Radio Control Scale Bob Dolly Wischer LONGITUDINAL STABILITY response March column subject unex pected stalls received letter James M Ruley aerospace engineer spe cializing aircraft stability control working Aeronautical Systems Division USAF Wright-Patterson AFB discussion stability theory follows Longitudinal stability tendency aircraft has trimmed fly cer tain angle attack AQA return AOA disturbed necessary airplane have longitudinal stability order controllable Therefore important ensure model airplanes longitudinally stable understand longitudinal stability necessary control lets take look what makes airplane stable Figure 1 shows Spitfire flying certain angle attack practical terms means certain air speed number Gs airplane has trimmed fly AQA Because total lift sum lift produced wing horizontal tail may consid ANGLE OF ATTACK RELATIVE WIND ered act center gravity CO Note other point identified known aerodynamic center AC Its importance will explained shortly Now Figure 2 Spitfire has dis turbed its trimmed AOA perhaps fly ing updraft AQA has creased because lift will crease happens because still flying same airspeed Figure 1 creased AQA demands increase lift Gs main thing notice crease lift due increase AQA acts CG AC defini tion ACthe point change lift due change AQA will act Notice case AC some dis tance behind CO Therefore change lift AL due i AAA moment torque about CG lever arm mo ment distance between CG AC measured perpendicular lift vectors As can see Figure 2 moment will tend pitch Spit fires nose down re storing its trimmed AOA situa tion shown Figure 1 Therefore CP position Spitfire longitudi nally stable Now suppose taken Spitfire up different loading resulting aft CG shown Figure 3 CENTER OF GRAVITY p AERODYNAMIC CENTER W FIGURE LEVER ARM AL AO RW wFIGURE 2 1 LLEVER ARM AL AOA RW wFIGURE 3 Bob Doily talk about center gravity CG month case Figure 2 have flown updraft increasing AQA get change lift appears AC before now AC forward CG resulting moment tends pitch aircraft nose upward increasing AQA still further very undesirable means pilot will have fly airplane out small change AQA occurs example unstable airplane Figures 1 2 3 can deduce important fact about longitudinal stability FACT longitudinal stability aircraft depends distance between aircrafts CO AC CG forward AC airplane stable CO behind AC airplane unstable Also degree stability proportinnI distance bet 46 Model Aviation Glossy polished aluminum spectacular finish 0 Westiand Lysander Toledo Orest Drobey master metal craftsman Compound curves wheel shrouds hammered cookie sheets Craft weighs 13-1/2 lb uses Enys 60 / Dennis Crooks won first Precision Scale atToledo WW ii Grumman TBM Avenger Craft built Bob Hoiman plans Servo-operated folding wings controlled transmitter before after flights Twenty-pound craft spans 82 uses Supertigre 2500 engine lift its 20-lb weight No decais used elaborate finish lettering Mike Barbees North American SNJ-2 three-year project Nick ZIroil plans fiberglass fuselage Engine isa Sacha Doimar 37 cu Eleven servos controls flaps retracts smoke William CarpersCurtiss Hawk POE built Royal kit its finish Sig dope over Koverail Engine 05 90 four-stroke CG located stable airplane Gee Yep con cept made easier work fact AC fixed point does move around AQA changes deflec tions control surfaces flaps incidence angle changes reason engi neers work AC rather center pressure CP Once have located AC stays put CP however moves around lift wing horizontal tail changes AC located harder question depends relative sizes wing horizontal tail vertical position horizontal tail small degree wing tail airfoil sections Therefore impossible give location true airplanes However some general rules AC location can given 1 AC will always somewhere tween AC wing AC horizontal tail ACs surfaces lie quarter-chord 25 mean aerodynamic chord MAC points Therefore AC will generally lie aft quarter-chord wing 2 far aft depends size horizontal tail compared wing far wing aver age-sized tail lOo MAC aft quarterchord point probably reasonable number have big tail long moment arm AC will still further aft have small short-coupled tall AC will closer quarter-chord Now CG must forward AC far forward depends stable want airplane airplane too stable CG too far ward will groove well maneuver poor ly Conversely stable very stable will maneuver very easily tend hunt continually oscillate about trim AQA simplest thing can flighttest model CG forward quarter-chord point model will unstable think too stable shift CG aft little time until like way flies Finally need clear up misconcep Continued page 137 do Tabby gave birth five Scale model offspring Sig exhibit Toledo Sports Arena chief mouse-catcher Save Money lable semi-kit $129 ly wood hardwareFIJ $18900 As Featured March 86 RCM Magazine wing span44 wing area609 sq length56 weight65 lbs engine40- 46 2 cycle radio4 channel BoB PARKINSON FLWNG MODELS RRI Queensvllle Ontario LOG IRO Canada Tel 416 478-2632 Z Please add *2000 ship end handling Dealer Inquiries invited August1986 47 ad small. s because depend OPS performance attract attention g4jjsPeoPIeof Co#4etU1o 9*9044 PO Box 26247 New Orleans La 70186 504 242-5967 High Performance Amphibian moat unIque aIrcraft today has added line delta wing kits designed Laddie Mikulasko fully aerobetic off both water lend onepiecs fiberglass fuselage cowl feiring wing-tip floats precision machine-cut foam delta wing assembles quickly end easily4 oz lighter original hales version unplug landing gser water-tight nose wheel mount factory instailedi fly off water snow ice addition floats akils Stability wind penetration overall performanoa combined un believably low landing apsed make Nerthstaa 2001 beat designs yet kit has bsen build end teat flown Laddie Mikulasko complete approval S aV0 iOld Timer fOttS66Si5A3 CbauiW0From sparK 1etS poliltS Taflt5 tjtooe IgnitiOn Engine Parts Only Over 600 items Send $200 current catalog PhD am now planning proposal orbit scale model large space struc ture inside Space Shuttle test using RC operating equipment ows. someday might see astronaut holding RC transmitter Space Shuffle RC Scale/Wischers Continued page 47 tion will recall said earlier AC location does depend relative cidence wing tail Since true might conclude incidence angles have nothing stability abso lutely correct contrary what modelers lieve What relative incidence between wing stabilizer actually does set AQA airplane will trim elevators neutral Since models fly various AQAs small AQAs fast parts flight large AQAs aerobatics takeoff landing relative incidence setting up model er depending flight condition wants model trimmed set wrong relative incidence its no big deal Thats have adjustable control linkages trim control transmitter mistake some people make setting incidences shown plans moving CG until model flies desired AQA speed elevators neutral very bright idea may move CG far aft goes aft AC making airplane unstable Rather fall trap set level longitudinal stability proper place ment CG play hori zontal tail incidence elevator trim until airplane trims desired AQA speed Youll like airplanes handling qualities bet ter crash less often save ballast weight thanks James Ruley foregoing treatise longitudinal stability Scale model ers build kits magazine drawings will have little concern difference inci dence angles between wing stabilizer would have properly set up designer model intentionally set up zero-zero incidence angles provide Patternmodel-type performance will probably have neutral stability will need flown like Pattern ship no relaxation during flight neutral stability model needs continuous control input will climb vertically until runs out energy straight down until meets earth no tendency recover level flight its own stability model will have its CO AC same vertical line experienced fli ers prefer such models especially have background Pattern flying have flown neutrally-stable trainers have hearing Pattern fliers zero-zero angle setup model no longer favored now preference about /2 0 1 0 incidence wing relative stabilizer equal amount downthrust engine mount intend ed provide straight flight transmitter control inputs during vertical maneuvers gravity forces directed toward tail modeler likely concerned about incidence angles person prefers design scratch-build fac tory drawings three-view drawings means measurements taken directly subject aircraft modeler die-hard Scale purist insists upon copying fullsize prototype down last detail including incidence angles wing stabilizer numerous examples aircraft drastic angular differences much 60 Taylorcraft Staggerwing Beechcraft come mind result such setup down-load stabilizer high-wing cabin type also down-load tail due downwash off wing trailing edge case AC affected since total lift sum lift produced wing horizontal tail difference between two forces wing now must lift airplane weight plus stabilizer down-force AC now moves far forward positive longitudi nal stability CG must also moved far forward ahead AC Balancing such model favored 25% 30% wing chord doesnt assure stability particularly takeoff its first flight flier isnt prepared initial steep