A IF YOU FLY dont stall stall dont spin spin dont crash crash dont burn aviator has heard sentiments ex pressed form another yet day stall remains prominent factor airplane accidents During 1923 successful effort overcome danger stalling Senior Juan de Ia Cierva Spain invented autoglro ancestor modern helicopter like helicopter sustained flight rotary wing similarity ends autoglros free-wheeling rotor turned aerodynamic forces created relative wind procedure quite unlike heli copters engine-driven rotor Because differences giro much less complex machine hence less costly also lacks much helicopters versatility Interestingly enough early auto glros produced mating Cierva-type rotor convenient airplane fuselage sans wing tail Although first flown 1923 autogiro still principal form rotorcraft enjoy success Control Line model own Avro C6A based famous Avro 504 fuselage chosen being representative early gyroplanes design philosophy model tractable realistic flight should give interesting hours Construction Since rotor makes model substantially different other models well describe assembly first Begin carefully sawing four blades 1/16 basswood rotor spider 3/32 ply wood tempted use balsa rotor need strength yes experi menter just love off beat CL fun projects ought try 1/2Aautogiro Full-size plans next two pagesE Frank Scott weight harder wood should bass unavailable ply will nicely blades sanded airfoil cross section epoxied plywood spider placing 1/16 balsa wedges between set proper blade angle Please note unlike helicopter auto giros blades set negative angle Thus leading edge lower trailing edge viewed above rotor should turn clockwise direction i plywood hub re inforcement glued place center rotor spider 3/32 brass tube bearing follows Make sure bearing absolutely perpendicular lest rotor track true drill press can used good advantage positioning operation couple coats clear dope usual sanding coat silver dope will complete rotor assembly critical finished rotor should balanced securing small weights lighter blades fact simple dabs epoxy glue applied tips may well suffice balance rotor epoxy useful unlike other glues does change weight hardens fuselage profile variety cut shape sheet firm a An interest ing variation however illusion cowling obtalned cutting fuselage out ahead firewall mounting englne sidewinder fashion insted usual method sawing fuselage off square firewall Bend rotor pylon shape 1/16 wire bind copper wire solder pieces securely apex taking care forming pylon duplicate very necessary 50 rear ward rake rotor pivot area Grooves cut 1/16-in deep fuselage left side accom modate rotor pylonwhich epoxied place joint covered cloth tape 1/32 plywood nose doublers firewall three-piece plywood sandwich within main landing gear secured assembly epoxied place Epoxylite fillet may added back strengthen joint funny lollipop-like ailerons produced gluing pieces sheet balsa both sides single spruce spar sanding ailerons though spar streamline shape important real C6 control system ailerons serve model ornamental line guide Plywood gussets added center spar strengthen spar-fuselage joint gussets bellcrank secured line guide formed wire paper clip glued spar tip tail unit consists two elevatorsjoined wire connector assembly hinged together tape cloth thread hinges stabil Continued page 110 January 1981 37 Fly-In notices plea will organizing Giant Scale activities 1981 Please let know details soon possible have chance let other people know past season lot Big Bird Bashes didnt hear about until too late Remember need three four months lead time get something column Since fly-ins arent included AMA calender various big bird columnists best bet getting word out Plan reviews last column gave list plans hand waiting reviewed couple add list Nick Ziroli sent set Corsair plans Doc Godfrey caine through Super Stearman plans Don says has put out 800 sets far Next month Ill review Wendell Hostetlers Liberty Sport Bucker Jungmeister month Ill try two plans order received Flash November issue just got out writing mentioned need larger stronger better hardware Ijust got off phone Darrell Higgins informs company starting production line tumbuckles devises ball joints Screw size 4-40 materials aluminum steel promised samples literature ASAP luck Ill able tell about next month Bob Beckman 8248 Holly Grove Court Manassas VA 22110 Phone 703 369-2432 Catalog 8150 7L@ 98 RUBBER POWER KITS plus Gliders C/L RIC Accessories Books MAJESTIC MODELS 3273 West 129th Street Cleveland Ohio 44111 Avro C6A/Scott Continued page 37 izer resulting assembly glued its slot fuselage Inasmuch gluing area small care should used gluing rudder fuselage As Control line models rudder should offset right onal very desirable center skid formed