How toAd justThat High-Powered AMA Gas Free Flightpart2 Last months installment covered aerodynamic theory construction tech niques contest models Concluding series author now describes typical flight-test problems appropriate adjustmentsE Ralph Prey THERE three elements leading consistent max dead air namely fast steep climb smooth transition low sink-rate glide key success select ing trim adjustments harmony other launch enda max go about making selection Answer Fly try fly again main ingredients new genera tion free-ffight models high speed climb super engine power quick response adjustments makes sense concen trate adjusting techniques affecting climb pattern Once climb ad justed liking glide can ironed out glide adjustment also affects climb well have re-adjust climb again before proceeding glide seesaw procedure needed because adjusting techniques such shift ing Center Gravity CG decalage often used adjust both climb glide begin hand test gliding highpowered high-performance model useful verify CG location decalage test glide shows us CG suffi ciently forward enough decalage keep nose up during initial climb first flight CG shifted farther forward decalage increased assure nose up attitude Very little time spent hand test gliding adjust glide sink rate glide circle reason being very difficult duplicate actual flying speed hand test glides Significant too adjusting proce dure use short engine runs 3 seconds very near full power fol lowed quick DT Engine runs successively increased 1 2 seconds provided climb pattern previous flight safe Conversely engine runs reduced 1 2 seconds depending upon trim adjustments made following last test flight logic using short engine runs very near full power sound Fewer adjustments need made using high power example test flights using longer runs low power will have re adjusted time power speed increase use quick DT 2 3 seconds after engine shut off must safety factor well time saver chasing interval before quick DT varies test flights progress climb transition eventual glide adjustment Lets consider some typical flight test problems select trim adjustments options available particular design design model must taken consideration because de sign has flight characteristics peculiar itself make matters complicated 32 Model Aviation - Illustrations Jim Newman \ \ N Problem 1 I\ \ K N N N Problem2N no two models same design will fly exactly alike same flight trim adjustments Thats name game fly try fly again Fortunately adjustments can used safely models compar able design planforms described following problems ones youll likely encounter careful application adjustment techniques explained should help adjust comparable modeL Problem 1 Model grooves steep right climb 6-8 seconds after right wing starts raise up turn begins straighten towards left climb atti tude remains steep Any further engine run would result climbing left roll problem involves Longitudinal Ver tical axes pylon designs wash-in right main wing panel use right left thrust raising right wing after 6-8 seconds due wash-in becoming effective speed eventual left roll Thrust effectiveness decreases speed cause reduce left roll decrease wash-in slightly Make no other adjustments pylon designs wash-out left main wing panel use right thrust wash-out left wing panel becomes effective speed raising right wing speed builds up 6-8 seconds rolling model left Some designs also use left fm rudder offset wash-out control right bank Fin II-\ August 1979 33 LI K Problem 4 Problem 3 / Problem 5 / K Problem 6 f / rudder tab effectiveness increase speed case have option reduce left rudder tab washout reduce left roll Increasing right thrust last chance option pylon designs no wing wash-in wash-out use left vertical fin rudder offset thrust offset raising right wing after 6-8 seconds due increased effectiveness left fin rudder offset speed creased Thrust looses effectiveness speed cause Decrease left fin rudder offset make no other adjustments high-thrust-line designs model climbing wrong direction Check carefully wing warps should no washin left main panel wash out right main panel Also check thrust offset should no right thrust Use rudder tab offset left control model climbing left turn Problem 2 Model grooves steep right climb 9-10 seconds after climb angle increased slightly turn started straighten towards left right wing starting raise Another few seconds full 12 seconds engine run wing would almost level horizon steep climb angle problem volves Longitudinal Vettical axes pylon designs wash-in right main wing panel use right left thrust wash-in still reason changes last few seconds Dont change wash-in Instead add very small amount right rudder-tab offset right tab will start become effective speed builds up 6-8 seconds will keep model grooving overpowering wash-in full run Moreover model set glide right preferred safest direction right tab will help transition holding model right turn As speed decreases right tab looses effectiveness stabilizer tilt takes over glide turn Make no other adjustments model set glide left small amount right-rudder tab should adversely affect transi tion glide dies dont use right tab offset reduce wash-in traditional right climb left glide pattern using stabilizer tilt wash-in right wing wash-out left wing could result model diving glide Particularly glide speed increases due upset gust wind increased speed increases effectiveness wash-in wash-out resulting left rolling dive pylon designs wash-out left main wing panel use right thrust designs also using left rudder wash-out left rudder still reason changes last few seconds 34 Model Aviation \ I II / / / Problem 7 / Problem 8 junior Joey Foster gets off perfect launch feet airof dads National Record Holder Class A-B called Buck powered Schnuerle K&B 325 35 nitro-breathing engines Again note steep angle barely perceptible right bank Sophisticated gimmickry Dad once world champ Wakefield leading Pylon flier struggling find time com plete article Buck future MA None other C berg making last check engine timer before launching latest high-thrust Skyrocket design Note forthcoming steep launch angle See text details ibt-fldidO PROPELLERS polyester boil color Go GRISH propeller True helical pitch airfoil win-power 2 BladeTractor 5-3each 5-45%35--4304 6364384 74 7-678504 84 8688654 94 969-7 9-810-410-6854needs 11-411611-8Si 12-412-512-6$150 2 Blade PusherAT YOUR DEALER 5A3 54-4 6-36-4354 8-6854 9610-6SiJ 3 Blade Tractor2 53 6364504 3 BladePushe 635043 -I -BIade Metallic Aluminum Color Tractor 1678Si 8688$125 96106104$150 Pusher106$150 Sizes pitches dations 5 Washers will used screws holding servos mounting trays also screws holding tray rails washers will approximately same diameter grommets Servos mounted directly rails will also have washers mounting screws addition servo trays will have least extra safety screw necessarily turned down tightly placed between grommets rear tray prevent tray slipping out grommets flight 6 A keeper collar will used pushrods have right-angle bend connects servos S-bends acceptable clevis used both ends pushrod clevis will secured will turn 7 All control surfaces will firm hinge line excess slop dis cretion safety inspector 8 Positive thread-type wing bolts screws will secure wing place two-piece aircraft 9 A positive method holding wheel axle will used wheel shall bind 10 The entire aircraft shall inspected stress cracks have comments please let know have no way knowing what opinions unless speak up Write Bill Hager 4622 Bridgeport Drive Garland TX 75041 GRISH LARGE WOOD PROPELLERS HARDWOOD too hard minimizes costly plane engine damage True pitch airfoil fully carved Crafts man addshis own final touches 3/B BORE ALL SIZES IN18 S7 6 B & 10 PITCH 208 22 10 24 13 NEWSIZE SPITCH 26 $16 BROS GRISH ST JOHN INDIANA 46373 RC Aerobatics/Van Putte continued page 3 1 operate 12 volts will drive speakers can picked up used reasonable price 7 Start contest time few things annoying competitor contest finally gets cranked up two hours late takes no effort start timejust proper planning An nounce contestants club members contest will start timethen 8 The