John Preston___________________________ Safety Comes First Some thoughts structural failures models pusher props can pose unexpected hazard PTEROSAURUS WRECKED radio inter ference Im sure modelers have heard project sponsored Smith sonian Institution Johnsons Wax build fly radio-controlled replica giant prehistoric pterosaur pterodactyl Paul MacCready charge project seemed success likely became aware project over year ago several readers sent clippings newspapers nounced giant reptile model flown Mall Washington DC front buildings housing Smithsoni ans various collections general opinion readers attempt flight such location hazardous undertaking time tended agree retrospect certainly agree Saturday May 17 tlg replica pterosaur attempted flight front large crowd attending Armed Forces Day Open House Andrews Air Force Base just outside District Columbia Although pterosaur on-board power flap its wings unable take off unassisted sustain level flight towline used pull up launch height about 400 feet addition requiring towline take off bird required addition tail boom conventional vertical hori zontal stabilizers provide sufficient stability during tow appendage could jetti soned radio command upon release towline point on-board computer supposed take over operate au topilot assist flying monster 44 lb 18 ft span Two flights scheduled opener Saturday airshow unfortunately cir cumstances reduced flight attempt jettisonable empennage mysteriously re leased prematurelybefore pilot acti vated autopilot appeared pterosaur executed snap roll still tow resulted creatures breaking its neck point during descent ap peared recovery might likely However impact caused its head severed no flights dayand maybe never again According report Washington Post pilot later speculated compet ing radio signals may have caused some inter ference resulted release tail boom assembly prematurely Also according newspaper report official paleontologist stated Now know its extinct reason Im reporting demise 12 Model Aviation pterosaur Safety column follows dont care raw beginner club hot-shot what fly trainer humdinger Pattern ship what equipment use control single-channel escapement seven-channel digital bells whistles may subject loss con trol due radio interference Im sure glad pterosaurs demonstration flight public did take place restricted airspace Mall Washington DC hope readers fly RC models never fly over peo ple just never know could victim radio interference Tales about taIls Staying subject tails parting company models flight prompts relate experience reported Joseph Breda modeler Gahanna OH Joe past tense very pretty P-s 1 picture appeared Bill Winters Plane Talk column January 1986 issue Model Aviation recent letter Joe Bill sub sequently forwarded related just model got become past tense Since Joes model suffered in-flight stabilizer failure since type structural failure directly indirectly resulted death modeler 1982 think following ex tracts Joes letter Bill Winter wor thy note Bill Im sorry report Mustang no longer airworthy playing cat mouse flying friend doing low pass full throttle pulled up quick ly followed would say hori zontal stab elevator became overstressed right side sheared off fluttered groundas did Mustang higher velocity Needless say instant tooth picks Luckily safe distance spectators After got over disappointment los ing favorite aircraft tried evalu ate reasons mishap first place plane about three years old did ding couple times Secondly recently changed engine original 05 35 K&B 40 Third last made abrupt change flight direction Conclusion empennage may have weakened airspeed increased turn sheared off stab elevator direction abruptly changed Joe much enjoyed flying particular model P-s 1 immediately mailed off order kit another Only time building model obvious rea sons reinforced A-in-thick sheet balsa stabilizer seven-in-long 3A either side centerline piece Light Ply 1-in wide x 1-in thick epoxied place subsequent letter responded some questions posed about rein forced stab Joe expounded what thinks Continued page 14 ATrERY PACKCJAECK 1 SCALE WHEELS RADIO CONTROL CONTROL-UNEFREE-FLIGHT 0 VINTAGE sizes21/2 3/ 133/4 1144/8 11A5 1/a6S/ GOLDEN AGE sizes214 3/43/ 1334 11443/s 11/45 1/61/i NEW BALLOON 21/z41/4 34514 334 SCALE PILOTS CYUNDERS- ENGINE KITS INE GUN KITS PLASTIC DISPLAY MODELS 4LLOAIaSSEND $2 FOR COMPLETE ILLUSTRATED CATALOG DEPT MA PAWNEE ST. SAN MARCOS CA 9 DETROIT EXPO fill GREATER MICHIGAN MODELERS HOSTED BY INDIAN CITY RADIO CONTROL CLUB AUCTION RAFFLES REFRESHMENTS FREE PARKING III HOW innjmln F Yack RmemeUm CanS ir 3131 Third Street Wyandolte