secured fuselage epoxy cloth tape bound fine copper wire soldered spreader bar also wire bound soldered landing gear model can glven couple coats filler cleardope talcum powder atthis time again sanded smooth doped silver nose painted black RAF decals applied appropriate Next Babe-Bee engine screwed place fitted its propeller Finally secure wheel retainer rotor mast sliding far will go add washer secure whole works another washer wheel retainer rotor bearing should prove too snug turn freely bearing may readily loosened applying drop oil has mixed dab toothpaste turning rotor hand Install control system wheels complete model After checking Avros balance must balance least inch forward rotor pivot placing drop oil rotor bearing wheels glro will ready flying field Flying Select flying site provides smooth area full circle Though fourbladed rotor will spin up very nicely its own recommend hand-spinning rotor autogiro will require somewhat lengthy takeoff run order bring rotor up flying speed Avros long tail will serve helper useful handle grasp ship starting also provides excellent flight stability control Wire flying lines 008-in x 35-ft suggested greater strength lesser drag compared Dacron flying lines Once airborne giro will fly much like other Control Line model until engine stops time model will immediately sort parachute ground say Control Line giro will descend nearly vertically rather slowly flat attitude regardless control inputs Factors landing peculiarity seem involve tre mendous drag rotor lack propwash tail surfaces fact rotor unlike helicopters cannot stall Also because such draggy ship has little reserve air speed best fly windless days its bit breezy might wish fly kite instead Avro C6A Materials List x 2-in sheet balsa x 1-in sheet balsa 3/32 x 3-in sheet balsa x -in spruce 1/16-in plywood 1/32-in plywood 1/16-in basswood 1/16-in diameter music wire 045-in diameter music wire 3/32-in outside diameter brass tube Fine copper wire Goldberg nylon bellcrank horn set Williams Brothers 1-in diameter WW wheels Small washers 1/16-in wheel retsiners 4 Paper clip Cox 049 Babe-Bee engine propeller mounting screws Titebond epoxy glue Solder -in wide nylon tape Fuelproof dope clear aluminum black RAF decals Few Notes Concerning Design Building Care Small CL Autogiros Probably few forms flying machines less understood autoglro unfortunately some material published recent years may have served further cloud already obscure subject Knowing ignorance superstition will always triumph embarked very empirical series generally successful iA CL autogiros have made following observations hope may prove useful 110 Model Aviation MAMMOTH SCALERS ave availableof Fine Quality Flying Models Ku P6 SAX 15255 1. .aeka C SAIlS chose Waco F-3 biplane flagship because bet represents Golden Era 1930s flying adventure Add easy snag-free building saie gentle flyingthe result thorough kit engineering careful prototype development features Platt Kits have satisfying building flying experience ahead Kit IeaturesTop-quality diecut machined balsa plywood Full size plans Separate instruction book isometrics Decals Injection-moulded vacuum-formed plastic cowl cowl blisters wheel pants required nylon fittings Formed wire langinggear&struts Span 60Area 950 Sq4to6channel Engine good 40 60 j 2657 NE 188th Street Miami Florida 33180 Telephone g35-1436 fellow modelers unorthodox aircraft important designing building un orthodox CL models keep mind presence CL leadouts wires will serve very nicely sort stabilizer functioning both yaw vertical roll longitudinal axes especially true case rotor craft can usually expected have roll stability problem thus observations herein presented may valid model types other CL 1 The flying speed autogiro extent inversely proportional rotor al though number blades area play important role have observed models having large diameter rotors will fly relatively low airspeed makes very susceptible effects wind gusts Furthermore machines will usually exhibit uncontrol lable pitch-up engine stops fortunately will followed parachute-like descent addition large diameter rotors may radially floppy can lead some real control difficulties Another disadvantage large rotor hard landing can cause blades flex downwards far enough strike fuselage tail 2 Other things being equal small rotor will require longer takeoff run attain flying rpm will spin faster have effective control resulting airplane-like flight 3 Number blades two-blade rotor easiest build also easiest handle starting engine obvious blades multiple-bladed rotor can real obstacle enthusiastic prop-flipping other hand multi-blade rotors spin-up faster giving shorter takeoffs will support heavier aircraft appears three-bladed rotor will satisfactory