SPORT AEROBATICS Ron Van Putte EVERY once columnists get caught own wit Such case recommended July 1980 issue both new experienced pattern fliers should read rule book Cited two situations rules changed recommended people look up rule book same issue recommended Dirty Birdy pattern fliers partly because rolled well inverted upright Two Point Roll Well Craig Arcari Worcester MA sent short letter couldnt resist writing after references look up July column Isnt Two Point Roll now Straight Inverted Flight Look up Ron Ouch really hurts wise guy comments come back haunt Hes right course another letter Dr Bill Lawless posed number questions relative flying higher altitudes Bill moved New Jersey small town high New Mexico plateau 7000 feet elevation few excerpts letter have new Kougar pump K&B 40 adequate New Jersey felt though could com petitive first-ever contest However its quite obvious 7000 feet difference has caused incredible differences aircraft handling response characteristics ways feel though Im having start learning fly over biggest problem far has inability land softly Kougar seems just fall out air unless coming higher-than-comfortable speeds still plan fly ship first Pre-Novice meet several weeks However would appre ciate opinion should proceed once pass Novice class main concerns what size ship much power will need able refine develop flying technique 7000 feet still competitive contests areas much lower elevations Bills problems probably very similar faced lot modelers around country think deserves covered column problems caused altitude due reduction air density 7000 feet density air 81% sea level Basically reduction air density manifests itself three waysaircraft performance air craft control requirements engine power lifting ability airplane directly proportional air density square airspeed 7000 feet lift developed 81% airplane sea level same angle attack airspeed develop same lift 7000 feet sea level same angle attack means airplane must fly 12% faster results higher landing speeds safe operation since stall angle attack airplane affected extent density variations Flying lower air density also means airplane cannot develop much lift looping maneuvers sea level density Since lower air density causes air plane exhibit characteristics heavy airplane would sea level obvious way improve performance airplane higher altitudes build light possible Techniques building light airplanes operate higher altitudes include use built-up wings fuselages covering mylar MonoKote Solar Film etc judicious use adhesives Experience building airplanes light possible can result airplanes take off perform maneuvers land altitude very little different identical design built little consideration weight reduction second effect operation airplanes higher altitudes different amounts control deflection required amount elevator required loops same size increased proportional inverse air Continued page 112 September 1980 25 Lastyear picture otthis airplane mycolumn 2 patches Itwas backatthe Baton Rouge contest again year sporting patches Old Laniers never die 4 Wnat part top wing skin departs contest Michael Johncock Texas City TX displays duct tape repair job model father Allan flew Baton Rouge contest repair worked like charm Necessity IS mother inventionl Butch Norckauer Huntsville AL gave boy interesting pull-toy Its actually 1/2A sport airplane does kid like WHEELS CONTROL-UNEFREE-FUGHT SCALE PILOTS CYUNDERS ENGINE KITS MACHINE GUN KITS PLASTIC DISPLAY MODELS SEND $1 FOR COMPLETE ILLUSTRATED CATALOG DEPT MA PAWNEE ST SAN MARCOS CA 9 VINTAGESMOOTHGOLDEN AGENEW sizes21/3CONTOURsizes214BALLOON 3431/i"234 31/i 13341314 133h2hz4/ 11443/i114334 11/44%31451/4 11451144s/ 11/i53 156/a214514 1/a6A AiMs sliding clearance mentioned above time hold-down tabs attached excess length extending below deck level assembly should tried its fit fuselage careful windshield rear closure correct height slide blocks ride size 1/32 diameter music wire laminated after groove filed both matching cemented surfaces groove will followed #60 drill sharp end piece freshly cut 1/32 wire Make least ten thesewell oversize may trimmed have wire hole parallel perpendicular edges After assembly checked fitting fuselage deck wise establish guide wire positions attach slider blocks working workboard fixture Once satisfaction can mask transparent sections paint frames Canopy frames painted using aluminum pig mented dope masked cellophane scotch tape Mounting fuselage becomes simple task can done last item final assembly RC Aerobatics/Van Putte continued page 25 purchased local electronics store $230 figure Im worth ground lug went under transformer mounting screw show elsewhere column Gerrys convinced Future lots charger will have charger short-circuit reverse-polarity protected batteries arent Five minutes hooked up backwards wont destroy bat teries 5 hours will right save Observations experiences MEN C-50/4 charger I The charger usually goes High rate charging few minutes no matter much have used batteries doesnt happen immediately Sometimes takes 30 seconds switch take place 2 If need reassurance charger really working two ways initiate High rate charging recommended way c batteries charger plug charger 110 VAC supply alterna tive Ivc using ill effects momentarily connect charger pack polarity reversed High rate usually comes plug charger correctly after treatment 3 This great last charger As examplc last Saturday spent morning yard helicopter came lunch plugged system C-50/4 lunch over ready continue flying half-hour charger puts back about charge 4 The trickle charger great too leave helicopter connected time its always fully charged ready go 5 If charger seems noisy tighten screws bend side-plates