C SPORT AEROBATICS Ron Van Putte ITS DIFFICULT get back regular column after Nats Nats easy cover because things going write about Nats article almost writes itself course getting pictures processed top 40 matrix put together no picnic Nats article still easier regular column After Nats article turned Pattern contests over year source lot ideas pictures gone until spring contests Thank goodness letters people send periodic stacks club newsletters receive AMA Otherwise Id sitting desk blank piece paper pen head absolutely empty ideas Paul Maharis Kew Gardens NY sent card asked could write little subject pushrods Since pushrod important part control system should properly designed fabricated Unfortunately fliers treat pushrod installation almost afterthought As instructor Ive inspected beginners airplanes theres con sistent theme its pushrods accident waiting happen same begin ner wraps center section wing heavy fiberglass cloth extra strength may use soft piece warped -in balsa pushrod Part beginners problems dont realize loads pushrods must stand pushrod has strong enough take both static vibration loads static load comes two sources control surface aircraft acceleration Due way us hinge control surfaces attach control horns airflow over control surface tends blow back surface neutral position force required hold control surface deflected position function amount deflection also aircraft speed make matters worse faster airplane goes control deflection needed perform maneuver like loop normal acceleration G-force causes unsupported pushrod bend Most us support pushrod cut down control friction bending pushrod causes effectively shorter control surface deflects Since elevator horn usually bottom elevator normal acceleration during inside loop causes elevator deflection less expected other hand during outside loop control deflection expected means everything else being equal outside loops will tighter inside loops same amount stick deflection situa tion itself causes problems aerobatic competition could cause serious problems both sport Pattern fliers As pushrod bendsan outside loop 28 Model Aviation Karen Van Puffs doL.-.andful pushrods Some good examplesothers bad Read article youll know which Iwo exampies OT gooa pusnrou consirucllon Note thread binding music wire dowel minimum-angle bends wiresjust enough clear fuselage Ioorly-execuseu puanroos u- genus IflHoIyim view ot Van PutteI ioenix wire flex under airloadscause play con-8 tail reveals thatthe rudder controlled bytwin trol system Such bends should never requiredcables thatall devises secured jam clear fuselage properlynutsto cutdown effects vibration Carb Needles &Throttle Accessible Engine Running $189i Pre-Paid Orders Pay Shipping KIORITZ Deep Fins Optimum Cooling 21/4 Flywheel Small MagnetoPoints Sealed Rear Housing V 1 5/8in Six Bolt Aluminum Hub Endorsed Don Godfrey Phone Limited 607 722-1765Warranty Pre-Drilled Props Available Ask About Custom Built KIORITZ Engines Dealer Inquiries Welcome ENGINES BY GIBBS HOBBY RESEARCH Original Developer Factory Trained Authorized Master Service Dealer SPEC FICATIONS 242 CU lfl 397CC 32HP 8000 rpm Weight 61/2 lb BaII Bearings Crank Caged Rollers Rod Piston Pin Walbro Pump Garb 3 Ring Piston & GIBBS HOBBY & RESEARCH 6195 Hillfield StNW N CANTON OHIO 44720 Phone216499-8854 After6OOPM Accept Visa & Master Card 9 HL GLIDERS KIT iooiirv GASWATCH 70R 3 SATELLITE KITS 1980 catalog 9 NORDIC MR ilIRt COMPETITION GAS FUEL DT TIMERS -$1075 FAI Model Supply P0 BOX 3957TORRANCE CA 90510mOC~IC Aileron flap servos low wing model usually least troublesome can hidden view beneath floor least desirable method concealment raise floor have seen Contest models done effect objectionable pilot sits legs stretched straight forward looking very uncomfortable space between floor instrument panel appears cramped unreal better have aileron pushrod above floor painted flat black minimum visibility Team selection Scale team members have chosen Nats Contestants want eligi bility following years World Champion ship team will need enter models Nats comply FAI rules beginning 1981 odd-numbered years thereafter say plane used Nats must also used World Championships entrant must have least FAI model 1982 WC team selection 1981 Nats means models must meet following specifications 6kg 1322 lb weight fuel wing loading 100 grams per square decimeter 3277 oz per square foot area wing horizontal tail surfaces com bined maximum area 150 sq deci meters 2325 sq foregoing applies both F4C Precision Standoff Sport Scale airplanes Precision Scale entrants 1981 Nats seek eligibility 1982 WC will limited total engine displacement regardless number engines 10cc 61 Cu 1983 engine size limit becomes same Sport Scale 10cc single engine 15cc twins 20cc three Contestants seeking place team will have models judged both static flight AMA rules Kitchener-Waterloo revisited Scale Rally Kitchener Ontario Canada continues growing size though organizers Flying Dutchmen