compromise 4 usual practice tilt rotor disc rear absolutely necessary rotor pivot left vertical model will fly quite nose-high attitude takeoff roll will excessive 5 CG model should balanced point about R ahead pivot flight may possible center-of-gravity pivot control will very hairy 6 Wings Although early full-scale auto giros used wings addition rotors appendages best avoided models winged model giros may find themselves precarious situation having become airborne virtue wing lift before rotor has attained flying rpm As rotor lift becomes factor however attendant rise drag may slow model wing stalls Therefore better far rely entirely rotor Wings may desirable other reasons though fitted should made too small support model flight 7 STOL operations properly constructed giro may relied upon land very small space indeed short takeoff desired may disappointed full-scale autogiros capable near-vertical takeoffs accomplished using power taken engine through system shafts clutches spin up rotor Unless willing undergo sort complexity well have settle takeoff run considered lengthy conventional airplane standards 8 Control Normalairplanetype tail surfaces will produce very good control will provide flight little different airplane long tail moment arm desirable model both elevator authority well conven ience handling launching model 9 Lift Avro C6 weighs 6 oz built will fly very nicely 9 oz two blades manageable 10-mph breeze final point model giros may made much easier transport provision made readily remove rotor sure lubricate rotor pivot inspect rotor security damage between flights Music Tach/Porter Continued page 40 nomogram plastic side pitch pipe Middle C157K C sharp166K D 176K D sharp186K E198K F21 0K F sharp222K G235K G sharp249K A264K sharp2796K B2964K C 314K range can extended both above below range pitch pipe humming lower higher harmonics simultaneously blowing selected note listening low beat frequency determine value unknown harmonic frequency example high C first harmonic above middle C Cto-C pitch pipe humming low C blowing high C very discernible beat frequency can experienced same effect takes place humming high C blowing low C pitch pipe very close toor right ona harmonic beat frequency very low hums higher lower note beat frequency increases humming tune engine sound have now found musical tone representing engine speed find note lower middle C blow B below high C hum frequency lower middle C until very low beat frequency experienced now have frequency exactly half B note lower middle C can hum low enough high enough can cover octaves below above pitch pipe frequencies allow cover range 7800 62800 cycles per minute wider needed recommended fullpower two-cycling rpm almost modern model engine However since human voices limited range does appreciably exceed range pitch pipe practical appli cation seems range available pipe Since fly CL models can make instantaneous in-flight rpm checks scheme hold control handle hand pitch pipe other wanted try RC model would have fly model constant-radius circle around model constant distance iffor exampleit coming toward flying away January1981 111
Edition: Model Aviation - 1981/01
Page Numbers: 37, 110, 111
A IF YOU FLY dont stall stall dont spin spin dont crash crash dont burn aviator has heard sentiments ex pressed form another yet day stall remains prominent factor airplane accidents During 1923 successful effort overcome danger stalling Senior Juan de Ia Cierva Spain invented autoglro ancestor modern helicopter like helicopter sustained flight rotary wing similarity ends autoglros free-wheeling rotor turned aerodynamic forces created relative wind procedure quite unlike heli copters engine-driven rotor Because differences giro much less complex machine hence less costly also lacks much helicopters versatility Interestingly enough early auto glros produced mating Cierva-type rotor convenient airplane fuselage sans wing tail Although first flown 1923 autogiro still principal form rotorcraft enjoy success Control Line model own Avro C6A based famous Avro 504 fuselage chosen being representative early gyroplanes design philosophy model tractable realistic flight should give interesting hours Construction Since rotor makes model substantially different other models well describe assembly first Begin carefully sawing four blades 1/16 basswood rotor spider 3/32 ply wood tempted use balsa rotor need strength yes experi menter just love off beat CL fun projects ought try 1/2Aautogiro Full-size plans next two pagesE Frank Scott weight harder wood should bass unavailable ply will nicely blades sanded airfoil cross section epoxied plywood spider placing 1/16 balsa wedges between set proper blade angle Please note unlike helicopter auto giros blades set negative