Control Line Aerobatics Ted Fancher OKAY grouplets design ourselves Stunt ship Remember going address parameters listed trim table May 1985 column page 67 relate design Well look discuss briefly its effect aircraft performance appropriate performance altered changes parameter Again let remind Im dealing concepts conclusions consider developing own ship Some things Ill saying will generally accepted few will Im sure quite controversial Controversial Fancher Say isnt cases Ill clearly label opinion such may want seek further enlighten ment another source course Im sure Im right however. first trim objective design stability subtle difference tween stability balance An air plane balanced forces acting equilibrium lift equals weight thrust equals drag An air plane balance will continue course speed until equilibrium disturbed Once disturbed its tendency return its balanced condition measure its stability tends return balanced state said positively stable maintains new attitude neutrally stable increases its divergence balanced state termed negatively stable Stability inextricably bound relationship between center gravity CU point known Aerody namic Neutral Point need know about N spot its location relative overall lift capability total aircraft wing plus tail will always fall between 25% positions wings tails respective MACs mean aerodynamic chords larger tail respect wing further aft N point will As long CU located forward N spot ship will positively stable therefore flyable CU moved aft point aircraft would uncontrolla ble Since Stunt ships very large tails N spot far aft normally-usable range CU safe say reasonable stability inherent remotely-conventional Stunt design should also stated further forward CU stable airplane will be. less maneuverContinued page 148 out thrilling days yesteryear two greatest Stunters 0 tfle early FIflieS icit Tom Nlebuhrs Fox 35-powered Trixter Barnstormer 10 years old flew Garden State Circle Burners very first Old-Time Stunt meet Plane right Bob Jongoleens deBolt American Senior has Fox 35 MonoKote-covered wing Sig dope fuselage Photos Bruce Gliford Jr Note neither designs used wing flaps Flying weights realm 32 oz Ohios Joe Reinhard won PAMPAs Concours dEiegance 1983 Nats magnificently-builtbut subtly-flnishedStunter L weighed 38 oz used OS Max 35 power photo right Bob Bear Gleseke ponders enormity Modern Stunt beholds windy Urtnowskis magnificent Mig 1983 Chicopee Nets Both craft exemplify use highaspect-ratio surfaces Mig has monstrous wing flaps Ted expounds aspect ratio flap size column 64 Model Aviation torque Record torque rpm reading taken just before caught model Make small change trim repeat rpm/torque measurements best trim will setting gives both lowest rpm lowest level-flight torque model slightly under-elevated needs inci dence wing will have slightly higher rpm approximately same level flight torque properly-trimmed model As incidence increased rpm torque will drop lower overelevated model rpm lower good trim torque will higher level-flight torque increases overelevated model because higher torque needed overcome higher drag extra wing incidence Actually model will start sinking faster good trim soon level flight ceases full flight will take longer properly trimmed model reach level flight either under- over-elevated model Wrap-up Heres holds together peak altitude flight depends launch torque altitude vs time curve levels off level-flight torque Unless air temperature air inversion well talk about next time inter venes model will descend slowly torque decreases motor runs out turns before touchdown reaches critical torque model will come down much come several other test procedures allow get trim big meet Im out room Next time Bud Tenny Box 545 Richardson TX 75080 CGS Hawk/Kruse Continued page 63 beneath smooth out wrinkles Three coats thinned nitrate dope top tissue trim should sufficient seal surfaces detailing including seat celluloid windscreens wheel pants struts rigging dummy engine can now added complete model make come alive Flying Balance plane shown plan adding lead shot and/or clay ballast box dont like test glide CO-2powered models because doesnt give much feel ship going perform under power Wait calm evening find softest grass surface can set motor low power setting give gas charge last filler cartridge Flick prop get motor started remember its apusher aim model spot about 50 ft front give gentle toss settles ground stalling diving crease gas charge no liquid yet please try again should show slight tendency climb gently turn right turns too tightly bend rudder just shade left try again power pattern seems safe increase motor speed bit watch climb right come back overhead full gas charge model being hand launched should get flights rang ing 45 sec updepending buoyant air isand quality CO-2 charge Hawk has enjoyable Free Flight Scale ships Ive built number years unique enough elicit both admiration questions spectatorsand competitive enough win Scale contest nation decide build have questions comments please write Larry Kruse Box 1137 Liberal KS 67901 Ill happy supply documentation infor mation cost CL Aerobatics/Fancher Continued page 64 able practical terms CG aft G/L center lift although technically stable rapidly becomes too sensitive RC Ts & Caps Super Quality.Super Price! TSHIRTS 50% cotloni5O% polyester complete range sizes RC hobbiest $595 Styte Ais yellnw hold black design Style B availahle navy white white navy CAPS tits Adjustable back mesh sides Only $595 SPECIAL COMBO OFFER Matching shirt cap set $995! shirt cap per set ORDER TODAY Send check money order US Please indicate size style cnlor Include $2 postage handling per item Florida residents add 5% sales tax Allew 4-6 weeks delivery IS YOUR CLUB LOOKING FOR FUNDRAISER ASK ABOUT OUR CLUB DISCOUNT PROGRAM RC NOVELTIES PO BOX 840205 PEMBROKE PINES FLORIDA 33084 TICK OFF TIMER Now Available 0-20 Seconds Fuel shut off Flood Off Auto rudder function Weight V oz Fuel line included EXTRA FUEL LINE TUmINGSO- ft DIRECT ORDER ON LV Send Cash Check MD COD $3 extra Calif 6% JOHN TATONE 62 BELHAVEN AVE DALY CITY CA 94015 Limited supply 148 Model Aviation faster Jim Clem coined appropriate phrasethe model becomes lead sled has push prop reasonable control should avoided purposes Tail effectiveness item No 2 table parameter Ive developed compare capability tail both stabilize wing also cause change direction maneuvers Tail effectiveness product distance CG C/L tail tail area larger tail longer distance CG greater effectiveness tail either its jobs Tail volume item No 3 table purposes tail volume area lifting surface multiplied its average chord tail given area can designed variety shapes either long skinny high aspect ratio short stubby low AR terms stability tail aspect ratio AR impor tant because lift coefficient given angle attack increases higher aspect ratios Therefore minor control deflections high AR tail will produce lift low AR tail AR becomes too great smooth level flight will become difficult since minor control inputs will result large lift coefficient changes aircraft pitch changes will result Okay lets have some practical applica tions What pilots looking ship flies straight level out constant attention balance 1-201-427-3845 er Mobile Phone After Noon Only 1-201-648-9249 disturbed either outside influences winds wake turbulence etc pilot maneuvers returns balanced state readily stability basics good stability designed ship CG N spot Some less important items consider follow Leadout position item No 4 table affects stability inasmuch airplane should fly CG line midpoint Up Down leadouts leadouts too far ward rare line tension controllabili ty will suffer too far aft line tension will good level flight airplane will start hunt up down result sustained vertical P-factor component narrow range correct leadout locations given aircraft weight speed line length