Radio Control Scale Bob Dolly Wischer FLAP OPERATION value flaps model performance has often argued Its true model has low wing loading never flies very fast flaps merely employed because used prototype models performance will change very little flaps deployed full-size airplane fast heavy model also flies like streamlined brick flaps indeed bene ficial Almost modern planes built past 50 years will have used some form flaps basic purpose allow decreased speed loss lift steepen glide path predictable touchdown landing Drag increased considerably throttle may need added compensate first flights new model have found best try flaps reason ably high altitude because have some surprises pitch-change flaps first lowered Most flap-equipped models will pitch nose-up attitude speed too high flaps extended careful management throttle ele vator trim controls speed can reduced pitch change minimized some models very noticeable change stability after flaps extended pronounced steadiness glide path down landing model becomes much less susceptible being upset gusts thermals turbulence flap Ryan SCW perforated strip between landing gear legs low ered about 400 Its effect startling first flight caused almost uncon trollable raising nose regardless speed find difficult fly model holding down-elevator control cure problem install linkage between flap elevator servos some downelevator trim applied flap lowered two servos conveniently located side-by-side model under stand drastic change pitch typical full-size Ryan peculiarity model probably due CG shift linkage described Septem ber 83 column Because models have wing loadings quite low tendency balloon upward exaggerated flaps lowered near cruising speed actual change speed whether model slowed fore extension flaps very noticeable ground expected change rate des cent along glide path has always source disappointment model often drifts past chosen landing spot considerably higher expected probably due light wing loading respect flaps arent worth time effort design install As Scale feature can quite impressive models have predictable reaction extended flaps ideal consequence would no change pitch angle rarely achieved Most will pitch nose-up some ex tent depending upon speed have seen some models lowered nose Holding bit up-elevator compensate downpitch natural reaction pilot therefore poses no real difficulty compared having hold down-elevator throughout gliding descent could lead disas ter quick flick down-elevator trim lever may sufficient would need readjustment speed bleeds off during descent resetting after landing prepara tion next flight have found use flaps takeoff has little no benefit no good reason increase drag model doesnt need greater lift may exceptions course such 40-pound monster marginal power contests sometimes use flaps takeoff because some judges expect Ten de grees flap takeoff supposed shorten distance lift-off under conditions no wind models difference dis Its Electric L Dr Keith Shaws newest creation Gee Bee R-1 spans 50 uses geared Astro cobalt 25 dozen 12 Ah cells airframe weighs 31 oz power system 36 oz radio 9 oz Herman Cholewlnskis gorgeous DH Chipmunk R MonoKote covered built Sig kit Power Enya 120 four-stroke Seen Mint Julep meet Rough River KY Dennis Cain scratch-built Travelair 2000 1 Bill Northrop plans Eight-lb ship uses OS 60 power Finish Sig dope over Sig Koverall Dornler 335 R scratch-built Al Masters factory drawings pair K&B 40s propel 14-lb fighter 44 Model Aviation tance nearly impossible detect Best advice first flights avoid using flaps take off landing Play later air reasonable altitude various settings first hint rising falling nose retract flaps proceed action contest example some contestants will use flap operation flight option Expect low score flaps arent easily visible air quite often true situation Flaps lowered some landing pattern dis tance arent easily seen preference forget flaps option use enhance realism full-size plane used flaps like wise flap operation should shown judges before flight will know both look center section wing trail ing edge amount deflection will used takeoff landing no requirement judges observe flap motion air flaps used flight option judges will expect see flaps extend retract proper rate model passes before during flight consis tent prototype aircraft Fowler flaps used modern air L craft actually increase wing area extending rearward downward tracks effective flap configuration crease lift flaps compensates loss lift due slower airspeed high drag Because complexity seldom seen models builders generally resort simulated action Anyone has oc cupied seat near wing trailing edge airliner screw-jack drive mechanism can observed will understand reluctance modeler reproduce such complex bit machinery Republic P-47 Thunderbolt similar flap extended rearward rarely seen true operation models because its linkage complexity can made operate scalelike manner ef fective steepening glide path also im presses judges spectators servos Scale model driven greatest workload retracts flaps retract servo draws heavy current batteries few sec onds current flow should drop back idle flap servo must lower flaps hold ex tended position against air loads throughout portion flight energy needed hold flaps down same regardless servo size probably doesnt make difference oversize servo used other words shouldnt expect same battery life between charges flaps used often should kept mind end long day flying field servo airborne model flaps down consuming power oth ers Use retract servo same time now two high-current devices lower ing battery voltage Does sound like scenario problem short radio rangedistance batteries marginal havent found need use larger servos flaps standard servo having 25 40 inch-pounds torque has always ade quate 1800 retract servo can used flaps advantage slower speed provides greater time raising lowering improves realism servo linkage arranged servo output lever disc comes halt end its travel flaps fully extended Continued page 136 oilers yOU IAos Co~pee r4O0 &iclP Al O 00 toi r October 1986 45 1 ACCWI 1/32 scale plastic model kits Golden Age classic aircraft Colorful highly detailed miniatures Send $1 fully illustrated cata log other kits accessories 13311 Beach Ave na Del Rey CA Horn Old Timer fl{2t born 7&QVii LANZOS 8 GAS 900Cc cAdO deL S~ cr1 cs RECORD BREAKER -1941 BROOKLYN DODGER 36 Cabi EWEST0 Retail $529505INTRODUCTORY PRICE0 $3900 1938 Record Breaker 96 $6956 tO39Zipper 54$5356 1938 Kloud King 63 $42 36 1941 Brigidier 56 $4076 1941 Super Ouaker 78 $7276 1940 So Long 50$3036 1936 Buccaneer 84 $5996 1938 Clipper MKI 72$4156 1937 Dallaire 108 $75 16 1935 Miss America 84$7196 1941 Playboy Sr 80 $5116 1991 Playboy Jr 54$31 16 1938 Powerhouse 84 $5356 1990 Sailplane 76 $0479 1938 Trenton Terror 72 $90 76 1990 Ranger 46$31 96 1939 Korda Wake 44 $1916 1939 Mercury 72 6 kits gualify SAM evento EF & RIG ond feature highest quabty machine cut 6 sanded parts Superior Competition ott ahoet atrip wood mire & window material Ptana orig EF modela easily convertible Och RIG KITS Sailplanes Electric power Gas Hobby Horn SENSOAR Glider 78 $1600 Midway Model GNOME RIG Hand Launch Glider$2400 Jolly Models FLINGER RIG HLG 50 Span$2400 Midway Model FAST EDDIE Aerobatic /05 EIec$19 00 Jolly Models ELECTRICUS Electric Glider 05s93250 Leisure PLAYBOY SR 67 Gear 05 Elect $3800 Astro ASTRO SPORT 37 Direct 05 Elect $2250 Leisure WASP 37 Direct 05 Electrics$2210 Midway ULTRA MK IV 86 Geared 04 EP $3900 Midway FLYING OUAKER 84 40-454 stroke $6976 4kslMidway DENNY JR 72 Alum Comel$6396 4kslMidwav BUZZARD BOMBSHELL 7200196 FULL LINE OF ELECTRIC SYSTEMS S Parts Avail SHIIlllll & HANDLING Up $000 add $150 $801 $2000 add $220 $2001 $4500 add $301 $4501 $7000 add $350 over $7000 add $4 00 CA Addressees add 65 tax Send MO VisaIMC# Eap Check allow up 30 days CK clearance COD Exact Charges plus $158 HdI Cash Only Designs 06 DA 0 0 S C 21 0 0 18 C 01 1 91 2_________ 0 0 a_________________ C 21 01__________________ ___ __________ S 0 C 21 C 0 0 0 C Ct k4 Page UAaALUUUO $200 PP/tat Clxos copy will sent free--when requested-with order HOBBY HORN 15173 Moran St PO Bow 2212 Westminster Ca 92604 714 0938311 [AftHrs 714 0951203] . 0ce Deslgfls 0 0 IC 18 S 0 SPORT BIPE S $21 PPD 0 PPDZl S _______________0 ~s15 __________0 It ________________0 0 PHOTO DOCUMENTATION PACKS availableon Scale Plans ALL PLANS ROLLEDSHIPPED UPS Compleie wlnetrection Osokiet Send slOO Catalog New York OlaRe Residenie aoO 7% selee tax. Osndsheak . Allow 3 weeks aleckfoalxar QUARTER SCALE PLANSQuarter Master Sport BIpe0 Guadra 35. 73Span.E-Z build. Great PIyer.*Semitif Acailable DAVIS D-1K 905 Span. Ouadra 35 power similar. 1933 KINNER SPORTSTER Model K.ll7Span.035 power. 