little Its quiet everything tight 6 Heres Gerry Jarvis Always dis connect charger before turning RC system might unlucky enough have switch makes up system before releases charger case high voltage charger might damage system 7 How about dont need ESV tell its right go flying High rate LED out youre ready Well George what really think charger obsoletes charger own complaint wasnt set up charge 9-cell Cox/Sanwa transmitters Gerry sold us adjusted satisfy needs stamped 5 its chest added catalog Model IV time next year expect see dozen imitations market theyll have hustle beat price $3695 list closing Id like acknowledge postcard John Deneke Glen Rock NJ sent May 1979 John reports has fixing RC systems 12 years has storing batteries C/l00 trickle charger longer Hes found no ill effects process C-50/4 works different principle may find Johns testimony dispells some doubts about continuous storage trickle charge Thanks John Keep postmen busy thanks reading column George M Myers 70 Froehlich Farm Roaa Hicks rule NY 11801 Canopies Kragness continued page 23 internal sliding element Locate make slots center canopy tabs make matching slots fuselage deck course good idea coat transparent areas masking material both inside out Fingers bench top tools will carry ccment thinncr scratches smears will occur unless some protection first applied Now determine proper windshield height drawing set place place forward unit between guides measure its height Trim away lower edges until reaches height doing take care remains symmetrical parallel deck Now cut other two pieces nested inside other relative heights allow about 0 10 clearance top between center element sliding section necessary establish front sliding element windshield height first others pro gressively reduced height result density example almost 25% elevator deflection required same size loop airplane 7000 feet sea level effect aileron control compli cated Lower air density causes reduction torque generated deflection ailerons also causes reduction reverse torque generated rolling airplane Since two torques oppose other maximum roll rate airplane can achieve full aileron throw effect air density maximum roll rate generally found increase roll rate altitude other words fliers find airplanes need less aileron throw altitude sea level third effect altitude can real problem pattern fliers Power output engines ability propellers convert rotary motion thrust dramatically affected air density overall effect operation altitude available thrust varies approximately square density Compared sea level thrust available 7000 feet about 66% can expected sea level Since vertical performance strongly affected thrust available loss st can disastrous Sport fliers will find flying altitude may require moving up engine size compensate loss available thrust Pattern fliers generally able since competition rules limit engine size 61 cubic inches possibility should considered pattern flying altitude build 40-size airplane power 60size engine Flying airplanes higher altitudes can done requires lot care persistence us sea level fliers can think about having fly 5000 10000 feet get depressed problems great things about RC oriented newsletters AMA forwards reading humor contain An excel lent example published SIRS Sentral Illinois Radio Society newsleter co-editors Bill Bev Sellberg feature sort Dear Abby column character called Rudder Brudder issue contained following Dear Rudder Brudder out flying beautiful day last fall bit problem 112 Model Aviation SCALE RADIO CONTROL cost Aeromaster smoking around sky diesel fuel sure stinks decided try some low level loops first beautiful ending about six feet off deck second attempt just thatan attempt Instead loop resembled figure 9 Could fact first loop upwind second downwind cause Al Kleinschmidt Dear Al Attempting low level loop downwind definitely problem should never anything downwind Besides watching way wind blowing may interested extensive research have conducting secret laboratory Warsaw have researching area refer breakmeup phenomenon seems life model aircraft begins tree down South America ends up trash bag filler span flying model very short indeed Trying lengthen span have developing newest anti-crash device have watching TV instead working shop like should have fprobably have noticed commercial camera sonar great brain like con cluded such device mounted aircraft pointing forward could sense approaching terra firma hard green stuff signal elevator servo pull up thus avoiding breakmeup have installed great boon RC world several models testing far have small detail work Out device does prevent sudden stop plane meets earth However have some neatest pictures little balsa pieces separating little plywod pieces surrounded beautiful colored bits flying MonoKote Maybe am using wrong exposure Rudder Brudder Im subject newsletters heres useful hintwhich contained StickTimes newsletter BlackHawk H/C Pilots Waterloo Iowa edited Bruce Stone DID YA KNOW Balsa-Rite mixed microballoons makes great filler dries fast sands easy smooths out real well just fingertip starts dry before get done just add little Balsa-Rite will flow right out Roger Stillhorn As being written still two months before Nats am frantically building new Phoenix 8 replace destroyed during mid-air collision practicing So see Nats flying orange white blue Phoenix 8 youll know successful Come up say hello Ron Van Putte 12 Connie Drive Shalimar FL 32579 light sanding between coats Dope has thinned requires coats Use smallest amount thinner will permit dope flow penetrate building up coating dope surfaces give good adhesion during covering silk As silk applied dope will pass through partially dissolve pre vious coats cause quick