Contest Director responsible conducting contest according rules judges should know rule book better anyone except contest director Inform judges direct rule book interpretations contest director hassles 9 Have confidence people Make sure understand jobs leave alone will probably surprise well will does wonders egos 10 Finish contest early enough permit people get home reasonable hour good contest can spoiled having drive well wee hours next day hope guidelines will help interested detailed article let know Encouragement what need overcome procrastination Recently newsletters have contained rash announcements about club flying site losses Usually noise complaints sale property developers reasons loss sites However Eglin Aero Modellers lost flying site abandoned runway Eglin AFB Florida unusual reason seems Air Force wants blow up runway training unit USAF Civil Engineering Center involved training rapid runway repair will move site order teach airmen repair craters runway must first blow holes case Eglin Aero Modellers have lost flying site 19 years Have gotten new FCC license lately would pay check make sure FCC sent right license should have Radio Control Service Quite few people fly RC have received license Citizens Band voice Service mistake would good idea older licenses check make sure have Class C license Apparently FCC receives license applications Citizens Band use Radio Control use sometimes send wrong license RC fliers Pattern/Sport Problem Month came result flying field discus sion about wing versus tail incidence downthrust problem does flier determine much downthrust required Most airplanes require 2 3 degrees negative incidence horizontal tail relative wing order have zero elevator deflection trim glide case aircraft center mass about right simple test deter proper downthrust Fly air plane straight level full power suddenly cut power Determine care fully what happens pitch attitude airplane pitches up downthrust must reduced Correspondingly pitches down downthrust needed may take several observations sure exactly what airplane doing sometimes difficult determine air plane really pitching down just setting steady sink pitch up easier detect because pitching tendency will keep airplane same altitude longer time course after thrust changes made sure readjust elevator trim level flight full power before making further test Continue adjusting downthrust until no tendency airplane pitch power rapidly reduced Next month hope have good selection problems pick Pattern/Sport Problem Month Ron Van Putte 12 Connie Drive Shal imar FL 32579 Adjust/Prey continued page 35 ways loop caused either forward CO location too much decalage both Check out CO CG farther 110 Model Aviation 1 styles RIGHT HAND TRACTOR SAFE FLYING IS NO ACCIDENT THE chose Waco F-a biplane flagship because represents Golden Era 1930s flying adventure Add easy snag-tree building safe gentle flyingthe result ot thorough kit engineering caretul prototype development features Platt Kits have satisfying building flying experience ahead Kit featuresTop-quality diecut machined balsa plywood Full size plans Separate instruction book isometrics Decals Injection-moulded vacuum-formed plastic cowl cowl blisters wheel pants required nylon fittings Formed wire langing gear & struts Span 60Area 950 Sqi 4 6 channel Engine good 40 60 2657 N E 188th Street Miami Fiorida 33180 Telephone g35-1436 forward plans specifr shift CG rearward time towards correct location Also check decalage against plan decalage plans specify also have option reduce decalage However proceed very cautiously making adjustment time Dont exceed specified CG location trying other options also some cases plans may call thrust offset wash-in wash-out main wing panel Check adjust ments too neither correct have options consider Problem 5 Model starts steep right climb after 1-2 seconds dips right building up speed resumes steep right climb problem involves Vertical axis other aspect problem dip can due angle direction model launched launched near vertical steeper normal climb angle will dip right after launch Also launched crosswind wind strikes left half wing greater right would occur nose banked pointed right wind launch very important model should pointed up about 80-degree angle almost dead center wind slight right bank Never launch pylon model left wind few degrees right wind never bank model few degrees right launching launch correct dip right after launch due thrust offset pylon designs wash-in right main wing panel use right left thrust check thrust offset right thrust used reduce right thrust left thrust used increase left thrust pylon designs wash-out left main wing panel use right thrust reduce right thrust pylon designs no wash-in wash-out use left vertical fin rudder offset thrust offset crank left thrust high-thrust-line designs better watch launch else put left rudder tab offset never want climb right Problem 6 Model grooves full engine run transition satisfactory glide starts out turning desired glide direction slows down upwind starts turning opposite direction now speeds up downwind again starts change turn direction slowing down up wind repeating wandering prob lem involves Longitudinal axis pylon designs wash-in right main wing panel stabilizer tilted left turn wash-in too much causing drag drag increases upwind model slows down turns model right As speed builds up downwind drag decreases liftincreases turn ing model left process keeps repeating have several options first change glide circle left right Depending upon size stabilizer amount tilt model may glide right changing wash-in want stay left glide other option would reduce wash-in readjust climb Increasing left tilt will cause model unstable dive left speed increases glide reduced wash-in model will bank turn tighter right during climb Use left vertical fin rudder tab August 1979 111 SCALE CLASCICS 7-4 Plans & Construction Manual CURTISS HAWK POESTINSON RELIANT SR9 Scala 54o Span $220 /o Scale 126 Span250 2Scala 83 Span 12 2Scal BA Span1810 1 Scale 4713Span jQ8O uS Scala 63 Span1280 CURTISS GOSHAWK P1100 2 Scale 83 SpatSf590 CURTISS GULFHAWK lA . 2Scal 63 Span S160O Scala 94/i Span S3OP pleas Add SISO P 00 Pstoead Ilandllog. 001500 US Add SOsMka eli PaymOOts tO Richard G Barron1213 Holly SprIng L Grand Blanc MIchIgan 46439 Sood 11cc COmplete I0t0atIc offset will help transition initiating left turn soon engine cuts will assist tilt left glide glide circle originally set right glide increase stabilizer tilt However may also necessary decrease wash-in stab tilt does make model turn right wash-in reduced readjust climb using right rudder required bank right climb pylon designs wash-out left main wing panel stabilizer tilt left glide turn wash-out becomes effec tive upwind due decreased speed stabilizer tilt trying overpower wing forces cant quite make fore increase stabilizer tilt left glide turn careful use too much tilt could cause model unstable glide turn Too much tilt would increase turn washed-out wing upset gust wind could cause dive left pylon designs no wash-in wash-out use left vertical fin rudder offset high-thrust-line designs stabilizer tilt enough keep model turning left right case may Also left rudder tab offsct may affecting turn speed increases downwind causing some wandering Increase tilt either left right turn case may Problem 7 Model grooves full engine run shallower angle like also makes about ht turn during full 12 seconds want least 1 1 turns transition good glide too fast nose down problem involves Lateral axis pylon models overall nosedown tendency caused insufficient de calage Increasing decalage de creasing positive angle incidence stabilizer will raise nose up climb glide decalage increased also increases tendency model turn right climb conversely decrease turn right left glide Therefore decreasing de calage will result increasing right turn climb desired ito 1 turns slow up sink rate glide Adjust glide turn stabilizer tilt Problem 8 Model grooves steep right climb transition perfect glide turn perfect occasional slight stall problem involves Lateral axis pylon designs high-thrust models easy problem cure