angle Thus leading edge lower trailing edge viewed above rotor should turn clockwise direction i plywood hub re inforcement glued place center rotor spider 3/32 brass tube bearing follows Make sure bearing absolutely perpendicular lest rotor track true drill press can used good advantage positioning operation couple coats clear dope usual sanding coat silver dope will complete rotor assembly critical finished rotor should balanced securing small weights lighter blades fact simple dabs epoxy glue applied tips may well suffice balance rotor epoxy useful unlike other glues does change weight hardens fuselage profile variety cut shape sheet firm a An interest ing variation however illusion cowling obtalned cutting fuselage out ahead firewall mounting englne sidewinder fashion insted usual method sawing fuselage off square firewall Bend rotor pylon shape 1/16 wire bind copper wire solder pieces securely apex taking care forming pylon duplicate very necessary 50 rear ward rake rotor pivot area Grooves cut 1/16-in deep fuselage left side accom modate rotor pylonwhich epoxied place joint covered cloth tape 1/32 plywood nose doublers firewall three-piece plywood sandwich within main landing gear secured assembly epoxied place Epoxylite fillet may added back strengthen joint funny lollipop-like ailerons produced gluing pieces sheet balsa both sides single spruce spar sanding ailerons though spar streamline shape important real C6 control system ailerons serve model ornamental line guide Plywood gussets added center spar strengthen spar-fuselage joint gussets bellcrank secured line guide formed wire paper clip glued spar tip tail unit consists two elevatorsjoined wire connector assembly hinged together tape cloth thread hinges stabil Continued page 110 January 1981 37 Fly-In notices plea will organizing Giant Scale activities 1981 Please let know details soon possible have chance let other people know past season lot Big Bird Bashes didnt hear about until too late Remember need three four months lead time get something column Since fly-ins arent included AMA calender various big bird columnists best bet getting word out Plan reviews last column gave list plans hand waiting reviewed couple add list Nick Ziroli sent set Corsair plans Doc Godfrey caine through Super Stearman plans Don says has put out 800 sets far Next month Ill review Wendell Hostetlers Liberty Sport Bucker Jungmeister month Ill try two plans order received Flash November issue just got out writing mentioned need larger stronger better hardware Ijust got off phone Darrell Higgins informs company starting production line tumbuckles devises ball joints Screw size 4-40 materials aluminum steel promised samples literature ASAP luck Ill able tell about next month Bob Beckman 8248 Holly Grove Court Manassas VA 22110 Phone 703 369-2432 Catalog 8150 7L@ 98 RUBBER POWER KITS plus Gliders C/L RIC Accessories Books MAJESTIC MODELS 3273 West 129th Street Cleveland Ohio 44111 Avro C6A/Scott Continued page 37 izer resulting assembly glued its slot fuselage Inasmuch gluing area small care should used gluing rudder fuselage As Control line models rudder should offset right onal very desirable center skid formed secured fuselage epoxy cloth tape bound fine copper wire soldered spreader bar also wire bound soldered landing gear model can glven couple coats filler cleardope talcum powder atthis time again sanded smooth doped silver nose painted black RAF decals applied appropriate Next Babe-Bee engine screwed place fitted its propeller Finally secure wheel retainer rotor mast sliding far will go add washer secure whole works another washer wheel retainer rotor bearing should prove too snug turn freely bearing may readily loosened applying drop oil has mixed dab toothpaste turning rotor hand Install control system wheels complete model After checking Avros balance must balance least inch forward rotor pivot placing drop oil rotor bearing wheels glro will ready flying field Flying Select flying site provides smooth area full circle Though fourbladed rotor will spin up very nicely its own recommend hand-spinning rotor autogiro will require somewhat lengthy takeoff run order bring rotor up flying speed Avros long tail will serve helper useful handle grasp ship starting also provides excellent flight stability control Wire flying lines 008-in x 35-ft suggested greater strength lesser drag compared Dacron flying lines Once airborne giro will fly much like other Control Line model until engine stops time model will immediately sort parachute ground say Control Line giro will descend nearly vertically rather slowly flat attitude regardless control inputs Factors landing peculiarity seem involve tre mendous drag rotor lack propwash tail surfaces fact rotor unlike