rule 52A8 shows six 20-point options including multi-engines allowed total 120 points dicating multi-engine option cannot interpreted being worth 20 pointsregardless number engines used However idea extra points beyond 20 models two engines does have merit such rule incorporated rules might possibly encourage model ers build complex models last area concern question asks jet model piston engine its nose propeller-driven bona fide entry Scale events believe best way look ques tion consider model entry AMA Scale events nothing could find Sport Scale rules would prohibit model being entered However would imagine some downgrading model during static flight judging would order because built performing prototype Precision Scale event however quite different model might kept entry basis Unified Scale Judging Regulation 50&a effect disallows addition pro peller wasnt during static judging might other hand consider entry propeller pkce instance Im sure penalty 152 Model Aviation model will hit spot straight-in line literally anywhere Just go high idle hold altitude some back stick until final flare play spoilers out open shut instead using throttle gives stair step approach heavens accurate easy can skim weeds runways entry settle oh-so-softly Quite conversation piece FIBERGLASS COWLS 70 cowls eelpants Sig Pica Top-Flite Jemco Nosen Pilot Stafford Radlals Behrens Garmhausen W E Tech other kits plans fine-piece laminated construction handlaid fiberglass strong lightweight Send SASE price list please include names models interested parts call between 9AM9 PM EDT informal ion COD ordering hope hear 703 890-6017 bpt MA es eo 530 Goodiew VA 24095 HOBBY HAMMER *995 APPROXLENGTH7/ExtraTip INCLUDES$125 ONE STEEL AND ONE BRASS TIP Send Check Money Order M&WMODELS PO Box 6627 Huntington Beach CA 92615 Add 150 Post & Hand CA Res add 6% tea Modelers Choice GMP EPOXIES High Quality Model Construction Jr Kwik Set 6 Minute5 oz $ 595 Kwik Set 6 Minute10 oz *996 Giant Kwik Set 6 Minute16 oz $1395 Half FastlOMinutelOoz$ 895 GMP AIRCRAFT INSTRUMENTS 80in31161/4318112$ 149 40 3/4 inch $ 149 EASY OFF PULLER proper tool removing drive waaher%and flywheels * 795 Gas Model Products 8773 Russet Dr Cincinnati OH 45239 513 385-7398 motel veer deal eider died Peet Heed edd $130