climb results stall snap roll crash disappoint ed modeler gathers pieces trash bag recommend reducing angular differ ence about 20 kits Spitfire full-size illustrated has 20 incidence wing 00 stabilizer 20 washout wing tip flier knows what expect large angular difference between wing stabilizer incidence built solidly fuselage structure cant easily changed model will have flown elevators drooping drastically experience know diffi cult hold Up elevator throughout first-flight 1748 AD GOES tWIN OUR BACK PA GE AD VERIISEAENT WORLDS 7 CH FM EXPERT len say own 7 diarmel 4 channel Expert FM tiei converson Systems say have 4 5 eliplanes want put receiver mdi eliplane era say tosterice yolfte diarmel 40 youl send franesltter will special line receivers VanenIlter -1 10 morethe nwnber exta receivers mares no ifleresce Retail pace therecelverls$8995Therewil odlwgelortrdngandwe1 pay outhozid freight have another franmeltrer diwnist 46 wait another mo&ie another receiver channel 4 thate eisa poselto hat cue have buy another tanmidlter mo&ie TranmnltW Mo6ie refi plc $4950 EXPERT 7 CHANNEL FEA TURES 1 Dual conversion FM erotIc 2 nicads chaiger 3 Reversing channels 4 Lodvng connectors 5 Dual rate aileron elevator 6 Mixing aileron & rudder elevator & Itapa 7 Servos use Mdstishi #15660 chp 8 ServOs use indirect drive 9 Excellent operation AM envimnment 10 Receiver uses ubra narrow band mufti-pole ceramic filters SERVO 52885 TJL sar LOClirda orweercrw JUSTARRIVEDI COMO 29 RIC Como 29 ie Ike eil engtoea tie cisro toe Sclsruerle pcrbd engtoe orankeliaft aipported doutoc bail beings 11w cano 29155 real powertdant planes like Woild Ennea Widoerd ARF comno 25 allwood Flince ARF rIta Retail plc Ccmo 29 $8495 JUSTARRIVED ZENOAHG-62 Zertoir 042 Isa 378 cikdc todrmagsetolrWonengtoethat toni power standpoInt drordd sqlivalent just tout eie thIs displacement tie madret 0-62 designed light weIrL lAilSer mont toduded lIds angita Retail pike tog pertonner $25985 EXPERT ACCESSORIES Shoen below ue acoessceles Expert FM ltoa cormectors selt-locidrig tyse prevent dtocorsiecton S-25 servo gaas wi avitla U2tfl 5weoTay fl fl I1i 2W1 Servo Ora Ii wAodg ousdor ss Rsa 0 ElEl iTS 24 5wvoEo-oi wAedJng onsiector $450 & ssou ReliC EiipsstNdx Step S59S Retodi NEW CHINA CLIPPER FROM ~TEH Sport version canopy town luIt consfruof Thgqran 5I 3-4 drarmela S- 40 sagne Otidrle 503 SMSS Reti WORLD ENGINES 0960 Rossash Ave cincinnati Ohio 45236 Phone 513 793-50OU Telex 214557 FAX 513 793-7337 August 1986 137 MABYCHI MOTOR $229 15 - 9 Volts HARRY B HIGLEY S SONS INC P 0 BOX 532 GLENWOOD ILL 60425 excitement model can brought back safe landing However opposite holding Down elevator because insuffi cient down-trim available transmitter controls hazardous skilled pilot Scale modeler insists upon reproducing large angular difference model should move CG far forward first flights progressively move rearward later sug gested Mr Ruley case overall airplane weight will probably substantially increased because volume lead nose As Mr Ruley states angular difference doesnt affect longitudinal stability know anguished experience can lead disaster resulting initial instability Toledo agaIn new Toledo exhibition hall under construction Question Will completed time Toledo Expo 1987 visited site impressed its size located newly restored downtown area city Toledo can proud what has accomplished restore beauty area blight Meanwhile old Sports Arena Weak Signals Club thirty-second annual RC Expo attracted usual overwhelming crowds exhibits manufacturers distribu tors retailers course Scale modelers Models display ranged size small Saito 30-powered Dormoy Bath tub monster Douglas DC-3 pair Quadra engines Two winners Precision Scale class models seen previously First place Best Show-winner Dennis Crooks displayed Grumman Avenger has flown two Scale Masters meets model also placed first Chicago Expo second place Cliff Tacies Savoia-Matchetti Pipistrello bomber will flying World Championships Oslo Norway July Larry Gordons 1-scale Grumman F4F-3 Wildcat Quadra engine placed third Military Scale class winner William Carper Curtiss Hawk P-6E Royal kit second-place Focke Wuif FW 190-D9 Don Parks came Pica kit Its unusual finish technique clear MonoKote Chevron Perfect Paint third place Hal Parentis newest Savoia Marchetti SM-79 Italian bomber fourth series Hal First flights made RC World Florida during March Non-Military Scale surprising entry North American SNJ Mike Barbee model finished civil colors Sky Typers skywriting group Mike used Ziroli kit fiberglass fuselage scratch-built Lake Buccaneer LA4200 amphibian secondplace winner Alvin Osminski Third place awarded Joe Mientkiewicz scratch-built Waco Taperwing year ago Orest Drobey displayed Bellanca Air Cruiser Toledo featured polished aluminum metalwork received great attention Orest returned Toledo Westland Lysander again elegantly finished large areas polished aluminum auto body repairman has neces sary skills work metal compound curves Lysanders wheel coverings produced hammering cookie sheets polishing high gloss model received Directors Award As always Toledo generates episodes within main event Toledo Tabby resi dent official Sports Arena rodent-control cat obviously ready have kittens Tabby proceded have offspring Sig ex hibit Hazel Sig-Hesters lap Hazel made hasty arrangements provide nest card board box Tabby gave birth five scale-model kittens did Tabby know among thou sands Toledo visitors Friday morning Hazel person would help time need family moved days end maintenance quarters Tabby returned through largest crowds crossing wide Arena Saturday pay visit Hazel Anyone has visited Sig estab lishment Montezuma knows Hazels love animals Bob Dolly Wischer S-221 Lapham Peak Rd Delafield WI 53018 RC Electrics/Kopski Continued page 51 important because save important ounces completed model always recommend minimum three-channel installation rud der elevator simple servo-driven ON OFF motor power switch recom mend fewer channels radio installation will weigh approximately six seven ounces Later interest proficiency grow can use leftover fourth channel ailerons some aerobatic Electric model Heres come will want decide what preferences number model types choose among include gliders Old-Timers everything else also called sport sport-trainer Within given type also choices Remember what dis cussing entry-level economy Electric will fly schoolyard down street friendly non-hair-raising way have seen power system recommenda tions above work very well quite range models Im partial own Spectra design Reference 2 offers three wing options such kits Olympic II Drifter II Olympic 650 Gentle Lady similar 2-Meter Sailplanes successful converts Electric Several fellow club members have learned fly such models Jim Zarembskis Sky Knight Reference 3 very good sport-trainer model fellow club members learned fly recommended power system Another Jims designs Wasp Leisure kit will fly comfortably Continued page 147 ATTENTION ERS QUAY BARBER MODELS C14 SHOESTRING SEMI-KiT $11995 KITSi5495 Rivets SEMI-KIT $11995 KIT -$15495 EPOXY/GLASS /FOAM/BALS CONSTRUCTION WITh DRAWINGS AND DATA FOR FORMULA 120 PYLON SPORT OR STANDOFF SCALE FULL OR SEMIKITSCosmic 8 10 lbs wAightWind 790 sq wing area SE511K1T $10995 60 2 stroke 12 4 stroke KIT $14495 kit prices plus shipping credit cards welcome Ohio residents add bi 1216 7774172 27106 8utternut Ridge Nnrth Olmated 081044070 Matched Finish System BEST APPEARANCE K&B FIBERGLASS CLOTH K&B Micra-Balloons FILLER K&B SUPER POXY RESIN K&B SUPER PONY THINNER K&B SUPER POXY PRIMER K&B SUPER PONY PAINT KaB MIXING CUPS 138 Model Aviation 0 Wing Span 52 4 cycle annels Acrobatic docile 6 8 hr rapid-fire essembiy precision pro-cut bale- end plywood complete hardware package Included capable complete AMA pattern Dave Robelens Windbreaker Playmate Featured April 1896 Model Aviation 3 Channel portFun Fly 52-4 cycle Fast assembly hand cut kit $4996 Pronto 48 span 5 2 4 cycle annel hand cut kit Easily converted electric excenent nor aegmn nar can ba sat up challenge expert *3996 50span15-25 Super Pronto2-4 cycle 4 channel Same excellent qualities Pronto acrobatic ailerons$4895 AvaIlable dealer order direct Add $2 shipping additional $2 COD save COD send check money order residents add 4% sales tasI TIDEWATER HOBBY ENTERPRISES Route 1 Box 241 D Lanexa Virginia 23089 804-966-5092 EPOXY GLASS COWLS FOR NOSEN PICA 510 MORGAN BALSA USA PLAiT CONCEPT FLEET HOSTETLER RCM T-cRAFT SHEBER PIUS ScALE SUPER cue FOEKER 0-7 BOEINO P-i 2 P26 F4a2 F4R4 SPARROW HAWK GEE BEE MOO Y MACBRIENS TURBULENT CHRISTEN EAGLE BRISIGHELLAS STAROUSTER II V SCALE J3-BI BABY FLYBARY & OTHERS WHEEL PANTS FOR CITABRIA STARSUSTER II PITTS SKYBOLT LIBERTY SPORT CHRISTEN EAGLE PRE HAWK MULLIGAN & OTHERS LARGE SCALE PLANS AVAILABLE Please send $100 complete list supply Modelers fiberglass parts plans Write call us T & D FIBERGLASS SPECIALTIES 3BR25 eLOCK GARDEN CiTY MI 48135 PHONE 313 421-6358 BRAzED So HEAT-TREATED WIRE GEARS 9 CABANER PHONE 1313261-9064 niuriug rurlurmuluu oyrnurn TOP PERFORMANCE K&B ENGINES AirplaneMarine K&B FUELSK&B GLOW PLUGS 9 Blends4 Choices
Edition: Model Aviation - 1986/08
