Free Flight: Duration

FREE FLIGHT DURATION LOCKED UP POWER proposals being discussed new Slow Open Power event SLOP might useful take look some ways power model can controlled use timer-actuated auto surfaces first quick refresher course basic problem Lift increases faster model goes Lift good thing wouldnt lift better its going cause model loop tendency model loop least nose up excessively its speed increases can counteracted several ways familiar tight spiral effect sideways loop can keep model looping efficient way adjust model maximum climb Another way control looping tendency decrease decalage angular difference between wing stabilizer popular trim 1950s used both wing stab set same positive angle effect giving zero decalage Often right main wing panel washed leading edge up give some slight amount decalage reduced decalage took care looping problem often required center gravity CC located behind wing trailing edge glide CC location has less effect during climb during glide have flown hand-launched gliders zero-zero wing-stab setting know what can happen straight up straight down could often did happen zero-zero 100% CC gas models such Civy Boy early Satellites Some compromise trims eventually developed small amount decalage slightly more-forward CC 75% combined give more-open spiral climb Designers also learned area airfoil used stab important idea have stab lift increase proportionally wing lift increase control looping tendency development reliable clockwork timers eventually lead use auto surfaces auto stab also called Variable Incidence Tailplane VITI auto rudder AR can set optimum climb during engine run released predetermined glide settings end engine run allowed model use smaller stabilizer important events total area limited moreforward CC Since climb glide could adjusted independently other optimizing climb glide became easier addition bunt give better transition climb glide autosurface-equipped model has become dominant type FIC FlJ open AMA Power events some people feel simpler locked-up models true Free Flight decry increased complexity autosurface model Some suggesting separate event Power models auto surfaces way attract people Power events Others feel auto-surface models complicated build easier trim Almost will agree auto-surface models hold performance edge few people looking some new ways design adjust Power model effort have simplicity locked-up model higher performance auto-surface model Slow Open Power model could compete Open Power Perhaps new best word As quick look through some Zaic Year Books 1950s 1960s will show some ideas arent new Keith Hoover has experimenting some unusual power models 40 years got started wasnt alone Erich Jedelsky Oscar Czepa Stan Hill Alan Brown Jeny Ritz few others experimenting Very High Thrust Line VHTL models idea position engine well above wing creating nose-down moment balance lift wing accompanying threeview 1 959-6 1 Model Aeronautic Year Book shows Keiths designs what happened VHTL Most people stick what other people fly 108 Model Aviation h Hoover adjusts engine VHTL Very High Thrust Line model Side view launch shows low pylon raises wing slightly above fuselage Compare below-the-fuselage wing position older design next page q -r-- Itzz/2zEzt r----. 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design restrictions says Keith Let us what want design Instead creating another separate class non-auto models Keith suggests simple handicap system allow models auto surfaces slightly longer motor run suggests 10-second engine run Category III current seven seconds models auto surfaces would no design construction restrictions either model type suggestion would increase number events older locked-up models would once again competitive Modelers would have option going high-tech low-tech wanted Keith feels important aspect run division between mechanically-oriented ones arent adds concept handicapping based different engine runs different model types has already tried England Could work What think Hoovers VHTL comparison photos taken 1998 Nats three-views some 37 years earlier show similarities differences construction has changed simple all-balsa Jedelsky style moreconventional built-up structure wing now mounted very low pylon rather being strapped underside fuselage most-obvious change reduction height engine pylon earlier version positioned engine center line four inches above wing more-recent model has engine little inch above Keith intends change Im going up engine says Keith has found amount side area front important needs balanced rudder area feels area front must distributed below above thrustline suggests about A- total area should above thrustline Keith also has found rudder should mounted below stab Another interesting idea new model what Keith calls Active Control Tail consists small aluminum tab mounted just above stab trailing edge rear portion tab bent down slightly idea low speed high angle attack ie glide air flowing over top stab has already separated time gets back tab tab has no effect However high speed low angle attack ie climb tab works like down elevator increase stab lift reduce looping tendency Active Control Tail simple idea could easily retrofitted type model just VHTL Keith has experimented span tab Originally about six inches long /2A model has recently July1999 109 Active Control Tail uses aluminum tab mounted just aboveHoover VHTL Aluminum engine mount attached wing stab trailing edge Explanation textShuriken shown Tee Dee 09 CS 049 power Hoover photo American Heart Association Fighting Heart Disease Stroke keeps memories alive AMERICAN HEART ASSOCIATION MEMORIALS & TRIBUTES wI reduced span about half reduces amount down force climb allows half-turn left climb Keith feels safer straight climb have have little insurance cant push maximum says flying enough edge center gravity new models 55-605about years ago other change Keith now sets wing 2O reduce drag increase nose-down tendency during power similar French PGI trim setup developed Wakefield models some years back youd like learn about VHTL good place start NFFS Book Power Models Keith edited book very complete compilation information aspects Power flying should have library Its available National Free Flight Society Contact Bob McLinden NFFS Publications 8256 W Morraine Ave #D Littleton CO 80128 price $1950 NFFS members $2150 nonmembers Postage $4 Zaic Year Books also filled information three-view drawings variety VHTL designs available through AMA Membership Services 765 287-1256 extension 212 Adding Color electronic aids finding models still important get some color model increased visibility Ive best luck fluorescent red wingtips rudder seems leap out bean field Rubber models simply spray light mist directly surface Power models would also need add fuel-proofer some sort Walt Rozelle told technique hes using new FIJ Power model applies color inside covering before applying details Cut covering material slightly oversize Walt uses clear Micafilm actually translucent white Tape down piece stiff cardboard Carefully draw out areas colored inside face Micafllm Note inside face rougher Walt uses two-tone black-andfluorescent-red scheme Use narrow Sharpie outline black areas Use straightedge elevated about 1/is inch above covering make three four quick passes make line about 1/ inch wide Walt says secret keep pen moving ink doesnt bleed may want practice first some scrap Micafllm Use broad-tipped permanent black marker fill area Mask off Micafilm leaving area want red exposed Walt used regular masking tape pieces newspaper Spray fluorescent red Allow dry mist light coat white Remember white will inside after model covered will help brighten fluorescent color Cover model normally Since marker paint will inside covering no need fuelproofing Walt used KrylonTM fluorescent spray paint hardware store have also used stuff good results problems put too-heavy coat some clear MylarTM paint did tend flake off 4[A OK 049F Extra Glow Plug tank[A 2 props sives[A 1 pint Sig [A Dope 25% [A Control lines[A Fuel Pump [A HandleUst Price Over $85U SigBrodakRing Akromaster Flite Streakmaster JrJr 1U7 following [A Fox 15BB CL Wheels engine Adhesive [A Acme BrassUst Plice Over sisr Fuel Tank TCI Price $12000 10 Fox 25DB CI engine add $1 r r4 El wo~u g Golden Golden RingTwister Otl State @fi State @b master Yak9 Mustang the following [A Fox 35 Stunt[A Wheels engine[A Adhesive [A Acme BrassVet Price Over $195 Fuel Tank TCI Price $14000 110 Model Aviation NOW AT LAV ONE PLACE GET U Any single engine 1/2A kit PLN following