Michigi n August 16 & 171986 PLANES S TIC S MANUFACTURERS STATIC DISPLAYS SW P-SHOP Pbene 3122914565 Vein Luedeman 25505 Chemick TaIor Mic igen 48180 caused stab failure first P-5 1 calls guillotine effect Consider fact P-Si tajidragger tend noseover much often ex perience models tricycle landing gear such situation Joe feels ver tical stab fin acts like guillotine strikes downwards blow upwards model its back center horizontal stab rests models other words according Joes theory horizon tal stab becomes chopping block has resist blows guillotine vertical stab whenever model noses over Joe thinks may have factor contributing in-flight failure P-S 1 sheet balsa stabi lizer Comments readers would welcomed time ever suffered in-flight failure models tail surfaces result mid-alr collision between Falcon 56 another during Pylon Race club staged models Everybody Falcon 56 would no excuse poor turnout race case entire empennage lifted off fuselage other modelbut managed land safely because pushrods rudder ele vator sufficient prevent parting company entirely rest model case asking incident relates failures sheet-wood stabilizers such described Joe Breda let explain Falcon 56 has built-up balsa structure spars ribs over must place some covering material case model pure silk about 16 coats Randolph butyrate dope dont have Falcon anymore best can remember stab thickness about 1-in root model powered Supertigre 23 Typically Falcon S6s will powered engines up about 40 cu displacement dont ever remember hearing about being involved in-flight stab failure leads point Im trying make built-up open-framework structure covered material has high tensile strength may stronger piece sheet balsa So alternative Joes suggestion reinforce P-S 1 sheet balsa stab Light Ply would cover silk other material Glitch preventer recent issue newsletter Chicagoland RC Modelers editor Ken Stencel noticed article Rich Frost concerning device sup posed isolate RC receivers interference glitches device also supposed give radio range beyond wildest dreams According Richs article favorable reports about performance device appeared hobby magazines after few months same magazines tech nical editor reviewed product stated boats cars unit might right aircraft dont know Rich went state following fellow 1-scale modeler installed units absolutely beautiful Sopwith Pup Well alrcraft number flights prior installing unit Upon installa tion first flown fly-in Milwau kee area Guess what first flight ended up rekitting Pup What happened Well obtained similar unit another modeler evaluation found amplify sorts signals outside RC band plus doing very fine job Continued page 16 14 Model Aviation SMOOTH CONTOUR 34234 1314 11/4334 11/241h 214514 LLL 13311 Beach Ave Marina uei CA 2 821-6242 WE ARE SHOOTING DOWN HIGH BALSA PRICES WITH SUPER QUALITTI Satisfaction Guaranteed Direct Only BALSA SHEETS 36 45 30 1/16233 3132240 18 243 3/16249 1/4 rr258 1/32337 1/20337 1/163374931 3/32 3445837 1/8 3547145 3/16 3628255 1/4 3739561 5/16385 3/8 3 88 124 71 1/2 3 110 155 3/4 3 1/1645878 49 3/324709458 1/8 e480 10686 31164 93 122 75 1/4 4 110 134 84 3/8 4 165 225 1/2 4 225 261 MATCHED SHEETS 42 31324100 1/84108 3/164120 1/44131 BALSA HOT LINE Call 806 74S6394 l0am 6pm Central Time LONE STAR MODELS 1623 57th St Lubbock TX 79412 1 BALSA STICKS3648 6 408 1/16 3/810 BALSA TRIANGLES36 1/16 1/2141/41425 3132 1/4103/83/830 3/32 3/812121/235 3/32 11216343445 1/8 3/81218 36 1/8 121824 95 3163161116100 314 3/817200 3/16 1122234280 1/4 1/416 24275 1/4 3/819 26360 114 1/221 34225 14 31434 44325 1/4140435 516 5/1621 28495 319 3/827 37668 3/8 1/232 46 3/8 3442 65 3/8152 12 112 36 53 1/2 3446 62 1/2156 5/8 S/846 3/4 3/467 BALSA PLANKS 11 12 13 14 11/23 11124 22 23 24 33 34 TAPERED SHEETS 1142 143 3/82 3/603 1/23 L ONE STAR EPOXY 8,1isr.805 Oeoo598 10 rrrrr598 30 erie098 aA 3A V CUSTOM CUT CONTEST BALSA Sheets Piece ed Close Tolerances AAA Grade Dried ped 100% a serious modeler want performance must try 4-6 lb balsa LIGHT 4-6 LB WOOD 11323 1/293 1163 332 3 1163 31163 1143 318 3 343 13 11164 3l32 4 31164 1/4 4 3184 124 36 49 48 49 58 67 76 95 115 134 220 300 78 01 100 117 138 207 292 36 65TRAILING EDGE36 851l4132 6851611439 96 318112 46 12012271/ IHSTANTGLUE 1 o Th/ck298 1o Th,268 2oo TSck550 2, Ihie550 BASSWOOD 3/163/16 316114 311638 3161/2 3116314 1/4 14 1/43/8 1/43/4 3/8318 3181/2 3/8 3/4 1/21/2 1234 48 26 30 38 46 60 42 49 80 60 70 90 90 100 BUHDLE DEALS 201/6336685 201164361020 20332336840 153/32436955 151/8336715 1018436675 15-3116336900 10316436810 101/4336630 101/4436990 10319 336650 53/6436625 51/2 336540 51/2434955 103/324 46945 516448485 