Page Numbers: 46, 47, 137, 138
Radio Control Scale Bob Dolly Wischer LONGITUDINAL STABILITY response March column subject unex pected stalls received letter James M Ruley aerospace engineer spe cializing aircraft stability control working Aeronautical Systems Division USAF Wright-Patterson AFB discussion stability theory follows Longitudinal stability tendency aircraft has trimmed fly cer tain angle attack AQA return AOA disturbed necessary airplane have longitudinal stability order controllable Therefore important ensure model airplanes longitudinally stable understand longitudinal stability necessary control lets take look what makes airplane stable Figure 1 shows Spitfire flying certain angle attack practical terms means certain air speed number Gs airplane has trimmed fly AQA Because total lift sum lift produced wing horizontal tail may consid ANGLE OF ATTACK RELATIVE WIND ered act center gravity CO Note other point identified known aerodynamic center AC Its importance will explained shortly Now Figure 2 Spitfire has dis turbed its trimmed AOA perhaps fly ing updraft AQA has creased because lift will crease happens because still flying same airspeed Figure 1 creased AQA demands increase lift Gs main thing notice crease lift due increase AQA acts CG AC defini tion ACthe point change lift due change AQA will act Notice case AC some dis tance behind CO Therefore change lift AL due i AAA moment torque about CG lever arm mo ment distance between CG AC measured perpendicular lift vectors As can see Figure 2 moment will tend pitch Spit fires nose down re storing its trimmed AOA situa tion shown Figure 1 Therefore CP position Spitfire longitudi nally stable Now suppose taken Spitfire up different loading resulting aft CG shown Figure 3 CENTER OF GRAVITY p AERODYNAMIC CENTER W FIGURE LEVER ARM AL AO RW wFIGURE 2 1 LLEVER ARM AL AOA RW wFIGURE 3 Bob Doily talk about center gravity CG month case Figure 2 have flown updraft increasing AQA get change lift appears AC before now AC forward CG resulting moment tends pitch aircraft nose upward increasing AQA still further very undesirable means pilot will have fly airplane out small change AQA occurs example unstable airplane Figures 1 2 3 can deduce important fact about longitudinal stability FACT longitudinal stability aircraft depends distance between aircrafts CO AC CG forward AC airplane stable CO behind AC airplane unstable Also degree stability proportinnI distance bet 46 Model Aviation Glossy polished aluminum spectacular finish 0 Westiand Lysander Toledo Orest Drobey master metal craftsman Compound curves wheel shrouds hammered cookie sheets Craft weighs 13-1/2 lb uses Enys 60 / Dennis Crooks won first Precision Scale atToledo WW ii Grumman TBM Avenger Craft built Bob Hoiman plans Servo-operated folding wings controlled transmitter before after flights Twenty-pound craft spans 82 uses Supertigre 2500 engine lift its 20-lb weight No decais used elaborate finish lettering Mike Barbees North American SNJ-2 three-year project Nick ZIroil plans fiberglass fuselage Engine isa Sacha Doimar 37 cu Eleven servos controls flaps retracts smoke William CarpersCurtiss Hawk POE built Royal kit its finish Sig dope over Koverail Engine 05 90 four-stroke CG located stable airplane Gee Yep con cept made easier work fact AC fixed point does move around AQA changes deflec tions control surfaces flaps incidence angle changes reason engi neers work AC rather center pressure CP Once have located AC stays put CP however moves around lift wing horizontal tail changes AC located harder question depends relative sizes wing horizontal tail vertical position horizontal tail small degree wing tail airfoil sections Therefore impossible give location true airplanes However some general rules AC location can given 1 AC will always somewhere tween AC wing AC horizontal tail ACs surfaces lie quarter-chord 25 mean aerodynamic chord MAC points Therefore AC will generally lie aft quarter-chord wing 2 far aft depends size horizontal tail compared wing far wing aver age-sized tail lOo MAC aft quarterchord point probably reasonable number have big tail long moment arm AC will still further aft have small short-coupled tall AC will closer quarter-chord Now CG must forward AC far forward depends stable want airplane airplane too stable CG too far ward will groove well maneuver poor ly Conversely stable very stable will maneuver very easily tend hunt continually oscillate about trim AQA simplest thing can flighttest model CG forward quarter-chord point model will unstable think too stable shift CG aft little time until like way flies Finally need clear up misconcep Continued page 137 do Tabby gave birth five Scale model offspring Sig exhibit Toledo Sports Arena chief mouse-catcher Save Money lable semi-kit $129 ly wood hardwareFIJ $18900 As Featured March 86 RCM Magazine wing span44 wing area609 sq length56 weight65 lbs engine40- 46 2 cycle radio4 channel BoB PARKINSON FLWNG MODELS RRI Queensvllle Ontario LOG IRO Canada Tel 416 478-2632 Z Please add *2000 ship end handling Dealer Inquiries invited August1986 47 ad small. s because depend OPS performance attract attention g4jjsPeoPIeof Co#4etU1o 9*9044 PO Box 26247 New Orleans La 70186 504 242-5967 High Performance Amphibian moat unIque aIrcraft today has added line delta wing kits designed Laddie Mikulasko fully aerobetic off both water lend onepiecs fiberglass fuselage cowl feiring wing-tip floats precision machine-cut foam delta wing assembles quickly end easily4 oz lighter original hales version unplug landing gser water-tight nose wheel mount factory instailedi fly off water snow ice addition floats akils Stability wind penetration overall performanoa combined un believably low landing apsed make Nerthstaa 2001 beat designs yet kit has bsen build end teat flown Laddie Mikulasko complete approval S aV0 iOld Timer fOttS66Si5A3 CbauiW0From sparK 1etS poliltS Taflt5 tjtooe IgnitiOn Engine Parts Only Over 600 items Send $200 current catalog PhD am now planning proposal orbit scale model large space struc ture inside Space Shuttle test using RC operating equipment ows. someday might see astronaut holding RC transmitter Space Shuffle RC Scale/Wischers Continued page 47 tion will recall said earlier AC location does depend relative cidence wing tail Since true might conclude incidence angles have nothing stability abso lutely correct contrary what modelers lieve What relative incidence between wing stabilizer actually does set AQA airplane will trim elevators neutral Since models fly various AQAs small AQAs fast parts flight large AQAs aerobatics takeoff landing relative incidence setting up model er depending flight condition wants model trimmed set wrong relative incidence its no big deal Thats have adjustable control linkages trim control transmitter mistake some people make setting incidences shown plans moving CG until model flies desired AQA speed elevators neutral very bright idea may move CG far aft goes aft AC making airplane unstable Rather fall trap set level longitudinal stability proper place ment CG play hori zontal tail incidence elevator trim until airplane trims desired AQA speed Youll like airplanes handling qualities bet ter crash less often save ballast weight thanks James Ruley foregoing treatise longitudinal stability Scale model ers build kits magazine drawings will have little concern difference inci dence angles between wing stabilizer would have properly set up designer model intentionally set up zero-zero incidence angles provide Patternmodel-type performance will probably have neutral stability will need flown like Pattern ship no relaxation during flight neutral stability model needs continuous control input will climb vertically until runs out energy straight down until meets earth no tendency recover level flight its own stability model will have its CO AC same vertical line experienced fli ers prefer such models especially have background Pattern flying have flown neutrally-stable trainers have hearing Pattern fliers zero-zero angle setup model no longer favored now preference about /2 0 1 0 incidence wing relative stabilizer equal amount downthrust engine mount intend ed provide straight flight transmitter control inputs during vertical maneuvers gravity forces directed toward tail modeler likely concerned about incidence angles person prefers design scratch-build fac tory drawings three-view drawings means measurements taken directly subject aircraft modeler die-hard Scale purist insists upon copying fullsize prototype down last detail including incidence angles wing stabilizer numerous examples aircraft drastic angular differences much 60 Taylorcraft Staggerwing Beechcraft come mind result such setup down-load stabilizer high-wing cabin type also down-load tail due downwash off wing trailing edge case AC affected since total lift sum lift produced wing horizontal tail difference between two forces wing now must lift airplane weight plus stabilizer down-force AC now moves far forward positive longitudi nal stability CG must also moved far forward ahead AC Balancing such model favored 25% 30% wing chord doesnt assure stability particularly takeoff its first flight flier isnt prepared