line diameter leading edge radius item No 6 table relative bluntness wing has affect stability Blunter wings tend stable exit cor ners bit flatter suspect because minor up down movement wardmost point airfoil strikes air stagnation point alters camber thus lift wing less would sharper leading edges debit side blunter airfoils have poorer penetration windand just plain ugly look PS opinion Nose moment item No 7 table distance CG prop thought some significant stability dont entirely agree some merit exists having longer nose gyroscopic inertia prop will act stabilizer longer arm personal opinion gyro effects minor best length nose just long enough airplane balances correctly adding weight Rule Thumb Ted designing stability Locate center gravity approximately 16% MAC plan use currently popular Super tigre 60 light airframesay under 55 ouncesyou might move aft 18-20% will allow additional fuel burnout 60 resulting initial noseheaviness compared same air craft using 40 46 couple ounces less gas Use low-to-moderate aspect ratios tails reduce sensitivity pitch inherent high aspect ratios use 45 1 Use long tail can balance normal hardware nose jury out relative tail thickness item No 8 table feel can get too thick over about 12% point response gets sluggish build too thin rigidity becomes prob Continued page 152 TIDEWATER ENGR & MACH CO P-21CAR SE/RE$6500P-21AERO SE$5000P-60AEROSE$8500CMB21 BUGGY6500 P21BUGGY SE/RE$6500P21AERO RE$5500P-60AERO RE$9000CMB-21 CAR SPEED6500 P-21DELTA$7500P-21STUNT SE/RE$5000P-60SPEED$9000CMB-21 CAR SPECIAL57500 P21MAR SE/RE$6500P-40PYLON RE$6500P-SOAERO SE$9000CMB-21 MAR SP$6500 p45MAR-DISC RV$8500P-40AEROSE$5800P80AERO RE$9500CMB21 Mar Valvola$8000 P-65MARINE$9000P-40STUNT SE$6500P-45DUCT FAN57500CMB-60 AERO$9000 P80MARINE$11000P-45STUNT SE$6800P-65DUCT FAN$9500CMB-90 MAR$14000 P-90MARINE$14000P45AERO SE$6000P-SODUCT FAN$10000ALL CMB PARTSAVAILABLE PACKING & HANDLING $400PICCO GLOW PLUGS $1500/Doz Pay Shipping ChargePICCO CAPS$500/EachHOT SPECIALS NITROMETHANE$3150/GalP45 MAR$8000P-90 MAR $12500 COD $190 CASH ONLYKLOTZ OIL$1375/GalP65 MAR$8500P-21 AREO SE $4000 COMPETITION BOAT KITS ANDALE IRE ABOUTP80 MAR $9800P60 AERO RE $7500 HARI WARE IN STOCKI.J IiiJX QUANTITY PRICES July1985 149 engines engineered meet demands discriminating modeler backed service match Engines have points easy starting carburetor linkage crankcase tapped smoke adapter six bolt prop hub mount mounting bolts muffler engines ready run Props tanks oil spark plugs etc available extra charge lexcept Kioritz 37 twin Sacha-Dolmar 34 48 Kioritz 56 Kioritz made order Cobra 23 Kiorltz 2A 31 HP 5/ lbs32 HP 6/ lbs $15995 96 x FOX FOX GLOWs-WAY PLUGWRENCH Standard $119 R/C $169 Sales Fox Glow Plug have now passed 10 million mark good reason too its machined idle bar cant break loose Its platinum-rhodium element worlds finest Its space age insulator never burns out tested before packaging Fox Wrench specially designed install Glow Plug properly Chances cross threading reduced 3/8 7/16 1/2 hex fit prop nuts too Bright chrome finish better model shops everywhere Fox MFG Co 5305 TOWSON AVE FORT SMITH AR 72901 15011 6461656 Fly same prop over over again Continuous filament fiberglass blades molded epoxy resin Hi-performance test proven propellor blade shape 2-piece 7075 aluminum T6 hardness hub anodized black Removeable steel pins quick blade changes Tested high RPM blades will change pitch PROP HUB ASSEMBLY N 109 1 size engines electric motor equivalent Weight 85 grams $1500 PROP BLADES FOR KUHN 109 Available Tx 25 7x 3 7x 35 8x 4 $400 per blade $800 per pair additional moan woight steel hub available PROP HUB ASSEUBLY N 108 285 grams $1500 PROP HUh ASSEMBLY # 110 049 051 engines electric motor equivalent Weights grams $1500 PlOP BLADES FOR HUB N 110 Available 6x 3 $400 per blade $800 per pair Additional sizes larger diameters available soon Send SSAE catalog sheet complete line DEALER INIIUIRIES INVITED 152 Model Aviation CL Aerobatics/Fancher Continued page 149 lem Use about 8% 12% design midpoint leadouts should approximately 30 sweep designed CU aircraft centerline allowance made A-in adjustment fore aft bellcrank location item No 9 table should right CU leadouts will exit wing tip straight line forced bend remember CU will lime up leadout exit midpoint Finally use moderate-to-blunt leading edge important sharp So much stability Now lets go second trim objective table make blamed thing turn Once again CU must take star bill ing along its relationship C/L wing item No 1 next section table tail volume effectiveness table items Nos 2 3 flap/elevator ratio item No 4 aircraft weight U loads lift required item No 5 aspect ratio item No 6 Since bound together lets discuss group might just well start out controversial stuff can draw bat tle lines early rate Stunter turns pitches primarily function lift light weight reasonable weight adequate lift desirable light wing loading primary requisite rapid pitch change. especially predictable controllable change Lets take quick look Stunt ship level flight lift exactly equals weight threepound airplane developing three pounds lift now desire pitch three-pound ship abruptly square corner will cause acceleration change direction aircrafts mass will result apparent weight increasing resultant weight termed G load U normal weight five Us five times normal weight etc Just fun heres formula figuring U forces G 0668V2R V speed mph R radius corner feet example three-pound Stunt er turns corner 10-foot radius flying 55 mph would incur U forces 20 times its own weight 60 pounds lift wing must produce support Stunter throughout cor ner Please note wing can produce lift required However unable produce amount lift must increase radius cor ner else aircraft will stall wing forced past its critical stalling angle attack As discussed April wing develops lift concentrated Center Lift normally aft CU Therefore lift causes pitch ing moment direction opposite desired pitch change force must overcome tail before change body angle can made Since lift necessary support U forces corner can reduce pitching moment lessening distance between CU C/L design phase can done increasing aspect ratio wing allows us narrow distance between CU C/L still retaining desired percentage location CU about 16% MAC Another significant factor about highaspect-ratio wings given amount lift will develop less duced drag drag results production lift primarily wingtip vor tices downwash reduces thrust requirements corner good will slow airplane less also good As tail remember high aspect ratios increase lift coeffi cient given angle attack therefore real-world limit maximum aspect ratio can control smoothly abrupt maneuvers Remember flaps high-lift devices contribute significant percentage increased lift generated corner Well get back Ted Fancher 158 Flying Cloud Isle Foster City CA 94409 CL Scale/Boss Continued page 65 landing gear requirements decided use single specially-made center wing rib base wheel well cover doors main bellcrank mounting As usual practice building plans meant RC use case plans Bryan Taylor Ureat Britain obtained Bob Holman Plans San Bernardino CA wings main spar ribsfrom center point landing gear will mountedare made 1-in plywood done make solid base possible build rest model See August 1982 MA column general information converting RC kits CL use case addition making ribs plywood wings center rib constructed lami nating two -in plywood -in balsa rib specially slotted accept main bellcrank platform accompanying photos show three basic steps design installation control system will provide eleva tor engine control still allow wheel well area kept clear pushrods etc first photos shows bellcrank leadouts well-laidout platform Care should exercised cutting platforms slot see ample clearance provided bellcranks sliding mechanism certain
Edition: Model Aviation - 1985/07