helicopters cannot stall Also because such draggy ship has little reserve air speed best fly windless days its bit breezy might wish fly kite instead Avro C6A Materials List x 2-in sheet balsa x 1-in sheet balsa 3/32 x 3-in sheet balsa x -in spruce 1/16-in plywood 1/32-in plywood 1/16-in basswood 1/16-in diameter music wire 045-in diameter music wire 3/32-in outside diameter brass tube Fine copper wire Goldberg nylon bellcrank horn set Williams Brothers 1-in diameter WW wheels Small washers 1/16-in wheel retsiners 4 Paper clip Cox 049 Babe-Bee engine propeller mounting screws Titebond epoxy glue Solder -in wide nylon tape Fuelproof dope clear aluminum black RAF decals Few Notes Concerning Design Building Care Small CL Autogiros Probably few forms flying machines less understood autoglro unfortunately some material published recent years may have served further cloud already obscure subject Knowing ignorance superstition will always triumph embarked very empirical series generally successful iA CL autogiros have made following observations hope may prove useful 110 Model Aviation MAMMOTH SCALERS ave availableof Fine Quality Flying Models Ku P6 SAX 15255 1. .aeka C SAIlS chose Waco F-3 biplane flagship because bet represents Golden Era 1930s flying adventure Add easy snag-free building saie gentle flyingthe result thorough kit engineering careful prototype development features Platt Kits have satisfying building flying experience ahead Kit IeaturesTop-quality diecut machined balsa plywood Full size plans Separate instruction book isometrics Decals Injection-moulded vacuum-formed plastic cowl cowl blisters wheel pants required nylon fittings Formed wire langinggear&struts Span 60Area 950 Sq4to6channel Engine good 40 60 j 2657 NE 188th Street Miami Florida 33180 Telephone g35-1436 fellow modelers unorthodox aircraft important designing building un orthodox CL models keep mind presence CL leadouts wires will serve very nicely sort stabilizer functioning both yaw vertical roll longitudinal axes especially true case rotor craft can usually expected have roll stability problem thus observations herein presented may valid model types other CL 1 The flying speed autogiro extent inversely proportional rotor al though number blades area play important role have observed models having large diameter rotors will fly relatively low airspeed makes very susceptible effects wind gusts Furthermore machines will usually exhibit uncontrol lable pitch-up engine stops fortunately will followed parachute-like descent addition large diameter rotors may radially floppy can lead some real control difficulties Another disadvantage large rotor hard landing can cause blades flex downwards far enough strike fuselage tail 2 Other things being equal small rotor will require longer takeoff run attain flying rpm will spin faster have effective control resulting airplane-like flight 3 Number blades two-blade rotor easiest build also easiest handle starting engine obvious blades multiple-bladed rotor can real obstacle enthusiastic prop-flipping other hand multi-blade rotors spin-up faster giving shorter takeoffs will support heavier aircraft appears three-bladed rotor will satisfactory compromise 4 usual practice tilt rotor disc rear absolutely necessary rotor pivot left vertical model will fly quite nose-high attitude takeoff roll will excessive 5 CG model should balanced point about R ahead pivot flight may possible center-of-gravity pivot control will very hairy 6 Wings Although early full-scale auto giros used wings addition rotors appendages best avoided models winged model giros may find themselves precarious situation having become airborne virtue wing lift before rotor has attained flying rpm As rotor lift becomes factor however attendant rise drag may slow model wing stalls Therefore better far rely entirely rotor Wings may desirable other reasons though fitted should made too small support model flight 7 STOL operations properly constructed giro may relied upon land very small space indeed short takeoff desired may disappointed full-scale autogiros capable near-vertical takeoffs accomplished using power taken engine through system shafts clutches spin up rotor Unless willing undergo sort complexity well have settle takeoff run considered lengthy conventional airplane standards 8 Control Normalairplanetype tail surfaces will produce very good control will provide flight little different airplane long tail moment arm desirable model both elevator authority well conven ience handling launching model 9 Lift Avro C6 weighs 6 oz built will fly very nicely 9 oz two blades manageable 10-mph breeze final point model giros may made much easier transport provision made readily remove rotor sure lubricate rotor pivot inspect rotor