RC Model Club no adver tising 1980 Rally attracted 208 airplanes 53 Giant Scale really one-day event heavy rains dampened activity Saturday Such efficiency organized flight line able make four flights Sunday could have popular frequencies fortunate course six planes air time common previous year seen several unfin ished models reappeared completed condition flown Spectacular impressive eight-engine Hughes Spruce Goose built Steve Gray Frank Evans Tom Dietrich four 05 25 engines half 16-ft wing controlled servo side system proved very effective steering water rudder needed auxiliary levers transmitter ganged together tie-bar throttle control Either side bar can advanced individually whole bar moved control eight engines Movies shown Waterloo University demonstrate very stable flight Goose has now flights prototype always attend KW Rally see out-ofordinary models year rewarded several may hard imagine mere Piper Cub meets expectations -scale J3 former World Champion Bob Nelitz truly outstanding Precision Scale quality too often found Giant Mammoth Scale planes Bobs Cub absolutely precise respect Quadra almost completely hidden detailed four-cylinder dummy Conti nental engine has wired spark plugs accurately formed cylinders heads cooling baffles properly shaped fuel tank filled correct location after removing tank cap has typical wire float gas gauge flying low close exposed wire gives indica tion fuel remaining tiny detail faithfully reproduced including characteristic brace wire terminations tail surfaces Ailerons operated cables extend along lift struts air no question Bob has achieved ultimate realism East Wings Club Memphis MI ac counted 14 high-quality planes rally including Henschel 126A1 Doug Moore collection four Carl Skiba Westland Lysander Fiesler Storch Curtiss Hawk P6-E Gee Bee R- 1 group also included Lockheed Hercules Skip Mast Lockheed Orion Steve Sauger Der Jaeger homebuilt Werner Doser represents portion output single Scale-oriented club As usual Giant Scale class dominated Stars Club Olean NY year number Fokker D-VIII models increased four addition usual squadron Bristol Scouts revealing facts rally 25% participants brought Giant airplanes good indication trend large models NASA membership Bob Underwood president National Association Scale Aeromodelers has requested anyone has paid dues has received membership card news letters should write Bob Underwood 4109 Concord Oaks StLouis MO 63128 John Preston 7012 Elvira Court Falls Church VA 22042 NASA needs know anyone has inadvertently forgotten past Bob Dolly Wischer Rt 1 S-221 Lapham Peak Road Delafield WI 53018 RC Aerobatics/Van Putte Continued page 28 increased deflection elevator causes higher normal acceleration tighter loop causes pushrod bend further causes elevator deflect more. combination conditions vicious cycle can end either wing pushrod failure course situation reversed elevator horn top elevator case inside loops will tighter outside loops Turbulence causes oscillatory loads control surfaces due dynamic magnification factor such loads higher static loads way elevator rudder horn clevis wear out rudder especial ly prone turbulence problems because its control horn short causing higher pushrod forces both neutral deflected positions situation sounds pretty grim doesnt However few good design procedures will alleviate problems prefer use 5/16-in wood dowels pushrods rather -in fiberglass arrow shafts 5/16-in dowel strong enough resist bending due normal loads light enough keep weight down end pushrod drill 1/16-in hole side-to-side about end cut 1/16-in groove hole end along side piece 1/16-in music wire bent 900 just enough wire bend go through dowel 106 Model Aviation TH vumi I1E-ItLU UULLLUIA iaeai mouei ror sport scale flyer Its gentle forgiving nature make perfect begin ners yet quite responsive skilled hands balsa construc tion light strong Porterfield can rog grass field climb steeply avoid obstacles Its light wing loading lets land dime give nine cents change Join quiet revolution enjoy Portertield Collegiate neighborhood park school yard Wing span 695 Area 695 sq Weight 4 lbs 3 channel radio Astro 15 can also use Astro 25 15 25 glow engine 1018 13377 Beach Ave Venice CA 90291 SPORT TRAINER ASTRO SPORT pert little sport trainer designed popular Astro 05 fight system can built high wing cabin rudder elevator control shoulder wing ailerons pylon racing aerobatic flying Span 37 inches wing area 292 sq inches weight 28 oz light weight 3 channel radio 1019 ASTRO FI1IUHT InC PIONEERS IN SILENT FLIGHT MASTER AIRSCREW ANNOUNCING NEW VIA SERIES Accurately Pitched Balanced High Performance Alble TSo,sh Ledng e wire positioned groove bound carpet thread along length wire dowel transverse hole end dowel Finally five-minute epoxy worked thread lock dowel Care should taken keep wire pieces end pushrod short possible because dowel has much bending strength music wire usually put right angle bend wire servo end pushrod use Ace Swing-In Keeper