Page Numbers: 64, 148, 149, 152
Control Line Aerobatics Ted Fancher OKAY grouplets design ourselves Stunt ship Remember going address parameters listed trim table May 1985 column page 67 relate design Well look discuss briefly its effect aircraft performance appropriate performance altered changes parameter Again let remind Im dealing concepts conclusions consider developing own ship Some things Ill saying will generally accepted few will Im sure quite controversial Controversial Fancher Say isnt cases Ill clearly label opinion such may want seek further enlighten ment another source course Im sure Im right however. first trim objective design stability subtle difference tween stability balance An air plane balanced forces acting equilibrium lift equals weight thrust equals drag An air plane balance will continue course speed until equilibrium disturbed Once disturbed its tendency return its balanced condition measure its stability tends return balanced state said positively stable maintains new attitude neutrally stable increases its divergence balanced state termed negatively stable Stability inextricably bound relationship between center gravity CU point known Aerody namic Neutral Point need know about N spot its location relative overall lift capability total aircraft wing plus tail will always fall between 25% positions wings tails respective MACs mean aerodynamic chords larger tail respect wing further aft N point will As long CU located forward N spot ship will positively stable therefore flyable CU moved aft point aircraft would uncontrolla ble Since Stunt ships very large tails N spot far aft normally-usable range CU safe say reasonable stability inherent remotely-conventional Stunt design should also stated further forward CU stable airplane will be. less maneuverContinued page 148 out thrilling days yesteryear two greatest Stunters 0 tfle early FIflieS icit Tom Nlebuhrs Fox 35-powered Trixter Barnstormer 10 years old flew Garden State Circle Burners very first Old-Time Stunt meet Plane right Bob Jongoleens deBolt American Senior has Fox 35 MonoKote-covered wing Sig dope fuselage Photos Bruce Gliford Jr Note neither designs used wing flaps Flying weights realm 32 oz Ohios Joe Reinhard won PAMPAs Concours dEiegance 1983 Nats magnificently-builtbut subtly-flnishedStunter L weighed 38 oz used OS Max 35 power photo right Bob Bear Gleseke ponders enormity Modern Stunt beholds windy Urtnowskis magnificent Mig 1983 Chicopee Nets Both craft exemplify use highaspect-ratio surfaces Mig has monstrous wing flaps Ted expounds aspect ratio flap size column 64 Model Aviation torque Record torque rpm reading taken just before caught model Make small change trim repeat rpm/torque measurements best trim will setting gives both lowest rpm lowest level-flight torque model slightly under-elevated needs inci dence wing will have slightly higher rpm approximately same level flight torque properly-trimmed model As incidence increased rpm torque will drop lower overelevated model rpm lower good trim torque will higher level-flight torque increases overelevated model because higher torque needed overcome higher drag extra wing incidence Actually model will start sinking faster good trim soon level flight ceases full flight will take longer properly trimmed model reach level flight either under- over-elevated model Wrap-up Heres holds together peak altitude flight depends launch torque altitude vs time curve levels off level-flight torque Unless air temperature air inversion well talk about next time inter venes model will descend slowly torque decreases motor runs out turns before touchdown reaches critical torque model will come down much come several other test procedures allow get trim big meet Im out room Next time Bud Tenny Box 545 Richardson TX 75080 CGS Hawk/Kruse Continued page 63 beneath smooth out wrinkles Three coats thinned nitrate dope top tissue trim should sufficient seal surfaces detailing including seat celluloid windscreens wheel pants struts rigging dummy engine can now added complete model make come alive Flying Balance plane shown plan adding lead shot and/or clay ballast box dont like test glide CO-2powered models because doesnt give much feel ship going perform under power Wait calm evening find softest grass surface can set motor low power setting give gas charge last filler cartridge Flick prop get motor started remember its apusher aim model spot about 50 ft front give gentle toss settles ground stalling diving crease gas charge no liquid yet please try again should show slight tendency climb gently turn right turns too tightly bend rudder just shade left try again power pattern seems safe increase motor speed bit watch climb right come back overhead full gas charge model being hand launched should get flights rang ing 45 sec updepending buoyant air isand quality CO-2 charge Hawk has enjoyable Free Flight Scale ships Ive built number years unique enough elicit both admiration questions spectatorsand competitive enough win Scale contest nation decide build have questions comments please write Larry Kruse Box 1137 Liberal KS 67901 Ill happy supply documentation infor mation cost CL Aerobatics/Fancher Continued page 64 able practical terms CG aft G/L center lift although technically stable rapidly becomes too sensitive RC Ts & Caps Super Quality.Super Price! TSHIRTS 50% cotloni5O% polyester complete range sizes RC hobbiest $595 Styte Ais yellnw hold black design Style B availahle navy white white navy CAPS tits Adjustable back mesh sides Only $595 SPECIAL COMBO OFFER Matching shirt cap set $995! shirt cap per set ORDER TODAY Send check money order US Please indicate size style cnlor Include $2 postage handling per item Florida residents add 5% sales tax Allew 4-6 weeks delivery IS YOUR CLUB LOOKING FOR FUNDRAISER ASK ABOUT OUR CLUB DISCOUNT PROGRAM RC NOVELTIES PO BOX 840205 PEMBROKE PINES FLORIDA 33084 TICK OFF TIMER Now Available 0-20 Seconds Fuel shut off Flood Off Auto rudder function Weight V oz Fuel line included EXTRA FUEL LINE TUmINGSO- ft DIRECT ORDER ON LV Send Cash Check MD COD $3 extra Calif 6% JOHN TATONE 62 BELHAVEN AVE DALY CITY CA 94015 Limited supply 148 Model Aviation faster Jim Clem coined appropriate phrasethe model becomes lead sled has push prop reasonable control should avoided purposes Tail effectiveness item No 2 table parameter Ive developed compare capability tail both stabilize wing also cause change direction maneuvers Tail effectiveness product distance CG C/L tail tail area larger tail longer distance CG greater effectiveness tail either its jobs Tail volume item No 3 table purposes tail volume area lifting surface multiplied its average chord tail given area can designed variety shapes either long skinny high aspect ratio short stubby low AR terms stability tail aspect ratio AR impor tant because lift coefficient given angle attack increases higher aspect ratios Therefore minor control deflections high AR tail will produce lift low AR tail AR becomes too great smooth level flight will become difficult since minor control inputs will result large lift coefficient changes aircraft pitch changes will result Okay lets have some practical applica tions What pilots looking ship flies straight level out constant attention balance 1-201-427-3845 er Mobile Phone After Noon Only 1-201-648-9249 disturbed either outside influences winds wake turbulence etc pilot maneuvers returns balanced state readily stability basics good stability designed ship CG N spot Some less important items consider follow Leadout position item No 4 table affects stability inasmuch airplane should fly CG line midpoint Up Down leadouts leadouts too far ward rare line tension controllabili ty will suffer too far aft line tension will good level flight airplane will start hunt up down result sustained vertical P-factor component narrow range correct leadout locations given aircraft weight