however fliers fight cure Simply add little weight nose reduce stall Youd surprised alibis used keep adding weight weight will actually help model penetrate upwind improve glide sink rate Problem 9 Model grooves steeper climb want transition good glide perfect calm day climb pattern would alright However least bit increase wind could make model loop climb problem involves Lateral axis pylon designs high-thrust models too can easy problem cure again adding weight cure seems offensive Reduce decalage flatten climb add weight tail adjust glide decalage can reduced shims under leading edge stabilizer will bring nose down climb reduced decalage will speed up glide however added weight tail will restore perfect glide few grams added tail get glide adjusted perfectly wont add wing loading enough change glide hope above problems will give better insight adjusting new gener ation gas free-flight models mak ing adjustments mentioned above few dos donts also merit consideration adding incidence wing stabilizer dont use balsa wood shims Balsa wood compresses will change adjustment Use 1/64 1/32 1/16 plywood shims shims less 1/64 needed use brass shims Any auto parts store has brass shim stock various sizes vertical fin used offset instead rudder tab sure re key stabilizer fin stabilizer Again use hard woods metal engine mount used sure side thrust can added also adding down thrust example adding side thrust mount three mounting holes down thrust also added needed Re-drill mount four mounting holes dont use original center bottom hole mounting four holes can spaced side thrust needed dont get down thrust Use metal shims engine thrust adjust ments using metal mounts keep shim pressing plywood firewall use 020 aluminum spacer against firewall metal mount Insert metal shim between alu minum spacer mount Check DT line tension Too much tension can bow fuselage changing either de calage vertical fin rudder offset final thought Stand own decisions what adjustments make Its model decision dont let some bystander try con other adjustments against judgment Youve built design model things doesnt know about make mistake let decision Youll learn making own decisions sincerely hope information series will help make right decision continuously max dead air FF Old Timers/Haught continued page 37 interest Northwest well other areas us will no doubt pouring through magazine collec tions looking sure winner Square peg round hole Newly manu factured spark plugs 1/4 X 32 threadsize have available quite sometime up point new plugs have available 3/8 X 24 thread size options scarcer day old Champion V use adapter bushing smaller size plug suitable alternative available local small engine shop form Japanese NKG brand CM-6 chain saw 112 Model Aviation Af7 ASS/S 7w2k6rGff GRwZ4VC OAr ThrAe *V3
Edition: Model Aviation - 1979/08
Page Numbers: 32, 33, 34, 110, 111, 112
How toAd justThat High-Powered AMA Gas Free Flightpart2 Last months installment covered aerodynamic theory construction tech niques contest models Concluding series author now describes typical flight-test problems appropriate adjustmentsE Ralph Prey THERE three elements leading consistent max dead air namely fast steep climb smooth transition low sink-rate glide key success select ing trim adjustments harmony other launch enda max go about making selection Answer Fly try fly again main ingredients new genera tion free-ffight models high speed climb super engine power quick response adjustments makes sense concen trate adjusting techniques affecting climb pattern Once climb ad justed liking glide can ironed out glide adjustment also affects climb well have re-adjust climb again before proceeding glide seesaw procedure needed because adjusting techniques such shift ing Center Gravity CG decalage often used adjust both climb glide begin hand test gliding highpowered high-performance model useful verify CG location decalage test glide shows us CG suffi ciently forward enough decalage keep nose up during initial climb first flight CG shifted farther forward decalage increased assure nose up attitude Very little time spent hand test gliding adjust glide sink rate glide circle reason being very difficult duplicate actual flying speed hand test glides Significant too adjusting proce dure use short engine runs 3 seconds very near full power fol lowed quick DT Engine runs successively increased 1 2 seconds provided climb pattern previous flight safe Conversely engine runs reduced 1 2 seconds depending upon trim adjustments made following last test flight logic using short engine runs very near full power sound Fewer adjustments need made using high power example test flights using longer runs low power will have re adjusted time power speed increase use quick DT 2 3 seconds after engine shut off must safety factor well time saver chasing interval before quick DT varies test flights progress climb transition eventual glide adjustment Lets consider some typical flight test problems select trim adjustments options available particular design design model must taken consideration because de sign has flight characteristics peculiar itself make matters complicated 32 Model Aviation - Illustrations Jim Newman \ \ N Problem 1 I\ \ K N N N Problem2N no two models same design will fly exactly alike same flight trim adjustments Thats name game fly try fly again Fortunately adjustments can used safely models compar able design planforms described following problems ones youll likely encounter careful application adjustment techniques explained should help adjust comparable modeL Problem 1 Model grooves steep right climb 6-8 seconds after right wing starts raise up turn begins straighten towards left climb atti tude remains steep Any further engine run would result climbing left roll problem involves Longitudinal Ver tical axes pylon designs wash-in right main wing panel use right left thrust raising right wing after 6-8 seconds due wash-in becoming effective speed eventual left roll Thrust effectiveness decreases speed cause reduce left roll decrease wash-in slightly Make no other adjustments pylon designs wash-out left main wing panel use right thrust wash-out left wing panel becomes effective speed raising right wing speed builds up 6-8 seconds rolling model left Some designs also use left fm rudder offset wash-out control right bank Fin II-\ August 1979 33 LI K Problem 4 Problem 3 / Problem 5 / K Problem 6 f / rudder tab effectiveness increase speed case have option reduce left rudder tab washout reduce left roll Increasing right thrust last chance option pylon designs no wing wash-in wash-out use left vertical fin rudder offset thrust offset raising right wing after 6-8 seconds due increased effectiveness left fin rudder offset speed creased Thrust looses effectiveness speed cause Decrease left fin rudder offset make no other adjustments high-thrust-line designs model climbing wrong direction Check carefully wing warps should no washin left main panel wash out right main panel Also check thrust offset should no right thrust Use rudder tab offset left control model climbing left turn Problem 2 Model grooves steep right climb 9-10 seconds after climb angle increased slightly turn started straighten towards left right wing starting raise Another few seconds full 12 seconds engine run wing would almost level horizon steep climb angle problem volves Longitudinal Vettical axes pylon designs wash-in right main wing panel use right left thrust wash-in still reason changes last few seconds Dont change wash-in Instead add very small amount right rudder-tab offset right tab will start become effective speed builds up 6-8 seconds will keep model grooving overpowering wash-in full run Moreover model set glide right preferred safest direction right tab will help transition holding model right turn As speed decreases right tab looses effectiveness stabilizer tilt takes over glide turn Make no other adjustments model set glide left small amount right-rudder tab should adversely affect transi tion glide dies dont use right tab offset reduce wash-in traditional right climb left glide pattern using stabilizer tilt wash-in right wing