adhesion Insufficient dope structure before covering faults increases covering difficulties causes discouragement builder using silk first time wing structure example leading trailing edges well center rib tip should well coated edges silk will fastened during covering Other ribs also need coating prevent pinholes later due over-absorption areas dope would enter balsa underneath rather coating silk actual covering best done sections such top wing half followed bottom repeated other half Fuselage sides top bottom covered like sequence Trying cover area single piece can lead problems house scissors considered sacred used cutting silk because have learned dull scissors will refuse cut smooth edge lightweight material large area such wing half silk cut dimension two three inches wider longer part covered Grain silk should run long direction parallel selvagethat edge woven prevent raveling covering wing dry silk laid over half span sprayed generously water using window laundry sprayer silk thoroughly soaked process may need repeated during covering large area humidity low Dope brushed across center rib rubbed gently weave stretching chord-wise will adhere securely about two minutes silk pulled tightly span-wise dope brushed through wet silk onto tip making certain weave runs parallel wing crossing threads run parallel ribs right angles wing length complete wing tip need doped time Start center tip work toward edges doping pulling until com pleted Most stretching will done spanwise direction Silk strong pulling can quite energetic will need held firm grip fingertips until adhesion occurs after additional area can doped stretched point will quite apparent substantial coating needed tip before beginning covering Without tension could maintained full length leading edge can doped pulling gently chord-wise remove wrinkles along way process repeated trailing edge wrinkles visible point will have removed softening dope along edge nearest wrinkle pulling avoid sag between ribs have stretched silk much greater force span-wise chordwise Excess silk can removed new razor blade loose edges stuck down dope Overlaps become invisible later because thin silk edges submerged heavier dope applications making imperfect edge consequential wing bottom covering can follow immediately general technique described also appli cable fuselage tail surfaces greatest stretch long direction Sheeted wood decks blocks also covered help harden surface wet silk will easily follow com pound curves curvature too severe slit sharp razor will remove wrinkle no after effects slit eventually becomes invisible After water has evaporated drum tight wrinkle-free covering should result point wrinkles can still removed rewetting softening doped-down edge dope pull out offending defects Application first coat clear dope critical operation dope too thick pressure brush open silk surface will force dope through loose weave will gather droplets Visible through surface small ring permanent should avoided very gentle brushing well thinned dope keeping soft brush relatively dry during first coat Subsequent coats require extra care application dope can thicker Adding thinner unnecessarily adds coats needed build finish fill weave economy time money use little thinner possible weave completely filled clear dope after three five brushed coats will noted dope will no longer penetrate under surface through tiny openings between threads sheeted block areas will now need filled hide balsa grain stage quite pronounced purpose prepared filler can brushed filler can made talcum powder purchased druggist need non-perfumed white talc mixture approximately part talc part clear dope four parts thinner pro portion thinner reduced sanding made September 1980 113 RC Scale/Wischers continued page 27
Edition: Model Aviation - 1980/09
Page Numbers: 25, 112, 113
SPORT AEROBATICS Ron Van Putte EVERY once columnists get caught own wit Such case recommended July 1980 issue both new experienced pattern fliers should read rule book Cited two situations rules changed recommended people look up rule book same issue recommended Dirty Birdy pattern fliers partly because rolled well inverted upright Two Point Roll Well Craig Arcari Worcester MA sent short letter couldnt resist writing after references look up July column Isnt Two Point Roll now Straight Inverted Flight Look up Ron Ouch really hurts wise guy comments come back haunt Hes right course another letter Dr Bill Lawless posed number questions relative flying higher altitudes Bill moved New Jersey small town high New Mexico plateau 7000 feet elevation few excerpts letter have new Kougar pump K&B 40 adequate New Jersey felt though could com petitive first-ever contest However its quite obvious 7000 feet difference has caused incredible differences aircraft handling response characteristics ways feel though Im having start learning fly over biggest problem far has inability land softly Kougar seems just fall out air unless coming higher-than-comfortable speeds still plan fly ship first Pre-Novice meet several weeks However would appre ciate opinion should proceed once pass Novice class main concerns what size ship much power will need able refine develop flying technique 7000 feet still competitive contests areas much lower elevations Bills problems probably very similar faced lot modelers around country think deserves covered column problems caused altitude due reduction air density 7000 feet density air 81% sea level Basically reduction air density manifests itself three waysaircraft performance air craft control requirements engine power lifting ability airplane directly proportional air density square airspeed 7000 feet lift developed 81% airplane sea level same angle attack