03/16449585 5114449625 PINE STICKS 36 16191317 1161141623 16392027 3i163l161724 316 362332 3161/73040 114142637 14383042 114173447 3163163752 SPRUCE STICKS 3648 1/9 1/815 119 141924 19 382029 31631162534 14 143145 14 383668 38 394563 38 1125570 112 1126086 12 346888 SPRUCE TRIANGLES 318318 112 12 34 314 48 HARD MAPLE IS 11431940 3/8 3/846 31811250 31831458 1231466 36 45 61 77 BIRCH DOWELS 118 3l16 14 516 318 36 00 11 14 25 32 3PLVBIRCH48 16412525 13212425 111612435 1l812450 SPLYBIRCH48 33212570 1812585 3/1612585 11412600 GROOVED LG MOUNTS 121ecINa 318314 1118/40 393/4/5/3240 112314 /3116/45 boosting signal TV Channel 4 As mat ter fact amplified signals higher others Milwaukee area has TV Channel 4 transmission probably what got Pup As know RC band falls between Channel 4 Channel 5 TV band Rich ended article telling club members wary so-called miracle devices guess Im echoing Richs words readers Safety column understand glitch-preventer no longer being advertised may still number modelers workshops propeller Incidents now probably totally bored reports incidents modelers getting bodily parts usually fin gers hands path rotating prop blades continue print reports merely because reader may next vic tim recent letter William Norflcet doctor MD Kenmore NY related bitter personal experience pusher prop following say setting needle valve pusherdriven model equipped fiberglass-rein forced plastic prop index finger strayed too near prop arc puller would have brushed back such stupidity pusher ar rangement seemed suck finger blade slicing three times nearly am putating happened very very fast Two hours surgery saved finger its distal joint completely fused Beware pusher props setting needle valve incident reminded very similar close friend years ago working RPV project very early days RPV development aircraft powered 60-size model aircraft engine twin-boom pusher-prop ar rangement chosen because vehicle carry TV camera its nose cir cumstances essentially identical related Bill Norfiect friend ad justing needle valve got finger too close prop Instead being brushed aside usual occurs tractor airscrew finger pulled severely chewed up Again surgery required reattach finger parts suggest flying models pusher props consider flexible extension needle valve keep fin gers away prop arc Getting struck leading side prop blades infinitely worse being struck trailing side blades Cyanoacrylate glue Another tidbit Chicagoland RC Modelers newsletter concerned cyanoacrylate CyA glue alleged CyA glue causes cancer laboratory rats article concluded saying judge whether want use glue record have no information sub stantiates statement readers can supply such information would appreciate hearing John Preston c/o Model Aviation 1810 Samuel Morse Dr Reston Virginia 22090 responding advertisers mention read about Model Aviation 16 Model Aviation LITEPLY 48 1196100 1/812300 Handling Charge$300 pay UPS Add $200 COD $300 extra PP APO FPO accept Visa Master Cad pesorral checks COD 4-1/8% Ia Te,s US co,ency Minrerr Oder 01000
Edition: Model Aviation - 1986/09
Page Numbers: 12, 14, 16
Edition: Model Aviation - 1986/09
Page Numbers: 12, 14, 16
John Preston___________________________ Safety Comes First Some thoughts structural failures models pusher props can pose unexpected hazard PTEROSAURUS WRECKED radio inter ference Im sure modelers have heard project sponsored Smith sonian Institution Johnsons Wax build fly radio-controlled replica giant prehistoric pterosaur pterodactyl Paul MacCready charge project seemed success likely became aware project over year ago several readers sent clippings newspapers nounced giant reptile model flown Mall Washington DC front buildings housing Smithsoni ans various collections general opinion readers attempt flight such location hazardous undertaking time tended agree retrospect certainly agree Saturday May 17 tlg replica pterosaur attempted flight front large crowd attending Armed Forces Day Open House Andrews Air Force Base just outside District Columbia Although pterosaur on-board power flap its wings unable take off unassisted sustain level flight towline used pull up launch height about 400 feet addition requiring towline take off bird required addition tail boom conventional vertical hori zontal stabilizers provide sufficient stability during tow appendage could jetti soned radio command upon release towline point on-board computer supposed take over operate au topilot assist flying monster 44 lb 18 ft span Two flights scheduled opener Saturday airshow unfortunately cir cumstances reduced flight attempt jettisonable empennage mysteriously re leased prematurelybefore