4-CYCLE PROJECTS aW AKRON FUNK ls Ocae 84span AO size 4 cesle. Faniasiic Flyer DAVIS D1K00 BOa Span. 40 4 cycle similar. Two losS wale 010th scale 1933 KINNER SPORTSTERRR Ce Model K. 79 Span. B1-75.4ny poo510 *e Photo roosoed ocr 1/4 Osele plans. Two loon scale Sloth seals DA Plans comino Propellers/Abbott Continued page 133 prop inches raise fourth power multiply pitch inches common model props will get number between 20000 5000000 find value upper right-hand part chart follow diagonal line down left rpm/hp combination will probably find value PD4 get particular prop does exactly agree values chart will have interpolate between given values need greater accuracy can always use formula other hand know power rpm engine wish select appropriate propeller find inter section hp rpm follow diagonal up right find value PD4 can use calculator find combinations pitch diameter equal value PD4 find diameter will have able find fourth root number must have scientific-type calculator least has exponential func tion have use exponen tial key usually labeled xy enter 25 exponent Finally Ive provided listing values PD4 some 32 typical model propellers chart works two-bladed props having aspect ratio between 61 91 typical props used RC CL models have tested thin toothpick props used racers also very useful have idea airspeed range may expected particular propeller given rpm will obvious higher pitch will result higher speed simple formula relates pitch airspeed rpm mph thousands X pitch nominal airspeed air speed would result propeller operating no slippage nominal airspeed chart shows relationship air speed rpm propeller pitches 3 12 rpm up 15000 covers model situations assumption no slippage course usually encountered actual flight However does give valuable insight selection propeller particular set conditions example suppose airplane planned fly 75 mph engine expected run 10000 rpm chart may immediately determined 10000 rpm propeller 8-in pitch will have nominal airspeed 75 mph Its therefore obvious propeller selected must have 8-in pitch greater airspeed 75 mph reached Its true under certain conditions speeds excess nominal airspeed may achieved due fact propeller blade airfoil may produce lift slightly negative angle attack Bear mind vail ables involved analysis propellers article have made number simplifying assumptions order provide fairly simple method estimating pro peller performance have found results better hp cases Ive checked method against data full-size aircraft engines propel lers well home-builts ultralights have always well within tha range Im confident method i adequate model purposes Conclusion discussed two formulac describe two important aspects 01 propeller behavior thrust power ab sorption formula thrust th importance diameter disk area came apparent discussion 01 power saw propeller powe varies third power rpm 2 fairly small change rpm indicates rathe larger change power chart pre sented makes possible estimate power required drive propeller particular rpm chart also pro vided find nominal airspeed function rpm propeller pitch RC Scale/Wischers Continued page 45 connecting link lined up directly across servo output shaft centerline will no load servo motor Current flow servo will drop idle flaps locked down securely course true full-flap position extra gear retract servo also helps reduce current con sumption intermediate flap positions Incidence angles again third time recent columns going dwell upon touchy subject disastrous crash club field model descended ver tically impact few feet pit area filled models fliers spectators Fortunately missed everyone thing destroying itself pilot us ing full up-elevator throughout dive several hundred feet no appar ent response plane Having built kit assumed incidence angles correct center gravity location concern its first flight case due building error stabilizer leading edge inad vertently raised bit too much providing lifting force Ordinarily sort thing causes no great problem model can readily flown trimming bit upelevator model ratio stabilizer area elevator area quite high large stab small elevator Elevator travel set near minimum prevent overcontrolling Whenever model built up speed tendency models nose tuck under required full upelevator recover level flight its final dive gathered excessive speed simply wouldnt pull out enough up-elevator travel say During its first flight 136 Model Aviation TOciarterMaster .ru 3] i 11 ous cModeler / NILITE III run four cycle have inverted engine have scale ship completely cowledin engine want dpendabta idle sport plane fly pattern cant afford flame out id/a need Niite Ill board glow plug lighter 38K0Nilite Ill Kit 38K90CAliita Ill Asmbld 38K91Twin Nilite lllKit 3819 ICTwin Nilite Ill Asmbld $3295 $3995 $3895 $4695 METERED NILITEII Metered Nilite II lights 12V l5V glow plug also monitors condition plug meter tell its open shorted flooded weak rechargeable 1200 MAH nicd provides enough dependable starts normal flying session Utilizes patented H eadlock device firmly hook easily unhook plug 38185Metered Nilite II Combo Complete wiCharger $2995 38186Metered Nilite IlLighterOnly$1995 COMPLETE CATALOG $200 ACE R/C INC 116W 19 St POBox 51IEN HIGGINSVILLE MO 64037 816 584-7121 model performed rather tight inside ioop large stabilizer area set positive angle acting reduce wings angle attack point no lift Eleva tot travel insufficient overcome sta bilizers force Quick thinking compe tent pilot probably could have saved model applying down-elevator isnt natural reaction nose-down situation Closing throttle may also have helped over about three seconds oc curred models second flight first reasonably successful hint hidden danger speed permitted increase landing normal Its questionable whether changing eleva tot travel would have made airplane man ageable under conditions case upward-deflected elevator disadvan tage because working lowered pres sure above lifting stabilizer existed deadly combination circumstances no recovery model built according plans crash would have happened Bob Dolly Wischer S-221 Lapham Peak Rd Delafield WI 53018 RC Aerobatics/Van Putte Continued page 46 thing Now very unusual Rossi Since engine didnt sag battery connector removed couldnt bad glow plug right Wrong bad glow plug hint obvious normally-reliable engine gets balky check glow plug knew thatI just forgot Ron Van Putte 111 Sleepy Oaks Rd Ft Walton Beach FL 32548 RC Soaring/Blakeslee Continued page 49 print technical organizational details slope gliding northern Europe little said about great fun have must way share enjoyment sport Lets keep contact see what will happen Preben Norholm editor photographer Modelflyue Nyt Denmark 10 years has chairman contest committee RC-Unionen national RC faction Royal Danish Aeroclub has also served board member organizations Mr Norholm will chairman next session Notdic Aeromodelers Council Copen hagen address Godtharbsvej 7 DK 7400 Herning Denmark Canadian connections An old friend Bill Petti grew Montreal sent letter Ive excerpted parts below Bill member Canadian F3B team 1981 Sacramento World Championships whole Canadian team flew design Dave Wright Victoria BC called FMF magazines editorial policy will allow name explained fully fact Carl Blake winner US team finals also flew Speaking Carl Blake what has become him lately FMF extremely strong ship designed operate 36-volt superwinch team used Yes winch three batteries series narrow drum about 12 inches diameter wound line fast ships couldnt climb very steep anglebut moving launches scared devil out everybody vicinity exciting part what Dave called remote launch used Speed task just down-and-back time Dave positioned himself Base alongside AU U&I&IM WaEM [Cl LI U N [Cl mu BENTOM- BROWN JR CAMPBELL COMET- COVERITE COX DUBRO EASY BUILT MODELS FOX GOLDBERG GOLDEN AGE REPRO EGENE DUBOIS GUILLOW- K&B- K&S L R MRC- OS MAX PACTRA- PECK-POLYMER PERFECT R N MODELS SEAGLEN SIG STERLING SULLIVAN SUPER TIGRE TAFFINDER TELCO TOP FLITE- TREXLER WILLIAMS & OTHERS ESTES MODEL ROCKETS Send S 100 C.h Cheek oc Stamp foe 44 page tabloid aice DISCOUNT Catalog 900 illustrationsover 700 Kits choose MAILORDER PHONEORDER IN STORE PENN VALLEY HOllY CENTER 837 WKain St LanuiaIela19446 turnaround winch plane winch 200 meters downwind signal guys winch would step pedal release plane like plane being shot out cannon can imagine difficulty controlling plane coming straight fast didnt always work did work once Dave set two-lap Speed record 85 secondswhich stands day because everybody said Lets have no changed rules 12-volt-winch rule instituted Speed laps increased four try slow down zealots Enough reminiscing Back Bills letter have flying Cumic year Its very nice kit docile old Aquila has much wider speed range Mine came out 10 oz/sq ft will still go up light stuff built polyhedral save time now wish put ailerons lost Pro Runner ship last fall got too high too far downwind never did find famous Just turn So have laboring cobbling together some parts big Dash Cash cross-country event July Joe Bedford Gary Bower won last year determined again new Canadian Soaring Society taking off good support finally have first Canadian LSF Level V John McMillan Central Ontario club cant think deserving person nicknamed him Bear Continued page 141 October 1986 137 .A BLAST FROM THE PAST JIM WALKERS CLASSIC GLIDERS 743 Pak5495 1 404 INTERCEPTOR Folding Wing Glider U-Build-It Kit$395 7 y Fly $795 Add $3 postage sod handling first -2 packages 10% additional AmeiieaA/wLA2P P0 Box 68132 AIRCRAFT CO Poriland OR 97268
Edition: Model Aviation - 1986/10
Page Numbers: 44, 45, 136, 137