wash-out left wing could result model diving glide Particularly glide speed increases due upset gust wind increased speed increases effectiveness wash-in wash-out resulting left rolling dive pylon designs wash-out left main wing panel use right thrust designs also using left rudder wash-out left rudder still reason changes last few seconds 34 Model Aviation \ I II / / / Problem 7 / Problem 8 junior Joey Foster gets off perfect launch feet airof dads National Record Holder Class A-B called Buck powered Schnuerle K&B 325 35 nitro-breathing engines Again note steep angle barely perceptible right bank Sophisticated gimmickry Dad once world champ Wakefield leading Pylon flier struggling find time com plete article Buck future MA None other C berg making last check engine timer before launching latest high-thrust Skyrocket design Note forthcoming steep launch angle See text details ibt-fldidO PROPELLERS polyester boil color Go GRISH propeller True helical pitch airfoil win-power 2 BladeTractor 5-3each 5-45%35--4304 6364384 74 7-678504 84 8688654 94 969-7 9-810-410-6854needs 11-411611-8Si 12-412-512-6$150 2 Blade PusherAT YOUR DEALER 5A3 54-4 6-36-4354 8-6854 9610-6SiJ 3 Blade Tractor2 53 6364504 3 BladePushe 635043 -I -BIade Metallic Aluminum Color Tractor 1678Si 8688$125 96106104$150 Pusher106$150 Sizes pitches dations 5 Washers will used screws holding servos mounting trays also screws holding tray rails washers will approximately same diameter grommets Servos mounted directly rails will also have washers mounting screws addition servo trays will have least extra safety screw necessarily turned down tightly placed between grommets rear tray prevent tray slipping out grommets flight 6 A keeper collar will used pushrods have right-angle bend connects servos S-bends acceptable clevis used both ends pushrod clevis will secured will turn 7 All control surfaces will firm hinge line excess slop dis cretion safety inspector 8 Positive thread-type wing bolts screws will secure wing place two-piece aircraft 9 A positive method holding wheel axle will used wheel shall bind 10 The entire aircraft shall inspected stress cracks have comments please let know have no way knowing what opinions unless speak up Write Bill Hager 4622 Bridgeport Drive Garland TX 75041 GRISH LARGE WOOD PROPELLERS HARDWOOD too hard minimizes costly plane engine damage True pitch airfoil fully carved Crafts man addshis own final touches 3/B BORE ALL SIZES IN18 S7 6 B & 10 PITCH 208 22 10 24 13 NEWSIZE SPITCH 26 $16 BROS GRISH ST JOHN INDIANA 46373 RC Aerobatics/Van Putte continued page 3 1 operate 12 volts will drive speakers can picked up used reasonable price 7 Start contest time few things annoying competitor contest finally gets cranked up two hours late takes no effort start timejust proper planning An nounce contestants club members contest will start timethen 8 The Contest Director responsible conducting contest according rules judges should know rule book better anyone except contest director Inform judges direct rule book interpretations contest director hassles 9 Have confidence people Make sure understand jobs leave alone will probably surprise well will does wonders egos 10 Finish contest early enough permit people get home reasonable hour good contest can spoiled having drive well wee hours next day hope guidelines will help interested detailed article let know Encouragement what need overcome procrastination Recently newsletters have contained rash announcements about club flying site losses Usually noise complaints sale property developers reasons loss sites However Eglin Aero Modellers lost flying site abandoned runway Eglin AFB Florida unusual reason seems Air Force wants blow up runway training unit USAF Civil Engineering Center involved training rapid runway repair will move site order teach airmen repair craters runway must first blow holes case Eglin Aero Modellers have lost flying site 19 years Have gotten new FCC license lately would pay check make sure FCC sent right license should have Radio Control Service Quite few people fly RC have received license Citizens Band voice Service mistake would good idea older licenses check make sure have Class C license Apparently FCC receives license applications Citizens Band use Radio Control use sometimes send wrong license RC fliers Pattern/Sport Problem Month came result flying field discus sion about wing versus tail incidence downthrust problem does flier determine much downthrust required Most airplanes require 2 3 degrees negative incidence horizontal tail relative wing order have zero elevator deflection trim glide case aircraft center mass about right simple test deter proper downthrust Fly air plane straight level full power suddenly cut power Determine care fully what happens pitch attitude airplane pitches up downthrust must reduced Correspondingly pitches down downthrust needed may take several observations sure exactly what airplane doing sometimes difficult determine air plane really pitching down just setting steady sink pitch up easier detect because pitching tendency will keep airplane same altitude longer time course after thrust changes made sure readjust elevator trim level flight full power before making further test Continue adjusting downthrust until no tendency airplane pitch power rapidly reduced Next month hope have good selection problems pick Pattern/Sport Problem Month Ron Van Putte 12 Connie Drive Shal imar FL 32579 Adjust/Prey continued page 35 ways loop caused either forward CO location too much decalage both Check out CO CG farther 110 Model Aviation 1 styles RIGHT HAND TRACTOR SAFE FLYING IS NO ACCIDENT THE chose Waco F-a biplane flagship because represents Golden Era 1930s flying adventure Add easy snag-tree building safe gentle flyingthe result ot thorough kit engineering caretul prototype development features Platt Kits have satisfying building flying experience ahead Kit featuresTop-quality diecut machined balsa plywood Full size plans Separate instruction book isometrics Decals Injection-moulded vacuum-formed plastic cowl cowl blisters wheel pants required nylon fittings Formed wire langing gear & struts Span 60Area 950 Sqi 4 6 channel Engine good 40 60 2657 N E 188th Street Miami Fiorida 33180 Telephone g35-1436 forward plans specifr shift CG rearward time towards correct location Also check decalage against plan decalage plans specify also have option reduce decalage However proceed very cautiously making adjustment time Dont exceed specified CG location trying other options also some cases plans may call thrust offset wash-in wash-out main wing panel Check adjust ments too neither correct have options consider Problem 5 Model starts steep right climb after 1-2 seconds dips right building up speed resumes steep right climb problem involves Vertical axis other aspect problem dip can due angle direction model launched launched near vertical steeper normal climb angle will dip right after launch Also launched crosswind wind strikes left half wing greater right would occur nose banked pointed right wind launch very important model should pointed up about 80-degree angle almost dead center wind slight right bank Never launch pylon model left wind few degrees right wind never bank model few degrees right launching launch correct dip right after launch due thrust offset pylon designs wash-in right main wing panel use right left thrust check thrust offset right thrust used reduce right thrust left thrust used increase left thrust pylon designs wash-out left main wing panel use right thrust reduce right thrust pylon designs no wash-in wash-out use left vertical fin rudder offset thrust offset crank left thrust high-thrust-line designs better watch launch else put left rudder tab offset never want climb right Problem 6 Model grooves full engine run transition satisfactory glide starts out turning desired glide direction slows down upwind starts turning opposite direction now speeds up downwind again starts change turn direction slowing down up wind repeating wandering prob lem involves Longitudinal axis pylon designs wash-in right main wing panel stabilizer tilted left turn wash-in too much causing drag drag increases upwind model slows down turns model right As speed builds up downwind drag decreases liftincreases turn ing model left process keeps repeating have several options first change glide circle left right Depending upon size stabilizer amount tilt model may glide right changing wash-in want stay left glide other option would reduce wash-in readjust climb Increasing left tilt will cause model unstable dive left speed increases glide reduced wash-in model will bank turn tighter right during climb Use left vertical fin rudder tab August 1979 111 SCALE CLASCICS 7-4 Plans & Construction Manual CURTISS HAWK POESTINSON RELIANT SR9 Scala 54o Span $220 /o Scale 126 Span250 2Scala 83 Span 12 2Scal BA Span1810 1 Scale 4713Span jQ8O uS Scala 63 Span1280 CURTISS GOSHAWK P1100 2 Scale 83 SpatSf590 CURTISS GULFHAWK lA . 