pilot acti vated autopilot appeared pterosaur executed snap roll still tow resulted creatures breaking its neck point during descent ap peared recovery might likely However impact caused its head severed no flights dayand maybe never again According report Washington Post pilot later speculated compet ing radio signals may have caused some inter ference resulted release tail boom assembly prematurely Also according newspaper report official paleontologist stated Now know its extinct reason Im reporting demise 12 Model Aviation pterosaur Safety column follows dont care raw beginner club hot-shot what fly trainer humdinger Pattern ship what equipment use control single-channel escapement seven-channel digital bells whistles may subject loss con trol due radio interference Im sure glad pterosaurs demonstration flight public did take place restricted airspace Mall Washington DC hope readers fly RC models never fly over peo ple just never know could victim radio interference Tales about taIls Staying subject tails parting company models flight prompts relate experience reported Joseph Breda modeler Gahanna OH Joe past tense very pretty P-s 1 picture appeared Bill Winters Plane Talk column January 1986 issue Model Aviation recent letter Joe Bill sub sequently forwarded related just model got become past tense Since Joes model suffered in-flight stabilizer failure since type structural failure directly indirectly resulted death modeler 1982 think following ex tracts Joes letter Bill Winter wor thy note Bill Im sorry report Mustang no longer airworthy playing cat mouse flying friend doing low pass full throttle pulled up quick ly followed would say hori zontal stab elevator became overstressed right side sheared off fluttered groundas did Mustang higher velocity Needless say instant tooth picks Luckily safe distance spectators After got over disappointment los ing favorite aircraft tried evalu ate reasons mishap first place plane about three years old did ding couple times Secondly recently changed engine original 05 35 K&B 40 Third last made abrupt change flight direction Conclusion empennage may have weakened airspeed increased turn sheared off stab elevator direction abruptly changed Joe much enjoyed flying particular model P-s 1 immediately mailed off order kit another Only time building model obvious rea sons reinforced A-in-thick sheet balsa stabilizer seven-in-long 3A either side centerline piece Light Ply 1-in wide x 1-in thick epoxied place subsequent letter responded some questions posed about rein forced stab Joe expounded what thinks Continued page 14 ATrERY PACKCJAECK 1 SCALE WHEELS RADIO CONTROL CONTROL-UNEFREE-FLIGHT 0 VINTAGE sizes21/2 3/ 133/4 1144/8 11A5 1/a6S/ GOLDEN AGE sizes214 3/43/ 1334 11443/s 11/45 1/61/i NEW BALLOON 21/z41/4 34514 334 SCALE PILOTS CYUNDERS- ENGINE KITS INE GUN KITS PLASTIC DISPLAY MODELS 4LLOAIaSSEND $2 FOR COMPLETE ILLUSTRATED CATALOG DEPT MA PAWNEE ST. SAN MARCOS CA 9 DETROIT EXPO fill GREATER MICHIGAN MODELERS HOSTED BY INDIAN CITY RADIO CONTROL CLUB AUCTION RAFFLES REFRESHMENTS FREE PARKING III HOW innjmln F Yack RmemeUm CanS ir 3131 Third Street Wyandolte Michigi n August 16 & 171986 PLANES S TIC S MANUFACTURERS STATIC DISPLAYS SW P-SHOP Pbene 3122914565 Vein Luedeman 25505 Chemick TaIor Mic igen 48180 caused stab failure first P-5 1 calls guillotine effect Consider fact P-Si tajidragger tend noseover much often ex perience models tricycle landing gear such situation Joe feels ver tical stab fin acts like guillotine strikes downwards blow upwards model its back center horizontal stab rests models other words according Joes theory horizon tal stab becomes chopping block has resist blows guillotine vertical stab whenever model noses over Joe thinks may have factor contributing in-flight failure P-S 1 sheet balsa stabi lizer Comments readers would welcomed time ever suffered in-flight failure models tail surfaces result mid-alr collision between Falcon 56 another during Pylon Race club staged models Everybody Falcon 56 would no excuse poor turnout race case entire empennage lifted off fuselage other modelbut managed land safely because pushrods rudder ele vator sufficient prevent parting company entirely rest model case asking incident relates failures sheet-wood stabilizers such described Joe Breda let explain Falcon 56 has built-up balsa structure spars ribs over must place some covering material case model pure silk about 16 coats Randolph butyrate dope dont have Falcon anymore best can remember stab thickness about 1-in root model powered Supertigre 23 Typically Falcon S6s will powered engines up about 40 cu displacement