airspeed develop same lift 7000 feet sea level same angle attack means airplane must fly 12% faster results higher landing speeds safe operation since stall angle attack airplane affected extent density variations Flying lower air density also means airplane cannot develop much lift looping maneuvers sea level density Since lower air density causes air plane exhibit characteristics heavy airplane would sea level obvious way improve performance airplane higher altitudes build light possible Techniques building light airplanes operate higher altitudes include use built-up wings fuselages covering mylar MonoKote Solar Film etc judicious use adhesives Experience building airplanes light possible can result airplanes take off perform maneuvers land altitude very little different identical design built little consideration weight reduction second effect operation airplanes higher altitudes different amounts control deflection required amount elevator required loops same size increased proportional inverse air Continued page 112 September 1980 25 Lastyear picture otthis airplane mycolumn 2 patches Itwas backatthe Baton Rouge contest again year sporting patches Old Laniers never die 4 Wnat part top wing skin departs contest Michael Johncock Texas City TX displays duct tape repair job model father Allan flew Baton Rouge contest repair worked like charm Necessity IS mother inventionl Butch Norckauer Huntsville AL gave boy interesting pull-toy Its actually 1/2A sport airplane does kid like WHEELS CONTROL-UNEFREE-FUGHT SCALE PILOTS CYUNDERS ENGINE KITS MACHINE GUN KITS PLASTIC DISPLAY MODELS SEND $1 FOR COMPLETE ILLUSTRATED CATALOG DEPT MA PAWNEE ST SAN MARCOS CA 9 VINTAGESMOOTHGOLDEN AGENEW sizes21/3CONTOURsizes214BALLOON 3431/i"234 31/i 13341314 133h2hz4/ 11443/i114334 11/44%31451/4 11451144s/ 11/i53 156/a214514 1/a6A AiMs sliding clearance mentioned above time hold-down tabs attached excess length extending below deck level assembly should tried its fit fuselage careful windshield rear closure correct height slide blocks ride size 1/32 diameter music wire laminated after groove filed both matching cemented surfaces groove will followed #60 drill sharp end piece freshly cut 1/32 wire Make least ten thesewell oversize may trimmed have wire hole parallel perpendicular edges After assembly checked fitting fuselage deck wise establish guide wire positions attach slider blocks working workboard fixture Once satisfaction can mask transparent sections paint frames Canopy frames painted using aluminum pig mented dope masked cellophane scotch tape Mounting fuselage becomes simple task can done last item final assembly RC Aerobatics/Van Putte continued page 25 purchased local electronics store $230 figure Im worth ground lug went under transformer mounting screw show elsewhere column Gerrys convinced Future lots charger will have charger short-circuit reverse-polarity protected batteries arent Five minutes hooked up backwards wont destroy bat teries 5 hours will right save Observations experiences MEN C-50/4 charger I The charger usually goes High rate charging few minutes no matter much have used batteries doesnt happen immediately Sometimes takes 30 seconds switch take place 2 If need reassurance charger really working two ways initiate High rate charging recommended way c batteries charger plug charger 110 VAC supply alterna tive Ivc using ill effects momentarily connect charger pack polarity reversed High rate usually comes plug charger correctly after treatment 3 This great last charger As examplc last Saturday spent morning yard helicopter came lunch plugged system C-50/4 lunch over ready continue flying half-hour charger puts back about charge 4 The trickle charger great too leave helicopter connected time its always fully charged ready go 5 If charger seems noisy tighten screws bend side-plates little Its quiet everything tight 6 Heres Gerry Jarvis Always dis connect charger before turning RC system might unlucky enough have switch makes up system before releases charger case high voltage charger might damage system 7 How about dont need ESV tell its right go flying High rate LED out youre ready Well George what really think charger obsoletes charger own complaint wasnt set up charge 9-cell Cox/Sanwa transmitters Gerry sold us adjusted satisfy needs stamped 5 its chest added catalog Model IV time next year expect see dozen imitations market theyll have hustle beat price $3695 list closing Id like acknowledge postcard John Deneke Glen Rock NJ sent May 1979 John reports has fixing RC systems 12 years has storing batteries C/l00 trickle charger longer Hes found no ill effects process C-50/4 works different principle may find Johns testimony dispells some doubts about continuous storage trickle charge Thanks John Keep postmen busy thanks reading column George M Myers 70 Froehlich Farm Roaa Hicks rule NY 11801 Canopies Kragness continued page 23 internal sliding element Locate make slots center canopy tabs make matching slots fuselage deck course good idea coat transparent areas masking material both inside out Fingers bench top tools will carry ccment thinncr scratches smears will occur unless some protection first applied Now determine proper windshield height drawing set place place forward unit between guides measure its height Trim away lower edges until reaches height doing take care remains symmetrical parallel deck Now cut other two pieces nested inside other relative heights allow about 0 10 clearance top between center element sliding section necessary establish front sliding element windshield height first others pro gressively reduced height result density example almost 25% elevator deflection required same size loop airplane 7000 feet sea level