2Scal 63 Span S160O Scala 94/i Span S3OP pleas Add SISO P 00 Pstoead Ilandllog. 001500 US Add SOsMka eli PaymOOts tO Richard G Barron1213 Holly SprIng L Grand Blanc MIchIgan 46439 Sood 11cc COmplete I0t0atIc offset will help transition initiating left turn soon engine cuts will assist tilt left glide glide circle originally set right glide increase stabilizer tilt However may also necessary decrease wash-in stab tilt does make model turn right wash-in reduced readjust climb using right rudder required bank right climb pylon designs wash-out left main wing panel stabilizer tilt left glide turn wash-out becomes effec tive upwind due decreased speed stabilizer tilt trying overpower wing forces cant quite make fore increase stabilizer tilt left glide turn careful use too much tilt could cause model unstable glide turn Too much tilt would increase turn washed-out wing upset gust wind could cause dive left pylon designs no wash-in wash-out use left vertical fin rudder offset high-thrust-line designs stabilizer tilt enough keep model turning left right case may Also left rudder tab offsct may affecting turn speed increases downwind causing some wandering Increase tilt either left right turn case may Problem 7 Model grooves full engine run shallower angle like also makes about ht turn during full 12 seconds want least 1 1 turns transition good glide too fast nose down problem involves Lateral axis pylon models overall nosedown tendency caused insufficient de calage Increasing decalage de creasing positive angle incidence stabilizer will raise nose up climb glide decalage increased also increases tendency model turn right climb conversely decrease turn right left glide Therefore decreasing de calage will result increasing right turn climb desired ito 1 turns slow up sink rate glide Adjust glide turn stabilizer tilt Problem 8 Model grooves steep right climb transition perfect glide turn perfect occasional slight stall problem involves Lateral axis pylon designs high-thrust models easy problem cure however fliers fight cure Simply add little weight nose reduce stall Youd surprised alibis used keep adding weight weight will actually help model penetrate upwind improve glide sink rate Problem 9 Model grooves steeper climb want transition good glide perfect calm day climb pattern would alright However least bit increase wind could make model loop climb problem involves Lateral axis pylon designs high-thrust models too can easy problem cure again adding weight cure seems offensive Reduce decalage flatten climb add weight tail adjust glide decalage can reduced shims under leading edge stabilizer will bring nose down climb reduced decalage will speed up glide however added weight tail will restore perfect glide few grams added tail get glide adjusted perfectly wont add wing loading enough change glide hope above problems will give better insight adjusting new gener ation gas free-flight models mak ing adjustments mentioned above few dos donts also merit consideration adding incidence wing stabilizer dont use balsa wood shims Balsa wood compresses will change adjustment Use 1/64 1/32 1/16 plywood shims shims less 1/64 needed use brass shims Any auto parts store has brass shim stock various sizes vertical fin used offset instead rudder tab sure re key stabilizer fin stabilizer Again use hard woods metal engine mount used sure side thrust can added also adding down thrust example adding side thrust mount three mounting holes down thrust also added needed Re-drill mount four mounting holes dont use original center bottom hole mounting four holes can spaced side thrust needed dont get down thrust Use metal shims engine thrust adjust ments using metal mounts keep shim pressing plywood firewall use 020 aluminum spacer against firewall metal mount Insert metal shim between alu minum spacer mount Check DT line tension Too much tension can bow fuselage changing either de calage vertical fin rudder offset final thought Stand own decisions what adjustments make Its model decision dont let some bystander try con other adjustments against judgment Youve built design model things doesnt know about make mistake let decision Youll learn making own decisions sincerely hope information series will help make right decision continuously max dead air FF Old Timers/Haught continued page 37 interest Northwest well other areas us will no doubt pouring through magazine collec tions looking sure winner Square peg round hole Newly manu factured spark plugs 1/4 X 32 threadsize have available quite sometime up point new plugs have available 3/8 X 24 thread size options scarcer day old Champion V use adapter bushing smaller size plug suitable alternative available local small engine shop form Japanese NKG brand CM-6 chain saw 112 Model Aviation Af7 ASS/S 7w2k6rGff GRwZ4VC OAr ThrAe *V3
Edition: Model Aviation - 1979/08
Page Numbers: 32, 33, 34, 110, 111, 112
How toAd justThat High-Powered AMA Gas Free Flightpart2 Last months installment covered aerodynamic theory construction tech niques contest models Concluding series author now describes typical flight-test problems appropriate adjustmentsE Ralph Prey THERE three elements leading consistent max dead air namely fast steep climb smooth transition low sink-rate glide key success select ing trim adjustments harmony other launch enda max go about making selection Answer Fly try fly again main ingredients new genera tion free-ffight models high speed climb super engine power quick response adjustments makes sense concen trate adjusting techniques affecting climb pattern Once climb ad justed liking glide can ironed out glide adjustment also affects climb well have re-adjust climb again before proceeding glide seesaw procedure needed because adjusting techniques such shift ing Center Gravity CG decalage often used adjust both climb glide begin hand test gliding highpowered high-performance model useful verify CG location decalage test glide shows us CG suffi ciently forward enough decalage keep nose up during initial climb first flight CG shifted farther forward decalage increased assure nose up attitude Very little time spent hand test gliding adjust glide sink rate glide circle reason being very difficult duplicate actual flying speed hand test glides Significant too adjusting proce dure use short engine runs 3 seconds very near full power fol lowed quick DT Engine runs successively increased 1 2 seconds provided climb pattern previous flight safe Conversely engine runs reduced 1 2 seconds depending upon trim adjustments made following last test flight logic using short engine runs very near full power sound Fewer adjustments need made using high power example test flights using longer runs low power will have re adjusted time power speed increase use quick DT 2 3 seconds after engine shut off must safety factor well time saver chasing interval before quick DT varies test flights progress climb transition eventual glide adjustment Lets consider some typical flight test problems select trim adjustments options available particular design design model must taken consideration because de sign has flight characteristics peculiar itself make matters complicated 32 Model Aviation - Illustrations Jim Newman \ \ N Problem 1 I\ \ K N N N Problem2N no two models same design will fly exactly