security damage between flights Music Tach/Porter Continued page 40 nomogram plastic side pitch pipe Middle C157K C sharp166K D 176K D sharp186K E198K F21 0K F sharp222K G235K G sharp249K A264K sharp2796K B2964K C 314K range can extended both above below range pitch pipe humming lower higher harmonics simultaneously blowing selected note listening low beat frequency determine value unknown harmonic frequency example high C first harmonic above middle C Cto-C pitch pipe humming low C blowing high C very discernible beat frequency can experienced same effect takes place humming high C blowing low C pitch pipe very close toor right ona harmonic beat frequency very low hums higher lower note beat frequency increases humming tune engine sound have now found musical tone representing engine speed find note lower middle C blow B below high C hum frequency lower middle C until very low beat frequency experienced now have frequency exactly half B note lower middle C can hum low enough high enough can cover octaves below above pitch pipe frequencies allow cover range 7800 62800 cycles per minute wider needed recommended fullpower two-cycling rpm almost modern model engine However since human voices limited range does appreciably exceed range pitch pipe practical appli cation seems range available pipe Since fly CL models can make instantaneous in-flight rpm checks scheme hold control handle hand pitch pipe other wanted try RC model would have fly model constant-radius circle around model constant distance iffor exampleit coming toward flying away January1981 111
Edition: Model Aviation - 1981/01
Page Numbers: 37, 110, 111
A IF YOU FLY dont stall stall dont spin spin dont crash crash dont burn aviator has heard sentiments ex pressed form another yet day stall remains prominent factor airplane accidents During 1923 successful effort overcome danger stalling Senior Juan de Ia Cierva Spain invented autoglro ancestor modern helicopter like helicopter sustained flight rotary wing similarity ends autoglros free-wheeling rotor turned aerodynamic forces created relative wind procedure quite unlike heli copters engine-driven rotor Because differences giro much less complex machine hence less costly also lacks much helicopters versatility Interestingly enough early auto glros produced mating Cierva-type rotor convenient airplane fuselage sans wing tail Although first flown 1923 autogiro still principal form rotorcraft enjoy success Control Line model own Avro C6A based famous Avro 504 fuselage chosen being representative early gyroplanes design philosophy model tractable realistic flight should give interesting hours Construction Since rotor makes model substantially different other models well describe assembly first Begin carefully sawing four blades 1/16 basswood rotor spider 3/32 ply wood tempted use balsa rotor need strength yes experi menter just love off beat CL fun projects ought try 1/2Aautogiro Full-size plans next two pagesE Frank Scott weight harder wood should bass unavailable ply will nicely blades sanded airfoil cross section epoxied plywood spider placing 1/16 balsa wedges between set proper blade angle Please note unlike helicopter auto giros blades set negative angle Thus leading edge lower trailing edge viewed above rotor should turn clockwise direction i plywood hub re inforcement glued place center rotor spider 3/32 brass tube bearing follows Make sure bearing absolutely perpendicular lest rotor track true drill press can used good advantage positioning operation couple coats clear dope usual sanding coat silver dope will complete rotor assembly critical finished rotor should balanced securing small weights lighter blades fact simple dabs epoxy glue applied tips may well suffice balance rotor epoxy useful unlike other glues does change weight hardens fuselage profile variety cut shape sheet firm a An interest ing variation however illusion cowling obtalned cutting fuselage out ahead firewall mounting englne sidewinder fashion insted usual method sawing fuselage off square firewall Bend rotor pylon shape 1/16 wire bind copper wire solder pieces securely apex taking care forming pylon duplicate very necessary 50 rear ward rake rotor pivot area Grooves cut 1/16-in deep fuselage left side accom modate rotor pylonwhich epoxied place joint covered cloth tape 1/32 plywood nose doublers firewall three-piece plywood sandwich within main landing gear secured assembly epoxied place Epoxylite fillet may added back strengthen joint funny lollipop-like ailerons produced gluing pieces sheet balsa both sides single spruce spar sanding ailerons though spar streamline shape important real C6 control system ailerons serve model ornamental line guide Plywood gussets added center spar strengthen spar-fuselage joint