initial steep climb results stall snap roll crash disappoint ed modeler gathers pieces trash bag recommend reducing angular differ ence about 20 kits Spitfire full-size illustrated has 20 incidence wing 00 stabilizer 20 washout wing tip flier knows what expect large angular difference between wing stabilizer incidence built solidly fuselage structure cant easily changed model will have flown elevators drooping drastically experience know diffi cult hold Up elevator throughout first-flight 1748 AD GOES tWIN OUR BACK PA GE AD VERIISEAENT WORLDS 7 CH FM EXPERT len say own 7 diarmel 4 channel Expert FM tiei converson Systems say have 4 5 eliplanes want put receiver mdi eliplane era say tosterice yolfte diarmel 40 youl send franesltter will special line receivers VanenIlter -1 10 morethe nwnber exta receivers mares no ifleresce Retail pace therecelverls$8995Therewil odlwgelortrdngandwe1 pay outhozid freight have another franmeltrer diwnist 46 wait another mo&ie another receiver channel 4 thate eisa poselto hat cue have buy another tanmidlter mo&ie TranmnltW Mo6ie refi plc $4950 EXPERT 7 CHANNEL FEA TURES 1 Dual conversion FM erotIc 2 nicads chaiger 3 Reversing channels 4 Lodvng connectors 5 Dual rate aileron elevator 6 Mixing aileron & rudder elevator & Itapa 7 Servos use Mdstishi #15660 chp 8 ServOs use indirect drive 9 Excellent operation AM envimnment 10 Receiver uses ubra narrow band mufti-pole ceramic filters SERVO 52885 TJL sar LOClirda orweercrw JUSTARRIVEDI COMO 29 RIC Como 29 ie Ike eil engtoea tie cisro toe Sclsruerle pcrbd engtoe orankeliaft aipported doutoc bail beings 11w cano 29155 real powertdant planes like Woild Ennea Widoerd ARF comno 25 allwood Flince ARF rIta Retail plc Ccmo 29 $8495 JUSTARRIVED ZENOAHG-62 Zertoir 042 Isa 378 cikdc todrmagsetolrWonengtoethat toni power standpoInt drordd sqlivalent just tout eie thIs displacement tie madret 0-62 designed light weIrL lAilSer mont toduded lIds angita Retail pike tog pertonner $25985 EXPERT ACCESSORIES Shoen below ue acoessceles Expert FM ltoa cormectors selt-locidrig tyse prevent dtocorsiecton S-25 servo gaas wi avitla U2tfl 5weoTay fl fl I1i 2W1 Servo Ora Ii wAodg ousdor ss Rsa 0 ElEl iTS 24 5wvoEo-oi wAedJng onsiector $450 & ssou ReliC EiipsstNdx Step S59S Retodi NEW CHINA CLIPPER FROM ~TEH Sport version canopy town luIt consfruof Thgqran 5I 3-4 drarmela S- 40 sagne Otidrle 503 SMSS Reti WORLD ENGINES 0960 Rossash Ave cincinnati Ohio 45236 Phone 513 793-50OU Telex 214557 FAX 513 793-7337 August 1986 137 MABYCHI MOTOR $229 15 - 9 Volts HARRY B HIGLEY S SONS INC P 0 BOX 532 GLENWOOD ILL 60425 excitement model can brought back safe landing However opposite holding Down elevator because insuffi cient down-trim available transmitter controls hazardous skilled pilot Scale modeler insists upon reproducing large angular difference model should move CG far forward first flights progressively move rearward later sug gested Mr Ruley case overall airplane weight will probably substantially increased because volume lead nose As Mr Ruley states angular difference doesnt affect longitudinal stability know anguished experience can lead disaster resulting initial instability Toledo agaIn new Toledo exhibition hall under construction Question Will completed time Toledo Expo 1987 visited site impressed its size located newly restored downtown area city Toledo can proud what has accomplished restore beauty area blight Meanwhile old Sports Arena Weak Signals Club thirty-second annual RC Expo attracted usual overwhelming crowds exhibits manufacturers distribu tors retailers course Scale modelers Models display ranged size small Saito 30-powered Dormoy Bath tub monster Douglas DC-3 pair Quadra engines Two winners Precision Scale class models seen previously First place Best Show-winner Dennis Crooks displayed Grumman Avenger has flown two Scale Masters meets model also placed first Chicago Expo second place Cliff Tacies Savoia-Matchetti Pipistrello bomber will flying World Championships Oslo Norway July Larry Gordons 1-scale Grumman F4F-3 Wildcat Quadra engine placed third Military Scale class winner William Carper Curtiss Hawk P-6E Royal kit second-place Focke Wuif FW 190-D9 Don Parks came Pica kit Its unusual finish technique clear MonoKote Chevron Perfect Paint third place Hal Parentis newest Savoia Marchetti SM-79 Italian bomber fourth series Hal First flights made RC World Florida during March Non-Military Scale surprising entry North American SNJ Mike Barbee model finished civil colors Sky Typers skywriting group Mike used Ziroli kit fiberglass fuselage scratch-built Lake Buccaneer LA4200 amphibian secondplace winner Alvin Osminski Third place awarded Joe Mientkiewicz scratch-built Waco Taperwing year ago Orest Drobey displayed Bellanca Air Cruiser Toledo featured polished aluminum metalwork received great attention Orest returned Toledo Westland Lysander again elegantly finished large areas polished aluminum auto body repairman has neces sary skills work metal compound curves Lysanders wheel coverings produced hammering cookie sheets polishing high gloss model received Directors Award As always Toledo generates episodes within main event Toledo Tabby resi dent official Sports Arena rodent-control cat obviously ready have kittens Tabby proceded have offspring Sig ex hibit Hazel Sig-Hesters lap Hazel made hasty arrangements provide nest card board box Tabby gave birth five scale-model kittens did Tabby know among thou sands Toledo visitors Friday morning Hazel person would help time need family moved days end maintenance quarters Tabby returned through largest crowds crossing wide Arena Saturday pay visit Hazel Anyone has visited Sig estab lishment Montezuma knows Hazels love animals Bob Dolly Wischer S-221 Lapham Peak Rd Delafield WI 53018 RC Electrics/Kopski Continued page 51 important because save important ounces completed model always recommend minimum three-channel installation rud der elevator simple servo-driven ON OFF motor power switch recom mend fewer channels radio installation will weigh approximately six seven ounces Later interest proficiency grow can use leftover fourth channel ailerons some aerobatic Electric model Heres come will want decide what preferences number model types choose among include gliders Old-Timers everything else also called sport sport-trainer Within given type also choices Remember what dis cussing entry-level economy Electric will fly schoolyard down street friendly non-hair-raising way have seen power system recommenda tions above work very well quite range models Im partial own Spectra design Reference 2 offers three wing options such kits Olympic II Drifter II Olympic 650 Gentle Lady similar 2-Meter Sailplanes successful converts Electric Several fellow club members have learned fly such models Jim Zarembskis Sky Knight Reference 3 very good sport-trainer model fellow club members learned fly recommended power system Another Jims designs Wasp Leisure kit will fly comfortably Continued page 147 ATTENTION ERS QUAY BARBER MODELS C14 SHOESTRING SEMI-KiT $11995 KITSi5495 Rivets SEMI-KIT $11995 KIT -$15495 EPOXY/GLASS /FOAM/BALS CONSTRUCTION WITh DRAWINGS AND DATA FOR FORMULA 120 PYLON SPORT OR STANDOFF SCALE FULL OR SEMIKITSCosmic 8 10 lbs wAightWind 790 sq wing area SE511K1T $10995 60 2 stroke 12 4 stroke KIT $14495 kit prices plus shipping credit cards welcome Ohio residents add bi 1216 7774172 27106 8utternut Ridge Nnrth Olmated 081044070 Matched Finish System BEST APPEARANCE K&B FIBERGLASS CLOTH K&B Micra-Balloons FILLER K&B SUPER POXY RESIN K&B SUPER PONY THINNER K&B SUPER POXY PRIMER K&B SUPER PONY PAINT KaB MIXING CUPS 138 Model Aviation 0 Wing Span 52 4 cycle annels Acrobatic docile 6 8 hr rapid-fire essembiy precision pro-cut bale- end plywood complete hardware package Included capable complete AMA pattern Dave Robelens Windbreaker Playmate Featured April 1896 Model Aviation 3 Channel portFun Fly 52-4 cycle Fast assembly hand cut kit $4996 Pronto 48 span 5 2 4 cycle annel hand cut kit Easily converted electric excenent nor aegmn nar can ba sat up challenge expert *3996 50span15-25 Super Pronto2-4 cycle 4 channel Same excellent qualities Pronto acrobatic ailerons$4895 AvaIlable dealer order direct Add $2 shipping additional $2 COD save COD send check money order residents add 4% sales tasI TIDEWATER HOBBY ENTERPRISES Route 1 Box 241 D Lanexa Virginia 23089 804-966-5092 EPOXY GLASS COWLS FOR NOSEN PICA 510 MORGAN BALSA USA PLAiT CONCEPT FLEET HOSTETLER RCM T-cRAFT SHEBER PIUS ScALE SUPER cue FOEKER 0-7 BOEINO P-i 2 P26 F4a2 F4R4 SPARROW HAWK GEE BEE MOO Y MACBRIENS TURBULENT CHRISTEN EAGLE BRISIGHELLAS STAROUSTER II V SCALE J3-BI BABY FLYBARY & OTHERS WHEEL PANTS FOR CITABRIA STARSUSTER II PITTS SKYBOLT LIBERTY SPORT CHRISTEN EAGLE PRE HAWK MULLIGAN & OTHERS LARGE SCALE PLANS AVAILABLE Please send $100 complete list supply Modelers fiberglass parts plans Write call us T & D FIBERGLASS SPECIALTIES 3BR25 eLOCK GARDEN CiTY MI 48135 PHONE 313 421-6358 BRAzED So HEAT-TREATED WIRE GEARS 9 CABANER PHONE 1313261-9064 niuriug rurlurmuluu oyrnurn TOP PERFORMANCE K&B ENGINES AirplaneMarine K&B FUELSK&B GLOW PLUGS 9 Blends4 Choices
Edition: Model Aviation - 1986/08