Edition: Model Aviation - 1986/10
Page Numbers: 44, 45, 136, 137
Radio Control Scale Bob Dolly Wischer FLAP OPERATION value flaps model performance has often argued Its true model has low wing loading never flies very fast flaps merely employed because used prototype models performance will change very little flaps deployed full-size airplane fast heavy model also flies like streamlined brick flaps indeed bene ficial Almost modern planes built past 50 years will have used some form flaps basic purpose allow decreased speed loss lift steepen glide path predictable touchdown landing Drag increased considerably throttle may need added compensate first flights new model have found best try flaps reason ably high altitude because have some surprises pitch-change flaps first lowered Most flap-equipped models will pitch nose-up attitude speed too high flaps extended careful management throttle ele vator trim controls speed can reduced pitch change minimized some models very noticeable change stability after flaps extended pronounced steadiness glide path down landing model becomes much less susceptible being upset gusts thermals turbulence flap Ryan SCW perforated strip between landing gear legs low ered about 400 Its effect startling first flight caused almost uncon trollable raising nose regardless speed find difficult fly model holding down-elevator control cure problem install linkage between flap elevator servos some downelevator trim applied flap lowered two servos conveniently located side-by-side model under stand drastic change pitch typical full-size Ryan peculiarity model probably due CG shift linkage described Septem ber 83 column Because models have wing loadings quite low tendency balloon upward exaggerated flaps lowered near cruising speed actual change speed whether model slowed fore extension flaps very noticeable ground expected change rate des cent along glide path has always source disappointment model often drifts past chosen landing spot considerably higher expected probably due light wing loading respect flaps arent worth time effort design install As Scale feature can quite impressive models have predictable reaction extended flaps ideal consequence would no change pitch angle rarely achieved Most will pitch nose-up some ex tent depending upon speed have seen some models lowered nose Holding bit up-elevator compensate downpitch natural reaction pilot therefore poses no real difficulty compared having hold down-elevator throughout gliding descent could lead disas ter quick flick down-elevator trim lever may sufficient would need readjustment speed bleeds off during descent resetting after landing prepara tion next flight have found use flaps takeoff has little no benefit no good reason increase drag model doesnt need greater lift may exceptions course such 40-pound monster marginal power contests sometimes use flaps takeoff because some judges expect Ten de grees flap takeoff supposed shorten distance lift-off under conditions no wind models difference dis Its Electric L Dr Keith Shaws newest creation Gee Bee R-1 spans 50 uses geared Astro cobalt 25 dozen 12 Ah cells airframe weighs 31 oz power system 36 oz radio 9 oz Herman Cholewlnskis gorgeous DH Chipmunk R MonoKote covered built Sig kit Power Enya 120 four-stroke Seen Mint Julep meet Rough River KY Dennis Cain scratch-built Travelair 2000 1 Bill Northrop plans Eight-lb ship uses OS 60 power Finish Sig dope over Sig Koverall Dornler 335 R scratch-built Al Masters factory drawings pair K&B 40s propel 14-lb fighter 44 Model Aviation tance nearly impossible detect Best advice first flights avoid using flaps take off landing Play later air reasonable altitude various settings first hint rising falling nose retract flaps proceed action contest example some contestants will use flap operation flight option Expect low score flaps arent easily visible air quite often true situation Flaps lowered some landing pattern dis tance arent easily seen preference forget flaps option use enhance realism full-size plane used flaps like wise flap operation should shown judges before flight will know both look center section wing trail ing edge amount deflection will used takeoff landing no requirement judges observe flap motion air flaps used flight option judges will expect see flaps extend retract proper rate model passes before during flight consis tent prototype aircraft Fowler flaps used modern air L craft actually increase wing area extending rearward downward tracks effective flap configuration crease lift flaps compensates loss lift due slower airspeed high drag Because complexity seldom seen models builders generally resort simulated action Anyone has oc cupied seat near wing trailing edge airliner screw-jack drive mechanism can observed will understand reluctance modeler reproduce such complex bit machinery Republic P-47 Thunderbolt similar flap extended rearward rarely seen true operation models because its linkage complexity can made operate scalelike manner ef fective steepening glide path also im presses judges spectators servos Scale model driven greatest workload retracts flaps retract servo draws heavy current batteries few sec onds current flow should drop back idle flap servo must lower flaps hold ex tended position against air loads throughout portion flight energy needed hold flaps down same regardless servo size probably doesnt make difference oversize servo used other words shouldnt expect same battery life between charges flaps used often should kept mind end long day flying field servo airborne model flaps down consuming power oth ers Use retract servo same time now two high-current devices lower ing battery voltage Does sound like scenario problem short radio rangedistance batteries marginal havent found need use larger servos flaps standard servo having 25 40 inch-pounds torque has always ade quate 1800 retract servo can used flaps advantage slower speed provides greater time raising lowering improves realism servo linkage arranged servo output lever disc comes halt end its travel flaps fully extended Continued page 136 oilers yOU IAos Co~pee r4O0 &iclP Al O 00 toi r October 1986 45 1 ACCWI 1/32 scale plastic model kits Golden Age classic aircraft Colorful highly detailed miniatures Send $1 fully illustrated cata log other kits accessories 13311 Beach Ave na Del Rey CA Horn Old Timer fl{2t born 7&QVii LANZOS 8 GAS 900Cc cAdO deL S~ cr1 cs RECORD BREAKER -1941 BROOKLYN DODGER 36 Cabi EWEST0 Retail $529505INTRODUCTORY PRICE0 $3900 1938 Record Breaker 96 $6956 tO39Zipper 54$5356 1938 Kloud King 63 $42 36 1941 Brigidier 56 $4076 1941 Super Ouaker 78 $7276 1940 So Long 50$3036 1936 Buccaneer 84 $5996 1938 Clipper MKI 72$4156 1937 Dallaire 108 $75 16 1935 Miss America 84$7196 1941 Playboy Sr 80 $5116 1991 Playboy Jr 54$31 16 1938 Powerhouse 84 $5356 1990 Sailplane 76 $0479 1938 Trenton Terror 72 $90 76 1990 Ranger 46$31 96 1939 Korda Wake 44 $1916 1939 Mercury 72 6 kits gualify SAM evento EF & RIG ond feature highest quabty machine cut 6 sanded parts Superior Competition ott ahoet atrip wood mire & window material Ptana orig EF modela easily convertible Och RIG KITS Sailplanes Electric power Gas Hobby Horn SENSOAR Glider 78 $1600 Midway Model GNOME RIG Hand Launch Glider$2400 Jolly Models FLINGER RIG HLG 50 Span$2400 Midway Model FAST EDDIE Aerobatic /05 EIec$19 00 Jolly Models ELECTRICUS Electric Glider 05s93250 Leisure PLAYBOY SR 67 Gear 05 Elect $3800 Astro ASTRO SPORT 37 Direct 05 Elect $2250 Leisure WASP 37 Direct 05 Electrics$2210 Midway ULTRA MK IV 86 Geared 04 EP $3900 Midway FLYING OUAKER 84 40-454 stroke $6976 4kslMidway DENNY JR 72 Alum Comel$6396 4kslMidwav BUZZARD BOMBSHELL 7200196 FULL LINE OF ELECTRIC SYSTEMS S Parts Avail SHIIlllll & HANDLING Up $000 add $150 $801 $2000 add $220 $2001 $4500 add $301 $4501 $7000 add $350 over $7000 add $4 00 CA Addressees add 65 tax Send MO VisaIMC# Eap Check allow up 30 days CK clearance COD Exact Charges plus $158 HdI Cash Only Designs 06 DA 0 0 S C 21 0 0 18 C 01 1 91 2_________ 0 0 a_________________ C 21 01__________________ ___ __________ S 0 C 21 C 0 0 0 C Ct k4 Page UAaALUUUO $200 PP/tat Clxos copy will sent free--when requested-with order HOBBY HORN 15173 Moran St PO Bow 2212 Westminster Ca 92604 714 0938311 [AftHrs 714 0951203] . 0ce Deslgfls 0 0 IC 18 S 0 SPORT BIPE S $21 PPD 0 PPDZl S _______________0 ~s15 __________0 It ________________0 0 PHOTO DOCUMENTATION PACKS availableon Scale Plans ALL PLANS ROLLEDSHIPPED UPS Compleie wlnetrection Osokiet Send slOO Catalog New York OlaRe Residenie aoO 7% selee tax. Osndsheak . Allow 3 weeks aleckfoalxar QUARTER SCALE PLANSQuarter Master Sport BIpe0 Guadra 35. 73Span.E-Z build. Great PIyer.*Semitif Acailable DAVIS D-1K 905 Span. Ouadra 35 power similar. 1933 KINNER SPORTSTER Model K.ll7Span.035 power. 