servo arm control horn end pushrod sweat-solder threaded coupler using silver solder install clevis provide adjustment also use ajam nut threaded coupler lock clevis place after adjust ments have made keeps clevis vibrating duringfltght wearing out threads Exit holes slots fuselage should fit wire end pushrod closely possible binding cut down control surface movement due wire flexing exit sure keep bends exit wire minimum avoid further play control surface installing rudder elevator pushrods make sure well clear another avoid both extra load servos servo centering problems due friction caused dowels rubbing together Thats takes have strong pushrod works well Take time good job youll never have worry about pushrods being problem Ed Cregger Pennsville NJ sent letter began am brand new Pattern tlying having flown first contest last Sunday am hooked first place Novice pretty well wrapped up third round buried Kaos during Three Horizonal Rolls Iplacedthird instead Ed went describe three factors thought contributed crash ailerons too sensitive Hes probably right Unfortunately its uncommon discover beginners have airplanes far too sensitive both pitch roll setting up ailerons its good idea have friend time three rolls adjust full-aileron deflection achieve five-second maneuver time Its lot easier apply correct amount elevator airplane rolling proper rate scores should better too because thats what says AMA rule book Ed went say decided compete Pattern flying last spring felt have latest sophisticated equipment know super radio super Schnuerle 60 latest fiberglass creation complete $100 retracts Needless say Im glad wasnt flying combination last Sunday competitive Kaos 60 powered Eagle 60 piloted Kraft KP-5C radio thumbs far important what fly long airplane capable performing maneuvers After No viceclass flying Im talking about Im sure plane like Curare Phoenix 8 desirable Novice flying anything less Nats-level competition course basic ally what said article Im sure plenty Pattern fliers started out latest pattern design equipment have very successful pursuit victory people Im concerned like myself have desire compete arent willing make large financial commit ment arent capable building aircraft commonly thought necessary competitive good news isnt necessary go route straight plane lots practice appear far important Thanks Ed couldnt have said better myself course agree what wrote because Ive preaching same story years Take good design build straight install reliable engine radioand practice get Expert Master class can worry about needing super Wifferdill III airplane Ripsnorter 61 PDP engine/pipe Electro Marvel J-9 radio youll still need practice Ron Van Putte 111 Sleepy Oaks Rd Fort Walton Beach FL 32548 Please note new address writing advestigen mentioui read about MA January 1981 107 SPORT SCALE BARRONS LGASSIGS PLANS & CONSTR MANUAL Curtiss Hawk P6E Stinson Reliant SR9 1/4SCALE 9455P $2250 IAScALE IZBSP $2500 2SCALE BISPAN 51250 SCALE 34SPAN $1500 13SCALE 471/4SR51050 12 SCALE GiSPAN $ 1250 Curtiss FIIC2 Curtiss Gulfhawk IA IA SCALE 94SP $3000 1/4SCALE 945SP3000 2SCALE 63SP $1500 2SCALE 63SP sO0 PLEASE ADD $200 FOR P/N suo $oo WO TE FOR MAIL NOgL~ INFORMAT ONCATALOGE NCLUDE $ 00 FOR CATALOGE I2I3HOLLY SPRING LANE GRAND BLANCMI 40430
Edition: Model Aviation - 1981/01
Page Numbers: 28, 106, 107
C SPORT AEROBATICS Ron Van Putte ITS DIFFICULT get back regular column after Nats Nats easy cover because things going write about Nats article almost writes itself course getting pictures processed top 40 matrix put together no picnic Nats article still easier regular column After Nats article turned Pattern contests over year source lot ideas pictures gone until spring contests Thank goodness letters people send periodic stacks club newsletters receive AMA Otherwise Id sitting desk blank piece paper pen head absolutely empty ideas Paul Maharis Kew Gardens NY sent card asked could write little subject pushrods Since pushrod important part control system should properly designed fabricated Unfortunately fliers treat pushrod installation almost afterthought As instructor Ive inspected beginners airplanes theres con sistent theme its pushrods accident waiting happen same begin ner wraps center section wing heavy fiberglass cloth extra strength may use soft piece warped -in balsa pushrod Part beginners problems dont realize loads pushrods must stand pushrod has strong enough take both static vibration loads static load comes two sources control surface aircraft acceleration Due way us hinge control surfaces attach control horns airflow over control surface tends blow back surface neutral position force required hold control surface deflected position function amount deflection also aircraft speed make matters worse faster airplane goes control deflection needed perform maneuver like loop normal acceleration G-force causes unsupported pushrod bend Most us support pushrod cut down control friction bending pushrod causes effectively shorter control surface deflects Since elevator horn usually bottom elevator normal acceleration during inside loop causes elevator deflection less expected other hand during outside loop control deflection expected means everything else being equal outside loops will tighter inside loops same amount stick deflection situa tion itself causes problems aerobatic competition could cause serious problems both sport Pattern fliers As pushrod bendsan outside loop 28 Model Aviation Karen Van Puffs doL.