dont ever remember hearing about being involved in-flight stab failure leads point Im trying make built-up open-framework structure covered material has high tensile strength may stronger piece sheet balsa So alternative Joes suggestion reinforce P-S 1 sheet balsa stab Light Ply would cover silk other material Glitch preventer recent issue newsletter Chicagoland RC Modelers editor Ken Stencel noticed article Rich Frost concerning device sup posed isolate RC receivers interference glitches device also supposed give radio range beyond wildest dreams According Richs article favorable reports about performance device appeared hobby magazines after few months same magazines tech nical editor reviewed product stated boats cars unit might right aircraft dont know Rich went state following fellow 1-scale modeler installed units absolutely beautiful Sopwith Pup Well alrcraft number flights prior installing unit Upon installa tion first flown fly-in Milwau kee area Guess what first flight ended up rekitting Pup What happened Well obtained similar unit another modeler evaluation found amplify sorts signals outside RC band plus doing very fine job Continued page 16 14 Model Aviation SMOOTH CONTOUR 34234 1314 11/4334 11/241h 214514 LLL 13311 Beach Ave Marina uei CA 2 821-6242 WE ARE SHOOTING DOWN HIGH BALSA PRICES WITH SUPER QUALITTI Satisfaction Guaranteed Direct Only BALSA SHEETS 36 45 30 1/16233 3132240 18 243 3/16249 1/4 rr258 1/32337 1/20337 1/163374931 3/32 3445837 1/8 3547145 3/16 3628255 1/4 3739561 5/16385 3/8 3 88 124 71 1/2 3 110 155 3/4 3 1/1645878 49 3/324709458 1/8 e480 10686 31164 93 122 75 1/4 4 110 134 84 3/8 4 165 225 1/2 4 225 261 MATCHED SHEETS 42 31324100 1/84108 3/164120 1/44131 BALSA HOT LINE Call 806 74S6394 l0am 6pm Central Time LONE STAR MODELS 1623 57th St Lubbock TX 79412 1 BALSA STICKS3648 6 408 1/16 3/810 BALSA TRIANGLES36 1/16 1/2141/41425 3132 1/4103/83/830 3/32 3/812121/235 3/32 11216343445 1/8 3/81218 36 1/8 121824 95 3163161116100 314 3/817200 3/16 1122234280 1/4 1/416 24275 1/4 3/819 26360 114 1/221 34225 14 31434 44325 1/4140435 516 5/1621 28495 319 3/827 37668 3/8 1/232 46 3/8 3442 65 3/8152 12 112 36 53 1/2 3446 62 1/2156 5/8 S/846 3/4 3/467 BALSA PLANKS 11 12 13 14 11/23 11124 22 23 24 33 34 TAPERED SHEETS 1142 143 3/82 3/603 1/23 L ONE STAR EPOXY 8,1isr.805 Oeoo598 10 rrrrr598 30 erie098 aA 3A V CUSTOM CUT CONTEST BALSA Sheets Piece ed Close Tolerances AAA Grade Dried ped 100% a serious modeler want performance must try 4-6 lb balsa LIGHT 4-6 LB WOOD 11323 1/293 1163 332 3 1163 31163 1143 318 3 343 13 11164 3l32 4 31164 1/4 4 3184 124 36 49 48 49 58 67 76 95 115 134 220 300 78 01 100 117 138 207 292 36 65TRAILING EDGE36 851l4132 6851611439 96 318112 46 12012271/ IHSTANTGLUE 1 o Th/ck298 1o Th,268 2oo TSck550 2, Ihie550 BASSWOOD 3/163/16 316114 311638 3161/2 3116314 1/4 14 1/43/8 1/43/4 3/8318 3181/2 3/8 3/4 1/21/2 1234 48 26 30 38 46 60 42 49 80 60 70 90 90 100 BUHDLE DEALS 201/6336685 201164361020 20332336840 153/32436955 151/8336715 1018436675 15-3116336900 10316436810 101/4336630 101/4436990 10319 336650 53/6436625 51/2 336540 51/2434955 103/324 46945 516448485 03/16449585 5114449625 PINE STICKS 36 16191317 1161141623 16392027 3i163l161724 316 362332 3161/73040 114142637 14383042 114173447 3163163752 SPRUCE STICKS 3648 1/9 1/815 119 141924 19 382029 31631162534 14 143145 14 383668 38 394563 38 1125570 112 1126086 12 346888 SPRUCE TRIANGLES 318318 112 12 34 314 48 HARD MAPLE IS 11431940 3/8 3/846 31811250 31831458 1231466 36 45 61 77 BIRCH DOWELS 118 3l16 14 516 318 36 00 11 14 25 32 3PLVBIRCH48 16412525 13212425 111612435 1l812450 SPLYBIRCH48 33212570 1812585 3/1612585 11412600 GROOVED LG MOUNTS 121ecINa 318314 1118/40 393/4/5/3240 112314 /3116/45 boosting signal TV Channel 4 As mat ter fact amplified signals higher others Milwaukee area has TV Channel 4 transmission probably what got Pup As know RC band falls between Channel 4 Channel 5 TV band Rich ended article telling club members wary so-called miracle devices guess Im echoing Richs words readers Safety column understand glitch-preventer no longer being advertised may still number modelers workshops propeller Incidents now probably totally bored reports incidents modelers getting bodily parts usually fin gers hands path rotating prop blades continue print reports merely because reader may next vic tim recent letter William Norflcet doctor MD Kenmore NY related bitter personal experience pusher prop following say setting needle valve pusherdriven model equipped fiberglass-rein forced plastic prop index finger strayed too near prop arc puller would have brushed back such