Page Numbers: 46, 47, 137, 138
Radio Control Scale Bob Dolly Wischer LONGITUDINAL STABILITY response March column subject unex pected stalls received letter James M Ruley aerospace engineer spe cializing aircraft stability control working Aeronautical Systems Division USAF Wright-Patterson AFB discussion stability theory follows Longitudinal stability tendency aircraft has trimmed fly cer tain angle attack AQA return AOA disturbed necessary airplane have longitudinal stability order controllable Therefore important ensure model airplanes longitudinally stable understand longitudinal stability necessary control lets take look what makes airplane stable Figure 1 shows Spitfire flying certain angle attack practical terms means certain air speed number Gs airplane has trimmed fly AQA Because total lift sum lift produced wing horizontal tail may consid ANGLE OF ATTACK RELATIVE WIND ered act center gravity CO Note other point identified known aerodynamic center AC Its importance will explained shortly Now Figure 2 Spitfire has dis turbed its trimmed AOA perhaps fly ing updraft AQA has creased because lift will crease happens because still flying same airspeed Figure 1 creased AQA demands increase lift Gs main thing notice crease lift due increase AQA acts CG AC defini tion ACthe point change lift due change AQA will act Notice case AC some dis tance behind CO Therefore change lift AL due i AAA moment torque about CG lever arm mo ment distance between CG AC measured perpendicular lift vectors As can see Figure 2 moment will tend pitch Spit fires nose down re storing its trimmed AOA situa tion shown Figure 1 Therefore CP position Spitfire longitudi nally stable Now suppose taken Spitfire up different loading resulting aft CG shown Figure 3 CENTER OF GRAVITY p AERODYNAMIC CENTER W FIGURE LEVER ARM AL AO RW wFIGURE 2 1 LLEVER ARM AL AOA RW wFIGURE 3 Bob Doily talk about center gravity CG month case Figure 2 have flown updraft increasing AQA get change lift appears AC before now AC forward CG resulting moment tends pitch aircraft nose upward increasing AQA still further very undesirable means pilot will have fly airplane out small change AQA occurs example unstable airplane Figures 1 2 3 can deduce important fact about longitudinal stability FACT longitudinal stability aircraft depends distance between aircrafts CO AC CG forward AC airplane stable CO behind AC airplane unstable Also degree stability proportinnI distance bet 46 Model Aviation Glossy polished aluminum spectacular finish 0 Westiand Lysander Toledo Orest Drobey master metal craftsman Compound curves wheel shrouds hammered cookie sheets Craft weighs 13-1/2 lb uses Enys 60 / Dennis Crooks won first Precision Scale atToledo WW ii Grumman TBM Avenger Craft built Bob Hoiman plans Servo-operated folding wings controlled transmitter before after flights Twenty-pound craft spans 82 uses Supertigre 2500 engine lift its 20-lb weight No decais used elaborate finish lettering Mike Barbees North American SNJ-2 three-year project Nick ZIroil plans fiberglass fuselage Engine isa Sacha Doimar 37 cu Eleven servos controls flaps retracts smoke William CarpersCurtiss Hawk POE built Royal kit its finish Sig dope over Koverail Engine 05 90 four-stroke CG located stable airplane Gee Yep con cept made easier work fact AC fixed point does move around AQA changes deflec tions control surfaces flaps incidence angle changes reason engi neers work AC rather center pressure CP Once have located AC stays put CP however moves around lift wing horizontal tail changes AC located harder question depends relative sizes wing horizontal tail vertical position horizontal tail small degree wing tail airfoil sections Therefore impossible give location true airplanes However some general rules AC location can given 1 AC will always somewhere tween AC wing AC horizontal tail ACs surfaces lie quarter-chord 25 mean aerodynamic chord MAC points Therefore AC will generally lie aft quarter-chord wing 2 far aft depends size horizontal tail compared wing far wing aver age-sized tail lOo MAC aft quarterchord point probably reasonable number have big tail long moment arm AC will still further aft have small short-coupled tall AC will closer quarter-chord Now CG must forward AC far forward depends stable want airplane airplane too stable CG too far ward will groove well maneuver poor ly Conversely stable very stable will maneuver very easily tend hunt continually oscillate about trim AQA simplest thing can flighttest model CG forward quarter-chord point model will unstable think too stable shift CG aft little time until like way flies Finally need clear up misconcep Continued page 137 do Tabby gave birth five Scale model offspring Sig exhibit Toledo Sports Arena chief mouse-catcher Save Money lable semi-kit $129 ly wood hardwareFIJ $18900 As Featured March 86 RCM Magazine wing span44 wing area609 sq length56 weight65 lbs engine40- 46 2 cycle radio4 channel BoB PARKINSON FLWNG MODELS RRI Queensvllle Ontario LOG IRO Canada Tel 416 478-2632 Z Please add *2000 ship end handling Dealer Inquiries invited August1986 47 ad small. s because depend OPS performance attract attention g4jjsPeoPIeof Co#4etU1o 9*9044 PO Box 26247 New Orleans La 70186 504 242-5967 High Performance Amphibian moat unIque aIrcraft today has added line delta wing kits designed Laddie Mikulasko fully aerobetic off both water lend onepiecs fiberglass fuselage cowl feiring wing-tip floats precision machine-cut foam delta wing assembles quickly end easily4 oz lighter original hales version unplug landing gser water-tight nose wheel mount factory instailedi fly off water snow ice addition floats akils Stability wind penetration overall performanoa combined un believably low landing apsed make Nerthstaa 2001 beat designs yet kit has bsen build end teat flown Laddie Mikulasko complete approval S aV0 iOld Timer fOttS66Si5A3 CbauiW0From sparK 1etS poliltS Taflt5 tjtooe IgnitiOn Engine Parts Only Over 600 items Send $200 current catalog PhD am now planning proposal orbit scale model large space struc ture inside Space Shuttle test using RC operating equipment ows. someday might see astronaut holding RC transmitter Space Shuffle RC Scale/Wischers Continued page 47 tion will recall said earlier AC location does depend relative cidence wing tail Since true might conclude incidence angles have nothing stability abso lutely correct contrary what modelers lieve What relative incidence between wing stabilizer actually does set AQA airplane will trim elevators neutral Since models fly various AQAs small AQAs fast parts flight large AQAs aerobatics takeoff landing relative incidence setting up model er depending flight condition wants model trimmed set wrong relative incidence its no big deal Thats have adjustable control linkages trim control transmitter mistake some people make setting incidences shown plans moving CG until model flies desired AQA speed elevators neutral very bright idea may move CG far aft goes aft AC making airplane unstable Rather fall trap set level longitudinal stability proper place ment CG play hori zontal tail incidence elevator trim until airplane trims desired AQA speed Youll like airplanes handling qualities bet ter crash less often save ballast weight thanks James Ruley foregoing treatise longitudinal stability Scale model ers build kits magazine drawings will have little concern difference inci dence angles between wing stabilizer would have properly set up designer model intentionally set up zero-zero incidence angles provide Patternmodel-type performance will probably have neutral stability will need flown like Pattern ship no relaxation during flight neutral stability model needs continuous control input will climb vertically until runs out energy straight down until meets earth no tendency recover level flight its own stability model will have its CO AC same vertical line experienced fli ers prefer such models especially have background Pattern flying have flown neutrally-stable trainers have hearing Pattern fliers zero-zero angle setup model no longer favored now preference about /2 0 1 0 incidence wing relative stabilizer equal amount downthrust engine mount intend ed provide straight flight transmitter control inputs during vertical maneuvers gravity forces directed toward tail modeler likely concerned about incidence angles person prefers design scratch-build fac tory drawings three-view drawings means measurements taken directly subject aircraft modeler die-hard Scale purist insists upon copying fullsize prototype down last detail including incidence angles wing stabilizer numerous examples aircraft drastic angular differences much 60 Taylorcraft Staggerwing Beechcraft come mind result such setup down-load stabilizer high-wing cabin type also down-load tail due downwash off wing trailing edge case AC affected since total lift sum lift produced wing horizontal tail difference between two forces wing now must lift airplane weight plus stabilizer down-force AC now moves far forward positive longitudi nal stability CG must also moved far forward ahead AC Balancing such model favored 25% 30% wing chord doesnt assure stability particularly takeoff its first flight