effect aileron control compli cated Lower air density causes reduction torque generated deflection ailerons also causes reduction reverse torque generated rolling airplane Since two torques oppose other maximum roll rate airplane can achieve full aileron throw effect air density maximum roll rate generally found increase roll rate altitude other words fliers find airplanes need less aileron throw altitude sea level third effect altitude can real problem pattern fliers Power output engines ability propellers convert rotary motion thrust dramatically affected air density overall effect operation altitude available thrust varies approximately square density Compared sea level thrust available 7000 feet about 66% can expected sea level Since vertical performance strongly affected thrust available loss st can disastrous Sport fliers will find flying altitude may require moving up engine size compensate loss available thrust Pattern fliers generally able since competition rules limit engine size 61 cubic inches possibility should considered pattern flying altitude build 40-size airplane power 60size engine Flying airplanes higher altitudes can done requires lot care persistence us sea level fliers can think about having fly 5000 10000 feet get depressed problems great things about RC oriented newsletters AMA forwards reading humor contain An excel lent example published SIRS Sentral Illinois Radio Society newsleter co-editors Bill Bev Sellberg feature sort Dear Abby column character called Rudder Brudder issue contained following Dear Rudder Brudder out flying beautiful day last fall bit problem 112 Model Aviation SCALE RADIO CONTROL cost Aeromaster smoking around sky diesel fuel sure stinks decided try some low level loops first beautiful ending about six feet off deck second attempt just thatan attempt Instead loop resembled figure 9 Could fact first loop upwind second downwind cause Al Kleinschmidt Dear Al Attempting low level loop downwind definitely problem should never anything downwind Besides watching way wind blowing may interested extensive research have conducting secret laboratory Warsaw have researching area refer breakmeup phenomenon seems life model aircraft begins tree down South America ends up trash bag filler span flying model very short indeed Trying lengthen span have developing newest anti-crash device have watching TV instead working shop like should have fprobably have noticed commercial camera sonar great brain like con cluded such device mounted aircraft pointing forward could sense approaching terra firma hard green stuff signal elevator servo pull up thus avoiding breakmeup have installed great boon RC world several models testing far have small detail work Out device does prevent sudden stop plane meets earth However have some neatest pictures little balsa pieces separating little plywod pieces surrounded beautiful colored bits flying MonoKote Maybe am using wrong exposure Rudder Brudder Im subject newsletters heres useful hintwhich contained StickTimes newsletter BlackHawk H/C Pilots Waterloo Iowa edited Bruce Stone DID YA KNOW Balsa-Rite mixed microballoons makes great filler dries fast sands easy smooths out real well just fingertip starts dry before get done just add little Balsa-Rite will flow right out Roger Stillhorn As being written still two months before Nats am frantically building new Phoenix 8 replace destroyed during mid-air collision practicing So see Nats flying orange white blue Phoenix 8 youll know successful Come up say hello Ron Van Putte 12 Connie Drive Shalimar FL 32579 light sanding between coats Dope has thinned requires coats Use smallest amount thinner will permit dope flow penetrate building up coating dope surfaces give good adhesion during covering silk As silk applied dope will pass through partially dissolve pre vious coats cause quick adhesion Insufficient dope structure before covering faults increases covering difficulties causes discouragement builder using silk first time wing structure example leading trailing edges well center rib tip should well coated edges silk will fastened during covering Other ribs also need coating prevent pinholes later due over-absorption areas dope would enter balsa underneath rather coating silk actual covering best done sections such top wing half followed bottom repeated other half Fuselage sides top bottom covered like sequence Trying cover area single piece can lead problems house scissors considered sacred used cutting silk because have learned dull scissors will refuse cut smooth edge lightweight material large area such wing half silk cut dimension two three inches wider longer part covered Grain silk should run long direction parallel selvagethat edge woven prevent raveling covering wing dry silk laid over half span sprayed generously water using window laundry sprayer silk thoroughly soaked process may need repeated during covering large area humidity low Dope brushed across center rib rubbed gently weave stretching chord-wise will adhere securely about two minutes silk pulled tightly span-wise dope brushed through wet silk onto tip making certain weave runs parallel wing crossing threads run parallel ribs right angles wing length complete wing tip need doped time Start center tip work toward edges doping pulling until com pleted Most stretching will done spanwise direction Silk strong pulling can quite energetic will need held firm grip fingertips until adhesion occurs after additional area can doped stretched point will quite apparent substantial coating needed tip before beginning covering Without tension could maintained full length leading edge can doped pulling gently chord-wise remove wrinkles along way process repeated trailing edge wrinkles