-.andful pushrods Some good examplesothers bad Read article youll know which Iwo exampies OT gooa pusnrou consirucllon Note thread binding music wire dowel minimum-angle bends wiresjust enough clear fuselage Ioorly-execuseu puanroos u- genus IflHoIyim view ot Van PutteI ioenix wire flex under airloadscause play con-8 tail reveals thatthe rudder controlled bytwin trol system Such bends should never requiredcables thatall devises secured jam clear fuselage properlynutsto cutdown effects vibration Carb Needles &Throttle Accessible Engine Running $189i Pre-Paid Orders Pay Shipping KIORITZ Deep Fins Optimum Cooling 21/4 Flywheel Small MagnetoPoints Sealed Rear Housing V 1 5/8in Six Bolt Aluminum Hub Endorsed Don Godfrey Phone Limited 607 722-1765Warranty Pre-Drilled Props Available Ask About Custom Built KIORITZ Engines Dealer Inquiries Welcome ENGINES BY GIBBS HOBBY RESEARCH Original Developer Factory Trained Authorized Master Service Dealer SPEC FICATIONS 242 CU lfl 397CC 32HP 8000 rpm Weight 61/2 lb BaII Bearings Crank Caged Rollers Rod Piston Pin Walbro Pump Garb 3 Ring Piston & GIBBS HOBBY & RESEARCH 6195 Hillfield StNW N CANTON OHIO 44720 Phone216499-8854 After6OOPM Accept Visa & Master Card 9 HL GLIDERS KIT iooiirv GASWATCH 70R 3 SATELLITE KITS 1980 catalog 9 NORDIC MR ilIRt COMPETITION GAS FUEL DT TIMERS -$1075 FAI Model Supply P0 BOX 3957TORRANCE CA 90510mOC~IC Aileron flap servos low wing model usually least troublesome can hidden view beneath floor least desirable method concealment raise floor have seen Contest models done effect objectionable pilot sits legs stretched straight forward looking very uncomfortable space between floor instrument panel appears cramped unreal better have aileron pushrod above floor painted flat black minimum visibility Team selection Scale team members have chosen Nats Contestants want eligi bility following years World Champion ship team will need enter models Nats comply FAI rules beginning 1981 odd-numbered years thereafter say plane used Nats must also used World Championships entrant must have least FAI model 1982 WC team selection 1981 Nats means models must meet following specifications 6kg 1322 lb weight fuel wing loading 100 grams per square decimeter 3277 oz per square foot area wing horizontal tail surfaces com bined maximum area 150 sq deci meters 2325 sq foregoing applies both F4C Precision Standoff Sport Scale airplanes Precision Scale entrants 1981 Nats seek eligibility 1982 WC will limited total engine displacement regardless number engines 10cc 61 Cu 1983 engine size limit becomes same Sport Scale 10cc single engine 15cc twins 20cc three Contestants seeking place team will have models judged both static flight AMA rules Kitchener-Waterloo revisited Scale Rally Kitchener Ontario Canada continues growing size though organizers Flying Dutchmen RC Model Club no adver tising 1980 Rally attracted 208 airplanes 53 Giant Scale really one-day event heavy rains dampened activity Saturday Such efficiency organized flight line able make four flights Sunday could have popular frequencies fortunate course six planes air time common previous year seen several unfin ished models reappeared completed condition flown Spectacular impressive eight-engine Hughes Spruce Goose built Steve Gray Frank Evans Tom Dietrich four 05 25 engines half 16-ft wing controlled servo side system proved very effective steering water rudder needed auxiliary levers transmitter ganged together tie-bar throttle control Either side bar can advanced individually whole bar moved control eight engines Movies shown Waterloo University demonstrate very stable flight Goose has now flights prototype always attend KW Rally see out-ofordinary models year rewarded several may hard imagine mere Piper Cub meets expectations -scale J3 former World Champion Bob Nelitz truly outstanding Precision Scale quality too often found Giant Mammoth Scale planes Bobs Cub absolutely precise respect Quadra almost completely hidden detailed four-cylinder dummy Conti nental engine has wired spark plugs accurately formed cylinders heads cooling baffles properly shaped fuel tank filled correct location after removing tank cap has typical wire float gas gauge flying low close exposed wire gives indica tion fuel remaining tiny detail faithfully reproduced including characteristic brace wire terminations tail surfaces Ailerons operated cables extend along lift struts air no question Bob has achieved ultimate realism East Wings Club