speed line length line diameter leading edge radius item No 6 table relative bluntness wing has affect stability Blunter wings tend stable exit cor ners bit flatter suspect because minor up down movement wardmost point airfoil strikes air stagnation point alters camber thus lift wing less would sharper leading edges debit side blunter airfoils have poorer penetration windand just plain ugly look PS opinion Nose moment item No 7 table distance CG prop thought some significant stability dont entirely agree some merit exists having longer nose gyroscopic inertia prop will act stabilizer longer arm personal opinion gyro effects minor best length nose just long enough airplane balances correctly adding weight Rule Thumb Ted designing stability Locate center gravity approximately 16% MAC plan use currently popular Super tigre 60 light airframesay under 55 ouncesyou might move aft 18-20% will allow additional fuel burnout 60 resulting initial noseheaviness compared same air craft using 40 46 couple ounces less gas Use low-to-moderate aspect ratios tails reduce sensitivity pitch inherent high aspect ratios use 45 1 Use long tail can balance normal hardware nose jury out relative tail thickness item No 8 table feel can get too thick over about 12% point response gets sluggish build too thin rigidity becomes prob Continued page 152 TIDEWATER ENGR & MACH CO P-21CAR SE/RE$6500P-21AERO SE$5000P-60AEROSE$8500CMB21 BUGGY6500 P21BUGGY SE/RE$6500P21AERO RE$5500P-60AERO RE$9000CMB-21 CAR SPEED6500 P-21DELTA$7500P-21STUNT SE/RE$5000P-60SPEED$9000CMB-21 CAR SPECIAL57500 P21MAR SE/RE$6500P-40PYLON RE$6500P-SOAERO SE$9000CMB-21 MAR SP$6500 p45MAR-DISC RV$8500P-40AEROSE$5800P80AERO RE$9500CMB21 Mar Valvola$8000 P-65MARINE$9000P-40STUNT SE$6500P-45DUCT FAN57500CMB-60 AERO$9000 P80MARINE$11000P-45STUNT SE$6800P-65DUCT FAN$9500CMB-90 MAR$14000 P-90MARINE$14000P45AERO SE$6000P-SODUCT FAN$10000ALL CMB PARTSAVAILABLE PACKING & HANDLING $400PICCO GLOW PLUGS $1500/Doz Pay Shipping ChargePICCO CAPS$500/EachHOT SPECIALS NITROMETHANE$3150/GalP45 MAR$8000P-90 MAR $12500 COD $190 CASH ONLYKLOTZ OIL$1375/GalP65 MAR$8500P-21 AREO SE $4000 COMPETITION BOAT KITS ANDALE IRE ABOUTP80 MAR $9800P60 AERO RE $7500 HARI WARE IN STOCKI.J IiiJX QUANTITY PRICES July1985 149 engines engineered meet demands discriminating modeler backed service match Engines have points easy starting carburetor linkage crankcase tapped smoke adapter six bolt prop hub mount mounting bolts muffler engines ready run Props tanks oil spark plugs etc available extra charge lexcept Kioritz 37 twin Sacha-Dolmar 34 48 Kioritz 56 Kioritz made order Cobra 23 Kiorltz 2A 31 HP 5/ lbs32 HP 6/ lbs $15995 96 x FOX FOX GLOWs-WAY PLUGWRENCH Standard $119 R/C $169 Sales Fox Glow Plug have now passed 10 million mark good reason too its machined idle bar cant break loose Its platinum-rhodium element worlds finest Its space age insulator never burns out tested before packaging Fox Wrench specially designed install Glow Plug properly Chances cross threading reduced 3/8 7/16 1/2 hex fit prop nuts too Bright chrome finish better model shops everywhere Fox MFG Co 5305 TOWSON AVE FORT SMITH AR 72901 15011 6461656 Fly same prop over over again Continuous filament fiberglass blades molded epoxy resin Hi-performance test proven propellor blade shape 2-piece 7075 aluminum T6 hardness hub anodized black Removeable steel pins quick blade changes Tested high RPM blades will change pitch PROP HUB ASSEMBLY N 109 1 size engines electric motor equivalent Weight 85 grams $1500 PROP BLADES FOR KUHN 109 Available Tx 25 7x 3 7x 35 8x 4 $400 per blade $800 per pair additional moan woight steel hub available PROP HUB ASSEUBLY N 108 285 grams $1500 PROP HUh ASSEMBLY # 110 049 051 engines electric motor equivalent Weights grams $1500 PlOP BLADES FOR HUB N 110 Available 6x 3 $400 per blade $800 per pair Additional sizes larger diameters available soon Send SSAE catalog sheet complete line DEALER INIIUIRIES INVITED 152 Model Aviation CL Aerobatics/Fancher Continued page 149 lem Use about 8% 12% design midpoint leadouts should approximately 30 sweep designed CU aircraft centerline allowance made A-in adjustment fore aft bellcrank location item No 9 table should right CU leadouts will exit wing tip straight line forced bend remember CU will lime up leadout exit midpoint Finally use moderate-to-blunt leading edge important sharp So much stability Now lets go second trim objective table make blamed thing turn Once again CU must take star bill ing along its relationship C/L wing item No 1 next section table tail volume effectiveness table items Nos 2 3 flap/elevator ratio item No 4 aircraft weight U loads lift required item No 5 aspect ratio item No 6 Since bound together lets discuss group might just well start out controversial stuff can draw bat tle lines early rate Stunter turns pitches primarily function lift light weight reasonable weight adequate lift desirable light wing loading primary requisite rapid pitch change. especially predictable controllable change Lets take quick look Stunt ship level flight lift exactly equals weight threepound airplane developing three pounds lift now desire pitch three-pound ship abruptly square corner will cause acceleration change direction aircrafts mass will result apparent weight increasing resultant weight termed G load U normal weight five Us five times normal weight etc Just fun heres formula figuring U forces G 0668V2R V speed mph R radius corner feet example three-pound Stunt er turns corner 10-foot radius flying 55 mph would incur U forces 20 times its own weight 60 pounds lift wing must produce support Stunter throughout cor ner Please note wing can produce lift required However unable produce amount lift must increase radius cor ner else aircraft will stall wing forced past its critical stalling angle attack As discussed April wing develops lift concentrated Center Lift normally aft CU Therefore lift causes pitch ing moment direction opposite desired pitch change force must overcome tail before change body angle can made Since lift necessary support U forces corner can reduce pitching moment lessening distance between CU C/L design phase can done increasing aspect ratio wing allows us narrow distance between CU C/L still retaining desired percentage location CU about 16% MAC Another significant factor about highaspect-ratio wings given amount lift will develop less duced drag drag results production lift primarily wingtip vor tices downwash reduces thrust requirements corner good will slow airplane less also good As tail remember high aspect ratios increase lift coeffi cient given angle attack therefore real-world limit maximum aspect ratio can control smoothly abrupt maneuvers Remember flaps high-lift devices contribute significant percentage increased lift generated corner Well get back Ted Fancher 158 Flying Cloud Isle Foster City CA 94409 CL Scale/Boss Continued page 65 landing gear requirements decided use single specially-made center wing rib base wheel well cover doors main bellcrank mounting As usual practice building plans meant RC use case plans Bryan Taylor Ureat Britain obtained Bob Holman Plans San Bernardino CA wings main spar ribsfrom center point landing gear will mountedare made 1-in plywood done make solid base possible build rest model See August 1982 MA column general information converting RC kits CL use case addition making ribs plywood wings center rib constructed lami nating two -in plywood -in balsa rib specially slotted accept main bellcrank platform accompanying photos show three basic steps design installation control system will provide eleva tor engine control still allow wheel well area kept clear pushrods etc first photos shows bellcrank leadouts well-laidout platform Care should exercised cutting platforms slot see ample clearance provided bellcranks sliding mechanism certain
Edition: Model Aviation - 1985/07