visible point will have removed softening dope along edge nearest wrinkle pulling avoid sag between ribs have stretched silk much greater force span-wise chordwise Excess silk can removed new razor blade loose edges stuck down dope Overlaps become invisible later because thin silk edges submerged heavier dope applications making imperfect edge consequential wing bottom covering can follow immediately general technique described also appli cable fuselage tail surfaces greatest stretch long direction Sheeted wood decks blocks also covered help harden surface wet silk will easily follow com pound curves curvature too severe slit sharp razor will remove wrinkle no after effects slit eventually becomes invisible After water has evaporated drum tight wrinkle-free covering should result point wrinkles can still removed rewetting softening doped-down edge dope pull out offending defects Application first coat clear dope critical operation dope too thick pressure brush open silk surface will force dope through loose weave will gather droplets Visible through surface small ring permanent should avoided very gentle brushing well thinned dope keeping soft brush relatively dry during first coat Subsequent coats require extra care application dope can thicker Adding thinner unnecessarily adds coats needed build finish fill weave economy time money use little thinner possible weave completely filled clear dope after three five brushed coats will noted dope will no longer penetrate under surface through tiny openings between threads sheeted block areas will now need filled hide balsa grain stage quite pronounced purpose prepared filler can brushed filler can made talcum powder purchased druggist need non-perfumed white talc mixture approximately part talc part clear dope four parts thinner pro portion thinner reduced sanding made September 1980 113 RC Scale/Wischers continued page 27
Edition: Model Aviation - 1980/09
Page Numbers: 25, 112, 113
SPORT AEROBATICS Ron Van Putte EVERY once columnists get caught own wit Such case recommended July 1980 issue both new experienced pattern fliers should read rule book Cited two situations rules changed recommended people look up rule book same issue recommended Dirty Birdy pattern fliers partly because rolled well inverted upright Two Point Roll Well Craig Arcari Worcester MA sent short letter couldnt resist writing after references look up July column Isnt Two Point Roll now Straight Inverted Flight Look up Ron Ouch really hurts wise guy comments come back haunt Hes right course another letter Dr Bill Lawless posed number questions relative flying higher altitudes Bill moved New Jersey small town high New Mexico plateau 7000 feet elevation few excerpts letter have new Kougar pump K&B 40 adequate New Jersey felt though could com petitive first-ever contest However its quite obvious 7000 feet difference has caused incredible differences aircraft handling response characteristics ways feel though Im having start learning fly over biggest problem far has inability land softly Kougar seems just fall out air unless coming higher-than-comfortable speeds still plan fly ship first Pre-Novice meet several weeks However would appre ciate opinion should proceed once pass Novice class main concerns what size ship much power will need able refine develop flying technique 7000 feet still competitive contests areas much lower elevations Bills problems probably very similar faced lot modelers around country think deserves covered column problems caused altitude due reduction air density 7000 feet density air 81% sea level Basically reduction air density manifests itself three waysaircraft performance air craft control requirements engine power lifting ability airplane directly proportional air density square airspeed 7000 feet lift developed 81% airplane sea level same angle attack airspeed develop same lift 7000 feet sea level same angle attack means airplane must fly 12% faster results higher landing speeds safe operation since stall angle attack airplane affected extent density variations Flying lower air density also means airplane cannot develop much lift looping maneuvers sea level density Since lower air density causes air plane exhibit characteristics heavy airplane would sea level obvious way improve performance airplane higher altitudes build light possible Techniques building light airplanes operate higher altitudes include use built-up wings fuselages covering mylar MonoKote Solar Film etc judicious use adhesives Experience building airplanes light possible can result airplanes take off perform maneuvers land altitude very little different identical design built little consideration weight reduction second effect operation airplanes higher altitudes different amounts control deflection required amount elevator required loops same size increased proportional inverse air Continued page 112 September 1980 25 Lastyear picture otthis airplane mycolumn 2 patches Itwas backatthe Baton Rouge contest again year sporting patches Old Laniers never die 4 Wnat part top wing skin departs contest Michael Johncock Texas City TX displays duct tape repair job model father Allan flew Baton Rouge contest repair worked like charm Necessity IS mother inventionl Butch Norckauer Huntsville AL gave boy interesting pull-toy Its actually 1/2A sport airplane does kid like WHEELS CONTROL-UNEFREE-FUGHT SCALE PILOTS CYUNDERS ENGINE KITS MACHINE GUN KITS PLASTIC DISPLAY MODELS SEND $1 FOR COMPLETE ILLUSTRATED CATALOG DEPT MA PAWNEE ST SAN MARCOS CA 9 VINTAGESMOOTHGOLDEN AGENEW sizes21/3CONTOURsizes214BALLOON 3431/i"234 31/i 13341314 133h2hz4/ 11443/i114334 11/44%31451/4 11451144s/ 11/i53 156/a214514 1/a6A AiMs sliding clearance mentioned above time hold-down