4-CYCLE PROJECTS aW AKRON FUNK ls Ocae 84span AO size 4 cesle. Faniasiic Flyer DAVIS D1K00 BOa Span. 40 4 cycle similar. Two losS wale 010th scale 1933 KINNER SPORTSTERRR Ce Model K. 79 Span. B1-75.4ny poo510 *e Photo roosoed ocr 1/4 Osele plans. Two loon scale Sloth seals DA Plans comino Propellers/Abbott Continued page 133 prop inches raise fourth power multiply pitch inches common model props will get number between 20000 5000000 find value upper right-hand part chart follow diagonal line down left rpm/hp combination will probably find value PD4 get particular prop does exactly agree values chart will have interpolate between given values need greater accuracy can always use formula other hand know power rpm engine wish select appropriate propeller find inter section hp rpm follow diagonal up right find value PD4 can use calculator find combinations pitch diameter equal value PD4 find diameter will have able find fourth root number must have scientific-type calculator least has exponential func tion have use exponen tial key usually labeled xy enter 25 exponent Finally Ive provided listing values PD4 some 32 typical model propellers chart works two-bladed props having aspect ratio between 61 91 typical props used RC CL models have tested thin toothpick props used racers also very useful have idea airspeed range may expected particular propeller given rpm will obvious higher pitch will result higher speed simple formula relates pitch airspeed rpm mph thousands X pitch nominal airspeed air speed would result propeller operating no slippage nominal airspeed chart shows relationship air speed rpm propeller pitches 3 12 rpm up 15000 covers model situations assumption no slippage course usually encountered actual flight However does give valuable insight selection propeller particular set conditions example suppose airplane planned fly 75 mph engine expected run 10000 rpm chart may immediately determined 10000 rpm propeller 8-in pitch will have nominal airspeed 75 mph Its therefore obvious propeller selected must have 8-in pitch greater airspeed 75 mph reached Its true under certain conditions speeds excess nominal airspeed may achieved due fact propeller blade airfoil may produce lift slightly negative angle attack Bear mind vail ables involved analysis propellers article have made number simplifying assumptions order provide fairly simple method estimating pro peller performance have found results better hp cases Ive checked method against data full-size aircraft engines propel lers well home-builts ultralights have always well within tha range Im confident method i adequate model purposes Conclusion discussed two formulac describe two important aspects 01 propeller behavior thrust power ab sorption formula thrust th importance diameter disk area came apparent discussion 01 power saw propeller powe varies third power rpm 2 fairly small change rpm indicates rathe larger change power chart pre sented makes possible estimate power required drive propeller particular rpm chart also pro vided find nominal airspeed function rpm propeller pitch RC Scale/Wischers Continued page 45 connecting link lined up directly across servo output shaft centerline will no load servo motor Current flow servo will drop idle flaps locked down securely course true full-flap position extra gear retract servo also helps reduce current con sumption intermediate flap positions Incidence angles again third time recent columns going dwell upon touchy subject disastrous crash club field model descended ver tically impact few feet pit area filled models fliers spectators Fortunately missed everyone thing destroying itself pilot us ing full up-elevator throughout dive several hundred feet no appar ent response plane Having built kit assumed incidence angles correct center gravity location concern its first flight case due building error stabilizer leading edge inad vertently raised bit too much providing lifting force Ordinarily sort thing causes no great problem model can readily flown trimming bit upelevator model ratio stabilizer area elevator area quite high large stab small elevator Elevator travel set near minimum prevent overcontrolling Whenever model built up speed tendency models nose tuck under required full upelevator recover level flight its final dive gathered excessive speed simply wouldnt pull out enough up-elevator travel say During its first flight 136 Model Aviation TOciarterMaster .ru 3] i 11 ous cModeler / NILITE III run four cycle have inverted engine have scale ship completely cowledin engine want dpendabta idle sport plane fly pattern cant afford flame out id/a need Niite Ill board glow plug lighter 38K0Nilite Ill Kit 38K90CAliita Ill Asmbld 38K91Twin Nilite lllKit 3819 ICTwin Nilite Ill Asmbld $3295 $3995 $3895 $4695 METERED NILITEII Metered Nilite II lights 12V l5V glow plug also monitors condition plug meter tell its open shorted flooded weak rechargeable 1200 MAH nicd provides enough dependable starts normal flying session Utilizes patented H eadlock device firmly hook easily unhook plug 38185Metered Nilite II Combo Complete wiCharger $2995 38186Metered Nilite IlLighterOnly$1995 COMPLETE CATALOG $200 ACE R/C INC 116W 19 St POBox 51IEN HIGGINSVILLE MO 64037 816 584-7121 model performed rather tight inside ioop large stabilizer area set positive angle acting reduce wings angle attack point no lift Eleva tot travel insufficient overcome sta bilizers force Quick thinking compe tent pilot probably could have saved model applying down-elevator isnt natural reaction nose-down situation Closing throttle may also have helped over about three seconds oc curred models second flight first reasonably successful hint hidden danger speed permitted increase landing normal Its questionable whether changing eleva tot travel would have made airplane man ageable under conditions case upward-deflected elevator disadvan tage because working lowered pres sure above lifting stabilizer existed deadly combination circumstances no recovery model built according plans crash would have happened Bob Dolly Wischer S-221 Lapham Peak Rd Delafield WI 53018 RC Aerobatics/Van Putte Continued page 46 thing Now very unusual Rossi Since engine didnt sag battery connector removed couldnt bad glow plug right Wrong bad glow plug hint obvious normally-reliable engine gets balky check glow plug knew thatI just forgot Ron Van Putte 111 Sleepy Oaks Rd Ft Walton Beach FL 32548 RC Soaring/Blakeslee Continued page 49 print technical organizational details slope gliding northern Europe little said about great fun have must way share enjoyment sport Lets keep contact see what will happen Preben Norholm editor photographer Modelflyue Nyt Denmark 10 years has chairman contest committee RC-Unionen national RC faction Royal Danish Aeroclub has also served board member organizations Mr Norholm will chairman next session Notdic Aeromodelers Council Copen hagen address Godtharbsvej 7 DK 7400 Herning Denmark Canadian connections An old friend Bill Petti grew Montreal sent letter Ive excerpted parts below Bill member Canadian F3B team 1981 Sacramento World Championships whole Canadian team flew design Dave Wright Victoria BC called FMF magazines editorial policy will allow name explained fully fact Carl Blake winner US team finals also flew Speaking Carl Blake what has become him lately FMF extremely strong ship designed operate 36-volt superwinch team used Yes winch three batteries series narrow drum about 12 inches diameter wound line fast ships couldnt climb very steep anglebut moving launches scared devil out everybody vicinity exciting part what Dave called remote launch used Speed task just down-and-back time Dave positioned himself Base alongside AU U&I&IM WaEM [Cl LI U N [Cl mu BENTOM- BROWN JR CAMPBELL COMET- COVERITE COX DUBRO EASY BUILT MODELS FOX GOLDBERG GOLDEN AGE REPRO EGENE DUBOIS GUILLOW- K&B- K&S L R MRC- OS MAX PACTRA- PECK-POLYMER PERFECT R N MODELS SEAGLEN SIG STERLING SULLIVAN SUPER TIGRE TAFFINDER TELCO TOP FLITE- TREXLER WILLIAMS & OTHERS ESTES MODEL ROCKETS Send S 100 C.h Cheek oc Stamp foe 44 page tabloid aice DISCOUNT Catalog 900 illustrationsover 700 Kits choose MAILORDER PHONEORDER IN STORE PENN VALLEY HOllY CENTER 837 WKain St LanuiaIela19446 turnaround winch plane winch 200 meters downwind signal guys winch would step pedal release plane like plane being shot out cannon can imagine difficulty controlling plane coming straight fast didnt always work did work once Dave set two-lap Speed record 85 secondswhich stands day because everybody said Lets have no changed rules 12-volt-winch rule instituted Speed laps increased four try slow down zealots Enough reminiscing Back Bills letter have flying Cumic year Its very nice kit docile old Aquila has much wider speed range Mine came out 10 oz/sq ft will still go up light stuff built polyhedral save time now wish put ailerons lost Pro Runner ship last fall got too high too far downwind never did find famous Just turn So have laboring cobbling together some parts big Dash Cash cross-country event July Joe Bedford Gary Bower won last year determined again new Canadian Soaring Society taking off good support finally have first Canadian LSF Level V John McMillan Central Ontario club cant think deserving person nicknamed him Bear Continued page 141 October 1986 137 .A BLAST FROM THE PAST JIM WALKERS CLASSIC GLIDERS 743 Pak5495 1 404 INTERCEPTOR Folding Wing Glider U-Build-It Kit$395 7 y Fly $795 Add $3 postage sod handling first -2 packages 10% additional AmeiieaA/wLA2P P0 Box 68132 AIRCRAFT CO Poriland OR 97268