flier isnt prepared initial steep climb results stall snap roll crash disappoint ed modeler gathers pieces trash bag recommend reducing angular differ ence about 20 kits Spitfire full-size illustrated has 20 incidence wing 00 stabilizer 20 washout wing tip flier knows what expect large angular difference between wing stabilizer incidence built solidly fuselage structure cant easily changed model will have flown elevators drooping drastically experience know diffi cult hold Up elevator throughout first-flight 1748 AD GOES tWIN OUR BACK PA GE AD VERIISEAENT WORLDS 7 CH FM EXPERT len say own 7 diarmel 4 channel Expert FM tiei converson Systems say have 4 5 eliplanes want put receiver mdi eliplane era say tosterice yolfte diarmel 40 youl send franesltter will special line receivers VanenIlter -1 10 morethe nwnber exta receivers mares no ifleresce Retail pace therecelverls$8995Therewil odlwgelortrdngandwe1 pay outhozid freight have another franmeltrer diwnist 46 wait another mo&ie another receiver channel 4 thate eisa poselto hat cue have buy another tanmidlter mo&ie TranmnltW Mo6ie refi plc $4950 EXPERT 7 CHANNEL FEA TURES 1 Dual conversion FM erotIc 2 nicads chaiger 3 Reversing channels 4 Lodvng connectors 5 Dual rate aileron elevator 6 Mixing aileron & rudder elevator & Itapa 7 Servos use Mdstishi #15660 chp 8 ServOs use indirect drive 9 Excellent operation AM envimnment 10 Receiver uses ubra narrow band mufti-pole ceramic filters SERVO 52885 TJL sar LOClirda orweercrw JUSTARRIVEDI COMO 29 RIC Como 29 ie Ike eil engtoea tie cisro toe Sclsruerle pcrbd engtoe orankeliaft aipported doutoc bail beings 11w cano 29155 real powertdant planes like Woild Ennea Widoerd ARF comno 25 allwood Flince ARF rIta Retail plc Ccmo 29 $8495 JUSTARRIVED ZENOAHG-62 Zertoir 042 Isa 378 cikdc todrmagsetolrWonengtoethat toni power standpoInt drordd sqlivalent just tout eie thIs displacement tie madret 0-62 designed light weIrL lAilSer mont toduded lIds angita Retail pike tog pertonner $25985 EXPERT ACCESSORIES Shoen below ue acoessceles Expert FM ltoa cormectors selt-locidrig tyse prevent dtocorsiecton S-25 servo gaas wi avitla U2tfl 5weoTay fl fl I1i 2W1 Servo Ora Ii wAodg ousdor ss Rsa 0 ElEl iTS 24 5wvoEo-oi wAedJng onsiector $450 & ssou ReliC EiipsstNdx Step S59S Retodi NEW CHINA CLIPPER FROM ~TEH Sport version canopy town luIt consfruof Thgqran 5I 3-4 drarmela S- 40 sagne Otidrle 503 SMSS Reti WORLD ENGINES 0960 Rossash Ave cincinnati Ohio 45236 Phone 513 793-50OU Telex 214557 FAX 513 793-7337 August 1986 137 MABYCHI MOTOR $229 15 - 9 Volts HARRY B HIGLEY S SONS INC P 0 BOX 532 GLENWOOD ILL 60425 excitement model can brought back safe landing However opposite holding Down elevator because insuffi cient down-trim available transmitter controls hazardous skilled pilot Scale modeler insists upon reproducing large angular difference model should move CG far forward first flights progressively move rearward later sug gested Mr Ruley case overall airplane weight will probably substantially increased because volume lead nose As Mr Ruley states angular difference doesnt affect longitudinal stability know anguished experience can lead disaster resulting initial instability Toledo agaIn new Toledo exhibition hall under construction Question Will completed time Toledo Expo 1987 visited site impressed its size located newly restored downtown area city Toledo can proud what has accomplished restore beauty area blight Meanwhile old Sports Arena Weak Signals Club thirty-second annual RC Expo attracted usual overwhelming crowds exhibits manufacturers distribu tors retailers course Scale modelers Models display ranged size small Saito 30-powered Dormoy Bath tub monster Douglas DC-3 pair Quadra engines Two winners Precision Scale class models seen previously First place Best Show-winner Dennis Crooks displayed Grumman Avenger has flown two Scale Masters meets model also placed first Chicago Expo second place Cliff Tacies Savoia-Matchetti Pipistrello bomber will flying World Championships Oslo Norway July Larry Gordons 1-scale Grumman F4F-3 Wildcat Quadra engine placed third Military Scale class winner William Carper Curtiss Hawk P-6E Royal kit second-place Focke Wuif FW 190-D9 Don Parks came Pica kit Its unusual finish technique clear MonoKote Chevron Perfect Paint third place Hal Parentis newest Savoia Marchetti SM-79 Italian bomber fourth series Hal First flights made RC World Florida during March Non-Military Scale surprising entry North American SNJ Mike Barbee model finished civil colors Sky Typers skywriting group Mike used Ziroli kit fiberglass fuselage scratch-built Lake Buccaneer LA4200 amphibian secondplace winner Alvin Osminski Third place awarded Joe Mientkiewicz scratch-built Waco Taperwing year ago Orest Drobey displayed Bellanca Air Cruiser Toledo featured polished aluminum metalwork received great attention Orest returned Toledo Westland Lysander again elegantly finished large areas polished aluminum auto body repairman has neces sary skills work metal compound curves Lysanders wheel coverings produced hammering cookie sheets polishing high gloss model received Directors Award As always Toledo generates episodes within main event Toledo Tabby resi dent official Sports Arena rodent-control cat obviously ready have kittens Tabby proceded have offspring Sig ex hibit Hazel Sig-Hesters lap Hazel made hasty arrangements provide nest card board box Tabby gave birth five scale-model kittens did Tabby know among thou sands Toledo visitors Friday morning Hazel person would help time need family moved days end maintenance quarters Tabby returned through largest crowds crossing wide Arena Saturday pay visit Hazel Anyone has visited Sig estab lishment Montezuma knows Hazels love animals Bob Dolly Wischer S-221 Lapham Peak Rd Delafield WI 53018 RC Electrics/Kopski Continued page 51 important because save important ounces completed model always recommend minimum three-channel installation rud der elevator simple servo-driven ON OFF motor power switch recom mend fewer channels radio installation will weigh approximately six seven ounces Later interest proficiency grow can use leftover fourth channel ailerons some aerobatic Electric model Heres come will want decide what preferences number model types choose among include gliders Old-Timers everything else also called sport sport-trainer Within given type also choices Remember what dis cussing entry-level economy Electric will fly schoolyard down street friendly non-hair-raising way have seen power system recommenda tions above work very well quite range models Im partial own Spectra design Reference 2 offers three wing options such kits Olympic II Drifter II Olympic 650 Gentle Lady similar 2-Meter Sailplanes successful converts Electric Several fellow club members have learned fly such models Jim Zarembskis Sky Knight Reference 3 very good sport-trainer model fellow club members learned fly recommended power system Another Jims designs Wasp Leisure kit will fly comfortably Continued page 147 ATTENTION ERS QUAY BARBER MODELS C14 SHOESTRING SEMI-KiT $11995 KITSi5495 Rivets SEMI-KIT $11995 KIT -$15495 EPOXY/GLASS /FOAM/BALS CONSTRUCTION WITh DRAWINGS AND DATA FOR FORMULA 120 PYLON SPORT OR STANDOFF SCALE FULL OR SEMIKITSCosmic 8 10 lbs wAightWind 790 sq wing area SE511K1T $10995 60 2 stroke 12 4 stroke KIT $14495 kit prices plus shipping credit cards welcome Ohio residents add bi 1216 7774172 27106 8utternut Ridge Nnrth Olmated 081044070 Matched Finish System BEST APPEARANCE K&B FIBERGLASS CLOTH K&B Micra-Balloons FILLER K&B SUPER POXY RESIN K&B SUPER PONY THINNER K&B SUPER POXY PRIMER K&B SUPER PONY PAINT KaB MIXING CUPS 138 Model Aviation 0 Wing Span 52 4 cycle annels Acrobatic docile 6 8 hr rapid-fire essembiy precision pro-cut bale- end plywood complete hardware package Included capable complete AMA pattern Dave Robelens Windbreaker Playmate Featured April 1896 Model Aviation 3 Channel portFun Fly 52-4 cycle Fast assembly hand cut kit $4996 Pronto 48 span 5 2 4 cycle annel hand cut kit Easily converted electric excenent nor aegmn nar can ba sat up challenge expert *3996 50span15-25 Super Pronto2-4 cycle 4 channel Same excellent qualities Pronto acrobatic ailerons$4895 AvaIlable dealer order direct Add $2 shipping additional $2 COD save COD send check money order residents add 4% sales tasI TIDEWATER HOBBY ENTERPRISES Route 1 Box 241 D Lanexa Virginia 23089 804-966-5092 EPOXY GLASS COWLS FOR NOSEN PICA 510 MORGAN BALSA USA PLAiT CONCEPT FLEET HOSTETLER RCM T-cRAFT SHEBER PIUS ScALE SUPER cue FOEKER 0-7 BOEINO P-i 2 P26 F4a2 F4R4 SPARROW HAWK GEE BEE MOO Y MACBRIENS TURBULENT CHRISTEN EAGLE BRISIGHELLAS STAROUSTER II V SCALE J3-BI BABY FLYBARY & OTHERS WHEEL PANTS FOR CITABRIA STARSUSTER II PITTS SKYBOLT LIBERTY SPORT CHRISTEN EAGLE PRE HAWK MULLIGAN & OTHERS LARGE SCALE PLANS AVAILABLE Please send $100 complete list supply Modelers fiberglass parts plans Write call us T & D FIBERGLASS SPECIALTIES 3BR25 eLOCK GARDEN CiTY MI 48135 PHONE 313 421-6358 BRAzED So HEAT-TREATED WIRE GEARS 9 CABANER PHONE 1313261-9064 niuriug rurlurmuluu oyrnurn TOP PERFORMANCE K&B ENGINES AirplaneMarine K&B FUELSK&B GLOW PLUGS 9 Blends4 Choices