gussets bellcrank secured line guide formed wire paper clip glued spar tip tail unit consists two elevatorsjoined wire connector assembly hinged together tape cloth thread hinges stabil Continued page 110 January 1981 37 Fly-In notices plea will organizing Giant Scale activities 1981 Please let know details soon possible have chance let other people know past season lot Big Bird Bashes didnt hear about until too late Remember need three four months lead time get something column Since fly-ins arent included AMA calender various big bird columnists best bet getting word out Plan reviews last column gave list plans hand waiting reviewed couple add list Nick Ziroli sent set Corsair plans Doc Godfrey caine through Super Stearman plans Don says has put out 800 sets far Next month Ill review Wendell Hostetlers Liberty Sport Bucker Jungmeister month Ill try two plans order received Flash November issue just got out writing mentioned need larger stronger better hardware Ijust got off phone Darrell Higgins informs company starting production line tumbuckles devises ball joints Screw size 4-40 materials aluminum steel promised samples literature ASAP luck Ill able tell about next month Bob Beckman 8248 Holly Grove Court Manassas VA 22110 Phone 703 369-2432 Catalog 8150 7L@ 98 RUBBER POWER KITS plus Gliders C/L RIC Accessories Books MAJESTIC MODELS 3273 West 129th Street Cleveland Ohio 44111 Avro C6A/Scott Continued page 37 izer resulting assembly glued its slot fuselage Inasmuch gluing area small care should used gluing rudder fuselage As Control line models rudder should offset right onal very desirable center skid formed secured fuselage epoxy cloth tape bound fine copper wire soldered spreader bar also wire bound soldered landing gear model can glven couple coats filler cleardope talcum powder atthis time again sanded smooth doped silver nose painted black RAF decals applied appropriate Next Babe-Bee engine screwed place fitted its propeller Finally secure wheel retainer rotor mast sliding far will go add washer secure whole works another washer wheel retainer rotor bearing should prove too snug turn freely bearing may readily loosened applying drop oil has mixed dab toothpaste turning rotor hand Install control system wheels complete model After checking Avros balance must balance least inch forward rotor pivot placing drop oil rotor bearing wheels glro will ready flying field Flying Select flying site provides smooth area full circle Though fourbladed rotor will spin up very nicely its own recommend hand-spinning rotor autogiro will require somewhat lengthy takeoff run order bring rotor up flying speed Avros long tail will serve helper useful handle grasp ship starting also provides excellent flight stability control Wire flying lines 008-in x 35-ft suggested greater strength lesser drag compared Dacron flying lines Once airborne giro will fly much like other Control Line model until engine stops time model will immediately sort parachute ground say Control Line giro will descend nearly vertically rather slowly flat attitude regardless control inputs Factors landing peculiarity seem involve tre mendous drag rotor lack propwash tail surfaces fact rotor unlike helicopters cannot stall Also because such draggy ship has little reserve air speed best fly windless days its bit breezy might wish fly kite instead Avro C6A Materials List x 2-in sheet balsa x 1-in sheet balsa 3/32 x 3-in sheet balsa x -in spruce 1/16-in plywood 1/32-in plywood 1/16-in basswood 1/16-in diameter music wire 045-in diameter music wire 3/32-in outside diameter brass tube Fine copper wire Goldberg nylon bellcrank horn set Williams Brothers 1-in diameter WW wheels Small washers 1/16-in wheel retsiners 4 Paper clip Cox 049 Babe-Bee engine propeller mounting screws Titebond epoxy glue Solder -in wide nylon tape Fuelproof dope clear aluminum black RAF decals Few Notes Concerning Design Building Care Small CL Autogiros Probably few forms flying machines less understood autoglro unfortunately some material published recent years may have served further cloud already obscure subject Knowing ignorance superstition will always triumph embarked very empirical series generally successful iA CL autogiros have made following observations hope may prove useful 110 Model Aviation MAMMOTH SCALERS ave availableof Fine Quality Flying Models Ku P6 SAX 15255 1. .aeka C SAIlS chose Waco F-3 biplane flagship because bet represents Golden Era 1930s flying adventure Add easy snag-free building saie gentle flyingthe result thorough kit engineering careful prototype development features Platt Kits have satisfying building flying experience ahead Kit IeaturesTop-quality diecut machined balsa plywood Full size plans Separate instruction book isometrics Decals