stupidity pusher ar rangement seemed suck finger blade slicing three times nearly am putating happened very very fast Two hours surgery saved finger its distal joint completely fused Beware pusher props setting needle valve incident reminded very similar close friend years ago working RPV project very early days RPV development aircraft powered 60-size model aircraft engine twin-boom pusher-prop ar rangement chosen because vehicle carry TV camera its nose cir cumstances essentially identical related Bill Norfiect friend ad justing needle valve got finger too close prop Instead being brushed aside usual occurs tractor airscrew finger pulled severely chewed up Again surgery required reattach finger parts suggest flying models pusher props consider flexible extension needle valve keep fin gers away prop arc Getting struck leading side prop blades infinitely worse being struck trailing side blades Cyanoacrylate glue Another tidbit Chicagoland RC Modelers newsletter concerned cyanoacrylate CyA glue alleged CyA glue causes cancer laboratory rats article concluded saying judge whether want use glue record have no information sub stantiates statement readers can supply such information would appreciate hearing John Preston c/o Model Aviation 1810 Samuel Morse Dr Reston Virginia 22090 responding advertisers mention read about Model Aviation 16 Model Aviation LITEPLY 48 1196100 1/812300 Handling Charge$300 pay UPS Add $200 COD $300 extra PP APO FPO accept Visa Master Cad pesorral checks COD 4-1/8% Ia Te,s US co,ency Minrerr Oder 01000
Edition: Model Aviation - 1986/09
Page Numbers: 12, 14, 16
John Preston___________________________ Safety Comes First Some thoughts structural failures models pusher props can pose unexpected hazard PTEROSAURUS WRECKED radio inter ference Im sure modelers have heard project sponsored Smith sonian Institution Johnsons Wax build fly radio-controlled replica giant prehistoric pterosaur pterodactyl Paul MacCready charge project seemed success likely became aware project over year ago several readers sent clippings newspapers nounced giant reptile model flown Mall Washington DC front buildings housing Smithsoni ans various collections general opinion readers attempt flight such location hazardous undertaking time tended agree retrospect certainly agree Saturday May 17 tlg replica pterosaur attempted flight front large crowd attending Armed Forces Day Open House Andrews Air Force Base just outside District Columbia Although pterosaur on-board power flap its wings unable take off unassisted sustain level flight towline used pull up launch height about 400 feet addition requiring towline take off bird required addition tail boom conventional vertical hori zontal stabilizers provide sufficient stability during tow appendage could jetti soned radio command upon release towline point on-board computer supposed take over operate au topilot assist flying monster 44 lb 18 ft span Two flights scheduled opener Saturday airshow unfortunately cir cumstances reduced flight attempt jettisonable empennage mysteriously re leased prematurelybefore pilot acti vated autopilot appeared pterosaur executed snap roll still tow resulted creatures breaking its neck point during descent ap peared recovery might likely However impact caused its head severed no flights dayand maybe never again According report Washington Post pilot later speculated compet ing radio signals may have caused some inter ference resulted release tail boom assembly prematurely Also according newspaper report official paleontologist stated Now know its extinct reason Im reporting demise 12 Model Aviation pterosaur Safety column follows dont care raw beginner club hot-shot what fly trainer humdinger Pattern ship what equipment use control single-channel escapement seven-channel digital bells whistles may subject loss con trol due radio interference Im sure glad pterosaurs demonstration flight public did take place restricted airspace Mall Washington DC hope readers fly RC models never fly over peo ple just never know could victim radio interference Tales about taIls Staying subject tails parting company models flight prompts relate experience reported Joseph Breda modeler Gahanna OH Joe past tense very pretty P-s 1 picture appeared Bill Winters Plane Talk column January 1986 issue Model Aviation recent letter Joe Bill sub sequently forwarded related just model got become past tense Since Joes model suffered in-flight stabilizer failure since type structural failure directly indirectly resulted death modeler 1982 think following ex tracts Joes letter Bill Winter wor thy note Bill Im sorry report Mustang