tabs attached excess length extending below deck level assembly should tried its fit fuselage careful windshield rear closure correct height slide blocks ride size 1/32 diameter music wire laminated after groove filed both matching cemented surfaces groove will followed #60 drill sharp end piece freshly cut 1/32 wire Make least ten thesewell oversize may trimmed have wire hole parallel perpendicular edges After assembly checked fitting fuselage deck wise establish guide wire positions attach slider blocks working workboard fixture Once satisfaction can mask transparent sections paint frames Canopy frames painted using aluminum pig mented dope masked cellophane scotch tape Mounting fuselage becomes simple task can done last item final assembly RC Aerobatics/Van Putte continued page 25 purchased local electronics store $230 figure Im worth ground lug went under transformer mounting screw show elsewhere column Gerrys convinced Future lots charger will have charger short-circuit reverse-polarity protected batteries arent Five minutes hooked up backwards wont destroy bat teries 5 hours will right save Observations experiences MEN C-50/4 charger I The charger usually goes High rate charging few minutes no matter much have used batteries doesnt happen immediately Sometimes takes 30 seconds switch take place 2 If need reassurance charger really working two ways initiate High rate charging recommended way c batteries charger plug charger 110 VAC supply alterna tive Ivc using ill effects momentarily connect charger pack polarity reversed High rate usually comes plug charger correctly after treatment 3 This great last charger As examplc last Saturday spent morning yard helicopter came lunch plugged system C-50/4 lunch over ready continue flying half-hour charger puts back about charge 4 The trickle charger great too leave helicopter connected time its always fully charged ready go 5 If charger seems noisy tighten screws bend side-plates little Its quiet everything tight 6 Heres Gerry Jarvis Always dis connect charger before turning RC system might unlucky enough have switch makes up system before releases charger case high voltage charger might damage system 7 How about dont need ESV tell its right go flying High rate LED out youre ready Well George what really think charger obsoletes charger own complaint wasnt set up charge 9-cell Cox/Sanwa transmitters Gerry sold us adjusted satisfy needs stamped 5 its chest added catalog Model IV time next year expect see dozen imitations market theyll have hustle beat price $3695 list closing Id like acknowledge postcard John Deneke Glen Rock NJ sent May 1979 John reports has fixing RC systems 12 years has storing batteries C/l00 trickle charger longer Hes found no ill effects process C-50/4 works different principle may find Johns testimony dispells some doubts about continuous storage trickle charge Thanks John Keep postmen busy thanks reading column George M Myers 70 Froehlich Farm Roaa Hicks rule NY 11801 Canopies Kragness continued page 23 internal sliding element Locate make slots center canopy tabs make matching slots fuselage deck course good idea coat transparent areas masking material both inside out Fingers bench top tools will carry ccment thinncr scratches smears will occur unless some protection first applied Now determine proper windshield height drawing set place place forward unit between guides measure its height Trim away lower edges until reaches height doing take care remains symmetrical parallel deck Now cut other two pieces nested inside other relative heights allow about 0 10 clearance top between center element sliding section necessary establish front sliding element windshield height first others pro gressively reduced height result density example almost 25% elevator deflection required same size loop airplane 7000 feet sea level effect aileron control compli cated Lower air density causes reduction torque generated deflection ailerons also causes reduction reverse torque generated rolling airplane Since two torques oppose other maximum roll rate airplane can achieve full aileron throw effect air density maximum roll rate generally found increase roll rate altitude other words fliers find airplanes need less aileron throw altitude sea level third effect altitude can real problem pattern fliers Power output engines ability propellers convert rotary motion thrust dramatically affected air density overall effect operation altitude available thrust varies approximately square density Compared sea level thrust available 7000 feet about 66% can expected sea level Since vertical performance strongly affected thrust available loss st can disastrous Sport fliers will find flying altitude may require moving up engine size compensate loss available thrust Pattern fliers generally able since competition rules limit engine size 61 cubic inches possibility should considered pattern flying altitude build 40-size airplane power 60size engine Flying airplanes higher altitudes can done requires lot care persistence us sea level fliers can think about having fly 5000 10000 feet get depressed problems great things about RC oriented newsletters AMA forwards reading humor contain An excel lent example published SIRS Sentral Illinois Radio Society newsleter co-editors Bill Bev Sellberg feature sort Dear Abby column character called Rudder Brudder issue contained following Dear Rudder Brudder out flying beautiful day last fall bit problem 112 Model Aviation SCALE RADIO CONTROL cost Aeromaster smoking around sky diesel fuel sure stinks decided try some low level loops first beautiful ending about six feet off deck second attempt just thatan attempt Instead loop resembled figure 9 Could fact first loop upwind second