Page Numbers: 64, 148, 149, 152
Control Line Aerobatics Ted Fancher OKAY grouplets design ourselves Stunt ship Remember going address parameters listed trim table May 1985 column page 67 relate design Well look discuss briefly its effect aircraft performance appropriate performance altered changes parameter Again let remind Im dealing concepts conclusions consider developing own ship Some things Ill saying will generally accepted few will Im sure quite controversial Controversial Fancher Say isnt cases Ill clearly label opinion such may want seek further enlighten ment another source course Im sure Im right however. first trim objective design stability subtle difference tween stability balance An air plane balanced forces acting equilibrium lift equals weight thrust equals drag An air plane balance will continue course speed until equilibrium disturbed Once disturbed its tendency return its balanced condition measure its stability tends return balanced state said positively stable maintains new attitude neutrally stable increases its divergence balanced state termed negatively stable Stability inextricably bound relationship between center gravity CU point known Aerody namic Neutral Point need know about N spot its location relative overall lift capability total aircraft wing plus tail will always fall between 25% positions wings tails respective MACs mean aerodynamic chords larger tail respect wing further aft N point will As long CU located forward N spot ship will positively stable therefore flyable CU moved aft point aircraft would uncontrolla ble Since Stunt ships very large tails N spot far aft normally-usable range CU safe say reasonable stability inherent remotely-conventional Stunt design should also stated further forward CU stable airplane will be. less maneuverContinued page 148 out thrilling days yesteryear two greatest Stunters 0 tfle early FIflieS icit Tom Nlebuhrs Fox 35-powered Trixter Barnstormer 10 years old flew Garden State Circle Burners very first Old-Time Stunt meet Plane right Bob Jongoleens deBolt American Senior has Fox 35 MonoKote-covered wing Sig dope fuselage Photos Bruce Gliford Jr Note neither designs used wing flaps Flying weights realm 32 oz Ohios Joe Reinhard won PAMPAs Concours dEiegance 1983 Nats magnificently-builtbut subtly-flnishedStunter L weighed 38 oz used OS Max 35 power photo right Bob Bear Gleseke ponders enormity Modern Stunt beholds windy Urtnowskis magnificent Mig 1983 Chicopee Nets Both craft exemplify use highaspect-ratio surfaces Mig has monstrous wing flaps Ted expounds aspect ratio flap size column 64 Model Aviation torque Record torque rpm reading taken just before caught model Make small change trim repeat rpm/torque measurements best trim will setting gives both lowest rpm lowest level-flight torque model slightly under-elevated needs inci dence wing will have slightly higher rpm approximately same level flight torque properly-trimmed model As incidence increased rpm torque will drop lower overelevated model rpm lower good trim torque will higher level-flight torque increases overelevated model because higher torque needed overcome higher drag extra wing incidence Actually model will start sinking faster good trim soon level flight ceases full flight will take longer properly trimmed model reach level flight either under- over-elevated model Wrap-up Heres holds together peak altitude flight depends launch torque altitude vs time curve levels off level-flight torque Unless air temperature air inversion well talk about next time inter venes model will descend slowly torque decreases motor runs out turns before touchdown reaches critical torque model will come down much come several other test procedures allow get trim big meet Im out room Next time Bud Tenny Box 545 Richardson TX 75080 CGS Hawk/Kruse Continued page 63 beneath smooth out wrinkles Three coats thinned nitrate dope top tissue trim should sufficient seal surfaces detailing including seat celluloid windscreens wheel pants struts rigging dummy engine can now added complete model make come alive Flying Balance plane shown plan adding lead shot and/or clay ballast box dont like test glide CO-2powered models because doesnt give much feel ship going perform under power Wait calm evening find softest grass surface can set motor low power setting give gas charge last filler cartridge Flick prop get motor started remember its apusher aim model spot about 50 ft front give gentle toss settles ground stalling diving crease gas charge no liquid yet please try again should show slight tendency climb gently turn right turns too tightly bend rudder just shade left try again power pattern seems safe increase motor speed bit watch climb right come back overhead full gas charge model being hand launched should get flights rang ing 45 sec updepending buoyant air isand quality CO-2 charge Hawk has enjoyable Free Flight Scale ships Ive built number years unique enough elicit both admiration questions spectatorsand competitive enough win Scale contest nation decide build have questions comments please write Larry Kruse Box 1137 Liberal KS 67901 Ill happy supply documentation infor mation cost CL Aerobatics/Fancher Continued page 64 able practical terms CG aft G/L center lift although technically stable rapidly becomes too sensitive RC Ts & Caps Super Quality.Super Price! TSHIRTS 50% cotloni5O% polyester complete range sizes RC hobbiest $595 Styte Ais yellnw hold black design Style B availahle navy white white navy CAPS tits Adjustable back mesh sides Only $595 SPECIAL COMBO OFFER Matching shirt cap set $995! shirt cap per set ORDER TODAY Send check money order US Please indicate size style cnlor Include $2 postage handling per item Florida residents add 5% sales tax Allew 4-6 weeks delivery IS YOUR CLUB LOOKING FOR FUNDRAISER ASK ABOUT OUR CLUB DISCOUNT PROGRAM RC NOVELTIES PO BOX 840205 PEMBROKE PINES FLORIDA 33084 TICK OFF TIMER Now Available 0-20 Seconds Fuel shut off Flood Off Auto rudder function Weight V oz Fuel line included EXTRA FUEL LINE TUmINGSO- ft DIRECT ORDER ON LV Send Cash Check MD COD $3 extra Calif 6% JOHN TATONE 62 BELHAVEN AVE DALY CITY CA 94015 Limited supply 148 Model Aviation faster Jim Clem coined appropriate phrasethe model becomes lead sled has push prop reasonable control should avoided purposes Tail effectiveness item No 2 table parameter Ive developed compare capability tail both stabilize wing also cause change direction maneuvers Tail effectiveness product distance CG C/L tail tail area larger tail longer distance CG greater effectiveness tail either its jobs Tail volume item No 3 table purposes tail volume area lifting surface multiplied its average chord tail given area can designed variety shapes either long skinny high aspect ratio short stubby low AR terms stability tail aspect ratio AR impor tant because lift coefficient given angle attack increases higher aspect ratios Therefore minor control deflections high AR tail will produce lift low AR tail AR becomes too great smooth level flight will become difficult since minor control inputs will result large lift coefficient changes aircraft pitch changes will result Okay lets have some practical applica tions What pilots looking ship flies straight level out constant attention balance 1-201-427-3845 er Mobile Phone After Noon Only 1-201-648-9249 disturbed either outside influences winds wake turbulence etc pilot maneuvers returns balanced state readily stability basics good stability designed ship CG N spot Some less important items consider follow Leadout position item No 4 table affects stability inasmuch airplane should fly CG line midpoint Up Down leadouts leadouts too far ward rare line tension controllabili ty will suffer too far aft line tension will good level flight airplane will start hunt up down result sustained vertical P-factor component narrow range correct leadout locations given