no longer airworthy playing cat mouse flying friend doing low pass full throttle pulled up quick ly followed would say hori zontal stab elevator became overstressed right side sheared off fluttered groundas did Mustang higher velocity Needless say instant tooth picks Luckily safe distance spectators After got over disappointment los ing favorite aircraft tried evalu ate reasons mishap first place plane about three years old did ding couple times Secondly recently changed engine original 05 35 K&B 40 Third last made abrupt change flight direction Conclusion empennage may have weakened airspeed increased turn sheared off stab elevator direction abruptly changed Joe much enjoyed flying particular model P-s 1 immediately mailed off order kit another Only time building model obvious rea sons reinforced A-in-thick sheet balsa stabilizer seven-in-long 3A either side centerline piece Light Ply 1-in wide x 1-in thick epoxied place subsequent letter responded some questions posed about rein forced stab Joe expounded what thinks Continued page 14 ATrERY PACKCJAECK 1 SCALE WHEELS RADIO CONTROL CONTROL-UNEFREE-FLIGHT 0 VINTAGE sizes21/2 3/ 133/4 1144/8 11A5 1/a6S/ GOLDEN AGE sizes214 3/43/ 1334 11443/s 11/45 1/61/i NEW BALLOON 21/z41/4 34514 334 SCALE PILOTS CYUNDERS- ENGINE KITS INE GUN KITS PLASTIC DISPLAY MODELS 4LLOAIaSSEND $2 FOR COMPLETE ILLUSTRATED CATALOG DEPT MA PAWNEE ST. SAN MARCOS CA 9 DETROIT EXPO fill GREATER MICHIGAN MODELERS HOSTED BY INDIAN CITY RADIO CONTROL CLUB AUCTION RAFFLES REFRESHMENTS FREE PARKING III HOW innjmln F Yack RmemeUm CanS ir 3131 Third Street Wyandolte Michigi n August 16 & 171986 PLANES S TIC S MANUFACTURERS STATIC DISPLAYS SW P-SHOP Pbene 3122914565 Vein Luedeman 25505 Chemick TaIor Mic igen 48180 caused stab failure first P-5 1 calls guillotine effect Consider fact P-Si tajidragger tend noseover much often ex perience models tricycle landing gear such situation Joe feels ver tical stab fin acts like guillotine strikes downwards blow upwards model its back center horizontal stab rests models other words according Joes theory horizon tal stab becomes chopping block has resist blows guillotine vertical stab whenever model noses over Joe thinks may have factor contributing in-flight failure P-S 1 sheet balsa stabi lizer Comments readers would welcomed time ever suffered in-flight failure models tail surfaces result mid-alr collision between Falcon 56 another during Pylon Race club staged models Everybody Falcon 56 would no excuse poor turnout race case entire empennage lifted off fuselage other modelbut managed land safely because pushrods rudder ele vator sufficient prevent parting company entirely rest model case asking incident relates failures sheet-wood stabilizers such described Joe Breda let explain Falcon 56 has built-up balsa structure spars ribs over must place some covering material case model pure silk about 16 coats Randolph butyrate dope dont have Falcon anymore best can remember stab thickness about 1-in root model powered Supertigre 23 Typically Falcon S6s will powered engines up about 40 cu displacement dont ever remember hearing about being involved in-flight stab failure leads point Im trying make built-up open-framework structure covered material has high tensile strength may stronger piece sheet balsa So alternative Joes suggestion reinforce P-S 1 sheet balsa stab Light Ply would cover silk other material Glitch preventer recent issue newsletter Chicagoland RC Modelers editor Ken Stencel noticed article Rich Frost concerning device sup posed isolate RC receivers interference glitches device also supposed give radio range beyond wildest dreams According Richs article favorable reports about performance device appeared hobby magazines after few months same magazines tech nical editor reviewed product stated boats cars unit might right aircraft dont know Rich went state following fellow 1-scale modeler installed units absolutely beautiful Sopwith Pup Well alrcraft number flights prior installing unit Upon installa tion first flown fly-in Milwau kee area Guess what first flight ended up rekitting Pup What happened Well obtained similar unit another modeler evaluation found amplify sorts signals outside RC band plus doing very fine job Continued page 16 14 Model Aviation SMOOTH CONTOUR 34234 1314 11/4334 11/241h 214514 LLL 13311 Beach Ave Marina uei CA 2 821-6242 WE ARE SHOOTING DOWN HIGH BALSA PRICES WITH SUPER QUALITTI Satisfaction Guaranteed Direct Only BALSA SHEETS 36 45 30 1/16233 3132240 18 243 3/16249 1/4 rr258 1/32337 1/20337 1/163374931 3/32 3445837 1/8 3547145 3/16 3628255 1/4 3739561 5/16385 3/8 3 88 124 71 