Edition: Model Aviation - 1986/10
Page Numbers: 44, 45, 136, 137
Radio Control Scale Bob Dolly Wischer FLAP OPERATION value flaps model performance has often argued Its true model has low wing loading never flies very fast flaps merely employed because used prototype models performance will change very little flaps deployed full-size airplane fast heavy model also flies like streamlined brick flaps indeed bene ficial Almost modern planes built past 50 years will have used some form flaps basic purpose allow decreased speed loss lift steepen glide path predictable touchdown landing Drag increased considerably throttle may need added compensate first flights new model have found best try flaps reason ably high altitude because have some surprises pitch-change flaps first lowered Most flap-equipped models will pitch nose-up attitude speed too high flaps extended careful management throttle ele vator trim controls speed can reduced pitch change minimized some models very noticeable change stability after flaps extended pronounced steadiness glide path down landing model becomes much less susceptible being upset gusts thermals turbulence flap Ryan SCW perforated strip between landing gear legs low ered about 400 Its effect startling first flight caused almost uncon trollable raising nose regardless speed find difficult fly model holding down-elevator control cure problem install linkage between flap elevator servos some downelevator trim applied flap lowered two servos conveniently located side-by-side model under stand drastic change pitch typical full-size Ryan peculiarity model probably due CG shift linkage described Septem ber 83 column Because models have wing loadings quite low tendency balloon upward exaggerated flaps lowered near cruising speed actual change speed whether model slowed fore extension flaps very noticeable ground expected change rate des cent along glide path has always source disappointment model often drifts past chosen landing spot considerably higher expected probably due light wing loading respect flaps arent worth time effort design install As Scale feature can quite impressive models have predictable reaction extended flaps ideal consequence would no change pitch angle rarely achieved Most will pitch nose-up some ex tent depending upon speed have seen some models lowered nose Holding bit up-elevator compensate downpitch natural reaction pilot therefore poses no real difficulty compared having hold down-elevator throughout gliding descent could lead disas ter quick flick down-elevator trim lever may sufficient would need readjustment speed bleeds off during descent resetting after landing prepara tion next flight have found use flaps takeoff has little no benefit no good reason increase drag model doesnt need greater lift may exceptions course such 40-pound monster marginal power contests sometimes use flaps takeoff because some judges expect Ten de grees flap takeoff supposed shorten distance lift-off under conditions no wind models difference dis Its Electric L Dr Keith Shaws newest creation Gee Bee R-1 spans 50 uses geared Astro cobalt 25 dozen 12 Ah cells airframe weighs 31 oz power system 36 oz radio 9 oz Herman Cholewlnskis gorgeous DH Chipmunk R MonoKote covered built Sig kit Power Enya 120 four-stroke Seen Mint Julep meet Rough River KY Dennis Cain scratch-built Travelair 2000 1 Bill Northrop plans Eight-lb ship uses OS 60 power Finish Sig dope over Sig Koverall Dornler 335 R scratch-built Al Masters factory drawings pair K&B 40s propel 14-lb fighter 44 Model Aviation tance nearly impossible detect Best advice first flights avoid using flaps take off landing Play later air reasonable altitude various settings first hint rising falling nose retract flaps proceed action contest example some contestants will use flap operation flight option Expect low score flaps arent easily visible air quite often true situation Flaps lowered some landing pattern dis tance arent easily seen preference forget flaps option use enhance realism full-size plane used flaps like wise flap operation should shown judges before flight will know both look center section wing trail ing edge amount deflection will used takeoff landing no requirement judges observe flap motion air flaps used flight option judges will expect see flaps extend retract proper rate model passes before during flight consis tent prototype aircraft Fowler flaps used modern air L craft actually increase wing area extending rearward downward tracks effective flap configuration crease lift flaps compensates loss lift due slower airspeed high drag Because complexity seldom seen models builders generally resort simulated action Anyone has oc cupied seat near wing trailing edge airliner screw-jack drive mechanism can observed will understand reluctance modeler reproduce such complex bit machinery Republic P-47 Thunderbolt similar flap extended rearward rarely seen true operation models because its linkage complexity can made operate scalelike manner ef fective steepening glide path also im presses judges spectators servos Scale model driven greatest workload retracts flaps retract servo draws heavy current batteries few sec onds current flow should drop back idle flap servo must lower flaps hold ex tended position against air loads throughout portion flight energy needed hold flaps down same regardless servo size probably doesnt make difference oversize servo used other words shouldnt expect same battery life between charges flaps used often should kept mind end long day flying field servo airborne model flaps down consuming power oth ers Use retract servo same time now two high-current devices lower ing battery voltage Does sound like scenario problem short radio rangedistance batteries marginal havent found need use larger servos flaps standard servo having 25 40 inch-pounds torque has always ade quate 1800 retract servo can used flaps advantage slower speed provides greater time raising lowering improves realism servo linkage arranged servo output lever disc comes halt end its travel flaps fully extended Continued page 136 oilers yOU IAos Co~pee r4O0 &iclP Al O 00 toi r October 1986 45 1 ACCWI 1/32 scale plastic model kits Golden Age classic aircraft Colorful highly detailed miniatures Send $1 fully illustrated cata log other kits accessories 13311 Beach Ave na Del Rey CA Horn Old Timer fl{2t born 7&QVii LANZOS 8 GAS 900Cc cAdO deL S~ cr1 cs RECORD BREAKER -1941 BROOKLYN DODGER 36 Cabi EWEST0 Retail $529505INTRODUCTORY PRICE0 $3900 1938 Record Breaker 96 $6956 tO39Zipper 54$5356 1938 Kloud King 63 $42 36 1941 Brigidier 56 $4076 1941 Super Ouaker 78 $7276 1940 So Long 50$3036 1936 Buccaneer 84 $5996 1938 Clipper MKI 72$4156 1937 Dallaire 108 $75 16 1935 Miss America 84$7196 1941 Playboy Sr 80 $5116 1991 Playboy Jr 54$31 16 1938 Powerhouse 84 $5356 1990 Sailplane 76 $0479 1938 Trenton Terror 72 $90 76 1990 Ranger 46$31 96 1939 Korda Wake 44 $1916 1939 Mercury 72 6 kits gualify SAM evento EF & RIG ond feature highest quabty machine cut 6 sanded parts Superior Competition ott ahoet atrip wood mire & window material Ptana orig EF modela easily convertible Och RIG KITS Sailplanes Electric power Gas Hobby Horn SENSOAR Glider 78 $1600 Midway Model GNOME RIG Hand Launch Glider$2400 Jolly Models FLINGER RIG HLG 50 Span$2400 Midway Model FAST EDDIE Aerobatic /05 EIec$19 00 Jolly Models ELECTRICUS Electric Glider 05s93250 Leisure PLAYBOY SR 67 Gear 05 Elect $3800 Astro ASTRO SPORT 37 Direct 05 Elect $2250 Leisure WASP 37 Direct 05 Electrics$2210 Midway ULTRA MK IV 86 Geared 04 EP $3900 Midway FLYING OUAKER 84 40-454 stroke $6976 4kslMidway DENNY JR 72 Alum Comel$6396 4kslMidwav BUZZARD BOMBSHELL 7200196 FULL LINE OF ELECTRIC SYSTEMS S Parts Avail SHIIlllll & HANDLING Up $000 add $150 $801 $2000 add $220 $2001 $4500 add $301 $4501 $7000 add $350 over $7000 add $4 00 CA Addressees add 65 tax Send MO VisaIMC# Eap Check allow up 30 days CK clearance COD Exact Charges plus $158 HdI Cash Only Designs 06 DA 0 0 S C 21 0 0 18 C 01 1 91 2_________ 0 0 a_________________ C 21 01__________________ ___ __________ S 0 C 21 C 0 0 0 C Ct k4 Page UAaALUUUO $200 PP/tat Clxos copy will sent free--when requested-with order HOBBY HORN 15173 Moran St PO Bow 2212 Westminster Ca 92604 714 0938311 [AftHrs 714 0951203] . 0ce Deslgfls 0 0 IC 18 S 0 SPORT BIPE S $21 PPD 0 PPDZl S _______________0 ~s15 __________0 It ________________0 0 PHOTO DOCUMENTATION PACKS availableon Scale Plans ALL PLANS ROLLEDSHIPPED UPS Compleie wlnetrection Osokiet Send slOO Catalog New York OlaRe Residenie aoO 7% selee tax. Osndsheak . Allow 3 weeks aleckfoalxar QUARTER SCALE PLANSQuarter Master Sport BIpe0 Guadra 35. 73Span.E-Z build. Great PIyer.*Semitif Acailable DAVIS D-1K 905 Span. Ouadra 35 power similar. 1933 KINNER SPORTSTER Model K.ll7Span.035 power. 