aircraft weight speed line length line diameter leading edge radius item No 6 table relative bluntness wing has affect stability Blunter wings tend stable exit cor ners bit flatter suspect because minor up down movement wardmost point airfoil strikes air stagnation point alters camber thus lift wing less would sharper leading edges debit side blunter airfoils have poorer penetration windand just plain ugly look PS opinion Nose moment item No 7 table distance CG prop thought some significant stability dont entirely agree some merit exists having longer nose gyroscopic inertia prop will act stabilizer longer arm personal opinion gyro effects minor best length nose just long enough airplane balances correctly adding weight Rule Thumb Ted designing stability Locate center gravity approximately 16% MAC plan use currently popular Super tigre 60 light airframesay under 55 ouncesyou might move aft 18-20% will allow additional fuel burnout 60 resulting initial noseheaviness compared same air craft using 40 46 couple ounces less gas Use low-to-moderate aspect ratios tails reduce sensitivity pitch inherent high aspect ratios use 45 1 Use long tail can balance normal hardware nose jury out relative tail thickness item No 8 table feel can get too thick over about 12% point response gets sluggish build too thin rigidity becomes prob Continued page 152 TIDEWATER ENGR & MACH CO P-21CAR SE/RE$6500P-21AERO SE$5000P-60AEROSE$8500CMB21 BUGGY6500 P21BUGGY SE/RE$6500P21AERO RE$5500P-60AERO RE$9000CMB-21 CAR SPEED6500 P-21DELTA$7500P-21STUNT SE/RE$5000P-60SPEED$9000CMB-21 CAR SPECIAL57500 P21MAR SE/RE$6500P-40PYLON RE$6500P-SOAERO SE$9000CMB-21 MAR SP$6500 p45MAR-DISC RV$8500P-40AEROSE$5800P80AERO RE$9500CMB21 Mar Valvola$8000 P-65MARINE$9000P-40STUNT SE$6500P-45DUCT FAN57500CMB-60 AERO$9000 P80MARINE$11000P-45STUNT SE$6800P-65DUCT FAN$9500CMB-90 MAR$14000 P-90MARINE$14000P45AERO SE$6000P-SODUCT FAN$10000ALL CMB PARTSAVAILABLE PACKING & HANDLING $400PICCO GLOW PLUGS $1500/Doz Pay Shipping ChargePICCO CAPS$500/EachHOT SPECIALS NITROMETHANE$3150/GalP45 MAR$8000P-90 MAR $12500 COD $190 CASH ONLYKLOTZ OIL$1375/GalP65 MAR$8500P-21 AREO SE $4000 COMPETITION BOAT KITS ANDALE IRE ABOUTP80 MAR $9800P60 AERO RE $7500 HARI WARE IN STOCKI.J IiiJX QUANTITY PRICES July1985 149 engines engineered meet demands discriminating modeler backed service match Engines have points easy starting carburetor linkage crankcase tapped smoke adapter six bolt prop hub mount mounting bolts muffler engines ready run Props tanks oil spark plugs etc available extra charge lexcept Kioritz 37 twin Sacha-Dolmar 34 48 Kioritz 56 Kioritz made order Cobra 23 Kiorltz 2A 31 HP 5/ lbs32 HP 6/ lbs $15995 96 x FOX FOX GLOWs-WAY PLUGWRENCH Standard $119 R/C $169 Sales Fox Glow Plug have now passed 10 million mark good reason too its machined idle bar cant break loose Its platinum-rhodium element worlds finest Its space age insulator never burns out tested before packaging Fox Wrench specially designed install Glow Plug properly Chances cross threading reduced 3/8 7/16 1/2 hex fit prop nuts too Bright chrome finish better model shops everywhere Fox MFG Co 5305 TOWSON AVE FORT SMITH AR 72901 15011 6461656 Fly same prop over over again Continuous filament fiberglass blades molded epoxy resin Hi-performance test proven propellor blade shape 2-piece 7075 aluminum T6 hardness hub anodized black Removeable steel pins quick blade changes Tested high RPM blades will change pitch PROP HUB ASSEMBLY N 109 1 size engines electric motor equivalent Weight 85 grams $1500 PROP BLADES FOR KUHN 109 Available Tx 25 7x 3 7x 35 8x 4 $400 per blade $800 per pair additional moan woight steel hub available PROP HUB ASSEUBLY N 108 285 grams $1500 PROP HUh ASSEMBLY # 110 049 051 engines electric motor equivalent Weights grams $1500 PlOP BLADES FOR HUB N 110 Available 6x 3 $400 per blade $800 per pair Additional sizes larger diameters available soon Send SSAE catalog sheet complete line DEALER INIIUIRIES INVITED 152 Model Aviation CL Aerobatics/Fancher Continued page 149 lem Use about 8% 12% design midpoint leadouts should approximately 30 sweep designed CU aircraft centerline allowance made A-in adjustment fore aft bellcrank location item No 9 table should right CU leadouts will exit wing tip straight line forced bend remember CU will lime up leadout exit midpoint Finally use moderate-to-blunt leading edge important sharp So much stability Now lets go second trim objective table make blamed thing turn Once again CU must take star bill ing along its relationship C/L wing item No 1 next section table tail volume effectiveness table items Nos 2 3 flap/elevator ratio item No 4 aircraft weight U loads lift required item No 5 aspect ratio item No 6 Since bound together lets discuss group might just well start out controversial stuff can draw bat tle lines early rate Stunter turns pitches primarily function lift light weight reasonable weight adequate lift desirable light wing loading primary requisite rapid pitch change. especially predictable controllable change Lets take quick look Stunt ship level flight lift exactly equals weight threepound airplane developing three pounds lift now desire pitch three-pound ship abruptly square corner will cause acceleration change direction aircrafts mass will result apparent weight increasing resultant weight termed G load U normal weight five Us five times normal weight etc Just fun heres formula figuring U forces G 0668V2R V speed mph R radius corner feet example three-pound Stunt er turns corner 10-foot radius flying 55 mph would incur U forces 20 times its own weight 60 pounds lift wing must produce support Stunter throughout cor ner Please note wing can produce lift required However unable produce amount lift must increase radius cor ner else aircraft will stall wing forced past its critical stalling angle attack As discussed April wing develops lift concentrated Center Lift normally aft CU Therefore lift causes pitch ing moment direction opposite desired pitch change force must overcome tail before change body angle can made Since lift necessary support U forces corner can reduce pitching moment lessening distance between CU C/L design phase can done increasing aspect ratio wing allows us narrow distance between CU C/L still retaining desired percentage location CU about 16% MAC Another significant factor about highaspect-ratio wings given amount lift will develop less duced drag drag results production lift primarily wingtip vor tices downwash reduces thrust requirements corner good will slow airplane less also good As tail remember high aspect ratios increase lift coeffi cient given angle attack therefore real-world limit maximum aspect ratio can control smoothly abrupt maneuvers Remember flaps high-lift devices contribute significant percentage increased lift generated corner Well get back Ted Fancher 158 Flying Cloud Isle Foster City CA 94409 CL Scale/Boss Continued page 65 landing gear requirements decided use single specially-made center wing rib base wheel well cover doors main bellcrank mounting As usual practice building plans meant RC use case plans Bryan Taylor Ureat Britain obtained Bob Holman Plans San Bernardino CA wings main spar ribsfrom center point landing gear will mountedare made 1-in plywood done make solid base possible build rest model See August 1982 MA column general information converting RC kits CL use case addition making ribs plywood wings center rib constructed lami nating two -in plywood -in balsa rib specially slotted accept main bellcrank platform accompanying photos show three basic steps design installation control system will provide eleva tor engine control still allow wheel well area kept clear pushrods etc first photos shows bellcrank leadouts well-laidout platform Care should exercised cutting platforms slot see ample clearance provided bellcranks sliding mechanism certain