Memphis MI ac counted 14 high-quality planes rally including Henschel 126A1 Doug Moore collection four Carl Skiba Westland Lysander Fiesler Storch Curtiss Hawk P6-E Gee Bee R- 1 group also included Lockheed Hercules Skip Mast Lockheed Orion Steve Sauger Der Jaeger homebuilt Werner Doser represents portion output single Scale-oriented club As usual Giant Scale class dominated Stars Club Olean NY year number Fokker D-VIII models increased four addition usual squadron Bristol Scouts revealing facts rally 25% participants brought Giant airplanes good indication trend large models NASA membership Bob Underwood president National Association Scale Aeromodelers has requested anyone has paid dues has received membership card news letters should write Bob Underwood 4109 Concord Oaks StLouis MO 63128 John Preston 7012 Elvira Court Falls Church VA 22042 NASA needs know anyone has inadvertently forgotten past Bob Dolly Wischer Rt 1 S-221 Lapham Peak Road Delafield WI 53018 RC Aerobatics/Van Putte Continued page 28 increased deflection elevator causes higher normal acceleration tighter loop causes pushrod bend further causes elevator deflect more. combination conditions vicious cycle can end either wing pushrod failure course situation reversed elevator horn top elevator case inside loops will tighter outside loops Turbulence causes oscillatory loads control surfaces due dynamic magnification factor such loads higher static loads way elevator rudder horn clevis wear out rudder especial ly prone turbulence problems because its control horn short causing higher pushrod forces both neutral deflected positions situation sounds pretty grim doesnt However few good design procedures will alleviate problems prefer use 5/16-in wood dowels pushrods rather -in fiberglass arrow shafts 5/16-in dowel strong enough resist bending due normal loads light enough keep weight down end pushrod drill 1/16-in hole side-to-side about end cut 1/16-in groove hole end along side piece 1/16-in music wire bent 900 just enough wire bend go through dowel 106 Model Aviation TH vumi I1E-ItLU UULLLUIA iaeai mouei ror sport scale flyer Its gentle forgiving nature make perfect begin ners yet quite responsive skilled hands balsa construc tion light strong Porterfield can rog grass field climb steeply avoid obstacles Its light wing loading lets land dime give nine cents change Join quiet revolution enjoy Portertield Collegiate neighborhood park school yard Wing span 695 Area 695 sq Weight 4 lbs 3 channel radio Astro 15 can also use Astro 25 15 25 glow engine 1018 13377 Beach Ave Venice CA 90291 SPORT TRAINER ASTRO SPORT pert little sport trainer designed popular Astro 05 fight system can built high wing cabin rudder elevator control shoulder wing ailerons pylon racing aerobatic flying Span 37 inches wing area 292 sq inches weight 28 oz light weight 3 channel radio 1019 ASTRO FI1IUHT InC PIONEERS IN SILENT FLIGHT MASTER AIRSCREW ANNOUNCING NEW VIA SERIES Accurately Pitched Balanced High Performance Alble TSo,sh Ledng e wire positioned groove bound carpet thread along length wire dowel transverse hole end dowel Finally five-minute epoxy worked thread lock dowel Care should taken keep wire pieces end pushrod short possible because dowel has much bending strength music wire usually put right angle bend wire servo end pushrod use Ace Swing-In Keeper servo arm control horn end pushrod sweat-solder threaded coupler using silver solder install clevis provide adjustment also use ajam nut threaded coupler lock clevis place after adjust ments have made keeps clevis vibrating duringfltght wearing out threads Exit holes slots fuselage should fit wire end pushrod closely possible binding cut down control surface movement due wire flexing exit sure keep bends exit wire minimum avoid further play control surface installing rudder elevator pushrods make sure well clear another avoid both extra load servos servo centering problems due friction caused dowels rubbing together Thats takes have strong pushrod works well Take time good job youll never have worry about pushrods being problem Ed Cregger Pennsville NJ sent letter began am brand new Pattern tlying having flown first contest last Sunday am hooked first place Novice pretty well wrapped up third round buried Kaos during Three Horizonal Rolls Iplacedthird instead Ed went describe three factors thought contributed crash ailerons too sensitive Hes probably right Unfortunately its uncommon discover beginners have airplanes far too sensitive both pitch roll setting up ailerons its good idea have friend time three rolls adjust full-aileron deflection achieve five-second maneuver time Its lot easier apply correct amount elevator airplane rolling proper rate scores should better too because thats what says AMA rule book Ed went say decided compete Pattern flying last spring felt have latest sophisticated equipment know super radio super Schnuerle 60 latest fiberglass creation complete $100 retracts Needless say Im glad wasnt