alike same flight trim adjustments Thats name game fly try fly again Fortunately adjustments can used safely models compar able design planforms described following problems ones youll likely encounter careful application adjustment techniques explained should help adjust comparable modeL Problem 1 Model grooves steep right climb 6-8 seconds after right wing starts raise up turn begins straighten towards left climb atti tude remains steep Any further engine run would result climbing left roll problem involves Longitudinal Ver tical axes pylon designs wash-in right main wing panel use right left thrust raising right wing after 6-8 seconds due wash-in becoming effective speed eventual left roll Thrust effectiveness decreases speed cause reduce left roll decrease wash-in slightly Make no other adjustments pylon designs wash-out left main wing panel use right thrust wash-out left wing panel becomes effective speed raising right wing speed builds up 6-8 seconds rolling model left Some designs also use left fm rudder offset wash-out control right bank Fin II-\ August 1979 33 LI K Problem 4 Problem 3 / Problem 5 / K Problem 6 f / rudder tab effectiveness increase speed case have option reduce left rudder tab washout reduce left roll Increasing right thrust last chance option pylon designs no wing wash-in wash-out use left vertical fin rudder offset thrust offset raising right wing after 6-8 seconds due increased effectiveness left fin rudder offset speed creased Thrust looses effectiveness speed cause Decrease left fin rudder offset make no other adjustments high-thrust-line designs model climbing wrong direction Check carefully wing warps should no washin left main panel wash out right main panel Also check thrust offset should no right thrust Use rudder tab offset left control model climbing left turn Problem 2 Model grooves steep right climb 9-10 seconds after climb angle increased slightly turn started straighten towards left right wing starting raise Another few seconds full 12 seconds engine run wing would almost level horizon steep climb angle problem volves Longitudinal Vettical axes pylon designs wash-in right main wing panel use right left thrust wash-in still reason changes last few seconds Dont change wash-in Instead add very small amount right rudder-tab offset right tab will start become effective speed builds up 6-8 seconds will keep model grooving overpowering wash-in full run Moreover model set glide right preferred safest direction right tab will help transition holding model right turn As speed decreases right tab looses effectiveness stabilizer tilt takes over glide turn Make no other adjustments model set glide left small amount right-rudder tab should adversely affect transi tion glide dies dont use right tab offset reduce wash-in traditional right climb left glide pattern using stabilizer tilt wash-in right wing wash-out left wing could result model diving glide Particularly glide speed increases due upset gust wind increased speed increases effectiveness wash-in wash-out resulting left rolling dive pylon designs wash-out left main wing panel use right thrust designs also using left rudder wash-out left rudder still reason changes last few seconds 34 Model Aviation \ I II / / / Problem 7 / Problem 8 junior Joey Foster gets off perfect launch feet airof dads National Record Holder Class A-B called Buck powered Schnuerle K&B 325 35 nitro-breathing engines Again note steep angle barely perceptible right bank Sophisticated gimmickry Dad once world champ Wakefield leading Pylon flier struggling find time com plete article Buck future MA None other C berg making last check engine timer before launching latest high-thrust Skyrocket design Note forthcoming steep launch angle See text details ibt-fldidO PROPELLERS polyester boil color Go GRISH propeller True helical pitch airfoil win-power 2 BladeTractor 5-3each 5-45%35--4304 6364384 74 7-678504 84 8688654 94 969-7 9-810-410-6854needs 11-411611-8Si 12-412-512-6$150 2 Blade PusherAT YOUR DEALER 5A3 54-4 6-36-4354 8-6854 9610-6SiJ 3 Blade Tractor2 53 6364504 3 BladePushe 635043 -I -BIade Metallic Aluminum Color Tractor 1678Si 8688$125 96106104$150 Pusher106$150 Sizes pitches dations 5 Washers will used screws holding servos mounting trays also screws holding tray rails washers will approximately same diameter grommets Servos mounted directly rails will also have washers mounting screws addition servo trays will have least extra safety screw necessarily turned down tightly placed between grommets rear tray prevent tray slipping out grommets flight 6 A keeper collar will used pushrods have right-angle bend connects servos S-bends acceptable clevis used both ends pushrod clevis will secured will turn 7 All control surfaces will firm hinge line excess slop dis cretion safety inspector 8 Positive thread-type wing bolts screws will secure wing place two-piece aircraft 9 A positive method holding wheel axle will used wheel shall bind 10 The entire aircraft shall inspected stress cracks have comments please let know have no way knowing what opinions unless speak up Write Bill Hager 4622 Bridgeport Drive Garland TX 75041 GRISH LARGE WOOD PROPELLERS HARDWOOD too hard minimizes costly plane engine damage True pitch airfoil fully carved Crafts man addshis own final touches 3/B BORE ALL SIZES IN18 S7 6 B & 10 PITCH 208 22 10 24 13 NEWSIZE SPITCH 26 $16 BROS GRISH ST JOHN INDIANA 46373 RC Aerobatics/Van Putte continued page 3 1 operate 12 volts will drive speakers can picked up used reasonable price 7 Start contest time few things annoying competitor contest finally gets cranked up two hours late takes no effort start timejust proper planning An nounce contestants club members contest will start timethen 8 The Contest Director responsible conducting contest according rules judges should know rule book better anyone except contest director Inform judges direct rule book interpretations contest director hassles 9 Have confidence people Make sure understand jobs leave alone will probably surprise well will does wonders egos 10 Finish contest early enough permit people get home reasonable hour good contest can spoiled having drive well wee hours next day hope guidelines will help interested detailed article let know Encouragement what need overcome procrastination Recently newsletters have contained rash announcements about club flying site losses Usually noise complaints sale property developers reasons loss sites However Eglin Aero Modellers lost flying site abandoned runway Eglin AFB Florida unusual reason seems Air Force wants blow up runway training unit USAF Civil Engineering Center involved training rapid runway repair will move site order teach airmen repair craters runway must first blow holes case Eglin Aero Modellers have lost flying site 19 years Have gotten new FCC license lately would pay check make sure FCC sent right license should have Radio Control Service Quite few people fly RC have received license Citizens Band voice Service mistake would good idea older licenses check make sure have Class C license Apparently FCC receives license applications Citizens Band use Radio Control use sometimes send wrong license RC fliers Pattern/Sport Problem Month came result flying field discus sion about wing versus tail incidence downthrust problem does flier determine much downthrust required Most airplanes require 2 3 degrees negative incidence horizontal tail relative wing order have zero elevator deflection trim glide case aircraft center mass about right simple test deter proper downthrust Fly air plane straight level full power suddenly cut power Determine care fully what happens pitch attitude airplane pitches up downthrust must reduced Correspondingly pitches down downthrust needed may take several observations sure exactly what airplane doing sometimes difficult determine air plane really pitching down just setting steady sink pitch up easier detect because pitching tendency will keep airplane same altitude longer time course after thrust changes made sure readjust elevator trim level flight full power before making further test Continue adjusting downthrust until no