Edition: Model Aviation - 1985/07
Page Numbers: 64, 148, 149, 152
Control Line Aerobatics Ted Fancher OKAY grouplets design ourselves Stunt ship Remember going address parameters listed trim table May 1985 column page 67 relate design Well look discuss briefly its effect aircraft performance appropriate performance altered changes parameter Again let remind Im dealing concepts conclusions consider developing own ship Some things Ill saying will generally accepted few will Im sure quite controversial Controversial Fancher Say isnt cases Ill clearly label opinion such may want seek further enlighten ment another source course Im sure Im right however. first trim objective design stability subtle difference tween stability balance An air plane balanced forces acting equilibrium lift equals weight thrust equals drag An air plane balance will continue course speed until equilibrium disturbed Once disturbed its tendency return its balanced condition measure its stability tends return balanced state said positively stable maintains new attitude neutrally stable increases its divergence balanced state termed negatively stable Stability inextricably bound relationship between center gravity CU point known Aerody namic Neutral Point need know about N spot its location relative overall lift capability total aircraft wing plus tail will always fall between 25% positions wings tails respective MACs mean aerodynamic chords larger tail respect wing further aft N point will As long CU located forward N spot ship will positively stable therefore flyable CU moved aft point aircraft would uncontrolla ble Since Stunt ships very large tails N spot far aft normally-usable range CU safe say reasonable stability inherent remotely-conventional Stunt design should also stated further forward CU stable airplane will be. less maneuverContinued page 148 out thrilling days yesteryear two greatest Stunters 0 tfle early FIflieS icit Tom Nlebuhrs Fox 35-powered Trixter Barnstormer 10 years old flew Garden State Circle Burners very first Old-Time Stunt meet Plane right Bob Jongoleens deBolt American Senior has Fox 35 MonoKote-covered wing Sig dope fuselage Photos Bruce Gliford Jr Note neither designs used wing flaps Flying weights realm 32 oz Ohios Joe Reinhard won PAMPAs Concours dEiegance 1983 Nats magnificently-builtbut subtly-flnishedStunter L weighed 38 oz used OS Max 35 power photo right Bob Bear Gleseke ponders enormity Modern Stunt beholds windy Urtnowskis magnificent Mig 1983 Chicopee Nets Both craft exemplify use highaspect-ratio surfaces Mig has monstrous wing flaps Ted expounds aspect ratio flap size column 64 Model Aviation torque Record torque rpm reading taken just before caught model Make small change trim repeat rpm/torque measurements best trim will setting gives both lowest rpm lowest level-flight torque model slightly under-elevated needs inci dence wing will have slightly higher rpm approximately same level flight torque properly-trimmed model As incidence increased rpm torque will drop lower overelevated model rpm lower good trim torque will higher level-flight torque increases overelevated model because higher torque needed overcome higher drag extra wing incidence Actually model will start sinking faster good trim soon level flight ceases full flight will take longer properly trimmed model reach level flight either under- over-elevated model Wrap-up Heres holds together peak altitude flight depends launch torque altitude vs time curve levels off level-flight torque Unless air temperature air inversion well talk about next time inter venes model will descend slowly torque decreases motor runs out turns before touchdown reaches critical torque model will come down much come several other test procedures allow get trim big meet Im out room Next time Bud Tenny Box 545 Richardson TX 75080 CGS Hawk/Kruse Continued page 63 beneath smooth out wrinkles Three coats thinned nitrate dope top tissue trim should sufficient seal surfaces detailing including seat celluloid windscreens wheel pants struts rigging dummy engine can now added complete model make come alive Flying Balance plane shown plan adding lead shot and/or clay ballast box dont like test glide CO-2powered models because doesnt give much feel ship going perform under power Wait calm evening find softest grass surface can set motor low power setting give gas charge last filler cartridge Flick prop get motor started remember its apusher aim model spot about 50 ft front give gentle toss settles ground stalling diving crease gas charge no liquid yet please try again should show slight tendency climb gently turn right turns too tightly bend rudder just shade left try again power pattern seems safe increase motor speed bit watch climb right come back overhead full gas charge model being hand launched should get flights rang ing 45 sec updepending buoyant air isand quality CO-2 charge Hawk has enjoyable Free Flight Scale ships Ive built number years unique enough elicit both admiration questions spectatorsand competitive enough win Scale contest nation decide build have questions comments please write Larry Kruse Box 1137 Liberal KS 67901 Ill happy supply documentation infor mation cost CL Aerobatics/Fancher Continued page 64 able practical terms CG aft G/L center lift although technically stable rapidly becomes too sensitive RC Ts & Caps Super Quality.Super Price! TSHIRTS 50% cotloni5O% polyester complete range sizes RC hobbiest $595 Styte Ais yellnw hold black design Style B availahle navy white white navy CAPS tits Adjustable back mesh sides Only $595 SPECIAL COMBO OFFER Matching shirt cap set $995! shirt cap per set ORDER TODAY Send check money order US Please indicate size style cnlor Include $2 postage handling per item Florida residents add 5% sales tax Allew 4-6 weeks delivery IS YOUR CLUB LOOKING FOR FUNDRAISER ASK ABOUT OUR CLUB DISCOUNT PROGRAM RC NOVELTIES PO BOX 840205 PEMBROKE PINES FLORIDA 33084 TICK OFF TIMER Now Available 0-20 Seconds Fuel shut off Flood Off Auto rudder function Weight V oz Fuel line included EXTRA FUEL LINE TUmINGSO- ft DIRECT ORDER ON LV Send Cash Check MD COD $3 extra Calif 6% JOHN TATONE 62 BELHAVEN AVE DALY CITY CA 94015 Limited supply 148 Model Aviation faster Jim Clem coined appropriate phrasethe model becomes lead sled has push prop reasonable control should avoided purposes Tail effectiveness item No 2 table parameter Ive developed compare capability tail both stabilize wing also cause change direction maneuvers Tail effectiveness product distance CG C/L tail tail area larger tail longer distance CG greater effectiveness tail either its jobs Tail volume item No 3 table purposes tail volume area lifting surface multiplied its average chord tail given area can designed variety shapes either long skinny high aspect ratio short stubby low AR terms stability tail aspect ratio AR impor tant because lift coefficient given angle attack increases higher aspect ratios Therefore minor control deflections high AR tail will produce lift low AR tail AR becomes too great smooth level flight will become difficult since minor control inputs will result large lift coefficient changes aircraft pitch changes will result Okay lets have some practical applica tions What pilots looking ship flies straight level out constant attention balance 1-201-427-3845 er Mobile Phone After Noon Only 1-201-648-9249 disturbed either outside influences winds wake turbulence etc pilot maneuvers returns balanced state readily stability basics good stability designed ship CG N spot Some less important items consider follow Leadout position item No 4 table affects stability inasmuch airplane should fly CG line midpoint Up Down leadouts leadouts too far ward rare line tension controllabili ty will suffer too far aft line tension will good level flight airplane will start hunt up down result sustained vertical P-factor component narrow range correct leadout