4-CYCLE PROJECTS aW AKRON FUNK ls Ocae 84span AO size 4 cesle. Faniasiic Flyer DAVIS D1K00 BOa Span. 40 4 cycle similar. Two losS wale 010th scale 1933 KINNER SPORTSTERRR Ce Model K. 79 Span. B1-75.4ny poo510 *e Photo roosoed ocr 1/4 Osele plans. Two loon scale Sloth seals DA Plans comino Propellers/Abbott Continued page 133 prop inches raise fourth power multiply pitch inches common model props will get number between 20000 5000000 find value upper right-hand part chart follow diagonal line down left rpm/hp combination will probably find value PD4 get particular prop does exactly agree values chart will have interpolate between given values need greater accuracy can always use formula other hand know power rpm engine wish select appropriate propeller find inter section hp rpm follow diagonal up right find value PD4 can use calculator find combinations pitch diameter equal value PD4 find diameter will have able find fourth root number must have scientific-type calculator least has exponential func tion have use exponen tial key usually labeled xy enter 25 exponent Finally Ive provided listing values PD4 some 32 typical model propellers chart works two-bladed props having aspect ratio between 61 91 typical props used RC CL models have tested thin toothpick props used racers also very useful have idea airspeed range may expected particular propeller given rpm will obvious higher pitch will result higher speed simple formula relates pitch airspeed rpm mph thousands X pitch nominal airspeed air speed would result propeller operating no slippage nominal airspeed chart shows relationship air speed rpm propeller pitches 3 12 rpm up 15000 covers model situations assumption no slippage course usually encountered actual flight However does give valuable insight selection propeller particular set conditions example suppose airplane planned fly 75 mph engine expected run 10000 rpm chart may immediately determined 10000 rpm propeller 8-in pitch will have nominal airspeed 75 mph Its therefore obvious propeller selected must have 8-in pitch greater airspeed 75 mph reached Its true under certain conditions speeds excess nominal airspeed may achieved due fact propeller blade airfoil may produce lift slightly negative angle attack Bear mind vail ables involved analysis propellers article have made number simplifying assumptions order provide fairly simple method estimating pro peller performance have found results better hp cases Ive checked method against data full-size aircraft engines propel lers well home-builts ultralights have always well within tha range Im confident method i adequate model purposes Conclusion discussed two formulac describe two important aspects 01 propeller behavior thrust power ab sorption formula thrust th importance diameter disk area came apparent discussion 01 power saw propeller powe varies third power rpm 2 fairly small change rpm indicates rathe larger change power chart pre sented makes possible estimate power required drive propeller particular rpm chart also pro vided find nominal airspeed function rpm propeller pitch RC Scale/Wischers Continued page 45 connecting link lined up directly across servo output shaft centerline will no load servo motor Current flow servo will drop idle flaps locked down securely course true full-flap position extra gear retract servo also helps reduce current con sumption intermediate flap positions Incidence angles again third time recent columns going dwell upon touchy subject disastrous crash club field model descended ver tically impact few feet pit area filled models fliers spectators Fortunately missed everyone thing destroying itself pilot us ing full up-elevator throughout dive several hundred feet no appar ent response plane Having built kit assumed incidence angles correct center gravity location concern its first flight case due building error stabilizer leading edge inad vertently raised bit too much providing lifting force Ordinarily sort thing causes no great problem model can readily flown trimming bit upelevator model ratio stabilizer area elevator area quite high large stab small elevator Elevator travel set near minimum prevent overcontrolling Whenever model built up speed tendency models nose tuck under required full upelevator recover level flight its final dive gathered excessive speed simply wouldnt pull out enough up-elevator travel say During its first flight 136 Model Aviation TOciarterMaster .ru 3] i 11 ous cModeler / NILITE III run four cycle have inverted engine have scale ship completely cowledin engine want dpendabta idle sport plane fly pattern cant afford flame out id/a need Niite Ill board glow plug lighter 38K0Nilite Ill Kit 38K90CAliita Ill Asmbld 38K91Twin Nilite lllKit 3819 ICTwin Nilite Ill Asmbld $3295 $3995 $3895 $4695 METERED NILITEII Metered Nilite II lights 12V l5V glow plug also monitors condition plug meter tell its open shorted flooded weak rechargeable 1200 MAH nicd provides enough dependable starts normal flying session Utilizes patented H eadlock device firmly hook easily unhook plug 38185Metered Nilite II Combo Complete wiCharger $2995 38186Metered Nilite IlLighterOnly$1995 COMPLETE CATALOG $200 ACE R/C INC 116W 19 St POBox 51IEN HIGGINSVILLE MO 64037 816 584-7121 model performed rather tight inside ioop large stabilizer area set positive angle acting reduce wings angle attack point no lift Eleva tot travel insufficient overcome sta bilizers force Quick thinking compe tent pilot probably could have saved model applying down-elevator isnt natural reaction nose-down situation Closing throttle may also have helped over about three seconds oc curred models second flight first reasonably successful hint hidden danger speed permitted increase landing normal Its questionable whether changing eleva tot travel would have made airplane man ageable under conditions case upward-deflected elevator disadvan tage because working lowered pres sure above lifting stabilizer existed deadly combination circumstances no recovery model built according plans crash would have happened Bob Dolly Wischer S-221 Lapham Peak Rd Delafield WI 53018 RC Aerobatics/Van Putte Continued page 46 thing Now very unusual Rossi Since engine didnt sag battery connector removed couldnt bad glow plug right Wrong bad glow plug hint obvious normally-reliable engine gets balky check glow plug knew thatI just forgot Ron Van Putte 111 Sleepy Oaks Rd Ft Walton Beach FL 32548 RC Soaring/Blakeslee Continued page 49 print technical organizational details slope gliding northern Europe little said about great fun have must way share enjoyment sport Lets keep contact see what will happen Preben Norholm editor photographer Modelflyue Nyt Denmark 10 years has chairman contest committee RC-Unionen national RC faction Royal Danish Aeroclub has also served board member organizations Mr Norholm will chairman next session Notdic Aeromodelers Council Copen hagen address Godtharbsvej 7 DK 7400 Herning Denmark Canadian connections An old friend Bill Petti grew Montreal sent letter Ive excerpted parts below Bill member Canadian F3B team 1981 Sacramento World Championships whole Canadian team flew design Dave Wright Victoria BC called FMF magazines editorial policy will allow name explained fully fact Carl Blake winner US team finals also flew Speaking Carl Blake what has become him lately FMF extremely strong ship designed operate 36-volt superwinch team used Yes winch three batteries series narrow drum about 12 inches diameter wound line fast ships couldnt climb very steep anglebut moving launches scared devil out everybody vicinity exciting part what Dave called remote launch used Speed task just down-and-back time Dave positioned himself Base alongside AU U&I&IM WaEM [Cl LI U N [Cl mu BENTOM- BROWN JR CAMPBELL COMET- COVERITE COX DUBRO EASY BUILT MODELS FOX GOLDBERG GOLDEN AGE REPRO EGENE DUBOIS GUILLOW- K&B- K&S L R MRC- OS MAX PACTRA- PECK-POLYMER PERFECT R N MODELS SEAGLEN SIG STERLING SULLIVAN SUPER TIGRE TAFFINDER TELCO TOP FLITE- TREXLER WILLIAMS & OTHERS ESTES MODEL ROCKETS Send S 100 C.h Cheek oc Stamp foe 44 page tabloid aice DISCOUNT Catalog 900 illustrationsover 700 Kits choose MAILORDER PHONEORDER IN STORE PENN VALLEY HOllY CENTER 837 WKain St LanuiaIela19446 turnaround winch plane winch 200 meters downwind signal guys winch would step pedal release plane like plane being shot out cannon can imagine difficulty controlling plane coming straight fast didnt always work did work once Dave set two-lap Speed record 85 secondswhich stands day because everybody said Lets have no changed rules 12-volt-winch rule instituted Speed laps increased four try slow down zealots Enough reminiscing Back Bills letter have flying Cumic year Its very nice kit docile old Aquila has much wider speed range Mine came out 10 oz/sq ft will still go up light stuff built polyhedral save time now wish put ailerons lost Pro Runner ship last fall got too high too far downwind never did find famous Just turn So have laboring cobbling together some parts big Dash Cash cross-country event July Joe Bedford Gary Bower won last year determined again new Canadian Soaring Society taking off good support finally have first Canadian LSF Level V John McMillan Central Ontario club cant think deserving person nicknamed him Bear Continued page 141 October 1986 137 .A BLAST FROM THE PAST JIM WALKERS CLASSIC GLIDERS 743 Pak5495 1 404 INTERCEPTOR Folding Wing Glider U-Build-It Kit$395 7 y Fly $795 Add $3 postage sod handling first -2 packages 10% additional AmeiieaA/wLA2P P0 Box 68132 AIRCRAFT CO Poriland OR 97268