Edition: Model Aviation - 1986/08
Page Numbers: 46, 47, 137, 138
Radio Control Scale Bob Dolly Wischer LONGITUDINAL STABILITY response March column subject unex pected stalls received letter James M Ruley aerospace engineer spe cializing aircraft stability control working Aeronautical Systems Division USAF Wright-Patterson AFB discussion stability theory follows Longitudinal stability tendency aircraft has trimmed fly cer tain angle attack AQA return AOA disturbed necessary airplane have longitudinal stability order controllable Therefore important ensure model airplanes longitudinally stable understand longitudinal stability necessary control lets take look what makes airplane stable Figure 1 shows Spitfire flying certain angle attack practical terms means certain air speed number Gs airplane has trimmed fly AQA Because total lift sum lift produced wing horizontal tail may consid ANGLE OF ATTACK RELATIVE WIND ered act center gravity CO Note other point identified known aerodynamic center AC Its importance will explained shortly Now Figure 2 Spitfire has dis turbed its trimmed AOA perhaps fly ing updraft AQA has creased because lift will crease happens because still flying same airspeed Figure 1 creased AQA demands increase lift Gs main thing notice crease lift due increase AQA acts CG AC defini tion ACthe point change lift due change AQA will act Notice case AC some dis tance behind CO Therefore change lift AL due i AAA moment torque about CG lever arm mo ment distance between CG AC measured perpendicular lift vectors As can see Figure 2 moment will tend pitch Spit fires nose down re storing its trimmed AOA situa tion shown Figure 1 Therefore CP position Spitfire longitudi nally stable Now suppose taken Spitfire up different loading resulting aft CG shown Figure 3 CENTER OF GRAVITY p AERODYNAMIC CENTER W FIGURE LEVER ARM AL AO RW wFIGURE 2 1 LLEVER ARM AL AOA RW wFIGURE 3 Bob Doily talk about center gravity CG month case Figure 2 have flown updraft increasing AQA get change lift appears AC before now AC forward CG resulting moment tends pitch aircraft nose upward increasing AQA still further very undesirable means pilot will have fly airplane out small change AQA occurs example unstable airplane Figures 1 2 3 can deduce important fact about longitudinal stability FACT longitudinal stability aircraft depends distance between aircrafts CO AC CG forward AC airplane stable CO behind AC airplane unstable Also degree stability proportinnI distance bet 46 Model Aviation Glossy polished aluminum spectacular finish 0 Westiand Lysander Toledo Orest Drobey master metal craftsman Compound curves wheel shrouds hammered cookie sheets Craft weighs 13-1/2 lb uses Enys 60 / Dennis Crooks won first Precision Scale atToledo WW ii Grumman TBM Avenger Craft built Bob Hoiman plans Servo-operated folding wings controlled transmitter before after flights Twenty-pound craft spans 82 uses Supertigre 2500 engine lift its 20-lb weight No decais used elaborate finish lettering Mike Barbees North American SNJ-2 three-year project Nick ZIroil plans fiberglass fuselage Engine isa Sacha Doimar 37 cu Eleven servos controls flaps retracts smoke William CarpersCurtiss Hawk POE built Royal kit its finish Sig dope over Koverail Engine 05 90 four-stroke CG located stable airplane Gee Yep con cept made easier work fact AC fixed point does move around AQA changes deflec tions control surfaces flaps incidence angle changes reason engi neers work AC rather center pressure CP Once have located AC stays put CP however moves around lift wing horizontal tail changes AC located harder question depends relative sizes wing horizontal tail vertical position horizontal tail small degree wing tail airfoil sections Therefore impossible give location true airplanes However some general rules AC location can given 1 AC will always somewhere tween AC wing AC horizontal tail ACs surfaces lie quarter-chord 25 mean aerodynamic chord MAC points Therefore AC will generally lie aft quarter-chord wing 2 far aft depends size horizontal tail compared wing far wing aver age-sized tail lOo MAC aft quarterchord point probably reasonable number have big tail long moment arm AC will still further aft have small short-coupled tall AC will closer quarter-chord Now CG must forward AC far forward depends stable want airplane airplane too stable CG too far ward will groove well maneuver poor ly Conversely stable very stable will maneuver very easily tend hunt continually oscillate about trim AQA simplest thing can flighttest model CG forward quarter-chord point model will unstable think too stable shift CG aft little time until like way flies Finally need clear up misconcep Continued page 137 do Tabby gave birth five Scale model offspring Sig exhibit Toledo Sports Arena chief mouse-catcher Save Money lable semi-kit $129 ly wood hardwareFIJ $18900 As Featured March 86 RCM Magazine wing span44 wing area609 sq length56 weight65 lbs engine40- 46 2 cycle radio4 channel BoB PARKINSON FLWNG MODELS RRI Queensvllle Ontario LOG IRO Canada Tel 416 478-2632 Z Please add *2000 ship end handling Dealer Inquiries invited August1986 47 ad small. s because depend OPS performance attract attention g4jjsPeoPIeof Co#4etU1o 9*9044 PO Box 26247 New Orleans La 70186 504 242-5967 High Performance Amphibian moat unIque aIrcraft today has added line delta wing kits designed Laddie Mikulasko fully aerobetic off both water lend onepiecs fiberglass fuselage cowl feiring wing-tip floats precision machine-cut foam delta wing assembles quickly end easily4 oz lighter original hales version unplug landing gser water-tight nose wheel mount factory instailedi fly off water snow ice addition floats akils Stability wind penetration overall performanoa combined un believably low landing apsed make Nerthstaa 2001 beat designs yet kit has bsen build end teat flown Laddie Mikulasko complete approval S aV0 iOld Timer fOttS66Si5A3 CbauiW0From sparK 1etS poliltS Taflt5 tjtooe IgnitiOn Engine Parts Only Over 600 items Send $200 current catalog PhD am now planning proposal orbit scale model large space struc ture inside Space Shuttle test using RC operating equipment ows. someday might see astronaut holding RC transmitter Space Shuffle RC Scale/Wischers Continued page 47 tion will recall said earlier AC location does depend relative cidence wing tail Since true might conclude incidence angles have nothing stability abso lutely correct contrary what modelers lieve What relative incidence between wing stabilizer actually does set AQA airplane will trim elevators neutral Since models fly various AQAs small AQAs fast parts flight large AQAs aerobatics takeoff landing relative incidence setting up model er depending flight condition wants model trimmed set wrong relative incidence its no big deal Thats have adjustable control linkages trim control transmitter mistake some people make setting incidences shown plans moving CG until model flies desired AQA speed elevators neutral very bright idea may move CG far aft goes aft AC making airplane unstable Rather fall trap set level longitudinal stability proper place ment CG play hori zontal tail incidence elevator trim until airplane trims desired AQA speed Youll like airplanes handling qualities bet ter crash less often save ballast weight thanks James Ruley foregoing treatise longitudinal stability Scale model ers build kits magazine drawings will have little concern difference inci dence angles between wing stabilizer would have properly set up designer model intentionally set up zero-zero incidence angles provide Patternmodel-type performance will probably have neutral stability will need flown like Pattern ship no relaxation during flight neutral stability model needs continuous control input will climb vertically until runs out energy straight down until meets earth no tendency recover level flight its own stability model will have its CO AC same vertical line experienced fli ers prefer such models especially have background Pattern flying have flown neutrally-stable trainers have hearing Pattern fliers zero-zero angle setup model no longer favored now preference about /2 0 1 0 incidence wing relative stabilizer equal amount downthrust engine mount intend ed provide straight flight transmitter control inputs during vertical maneuvers gravity forces directed toward tail modeler likely concerned about incidence angles person prefers design scratch-build fac tory drawings three-view drawings means measurements taken directly subject aircraft modeler die-hard Scale purist insists upon copying fullsize prototype down last detail including incidence angles wing stabilizer numerous examples aircraft drastic angular differences much 60 Taylorcraft Staggerwing Beechcraft come mind result such setup down-load stabilizer high-wing cabin type also down-load tail due downwash off wing trailing edge case AC affected since total lift sum lift produced wing horizontal tail difference between two forces wing now must lift airplane weight plus stabilizer down-force AC now moves far forward positive longitudi nal stability CG must also moved far forward ahead AC Balancing such model favored 25% 30% wing chord doesnt assure stability particularly takeoff