locations given aircraft weight speed line length line diameter leading edge radius item No 6 table relative bluntness wing has affect stability Blunter wings tend stable exit cor ners bit flatter suspect because minor up down movement wardmost point airfoil strikes air stagnation point alters camber thus lift wing less would sharper leading edges debit side blunter airfoils have poorer penetration windand just plain ugly look PS opinion Nose moment item No 7 table distance CG prop thought some significant stability dont entirely agree some merit exists having longer nose gyroscopic inertia prop will act stabilizer longer arm personal opinion gyro effects minor best length nose just long enough airplane balances correctly adding weight Rule Thumb Ted designing stability Locate center gravity approximately 16% MAC plan use currently popular Super tigre 60 light airframesay under 55 ouncesyou might move aft 18-20% will allow additional fuel burnout 60 resulting initial noseheaviness compared same air craft using 40 46 couple ounces less gas Use low-to-moderate aspect ratios tails reduce sensitivity pitch inherent high aspect ratios use 45 1 Use long tail can balance normal hardware nose jury out relative tail thickness item No 8 table feel can get too thick over about 12% point response gets sluggish build too thin rigidity becomes prob Continued page 152 TIDEWATER ENGR & MACH CO P-21CAR SE/RE$6500P-21AERO SE$5000P-60AEROSE$8500CMB21 BUGGY6500 P21BUGGY SE/RE$6500P21AERO RE$5500P-60AERO RE$9000CMB-21 CAR SPEED6500 P-21DELTA$7500P-21STUNT SE/RE$5000P-60SPEED$9000CMB-21 CAR SPECIAL57500 P21MAR SE/RE$6500P-40PYLON RE$6500P-SOAERO SE$9000CMB-21 MAR SP$6500 p45MAR-DISC RV$8500P-40AEROSE$5800P80AERO RE$9500CMB21 Mar Valvola$8000 P-65MARINE$9000P-40STUNT SE$6500P-45DUCT FAN57500CMB-60 AERO$9000 P80MARINE$11000P-45STUNT SE$6800P-65DUCT FAN$9500CMB-90 MAR$14000 P-90MARINE$14000P45AERO SE$6000P-SODUCT FAN$10000ALL CMB PARTSAVAILABLE PACKING & HANDLING $400PICCO GLOW PLUGS $1500/Doz Pay Shipping ChargePICCO CAPS$500/EachHOT SPECIALS NITROMETHANE$3150/GalP45 MAR$8000P-90 MAR $12500 COD $190 CASH ONLYKLOTZ OIL$1375/GalP65 MAR$8500P-21 AREO SE $4000 COMPETITION BOAT KITS ANDALE IRE ABOUTP80 MAR $9800P60 AERO RE $7500 HARI WARE IN STOCKI.J IiiJX QUANTITY PRICES July1985 149 engines engineered meet demands discriminating modeler backed service match Engines have points easy starting carburetor linkage crankcase tapped smoke adapter six bolt prop hub mount mounting bolts muffler engines ready run Props tanks oil spark plugs etc available extra charge lexcept Kioritz 37 twin Sacha-Dolmar 34 48 Kioritz 56 Kioritz made order Cobra 23 Kiorltz 2A 31 HP 5/ lbs32 HP 6/ lbs $15995 96 x FOX FOX GLOWs-WAY PLUGWRENCH Standard $119 R/C $169 Sales Fox Glow Plug have now passed 10 million mark good reason too its machined idle bar cant break loose Its platinum-rhodium element worlds finest Its space age insulator never burns out tested before packaging Fox Wrench specially designed install Glow Plug properly Chances cross threading reduced 3/8 7/16 1/2 hex fit prop nuts too Bright chrome finish better model shops everywhere Fox MFG Co 5305 TOWSON AVE FORT SMITH AR 72901 15011 6461656 Fly same prop over over again Continuous filament fiberglass blades molded epoxy resin Hi-performance test proven propellor blade shape 2-piece 7075 aluminum T6 hardness hub anodized black Removeable steel pins quick blade changes Tested high RPM blades will change pitch PROP HUB ASSEMBLY N 109 1 size engines electric motor equivalent Weight 85 grams $1500 PROP BLADES FOR KUHN 109 Available Tx 25 7x 3 7x 35 8x 4 $400 per blade $800 per pair additional moan woight steel hub available PROP HUB ASSEUBLY N 108 285 grams $1500 PROP HUh ASSEMBLY # 110 049 051 engines electric motor equivalent Weights grams $1500 PlOP BLADES FOR HUB N 110 Available 6x 3 $400 per blade $800 per pair Additional sizes larger diameters available soon Send SSAE catalog sheet complete line DEALER INIIUIRIES INVITED 152 Model Aviation CL Aerobatics/Fancher Continued page 149 lem Use about 8% 12% design midpoint leadouts should approximately 30 sweep designed CU aircraft centerline allowance made A-in adjustment fore aft bellcrank location item No 9 table should right CU leadouts will exit wing tip straight line forced bend remember CU will lime up leadout exit midpoint Finally use moderate-to-blunt leading edge important sharp So much stability Now lets go second trim objective table make blamed thing turn Once again CU must take star bill ing along its relationship C/L wing item No 1 next section table tail volume effectiveness table items Nos 2 3 flap/elevator ratio item No 4 aircraft weight U loads lift required item No 5 aspect ratio item No 6 Since bound together lets discuss group might just well start out controversial stuff can draw bat tle lines early rate Stunter turns pitches primarily function lift light weight reasonable weight adequate lift desirable light wing loading primary requisite rapid pitch change. especially predictable controllable change Lets take quick look Stunt ship level flight lift exactly equals weight threepound airplane developing three pounds lift now desire pitch three-pound ship abruptly square corner will cause acceleration change direction aircrafts mass will result apparent weight increasing resultant weight termed G load U normal weight five Us five times normal weight etc Just fun heres formula figuring U forces G 0668V2R V speed mph R radius corner feet example three-pound Stunt er turns corner 10-foot radius flying 55 mph would incur U forces 20 times its own weight 60 pounds lift wing must produce support Stunter throughout cor ner Please note wing can produce lift required However unable produce amount lift must increase radius cor ner else aircraft will stall wing forced past its critical stalling angle attack As discussed April wing develops lift concentrated Center Lift normally aft CU Therefore lift causes pitch ing moment direction opposite desired pitch change force must overcome tail before change body angle can made Since lift necessary support U forces corner can reduce pitching moment lessening distance between CU C/L design phase can done increasing aspect ratio wing allows us narrow distance between CU C/L still retaining desired percentage location CU about 16% MAC Another significant factor about highaspect-ratio wings given amount lift will develop less duced drag drag results production lift primarily wingtip vor tices downwash reduces thrust requirements corner good will slow airplane less also good As tail remember high aspect ratios increase lift coeffi cient given angle attack therefore real-world limit maximum aspect ratio can control smoothly abrupt maneuvers Remember flaps high-lift devices contribute significant percentage increased lift generated corner Well get back Ted Fancher 158 Flying Cloud Isle Foster City CA 94409 CL Scale/Boss Continued page 65 landing gear requirements decided use single specially-made center wing rib base wheel well cover doors main bellcrank mounting As usual practice building plans meant RC use case plans Bryan Taylor Ureat Britain obtained Bob Holman Plans San Bernardino CA wings main spar ribsfrom center point landing gear will mountedare made 1-in plywood done make solid base possible build rest model See August 1982 MA column general information converting RC kits CL use case addition making ribs plywood wings center rib constructed lami nating two -in plywood -in balsa rib specially slotted accept main bellcrank platform accompanying photos show three basic steps design installation control system will provide eleva tor engine control still allow wheel well area kept clear pushrods etc first photos shows bellcrank leadouts well-laidout platform Care should exercised cutting platforms slot see ample clearance provided bellcranks sliding mechanism certain