Edition: Model Aviation - 1986/10
Page Numbers: 44, 45, 136, 137
Radio Control Scale Bob Dolly Wischer FLAP OPERATION value flaps model performance has often argued Its true model has low wing loading never flies very fast flaps merely employed because used prototype models performance will change very little flaps deployed full-size airplane fast heavy model also flies like streamlined brick flaps indeed bene ficial Almost modern planes built past 50 years will have used some form flaps basic purpose allow decreased speed loss lift steepen glide path predictable touchdown landing Drag increased considerably throttle may need added compensate first flights new model have found best try flaps reason ably high altitude because have some surprises pitch-change flaps first lowered Most flap-equipped models will pitch nose-up attitude speed too high flaps extended careful management throttle ele vator trim controls speed can reduced pitch change minimized some models very noticeable change stability after flaps extended pronounced steadiness glide path down landing model becomes much less susceptible being upset gusts thermals turbulence flap Ryan SCW perforated strip between landing gear legs low ered about 400 Its effect startling first flight caused almost uncon trollable raising nose regardless speed find difficult fly model holding down-elevator control cure problem install linkage between flap elevator servos some downelevator trim applied flap lowered two servos conveniently located side-by-side model under stand drastic change pitch typical full-size Ryan peculiarity model probably due CG shift linkage described Septem ber 83 column Because models have wing loadings quite low tendency balloon upward exaggerated flaps lowered near cruising speed actual change speed whether model slowed fore extension flaps very noticeable ground expected change rate des cent along glide path has always source disappointment model often drifts past chosen landing spot considerably higher expected probably due light wing loading respect flaps arent worth time effort design install As Scale feature can quite impressive models have predictable reaction extended flaps ideal consequence would no change pitch angle rarely achieved Most will pitch nose-up some ex tent depending upon speed have seen some models lowered nose Holding bit up-elevator compensate downpitch natural reaction pilot therefore poses no real difficulty compared having hold down-elevator throughout gliding descent could lead disas ter quick flick down-elevator trim lever may sufficient would need readjustment speed bleeds off during descent resetting after landing prepara tion next flight have found use flaps takeoff has little no benefit no good reason increase drag model doesnt need greater lift may exceptions course such 40-pound monster marginal power contests sometimes use flaps takeoff because some judges expect Ten de grees flap takeoff supposed shorten distance lift-off under conditions no wind models difference dis Its Electric L Dr Keith Shaws newest creation Gee Bee R-1 spans 50 uses geared Astro cobalt 25 dozen 12 Ah cells airframe weighs 31 oz power system 36 oz radio 9 oz Herman Cholewlnskis gorgeous DH Chipmunk R MonoKote covered built Sig kit Power Enya 120 four-stroke Seen Mint Julep meet Rough River KY Dennis Cain scratch-built Travelair 2000 1 Bill Northrop plans Eight-lb ship uses OS 60 power Finish Sig dope over Sig Koverall Dornler 335 R scratch-built Al Masters factory drawings pair K&B 40s propel 14-lb fighter 44 Model Aviation tance nearly impossible detect Best advice first flights avoid using flaps take off landing Play later air reasonable altitude various settings first hint rising falling nose retract flaps proceed action contest example some contestants will use flap operation flight option Expect low score flaps arent easily visible air quite often true situation Flaps lowered some landing pattern dis tance arent easily seen preference forget flaps option use enhance realism full-size plane used flaps like wise flap operation should shown judges before flight will know both look center section wing trail ing edge amount deflection will used takeoff landing no requirement judges observe flap motion air flaps used flight option judges will expect see flaps extend retract proper rate model passes before during flight consis tent prototype aircraft Fowler flaps used modern air L craft actually increase wing area extending rearward downward tracks effective flap configuration crease lift flaps compensates loss lift due slower airspeed high drag Because complexity seldom seen models builders generally resort simulated action Anyone has oc cupied seat near wing trailing edge airliner screw-jack drive mechanism can observed will understand reluctance modeler reproduce such complex bit machinery Republic P-47 Thunderbolt similar flap extended rearward rarely seen true operation models because its linkage complexity can made operate scalelike manner ef fective steepening glide path also im presses judges spectators servos Scale model driven greatest workload retracts flaps retract servo draws heavy current batteries few sec onds current flow should drop back idle flap servo must lower flaps hold ex tended position against air loads throughout portion flight energy needed hold flaps down same regardless servo size probably doesnt make difference oversize servo used other words shouldnt expect same battery life between charges flaps used often should kept mind end long day flying field servo airborne model flaps down consuming power oth ers Use retract servo same time now two high-current devices lower ing battery voltage Does sound like scenario problem short radio rangedistance batteries marginal havent found need use larger servos flaps standard servo having 25 40 inch-pounds torque has always ade quate 1800 retract servo can used flaps advantage slower speed provides greater time raising lowering improves realism servo linkage arranged servo output lever disc comes halt end its travel flaps fully extended Continued page 136 oilers yOU IAos Co~pee r4O0 &iclP Al O 00 toi r October 1986 45 1 ACCWI 1/32 scale plastic model kits Golden Age classic aircraft Colorful highly detailed miniatures Send $1 fully illustrated cata log other kits accessories 13311 Beach Ave na Del Rey CA Horn Old Timer fl{2t born 7&QVii LANZOS 8 GAS 900Cc cAdO deL S~ cr1 cs RECORD BREAKER -1941 BROOKLYN DODGER 36 Cabi EWEST0 Retail $529505INTRODUCTORY PRICE0 $3900 1938 Record Breaker 96 $6956 tO39Zipper 54$5356 1938 Kloud King 63 $42 36 1941 Brigidier 56 $4076 1941 Super Ouaker 78 $7276 1940 So Long 50$3036 1936 Buccaneer 84 $5996 1938 Clipper MKI 72$4156 1937 Dallaire 108 $75 16 1935 Miss America 84$7196 1941 Playboy Sr 80 $5116 1991 Playboy Jr 54$31 16 1938 Powerhouse 84 $5356 1990 Sailplane 76 $0479 1938 Trenton Terror 72 $90 76 1990 Ranger 46$31 96 1939 Korda Wake 44 $1916 1939 Mercury 72 6 kits gualify SAM evento EF & RIG ond feature highest quabty machine cut 6 sanded parts Superior Competition ott ahoet atrip wood mire & window material Ptana orig EF modela easily convertible Och RIG KITS Sailplanes Electric power Gas Hobby Horn SENSOAR Glider 78 $1600 Midway Model GNOME RIG Hand Launch Glider$2400 Jolly Models FLINGER RIG HLG 50 Span$2400 Midway Model FAST EDDIE Aerobatic /05 EIec$19 00 Jolly Models ELECTRICUS Electric Glider 05s93250 Leisure PLAYBOY SR 67 Gear 05 Elect $3800 Astro ASTRO SPORT 37 Direct 05 Elect $2250 Leisure WASP 37 Direct 05 Electrics$2210 Midway ULTRA MK IV 86 Geared 04 EP $3900 Midway FLYING OUAKER 84 40-454 stroke $6976 4kslMidway DENNY JR 72 Alum Comel$6396 4kslMidwav BUZZARD BOMBSHELL 7200196 FULL LINE OF ELECTRIC SYSTEMS S Parts Avail SHIIlllll & HANDLING Up $000 add $150 $801 $2000 add $220 $2001 $4500 add $301 $4501 $7000 add $350 over $7000 add $4 00 CA Addressees add 65 tax Send MO VisaIMC# Eap Check allow up 30 days CK clearance COD Exact Charges plus $158 HdI Cash Only Designs 06 DA 0 0 S C 21 0 0 18 C 01 1 91 2_________ 0 0 a_________________ C 21 01__________________ ___ __________ S 0 C 21 C 0 0 0 C Ct k4 Page UAaALUUUO $200 PP/tat Clxos copy will sent free--when requested-with order HOBBY HORN 15173 Moran St PO Bow 2212 Westminster Ca 92604 714 0938311 [AftHrs 714 0951203] . 0ce Deslgfls 0 0 IC 18 S 0 SPORT BIPE S $21 PPD 0 PPDZl S _______________0 ~s15 __________0 It ________________0 0 PHOTO DOCUMENTATION PACKS availableon Scale Plans ALL PLANS ROLLEDSHIPPED UPS Compleie wlnetrection Osokiet Send slOO Catalog New York OlaRe Residenie aoO 7% selee tax. Osndsheak . Allow 3 weeks aleckfoalxar QUARTER SCALE PLANSQuarter Master Sport BIpe0 Guadra 35. 73Span.E-Z build. Great PIyer.*Semitif Acailable DAVIS D-1K 905 Span. Ouadra 35 power similar. 1933 KINNER SPORTSTER Model K.ll7Span.035 power. 