flying combination last Sunday competitive Kaos 60 powered Eagle 60 piloted Kraft KP-5C radio thumbs far important what fly long airplane capable performing maneuvers After No viceclass flying Im talking about Im sure plane like Curare Phoenix 8 desirable Novice flying anything less Nats-level competition course basic ally what said article Im sure plenty Pattern fliers started out latest pattern design equipment have very successful pursuit victory people Im concerned like myself have desire compete arent willing make large financial commit ment arent capable building aircraft commonly thought necessary competitive good news isnt necessary go route straight plane lots practice appear far important Thanks Ed couldnt have said better myself course agree what wrote because Ive preaching same story years Take good design build straight install reliable engine radioand practice get Expert Master class can worry about needing super Wifferdill III airplane Ripsnorter 61 PDP engine/pipe Electro Marvel J-9 radio youll still need practice Ron Van Putte 111 Sleepy Oaks Rd Fort Walton Beach FL 32548 Please note new address writing advestigen mentioui read about MA January 1981 107 SPORT SCALE BARRONS LGASSIGS PLANS & CONSTR MANUAL Curtiss Hawk P6E Stinson Reliant SR9 1/4SCALE 9455P $2250 IAScALE IZBSP $2500 2SCALE BISPAN 51250 SCALE 34SPAN $1500 13SCALE 471/4SR51050 12 SCALE GiSPAN $ 1250 Curtiss FIIC2 Curtiss Gulfhawk IA IA SCALE 94SP $3000 1/4SCALE 945SP3000 2SCALE 63SP $1500 2SCALE 63SP sO0 PLEASE ADD $200 FOR P/N suo $oo WO TE FOR MAIL NOgL~ INFORMAT ONCATALOGE NCLUDE $ 00 FOR CATALOGE I2I3HOLLY SPRING LANE GRAND BLANCMI 40430
Edition: Model Aviation - 1981/01
Page Numbers: 28, 106, 107
C SPORT AEROBATICS Ron Van Putte ITS DIFFICULT get back regular column after Nats Nats easy cover because things going write about Nats article almost writes itself course getting pictures processed top 40 matrix put together no picnic Nats article still easier regular column After Nats article turned Pattern contests over year source lot ideas pictures gone until spring contests Thank goodness letters people send periodic stacks club newsletters receive AMA Otherwise Id sitting desk blank piece paper pen head absolutely empty ideas Paul Maharis Kew Gardens NY sent card asked could write little subject pushrods Since pushrod important part control system should properly designed fabricated Unfortunately fliers treat pushrod installation almost afterthought As instructor Ive inspected beginners airplanes theres con sistent theme its pushrods accident waiting happen same begin ner wraps center section wing heavy fiberglass cloth extra strength may use soft piece warped -in balsa pushrod Part beginners problems dont realize loads pushrods must stand pushrod has strong enough take both static vibration loads static load comes two sources control surface aircraft acceleration Due way us hinge control surfaces attach control horns airflow over control surface tends blow back surface neutral position force required hold control surface deflected position function amount deflection also aircraft speed make matters worse faster airplane goes control deflection needed perform maneuver like loop normal acceleration G-force causes unsupported pushrod bend Most us support pushrod cut down control friction bending pushrod causes effectively shorter control surface deflects Since elevator horn usually bottom elevator normal acceleration during inside loop causes elevator deflection less expected other hand during outside loop control deflection expected means everything else being equal outside loops will tighter inside loops same amount stick deflection situa tion itself causes problems aerobatic competition could cause serious problems both sport Pattern fliers As pushrod bendsan outside loop 28 Model Aviation Karen Van Puffs doL.-.andful pushrods Some good examplesothers bad Read article youll know which Iwo exampies OT gooa pusnrou consirucllon Note thread binding music wire dowel minimum-angle bends wiresjust enough clear fuselage Ioorly-execuseu puanroos u- genus IflHoIyim view ot Van PutteI ioenix wire flex under airloadscause play con-8 tail reveals thatthe rudder controlled bytwin trol system Such bends should never requiredcables thatall devises secured jam clear fuselage properlynutsto cutdown effects vibration Carb Needles &Throttle Accessible Engine Running $189i Pre-Paid Orders Pay Shipping KIORITZ Deep Fins Optimum Cooling 21/4 Flywheel Small MagnetoPoints Sealed Rear Housing V 1 5/8in Six Bolt Aluminum Hub Endorsed Don Godfrey Phone Limited 607 722-1765Warranty Pre-Drilled Props Available Ask About Custom Built KIORITZ Engines Dealer Inquiries Welcome ENGINES BY GIBBS HOBBY RESEARCH Original Developer Factory Trained Authorized Master Service Dealer SPEC FICATIONS 242 CU lfl 397CC 32HP 8000 rpm Weight 61/2 lb BaII Bearings Crank Caged Rollers Rod Piston Pin Walbro Pump Garb 3 Ring Piston & GIBBS HOBBY & RESEARCH 6195 Hillfield StNW