its first flight flier isnt prepared initial steep climb results stall snap roll crash disappoint ed modeler gathers pieces trash bag recommend reducing angular differ ence about 20 kits Spitfire full-size illustrated has 20 incidence wing 00 stabilizer 20 washout wing tip flier knows what expect large angular difference between wing stabilizer incidence built solidly fuselage structure cant easily changed model will have flown elevators drooping drastically experience know diffi cult hold Up elevator throughout first-flight 1748 AD GOES tWIN OUR BACK PA GE AD VERIISEAENT WORLDS 7 CH FM EXPERT len say own 7 diarmel 4 channel Expert FM tiei converson Systems say have 4 5 eliplanes want put receiver mdi eliplane era say tosterice yolfte diarmel 40 youl send franesltter will special line receivers VanenIlter -1 10 morethe nwnber exta receivers mares no ifleresce Retail pace therecelverls$8995Therewil odlwgelortrdngandwe1 pay outhozid freight have another franmeltrer diwnist 46 wait another mo&ie another receiver channel 4 thate eisa poselto hat cue have buy another tanmidlter mo&ie TranmnltW Mo6ie refi plc $4950 EXPERT 7 CHANNEL FEA TURES 1 Dual conversion FM erotIc 2 nicads chaiger 3 Reversing channels 4 Lodvng connectors 5 Dual rate aileron elevator 6 Mixing aileron & rudder elevator & Itapa 7 Servos use Mdstishi #15660 chp 8 ServOs use indirect drive 9 Excellent operation AM envimnment 10 Receiver uses ubra narrow band mufti-pole ceramic filters SERVO 52885 TJL sar LOClirda orweercrw JUSTARRIVEDI COMO 29 RIC Como 29 ie Ike eil engtoea tie cisro toe Sclsruerle pcrbd engtoe orankeliaft aipported doutoc bail beings 11w cano 29155 real powertdant planes like Woild Ennea Widoerd ARF comno 25 allwood Flince ARF rIta Retail plc Ccmo 29 $8495 JUSTARRIVED ZENOAHG-62 Zertoir 042 Isa 378 cikdc todrmagsetolrWonengtoethat toni power standpoInt drordd sqlivalent just tout eie thIs displacement tie madret 0-62 designed light weIrL lAilSer mont toduded lIds angita Retail pike tog pertonner $25985 EXPERT ACCESSORIES Shoen below ue acoessceles Expert FM ltoa cormectors selt-locidrig tyse prevent dtocorsiecton S-25 servo gaas wi avitla U2tfl 5weoTay fl fl I1i 2W1 Servo Ora Ii wAodg ousdor ss Rsa 0 ElEl iTS 24 5wvoEo-oi wAedJng onsiector $450 & ssou ReliC EiipsstNdx Step S59S Retodi NEW CHINA CLIPPER FROM ~TEH Sport version canopy town luIt consfruof Thgqran 5I 3-4 drarmela S- 40 sagne Otidrle 503 SMSS Reti WORLD ENGINES 0960 Rossash Ave cincinnati Ohio 45236 Phone 513 793-50OU Telex 214557 FAX 513 793-7337 August 1986 137 MABYCHI MOTOR $229 15 - 9 Volts HARRY B HIGLEY S SONS INC P 0 BOX 532 GLENWOOD ILL 60425 excitement model can brought back safe landing However opposite holding Down elevator because insuffi cient down-trim available transmitter controls hazardous skilled pilot Scale modeler insists upon reproducing large angular difference model should move CG far forward first flights progressively move rearward later sug gested Mr Ruley case overall airplane weight will probably substantially increased because volume lead nose As Mr Ruley states angular difference doesnt affect longitudinal stability know anguished experience can lead disaster resulting initial instability Toledo agaIn new Toledo exhibition hall under construction Question Will completed time Toledo Expo 1987 visited site impressed its size located newly restored downtown area city Toledo can proud what has accomplished restore beauty area blight Meanwhile old Sports Arena Weak Signals Club thirty-second annual RC Expo attracted usual overwhelming crowds exhibits manufacturers distribu tors retailers course Scale modelers Models display ranged size small Saito 30-powered Dormoy Bath tub monster Douglas DC-3 pair Quadra engines Two winners Precision Scale class models seen previously First place Best Show-winner Dennis Crooks displayed Grumman Avenger has flown two Scale Masters meets model also placed first Chicago Expo second place Cliff Tacies Savoia-Matchetti Pipistrello bomber will flying World Championships Oslo Norway July Larry Gordons 1-scale Grumman F4F-3 Wildcat Quadra engine placed third Military Scale class winner William Carper Curtiss Hawk P-6E Royal kit second-place Focke Wuif FW 190-D9 Don Parks came Pica kit Its unusual finish technique clear MonoKote Chevron Perfect Paint third place Hal Parentis newest Savoia Marchetti SM-79 Italian bomber fourth series Hal First flights made RC World Florida during March Non-Military Scale surprising entry North American SNJ Mike Barbee model finished civil colors Sky Typers skywriting group Mike used Ziroli kit fiberglass fuselage scratch-built Lake Buccaneer LA4200 amphibian secondplace winner Alvin Osminski Third place awarded Joe Mientkiewicz scratch-built Waco Taperwing year ago Orest Drobey displayed Bellanca Air Cruiser Toledo featured polished aluminum metalwork received great attention Orest returned Toledo Westland Lysander again elegantly finished large areas polished aluminum auto body repairman has neces sary skills work metal compound curves Lysanders wheel coverings produced hammering cookie sheets polishing high gloss model received Directors Award As always Toledo generates episodes within main event Toledo Tabby resi dent official Sports Arena rodent-control cat obviously ready have kittens Tabby proceded have offspring Sig ex hibit Hazel Sig-Hesters lap Hazel made hasty arrangements provide nest card board box Tabby gave birth five scale-model kittens did Tabby know among thou sands Toledo visitors Friday morning Hazel person would help time need family moved days end maintenance quarters Tabby returned through largest crowds crossing wide Arena Saturday pay visit Hazel Anyone has visited Sig estab lishment Montezuma knows Hazels love animals Bob Dolly Wischer S-221 Lapham Peak Rd Delafield WI 53018 RC Electrics/Kopski Continued page 51 important because save important ounces completed model always recommend minimum three-channel installation rud der elevator simple servo-driven ON OFF motor power switch recom mend fewer channels radio installation will weigh approximately six seven ounces Later interest proficiency grow can use leftover fourth channel ailerons some aerobatic Electric model Heres come will want decide what preferences number model types choose among include gliders Old-Timers everything else also called sport sport-trainer Within given type also choices Remember what dis cussing entry-level economy Electric will fly schoolyard down street friendly non-hair-raising way have seen power system recommenda tions above work very well quite range models Im partial own Spectra design Reference 2 offers three wing options such kits Olympic II Drifter II Olympic 650 Gentle Lady similar 2-Meter Sailplanes successful converts Electric Several fellow club members have learned fly such models Jim Zarembskis Sky Knight Reference 3 very good sport-trainer model fellow club members learned fly recommended power system Another Jims designs Wasp Leisure kit will fly comfortably Continued page 147 ATTENTION ERS QUAY BARBER MODELS C14 SHOESTRING SEMI-KiT $11995 KITSi5495 Rivets SEMI-KIT $11995 KIT -$15495 EPOXY/GLASS /FOAM/BALS CONSTRUCTION WITh DRAWINGS AND DATA FOR FORMULA 120 PYLON SPORT OR STANDOFF SCALE FULL OR SEMIKITSCosmic 8 10 lbs wAightWind 790 sq wing area SE511K1T $10995 60 2 stroke 12 4 stroke KIT $14495 kit prices plus shipping credit cards welcome Ohio residents add bi 1216 7774172 27106 8utternut Ridge Nnrth Olmated 081044070 Matched Finish System BEST APPEARANCE K&B FIBERGLASS CLOTH K&B Micra-Balloons FILLER K&B SUPER POXY RESIN K&B SUPER PONY THINNER K&B SUPER POXY PRIMER K&B SUPER PONY PAINT KaB MIXING CUPS 138 Model Aviation 0 Wing Span 52 4 cycle annels Acrobatic docile 6 8 hr rapid-fire essembiy precision pro-cut bale- end plywood complete hardware package Included capable complete AMA pattern Dave Robelens Windbreaker Playmate Featured April 1896 Model Aviation 3 Channel portFun Fly 52-4 cycle Fast assembly hand cut kit $4996 Pronto 48 span 5 2 4 cycle annel hand cut kit Easily converted electric excenent nor aegmn nar can ba sat up challenge expert *3996 50span15-25 Super Pronto2-4 cycle 4 channel Same excellent qualities Pronto acrobatic ailerons$4895 AvaIlable dealer order direct Add $2 shipping additional $2 COD save COD send check money order residents add 4% sales tasI TIDEWATER HOBBY ENTERPRISES Route 1 Box 241 D Lanexa Virginia 23089 804-966-5092 EPOXY GLASS COWLS FOR NOSEN PICA 510 MORGAN BALSA USA PLAiT CONCEPT FLEET HOSTETLER RCM T-cRAFT SHEBER PIUS ScALE SUPER cue FOEKER 0-7 BOEINO P-i 2 P26 F4a2 F4R4 SPARROW HAWK GEE BEE MOO Y MACBRIENS TURBULENT CHRISTEN EAGLE BRISIGHELLAS STAROUSTER II V SCALE J3-BI BABY FLYBARY & OTHERS WHEEL PANTS FOR CITABRIA STARSUSTER II PITTS SKYBOLT LIBERTY SPORT CHRISTEN EAGLE PRE HAWK MULLIGAN & OTHERS LARGE SCALE PLANS AVAILABLE Please send $100 complete list supply Modelers fiberglass parts plans Write call us T & D FIBERGLASS SPECIALTIES 3BR25 eLOCK GARDEN CiTY MI 48135 PHONE 313 421-6358 BRAzED So HEAT-TREATED WIRE GEARS 9 CABANER PHONE 1313261-9064 niuriug rurlurmuluu oyrnurn TOP PERFORMANCE K&B ENGINES AirplaneMarine K&B FUELSK&B GLOW PLUGS 9 Blends4 Choices