Injection-moulded vacuum-formed plastic cowl cowl blisters wheel pants required nylon fittings Formed wire langinggear&struts Span 60Area 950 Sq4to6channel Engine good 40 60 j 2657 NE 188th Street Miami Florida 33180 Telephone g35-1436 fellow modelers unorthodox aircraft important designing building un orthodox CL models keep mind presence CL leadouts wires will serve very nicely sort stabilizer functioning both yaw vertical roll longitudinal axes especially true case rotor craft can usually expected have roll stability problem thus observations herein presented may valid model types other CL 1 The flying speed autogiro extent inversely proportional rotor al though number blades area play important role have observed models having large diameter rotors will fly relatively low airspeed makes very susceptible effects wind gusts Furthermore machines will usually exhibit uncontrol lable pitch-up engine stops fortunately will followed parachute-like descent addition large diameter rotors may radially floppy can lead some real control difficulties Another disadvantage large rotor hard landing can cause blades flex downwards far enough strike fuselage tail 2 Other things being equal small rotor will require longer takeoff run attain flying rpm will spin faster have effective control resulting airplane-like flight 3 Number blades two-blade rotor easiest build also easiest handle starting engine obvious blades multiple-bladed rotor can real obstacle enthusiastic prop-flipping other hand multi-blade rotors spin-up faster giving shorter takeoffs will support heavier aircraft appears three-bladed rotor will satisfactory compromise 4 usual practice tilt rotor disc rear absolutely necessary rotor pivot left vertical model will fly quite nose-high attitude takeoff roll will excessive 5 CG model should balanced point about R ahead pivot flight may possible center-of-gravity pivot control will very hairy 6 Wings Although early full-scale auto giros used wings addition rotors appendages best avoided models winged model giros may find themselves precarious situation having become airborne virtue wing lift before rotor has attained flying rpm As rotor lift becomes factor however attendant rise drag may slow model wing stalls Therefore better far rely entirely rotor Wings may desirable other reasons though fitted should made too small support model flight 7 STOL operations properly constructed giro may relied upon land very small space indeed short takeoff desired may disappointed full-scale autogiros capable near-vertical takeoffs accomplished using power taken engine through system shafts clutches spin up rotor Unless willing undergo sort complexity well have settle takeoff run considered lengthy conventional airplane standards 8 Control Normalairplanetype tail surfaces will produce very good control will provide flight little different airplane long tail moment arm desirable model both elevator authority well conven ience handling launching model 9 Lift Avro C6 weighs 6 oz built will fly very nicely 9 oz two blades manageable 10-mph breeze final point model giros may made much easier transport provision made readily remove rotor sure lubricate rotor pivot inspect rotor security damage between flights Music Tach/Porter Continued page 40 nomogram plastic side pitch pipe Middle C157K C sharp166K D 176K D sharp186K E198K F21 0K F sharp222K G235K G sharp249K A264K sharp2796K B2964K C 314K range can extended both above below range pitch pipe humming lower higher harmonics simultaneously blowing selected note listening low beat frequency determine value unknown harmonic frequency example high C first harmonic above middle C Cto-C pitch pipe humming low C blowing high C very discernible beat frequency can experienced same effect takes place humming high C blowing low C pitch pipe very close toor right ona harmonic beat frequency very low hums higher lower note beat frequency increases humming tune engine sound have now found musical tone representing engine speed find note lower middle C blow B below high C hum frequency lower middle C until very low beat frequency experienced now have frequency exactly half B note lower middle C can hum low enough high enough can cover octaves below above pitch pipe frequencies allow cover range 7800 62800 cycles per minute wider needed recommended fullpower two-cycling rpm almost modern model engine However since human voices limited range does appreciably exceed range pitch pipe practical appli cation seems range available pipe Since fly CL models can make instantaneous in-flight rpm checks scheme hold control handle hand pitch pipe other wanted try RC model would have fly model constant-radius circle around model constant distance iffor exampleit coming toward flying away January1981 111