downwind cause Al Kleinschmidt Dear Al Attempting low level loop downwind definitely problem should never anything downwind Besides watching way wind blowing may interested extensive research have conducting secret laboratory Warsaw have researching area refer breakmeup phenomenon seems life model aircraft begins tree down South America ends up trash bag filler span flying model very short indeed Trying lengthen span have developing newest anti-crash device have watching TV instead working shop like should have fprobably have noticed commercial camera sonar great brain like con cluded such device mounted aircraft pointing forward could sense approaching terra firma hard green stuff signal elevator servo pull up thus avoiding breakmeup have installed great boon RC world several models testing far have small detail work Out device does prevent sudden stop plane meets earth However have some neatest pictures little balsa pieces separating little plywod pieces surrounded beautiful colored bits flying MonoKote Maybe am using wrong exposure Rudder Brudder Im subject newsletters heres useful hintwhich contained StickTimes newsletter BlackHawk H/C Pilots Waterloo Iowa edited Bruce Stone DID YA KNOW Balsa-Rite mixed microballoons makes great filler dries fast sands easy smooths out real well just fingertip starts dry before get done just add little Balsa-Rite will flow right out Roger Stillhorn As being written still two months before Nats am frantically building new Phoenix 8 replace destroyed during mid-air collision practicing So see Nats flying orange white blue Phoenix 8 youll know successful Come up say hello Ron Van Putte 12 Connie Drive Shalimar FL 32579 light sanding between coats Dope has thinned requires coats Use smallest amount thinner will permit dope flow penetrate building up coating dope surfaces give good adhesion during covering silk As silk applied dope will pass through partially dissolve pre vious coats cause quick adhesion Insufficient dope structure before covering faults increases covering difficulties causes discouragement builder using silk first time wing structure example leading trailing edges well center rib tip should well coated edges silk will fastened during covering Other ribs also need coating prevent pinholes later due over-absorption areas dope would enter balsa underneath rather coating silk actual covering best done sections such top wing half followed bottom repeated other half Fuselage sides top bottom covered like sequence Trying cover area single piece can lead problems house scissors considered sacred used cutting silk because have learned dull scissors will refuse cut smooth edge lightweight material large area such wing half silk cut dimension two three inches wider longer part covered Grain silk should run long direction parallel selvagethat edge woven prevent raveling covering wing dry silk laid over half span sprayed generously water using window laundry sprayer silk thoroughly soaked process may need repeated during covering large area humidity low Dope brushed across center rib rubbed gently weave stretching chord-wise will adhere securely about two minutes silk pulled tightly span-wise dope brushed through wet silk onto tip making certain weave runs parallel wing crossing threads run parallel ribs right angles wing length complete wing tip need doped time Start center tip work toward edges doping pulling until com pleted Most stretching will done spanwise direction Silk strong pulling can quite energetic will need held firm grip fingertips until adhesion occurs after additional area can doped stretched point will quite apparent substantial coating needed tip before beginning covering Without tension could maintained full length leading edge can doped pulling gently chord-wise remove wrinkles along way process repeated trailing edge wrinkles visible point will have removed softening dope along edge nearest wrinkle pulling avoid sag between ribs have stretched silk much greater force span-wise chordwise Excess silk can removed new razor blade loose edges stuck down dope Overlaps become invisible later because thin silk edges submerged heavier dope applications making imperfect edge consequential wing bottom covering can follow immediately general technique described also appli cable fuselage tail surfaces greatest stretch long direction Sheeted wood decks blocks also covered help harden surface wet silk will easily follow com pound curves curvature too severe slit sharp razor will remove wrinkle no after effects slit eventually becomes invisible After water has evaporated drum tight wrinkle-free covering should result point wrinkles can still removed rewetting softening doped-down edge dope pull out offending defects Application first coat clear dope critical operation dope too thick pressure brush open silk surface will force dope through loose weave will gather droplets Visible through surface small ring permanent should avoided very gentle brushing well thinned dope keeping soft brush relatively dry during first coat Subsequent coats require extra care application dope can thicker Adding thinner unnecessarily adds coats needed build finish fill weave economy time money use little thinner possible weave completely filled clear dope after three five brushed coats will noted dope will no longer penetrate under surface through tiny openings between threads sheeted block areas will now need filled hide balsa grain stage quite pronounced purpose prepared filler can brushed filler can made talcum powder purchased druggist need non-perfumed white talc mixture approximately part talc part clear dope four parts thinner pro portion thinner reduced sanding made September 1980 113 RC Scale/Wischers continued page 27