4-CYCLE PROJECTS aW AKRON FUNK ls Ocae 84span AO size 4 cesle. Faniasiic Flyer DAVIS D1K00 BOa Span. 40 4 cycle similar. Two losS wale 010th scale 1933 KINNER SPORTSTERRR Ce Model K. 79 Span. B1-75.4ny poo510 *e Photo roosoed ocr 1/4 Osele plans. Two loon scale Sloth seals DA Plans comino Propellers/Abbott Continued page 133 prop inches raise fourth power multiply pitch inches common model props will get number between 20000 5000000 find value upper right-hand part chart follow diagonal line down left rpm/hp combination will probably find value PD4 get particular prop does exactly agree values chart will have interpolate between given values need greater accuracy can always use formula other hand know power rpm engine wish select appropriate propeller find inter section hp rpm follow diagonal up right find value PD4 can use calculator find combinations pitch diameter equal value PD4 find diameter will have able find fourth root number must have scientific-type calculator least has exponential func tion have use exponen tial key usually labeled xy enter 25 exponent Finally Ive provided listing values PD4 some 32 typical model propellers chart works two-bladed props having aspect ratio between 61 91 typical props used RC CL models have tested thin toothpick props used racers also very useful have idea airspeed range may expected particular propeller given rpm will obvious higher pitch will result higher speed simple formula relates pitch airspeed rpm mph thousands X pitch nominal airspeed air speed would result propeller operating no slippage nominal airspeed chart shows relationship air speed rpm propeller pitches 3 12 rpm up 15000 covers model situations assumption no slippage course usually encountered actual flight However does give valuable insight selection propeller particular set conditions example suppose airplane planned fly 75 mph engine expected run 10000 rpm chart may immediately determined 10000 rpm propeller 8-in pitch will have nominal airspeed 75 mph Its therefore obvious propeller selected must have 8-in pitch greater airspeed 75 mph reached Its true under certain conditions speeds excess nominal airspeed may achieved due fact propeller blade airfoil may produce lift slightly negative angle attack Bear mind vail ables involved analysis propellers article have made number simplifying assumptions order provide fairly simple method estimating pro peller performance have found results better hp cases Ive checked method against data full-size aircraft engines propel lers well home-builts ultralights have always well within tha range Im confident method i adequate model purposes Conclusion discussed two formulac describe two important aspects 01 propeller behavior thrust power ab sorption formula thrust th importance diameter disk area came apparent discussion 01 power saw propeller powe varies third power rpm 2 fairly small change rpm indicates rathe larger change power chart pre sented makes possible estimate power required drive propeller particular rpm chart also pro vided find nominal airspeed function rpm propeller pitch RC Scale/Wischers Continued page 45 connecting link lined up directly across servo output shaft centerline will no load servo motor Current flow servo will drop idle flaps locked down securely course true full-flap position extra gear retract servo also helps reduce current con sumption intermediate flap positions Incidence angles again third time recent columns going dwell upon touchy subject disastrous crash club field model descended ver tically impact few feet pit area filled models fliers spectators Fortunately missed everyone thing destroying itself pilot us ing full up-elevator throughout dive several hundred feet no appar ent response plane Having built kit assumed incidence angles correct center gravity location concern its first flight case due building error stabilizer leading edge inad vertently raised bit too much providing lifting force Ordinarily sort thing causes no great problem model can readily flown trimming bit upelevator model ratio stabilizer area elevator area quite high large stab small elevator Elevator travel set near minimum prevent overcontrolling Whenever model built up speed tendency models nose tuck under required full upelevator recover level flight its final dive gathered excessive speed simply wouldnt pull out enough up-elevator travel say During its first flight 136 Model Aviation TOciarterMaster .ru 3] i 11 ous cModeler / NILITE III run four cycle have inverted engine have scale ship completely cowledin engine want dpendabta idle sport plane fly pattern cant afford flame out id/a need Niite Ill board glow plug lighter 38K0Nilite Ill Kit 38K90CAliita Ill Asmbld 38K91Twin Nilite lllKit 3819 ICTwin Nilite Ill Asmbld $3295 $3995 $3895 $4695 METERED NILITEII Metered Nilite II lights 12V l5V glow plug also monitors condition plug meter tell its open shorted flooded weak rechargeable 1200 MAH nicd provides enough dependable starts normal flying session Utilizes patented H eadlock device firmly hook easily unhook plug 38185Metered Nilite II Combo Complete wiCharger $2995 38186Metered Nilite IlLighterOnly$1995 COMPLETE CATALOG $200 ACE R/C INC 116W 19 St POBox 51IEN HIGGINSVILLE MO 64037 816 584-7121 model performed rather tight inside ioop large stabilizer area set positive angle acting reduce wings angle attack point no lift Eleva tot travel insufficient overcome sta bilizers force Quick thinking compe tent pilot probably could have saved model applying down-elevator isnt natural reaction nose-down situation Closing throttle may also have helped over about three seconds oc curred models second flight first reasonably successful hint hidden danger speed permitted increase landing normal Its questionable whether changing eleva tot travel would have made airplane man ageable under conditions case upward-deflected elevator disadvan tage because working lowered pres sure above lifting stabilizer existed deadly combination circumstances no recovery model built according plans crash would have happened Bob Dolly Wischer S-221 Lapham Peak Rd Delafield WI 53018 RC Aerobatics/Van Putte Continued page 46 thing Now very unusual Rossi Since engine didnt sag battery connector removed couldnt bad glow plug right Wrong bad glow plug hint obvious normally-reliable engine gets balky check glow plug knew thatI just forgot Ron Van Putte 111 Sleepy Oaks Rd Ft Walton Beach FL 32548 RC Soaring/Blakeslee Continued page 49 print technical organizational details slope gliding northern Europe little said about great fun have must way share enjoyment sport Lets keep contact see what will happen Preben Norholm editor photographer Modelflyue Nyt Denmark 10 years has chairman contest committee RC-Unionen national RC faction Royal Danish Aeroclub has also served board member organizations Mr Norholm will chairman next session Notdic Aeromodelers Council Copen hagen address Godtharbsvej 7 DK 7400 Herning Denmark Canadian connections An old friend Bill Petti grew Montreal sent letter Ive excerpted parts below Bill member Canadian F3B team 1981 Sacramento World Championships whole Canadian team flew design Dave Wright Victoria BC called FMF magazines editorial policy will allow name explained fully fact Carl Blake winner US team finals also flew Speaking Carl Blake what has become him lately FMF extremely strong ship designed operate 36-volt superwinch team used Yes winch three batteries series narrow drum about 12 inches diameter wound line fast ships couldnt climb very steep anglebut moving launches scared devil out everybody vicinity exciting part what Dave called remote launch used Speed task just down-and-back time Dave positioned himself Base alongside AU U&I&IM WaEM [Cl LI U N [Cl mu BENTOM- BROWN JR CAMPBELL COMET- COVERITE COX DUBRO EASY BUILT MODELS FOX GOLDBERG GOLDEN AGE REPRO EGENE DUBOIS GUILLOW- K&B- K&S L R MRC- OS MAX PACTRA- PECK-POLYMER PERFECT R N MODELS SEAGLEN SIG STERLING SULLIVAN SUPER TIGRE TAFFINDER TELCO TOP FLITE- TREXLER WILLIAMS & OTHERS ESTES MODEL ROCKETS Send S 100 C.h Cheek oc Stamp foe 44 page tabloid aice DISCOUNT Catalog 900 illustrationsover 700 Kits choose MAILORDER PHONEORDER IN STORE PENN VALLEY HOllY CENTER 837 WKain St LanuiaIela19446 turnaround winch plane winch 200 meters downwind signal guys winch would step pedal release plane like plane being shot out cannon can imagine difficulty controlling plane coming straight fast didnt always work did work once Dave set two-lap Speed record 85 secondswhich stands day because everybody said Lets have no changed rules 12-volt-winch rule instituted Speed laps increased four try slow down zealots Enough reminiscing Back Bills letter have flying Cumic year Its very nice kit docile old Aquila has much wider speed range Mine came out 10 oz/sq ft will still go up light stuff built polyhedral save time now wish put ailerons lost Pro Runner ship last fall got too high too far downwind never did find famous Just turn So have laboring cobbling together some parts big Dash Cash cross-country event July Joe Bedford Gary Bower won last year determined again new Canadian Soaring Society taking off good support finally have first Canadian LSF Level V John McMillan Central Ontario club cant think deserving person nicknamed him Bear Continued page 141 October 1986 137 .A BLAST FROM THE PAST JIM WALKERS CLASSIC GLIDERS 743 Pak5495 1 404 INTERCEPTOR Folding Wing Glider U-Build-It Kit$395 7 y Fly $795 Add $3 postage sod handling first -2 packages 10% additional AmeiieaA/wLA2P P0 Box 68132 AIRCRAFT CO Poriland OR 97268