N CANTON OHIO 44720 Phone216499-8854 After6OOPM Accept Visa & Master Card 9 HL GLIDERS KIT iooiirv GASWATCH 70R 3 SATELLITE KITS 1980 catalog 9 NORDIC MR ilIRt COMPETITION GAS FUEL DT TIMERS -$1075 FAI Model Supply P0 BOX 3957TORRANCE CA 90510mOC~IC Aileron flap servos low wing model usually least troublesome can hidden view beneath floor least desirable method concealment raise floor have seen Contest models done effect objectionable pilot sits legs stretched straight forward looking very uncomfortable space between floor instrument panel appears cramped unreal better have aileron pushrod above floor painted flat black minimum visibility Team selection Scale team members have chosen Nats Contestants want eligi bility following years World Champion ship team will need enter models Nats comply FAI rules beginning 1981 odd-numbered years thereafter say plane used Nats must also used World Championships entrant must have least FAI model 1982 WC team selection 1981 Nats means models must meet following specifications 6kg 1322 lb weight fuel wing loading 100 grams per square decimeter 3277 oz per square foot area wing horizontal tail surfaces com bined maximum area 150 sq deci meters 2325 sq foregoing applies both F4C Precision Standoff Sport Scale airplanes Precision Scale entrants 1981 Nats seek eligibility 1982 WC will limited total engine displacement regardless number engines 10cc 61 Cu 1983 engine size limit becomes same Sport Scale 10cc single engine 15cc twins 20cc three Contestants seeking place team will have models judged both static flight AMA rules Kitchener-Waterloo revisited Scale Rally Kitchener Ontario Canada continues growing size though organizers Flying Dutchmen RC Model Club no adver tising 1980 Rally attracted 208 airplanes 53 Giant Scale really one-day event heavy rains dampened activity Saturday Such efficiency organized flight line able make four flights Sunday could have popular frequencies fortunate course six planes air time common previous year seen several unfin ished models reappeared completed condition flown Spectacular impressive eight-engine Hughes Spruce Goose built Steve Gray Frank Evans Tom Dietrich four 05 25 engines half 16-ft wing controlled servo side system proved very effective steering water rudder needed auxiliary levers transmitter ganged together tie-bar throttle control Either side bar can advanced individually whole bar moved control eight engines Movies shown Waterloo University demonstrate very stable flight Goose has now flights prototype always attend KW Rally see out-ofordinary models year rewarded several may hard imagine mere Piper Cub meets expectations -scale J3 former World Champion Bob Nelitz truly outstanding Precision Scale quality too often found Giant Mammoth Scale planes Bobs Cub absolutely precise respect Quadra almost completely hidden detailed four-cylinder dummy Conti nental engine has wired spark plugs accurately formed cylinders heads cooling baffles properly shaped fuel tank filled correct location after removing tank cap has typical wire float gas gauge flying low close exposed wire gives indica tion fuel remaining tiny detail faithfully reproduced including characteristic brace wire terminations tail surfaces Ailerons operated cables extend along lift struts air no question Bob has achieved ultimate realism East Wings Club Memphis MI ac counted 14 high-quality planes rally including Henschel 126A1 Doug Moore collection four Carl Skiba Westland Lysander Fiesler Storch Curtiss Hawk P6-E Gee Bee R- 1 group also included Lockheed Hercules Skip Mast Lockheed Orion Steve Sauger Der Jaeger homebuilt Werner Doser represents portion output single Scale-oriented club As usual Giant Scale class dominated Stars Club Olean NY year number Fokker D-VIII models increased four addition usual squadron Bristol Scouts revealing facts rally 25% participants brought Giant airplanes good indication trend large models NASA membership Bob Underwood president National Association Scale Aeromodelers has requested anyone has paid dues has received membership card news letters should write Bob Underwood 4109 Concord Oaks StLouis MO 63128 John Preston 7012 Elvira Court Falls Church VA 22042 NASA needs know anyone has inadvertently forgotten past Bob Dolly Wischer Rt 1 S-221 Lapham Peak Road Delafield WI 53018 RC Aerobatics/Van Putte Continued page 28 increased deflection elevator causes higher normal acceleration tighter loop causes pushrod bend further causes elevator deflect more. combination conditions vicious cycle can end either wing pushrod failure course situation reversed elevator horn top elevator case inside loops will tighter outside loops Turbulence causes oscillatory loads control surfaces due dynamic magnification factor such loads higher static loads way elevator rudder horn clevis wear out rudder especial ly prone turbulence problems because its control horn short causing higher pushrod forces both neutral deflected positions situation sounds pretty