tendency airplane pitch power rapidly reduced Next month hope have good selection problems pick Pattern/Sport Problem Month Ron Van Putte 12 Connie Drive Shal imar FL 32579 Adjust/Prey continued page 35 ways loop caused either forward CO location too much decalage both Check out CO CG farther 110 Model Aviation 1 styles RIGHT HAND TRACTOR SAFE FLYING IS NO ACCIDENT THE chose Waco F-a biplane flagship because represents Golden Era 1930s flying adventure Add easy snag-tree building safe gentle flyingthe result ot thorough kit engineering caretul prototype development features Platt Kits have satisfying building flying experience ahead Kit featuresTop-quality diecut machined balsa plywood Full size plans Separate instruction book isometrics Decals Injection-moulded vacuum-formed plastic cowl cowl blisters wheel pants required nylon fittings Formed wire langing gear & struts Span 60Area 950 Sqi 4 6 channel Engine good 40 60 2657 N E 188th Street Miami Fiorida 33180 Telephone g35-1436 forward plans specifr shift CG rearward time towards correct location Also check decalage against plan decalage plans specify also have option reduce decalage However proceed very cautiously making adjustment time Dont exceed specified CG location trying other options also some cases plans may call thrust offset wash-in wash-out main wing panel Check adjust ments too neither correct have options consider Problem 5 Model starts steep right climb after 1-2 seconds dips right building up speed resumes steep right climb problem involves Vertical axis other aspect problem dip can due angle direction model launched launched near vertical steeper normal climb angle will dip right after launch Also launched crosswind wind strikes left half wing greater right would occur nose banked pointed right wind launch very important model should pointed up about 80-degree angle almost dead center wind slight right bank Never launch pylon model left wind few degrees right wind never bank model few degrees right launching launch correct dip right after launch due thrust offset pylon designs wash-in right main wing panel use right left thrust check thrust offset right thrust used reduce right thrust left thrust used increase left thrust pylon designs wash-out left main wing panel use right thrust reduce right thrust pylon designs no wash-in wash-out use left vertical fin rudder offset thrust offset crank left thrust high-thrust-line designs better watch launch else put left rudder tab offset never want climb right Problem 6 Model grooves full engine run transition satisfactory glide starts out turning desired glide direction slows down upwind starts turning opposite direction now speeds up downwind again starts change turn direction slowing down up wind repeating wandering prob lem involves Longitudinal axis pylon designs wash-in right main wing panel stabilizer tilted left turn wash-in too much causing drag drag increases upwind model slows down turns model right As speed builds up downwind drag decreases liftincreases turn ing model left process keeps repeating have several options first change glide circle left right Depending upon size stabilizer amount tilt model may glide right changing wash-in want stay left glide other option would reduce wash-in readjust climb Increasing left tilt will cause model unstable dive left speed increases glide reduced wash-in model will bank turn tighter right during climb Use left vertical fin rudder tab August 1979 111 SCALE CLASCICS 7-4 Plans & Construction Manual CURTISS HAWK POESTINSON RELIANT SR9 Scala 54o Span $220 /o Scale 126 Span250 2Scala 83 Span 12 2Scal BA Span1810 1 Scale 4713Span jQ8O uS Scala 63 Span1280 CURTISS GOSHAWK P1100 2 Scale 83 SpatSf590 CURTISS GULFHAWK lA . 2Scal 63 Span S160O Scala 94/i Span S3OP pleas Add SISO P 00 Pstoead Ilandllog. 001500 US Add SOsMka eli PaymOOts tO Richard G Barron1213 Holly SprIng L Grand Blanc MIchIgan 46439 Sood 11cc COmplete I0t0atIc offset will help transition initiating left turn soon engine cuts will assist tilt left glide glide circle originally set right glide increase stabilizer tilt However may also necessary decrease wash-in stab tilt does make model turn right wash-in reduced readjust climb using right rudder required bank right climb pylon designs wash-out left main wing panel stabilizer tilt left glide turn wash-out becomes effec tive upwind due decreased speed stabilizer tilt trying overpower wing forces cant quite make fore increase stabilizer tilt left glide turn careful use too much tilt could cause model unstable glide turn Too much tilt would increase turn washed-out wing upset gust wind could cause dive left pylon designs no wash-in wash-out use left vertical fin rudder offset high-thrust-line designs stabilizer tilt enough keep model turning left right case may Also left rudder tab offsct may affecting turn speed increases downwind causing some wandering Increase tilt either left right turn case may Problem 7 Model grooves full engine run shallower angle like also makes about ht turn during full 12 seconds want least 1 1 turns transition good glide too fast nose down problem involves Lateral axis pylon models overall nosedown tendency caused insufficient de calage Increasing decalage de creasing positive angle incidence stabilizer will raise nose up climb glide decalage increased also increases tendency model turn right climb conversely decrease turn right left glide Therefore decreasing de calage will result increasing right turn climb desired ito 1 turns slow up sink rate glide Adjust glide turn stabilizer tilt Problem 8 Model grooves steep right climb transition perfect glide turn perfect occasional slight stall problem involves Lateral axis pylon designs high-thrust models easy problem cure however fliers fight cure Simply add little weight nose reduce stall Youd surprised alibis used keep adding weight weight will actually help model penetrate upwind improve glide sink rate Problem 9 Model grooves steeper climb want transition good glide perfect calm day climb pattern would alright However least bit increase wind could make model loop climb problem involves Lateral axis pylon designs high-thrust models too can easy problem cure again adding weight cure seems offensive Reduce decalage flatten climb add weight tail adjust glide decalage can reduced shims under leading edge stabilizer will bring nose down climb reduced decalage will speed up glide however added weight tail will restore perfect glide few grams added tail get glide adjusted perfectly wont add wing loading enough change glide hope above problems will give better insight adjusting new gener ation gas free-flight models mak ing adjustments mentioned above few dos donts also merit consideration adding incidence wing stabilizer dont use balsa wood shims Balsa wood compresses will change adjustment Use 1/64 1/32 1/16 plywood shims shims less 1/64 needed use brass shims Any auto parts store has brass shim stock various sizes vertical fin used offset instead rudder tab sure re key stabilizer fin stabilizer Again use hard woods metal engine mount used sure side thrust can added also adding down thrust example adding side thrust mount three mounting holes down thrust also added needed Re-drill mount four mounting holes dont use original center bottom hole mounting four holes can spaced side thrust needed dont get down thrust Use metal shims engine thrust adjust ments using metal mounts keep shim pressing plywood firewall use 020 aluminum spacer against firewall metal mount Insert metal shim between alu minum spacer mount Check DT line tension Too much tension can bow fuselage changing either de calage vertical fin rudder offset final thought Stand own decisions what adjustments make Its model decision dont let some bystander try con other adjustments against judgment Youve built design model things doesnt know about make mistake let decision Youll learn making own decisions sincerely hope information series will help make right decision continuously max dead air FF Old Timers/Haught continued page 37 interest Northwest well other areas us will no doubt pouring through magazine collec tions looking sure winner Square peg round hole Newly manu factured spark plugs 1/4 X 32 threadsize have available quite sometime up point new plugs have available 3/8 X 24 thread size options scarcer day old Champion V use adapter bushing smaller size plug suitable alternative available local small engine shop form Japanese NKG brand CM-6 chain saw 112 Model Aviation Af7 ASS/S 7w2k6rGff GRwZ4VC OAr ThrAe *V3