1/2 3 110 155 3/4 3 1/1645878 49 3/324709458 1/8 e480 10686 31164 93 122 75 1/4 4 110 134 84 3/8 4 165 225 1/2 4 225 261 MATCHED SHEETS 42 31324100 1/84108 3/164120 1/44131 BALSA HOT LINE Call 806 74S6394 l0am 6pm Central Time LONE STAR MODELS 1623 57th St Lubbock TX 79412 1 BALSA STICKS3648 6 408 1/16 3/810 BALSA TRIANGLES36 1/16 1/2141/41425 3132 1/4103/83/830 3/32 3/812121/235 3/32 11216343445 1/8 3/81218 36 1/8 121824 95 3163161116100 314 3/817200 3/16 1122234280 1/4 1/416 24275 1/4 3/819 26360 114 1/221 34225 14 31434 44325 1/4140435 516 5/1621 28495 319 3/827 37668 3/8 1/232 46 3/8 3442 65 3/8152 12 112 36 53 1/2 3446 62 1/2156 5/8 S/846 3/4 3/467 BALSA PLANKS 11 12 13 14 11/23 11124 22 23 24 33 34 TAPERED SHEETS 1142 143 3/82 3/603 1/23 L ONE STAR EPOXY 8,1isr.805 Oeoo598 10 rrrrr598 30 erie098 aA 3A V CUSTOM CUT CONTEST BALSA Sheets Piece ed Close Tolerances AAA Grade Dried ped 100% a serious modeler want performance must try 4-6 lb balsa LIGHT 4-6 LB WOOD 11323 1/293 1163 332 3 1163 31163 1143 318 3 343 13 11164 3l32 4 31164 1/4 4 3184 124 36 49 48 49 58 67 76 95 115 134 220 300 78 01 100 117 138 207 292 36 65TRAILING EDGE36 851l4132 6851611439 96 318112 46 12012271/ IHSTANTGLUE 1 o Th/ck298 1o Th,268 2oo TSck550 2, Ihie550 BASSWOOD 3/163/16 316114 311638 3161/2 3116314 1/4 14 1/43/8 1/43/4 3/8318 3181/2 3/8 3/4 1/21/2 1234 48 26 30 38 46 60 42 49 80 60 70 90 90 100 BUHDLE DEALS 201/6336685 201164361020 20332336840 153/32436955 151/8336715 1018436675 15-3116336900 10316436810 101/4336630 101/4436990 10319 336650 53/6436625 51/2 336540 51/2434955 103/324 46945 516448485 03/16449585 5114449625 PINE STICKS 36 16191317 1161141623 16392027 3i163l161724 316 362332 3161/73040 114142637 14383042 114173447 3163163752 SPRUCE STICKS 3648 1/9 1/815 119 141924 19 382029 31631162534 14 143145 14 383668 38 394563 38 1125570 112 1126086 12 346888 SPRUCE TRIANGLES 318318 112 12 34 314 48 HARD MAPLE IS 11431940 3/8 3/846 31811250 31831458 1231466 36 45 61 77 BIRCH DOWELS 118 3l16 14 516 318 36 00 11 14 25 32 3PLVBIRCH48 16412525 13212425 111612435 1l812450 SPLYBIRCH48 33212570 1812585 3/1612585 11412600 GROOVED LG MOUNTS 121ecINa 318314 1118/40 393/4/5/3240 112314 /3116/45 boosting signal TV Channel 4 As mat ter fact amplified signals higher others Milwaukee area has TV Channel 4 transmission probably what got Pup As know RC band falls between Channel 4 Channel 5 TV band Rich ended article telling club members wary so-called miracle devices guess Im echoing Richs words readers Safety column understand glitch-preventer no longer being advertised may still number modelers workshops propeller Incidents now probably totally bored reports incidents modelers getting bodily parts usually fin gers hands path rotating prop blades continue print reports merely because reader may next vic tim recent letter William Norflcet doctor MD Kenmore NY related bitter personal experience pusher prop following say setting needle valve pusherdriven model equipped fiberglass-rein forced plastic prop index finger strayed too near prop arc puller would have brushed back such stupidity pusher ar rangement seemed suck finger blade slicing three times nearly am putating happened very very fast Two hours surgery saved finger its distal joint completely fused Beware pusher props setting needle valve incident reminded very similar close friend years ago working RPV project very early days RPV development aircraft powered 60-size model aircraft engine twin-boom pusher-prop ar rangement chosen because vehicle carry TV camera its nose cir cumstances essentially identical related Bill Norfiect friend ad justing needle valve got finger too close prop Instead being brushed aside usual occurs tractor airscrew finger pulled severely chewed up Again surgery required reattach finger parts suggest flying models pusher props consider flexible extension needle valve keep fin gers away prop arc Getting struck leading side prop blades infinitely worse being struck trailing side blades Cyanoacrylate glue Another tidbit Chicagoland RC Modelers newsletter concerned cyanoacrylate CyA glue alleged CyA glue causes cancer laboratory rats article concluded saying judge whether want use glue record have no information sub stantiates statement readers can supply such information would appreciate hearing John Preston c/o Model Aviation 1810 Samuel Morse Dr Reston Virginia 22090 responding advertisers mention read about Model Aviation 16 Model Aviation LITEPLY 48 1196100 1/812300 Handling Charge$300 pay UPS Add $200 COD $300 extra PP APO FPO accept Visa Master Cad pesorral checks COD 4-1/8% Ia Te,s US co,ency Minrerr Oder 01000