grim doesnt However few good design procedures will alleviate problems prefer use 5/16-in wood dowels pushrods rather -in fiberglass arrow shafts 5/16-in dowel strong enough resist bending due normal loads light enough keep weight down end pushrod drill 1/16-in hole side-to-side about end cut 1/16-in groove hole end along side piece 1/16-in music wire bent 900 just enough wire bend go through dowel 106 Model Aviation TH vumi I1E-ItLU UULLLUIA iaeai mouei ror sport scale flyer Its gentle forgiving nature make perfect begin ners yet quite responsive skilled hands balsa construc tion light strong Porterfield can rog grass field climb steeply avoid obstacles Its light wing loading lets land dime give nine cents change Join quiet revolution enjoy Portertield Collegiate neighborhood park school yard Wing span 695 Area 695 sq Weight 4 lbs 3 channel radio Astro 15 can also use Astro 25 15 25 glow engine 1018 13377 Beach Ave Venice CA 90291 SPORT TRAINER ASTRO SPORT pert little sport trainer designed popular Astro 05 fight system can built high wing cabin rudder elevator control shoulder wing ailerons pylon racing aerobatic flying Span 37 inches wing area 292 sq inches weight 28 oz light weight 3 channel radio 1019 ASTRO FI1IUHT InC PIONEERS IN SILENT FLIGHT MASTER AIRSCREW ANNOUNCING NEW VIA SERIES Accurately Pitched Balanced High Performance Alble TSo,sh Ledng e wire positioned groove bound carpet thread along length wire dowel transverse hole end dowel Finally five-minute epoxy worked thread lock dowel Care should taken keep wire pieces end pushrod short possible because dowel has much bending strength music wire usually put right angle bend wire servo end pushrod use Ace Swing-In Keeper servo arm control horn end pushrod sweat-solder threaded coupler using silver solder install clevis provide adjustment also use ajam nut threaded coupler lock clevis place after adjust ments have made keeps clevis vibrating duringfltght wearing out threads Exit holes slots fuselage should fit wire end pushrod closely possible binding cut down control surface movement due wire flexing exit sure keep bends exit wire minimum avoid further play control surface installing rudder elevator pushrods make sure well clear another avoid both extra load servos servo centering problems due friction caused dowels rubbing together Thats takes have strong pushrod works well Take time good job youll never have worry about pushrods being problem Ed Cregger Pennsville NJ sent letter began am brand new Pattern tlying having flown first contest last Sunday am hooked first place Novice pretty well wrapped up third round buried Kaos during Three Horizonal Rolls Iplacedthird instead Ed went describe three factors thought contributed crash ailerons too sensitive Hes probably right Unfortunately its uncommon discover beginners have airplanes far too sensitive both pitch roll setting up ailerons its good idea have friend time three rolls adjust full-aileron deflection achieve five-second maneuver time Its lot easier apply correct amount elevator airplane rolling proper rate scores should better too because thats what says AMA rule book Ed went say decided compete Pattern flying last spring felt have latest sophisticated equipment know super radio super Schnuerle 60 latest fiberglass creation complete $100 retracts Needless say Im glad wasnt flying combination last Sunday competitive Kaos 60 powered Eagle 60 piloted Kraft KP-5C radio thumbs far important what fly long airplane capable performing maneuvers After No viceclass flying Im talking about Im sure plane like Curare Phoenix 8 desirable Novice flying anything less Nats-level competition course basic ally what said article Im sure plenty Pattern fliers started out latest pattern design equipment have very successful pursuit victory people Im concerned like myself have desire compete arent willing make large financial commit ment arent capable building aircraft commonly thought necessary competitive good news isnt necessary go route straight plane lots practice appear far important Thanks Ed couldnt have said better myself course agree what wrote because Ive preaching same story years Take good design build straight install reliable engine radioand practice get Expert Master class can worry about needing super Wifferdill III airplane Ripsnorter 61 PDP engine/pipe Electro Marvel J-9 radio youll still need practice Ron Van Putte 111 Sleepy Oaks Rd Fort Walton Beach FL 32548 Please note new address writing advestigen mentioui read about MA January 1981 107 SPORT SCALE BARRONS LGASSIGS PLANS & CONSTR MANUAL Curtiss Hawk P6E Stinson Reliant SR9 1/4SCALE 9455P $2250 IAScALE IZBSP $2500 2SCALE BISPAN 51250 SCALE 34SPAN $1500 13SCALE 471/4SR51050 12 SCALE GiSPAN $ 1250 Curtiss FIIC2 Curtiss Gulfhawk IA IA SCALE 94SP $3000 1/4SCALE 945SP3000 2SCALE 63SP $1500 2SCALE 63SP sO0 PLEASE ADD $200 FOR P/N suo $oo WO TE FOR MAIL NOgL~ INFORMAT ONCATALOGE NCLUDE $ 00 FOR CATALOGE I2I3HOLLY SPRING LANE GRAND BLANCMI 40430