Edition: Model Aviation - 1979/08
Page Numbers: 32, 33, 34, 110, 111, 112
How toAd justThat High-Powered AMA Gas Free Flightpart2 Last months installment covered aerodynamic theory construction tech niques contest models Concluding series author now describes typical flight-test problems appropriate adjustmentsE Ralph Prey THERE three elements leading consistent max dead air namely fast steep climb smooth transition low sink-rate glide key success select ing trim adjustments harmony other launch enda max go about making selection Answer Fly try fly again main ingredients new genera tion free-ffight models high speed climb super engine power quick response adjustments makes sense concen trate adjusting techniques affecting climb pattern Once climb ad justed liking glide can ironed out glide adjustment also affects climb well have re-adjust climb again before proceeding glide seesaw procedure needed because adjusting techniques such shift ing Center Gravity CG decalage often used adjust both climb glide begin hand test gliding highpowered high-performance model useful verify CG location decalage test glide shows us CG suffi ciently forward enough decalage keep nose up during initial climb first flight CG shifted farther forward decalage increased assure nose up attitude Very little time spent hand test gliding adjust glide sink rate glide circle reason being very difficult duplicate actual flying speed hand test glides Significant too adjusting proce dure use short engine runs 3 seconds very near full power fol lowed quick DT Engine runs successively increased 1 2 seconds provided climb pattern previous flight safe Conversely engine runs reduced 1 2 seconds depending upon trim adjustments made following last test flight logic using short engine runs very near full power sound Fewer adjustments need made using high power example test flights using longer runs low power will have re adjusted time power speed increase use quick DT 2 3 seconds after engine shut off must safety factor well time saver chasing interval before quick DT varies test flights progress climb transition eventual glide adjustment Lets consider some typical flight test problems select trim adjustments options available particular design design model must taken consideration because de sign has flight characteristics peculiar itself make matters complicated 32 Model Aviation - Illustrations Jim Newman \ \ N Problem 1 I\ \ K N N N Problem2N no two models same design will fly exactly alike same flight trim adjustments Thats name game fly try fly again Fortunately adjustments can used safely models compar able design planforms described following problems ones youll likely encounter careful application adjustment techniques explained should help adjust comparable modeL Problem 1 Model grooves steep right climb 6-8 seconds after right wing starts raise up turn begins straighten towards left climb atti tude remains steep Any further engine run would result climbing left roll problem involves Longitudinal Ver tical axes pylon designs wash-in right main wing panel use right left thrust raising right wing after 6-8 seconds due wash-in becoming effective speed eventual left roll Thrust effectiveness decreases speed cause reduce left roll decrease wash-in slightly Make no other adjustments pylon designs wash-out left main wing panel use right thrust wash-out left wing panel becomes effective speed raising right wing speed builds up 6-8 seconds rolling model left Some designs also use left fm rudder offset wash-out control right bank Fin II-\ August 1979 33 LI K Problem 4 Problem 3 / Problem 5 / K Problem 6 f / rudder tab effectiveness increase speed case have option reduce left rudder tab washout reduce left roll Increasing right thrust last chance option pylon designs no wing wash-in wash-out use left vertical fin rudder offset thrust offset raising right wing after 6-8 seconds due increased effectiveness left fin rudder offset speed creased Thrust looses effectiveness speed cause Decrease left fin rudder offset make no other adjustments high-thrust-line designs model climbing wrong direction Check carefully wing warps should no washin left main panel wash out right main panel Also check thrust offset should no right thrust Use rudder tab offset left control model climbing left turn Problem 2 Model grooves steep right climb 9-10 seconds after climb angle increased slightly turn started straighten towards left right wing starting raise Another few seconds full 12 seconds engine run wing would almost level horizon steep climb angle problem volves Longitudinal Vettical axes pylon designs wash-in right main wing panel use right left thrust wash-in still reason changes last few seconds Dont change wash-in Instead add very small amount right rudder-tab offset right tab will start become effective speed builds up 6-8 seconds will keep model grooving overpowering wash-in full run Moreover model set glide right preferred safest direction right tab will help transition holding model right turn As speed decreases right tab looses effectiveness stabilizer tilt takes over glide turn Make no other adjustments model set glide left small amount right-rudder tab should adversely affect transi tion glide dies dont use right tab offset reduce wash-in traditional right climb left glide pattern using stabilizer tilt wash-in right wing wash-out left wing could result model diving glide Particularly glide speed increases due upset gust wind increased speed increases effectiveness wash-in wash-out resulting left rolling dive pylon designs wash-out left main wing panel use right thrust designs also using left rudder wash-out left rudder still reason changes last few seconds 34 Model Aviation \ I II / / / Problem 7 / Problem 8 junior Joey Foster gets off perfect launch feet airof dads National Record Holder Class A-B called Buck powered Schnuerle K&B 325 35 nitro-breathing engines Again note steep angle barely perceptible right bank Sophisticated gimmickry Dad once world champ Wakefield leading Pylon flier struggling find time com plete article Buck future MA None other C berg making last check engine timer before launching latest high-thrust Skyrocket design Note forthcoming steep launch angle See text details ibt-fldidO PROPELLERS polyester boil color Go GRISH propeller True helical pitch airfoil win-power 2 BladeTractor 5-3each 5-45%35--4304 6364384 74 7-678504 84 8688654 94 969-7 9-810-410-6854needs 11-411611-8Si 12-412-512-6$150 2 Blade PusherAT YOUR DEALER 5A3 54-4 6-36-4354 8-6854 9610-6SiJ 3 Blade Tractor2 53 6364504 3 BladePushe 635043 -I -BIade Metallic Aluminum Color Tractor 1678Si 8688$125 96106104$150 Pusher106$150 Sizes pitches dations 5 Washers will used screws holding servos mounting trays also screws holding tray rails washers will approximately same diameter grommets Servos mounted directly rails will also have washers mounting screws addition servo trays will have least extra safety screw necessarily turned down tightly placed between grommets rear tray prevent tray slipping out grommets flight 6 A keeper collar will used pushrods have right-angle bend connects servos S-bends acceptable clevis used both ends pushrod clevis will secured will turn 7 All control surfaces will firm hinge line excess slop dis cretion safety inspector 8 Positive thread-type wing bolts screws will secure wing place two-piece aircraft 9 A positive method holding wheel axle will used wheel shall bind 10 The entire aircraft shall inspected stress cracks have comments please let know have no way knowing what opinions unless speak up Write Bill Hager 4622 Bridgeport Drive Garland TX 75041 GRISH LARGE WOOD PROPELLERS HARDWOOD too hard minimizes costly plane engine damage True pitch airfoil fully carved Crafts man addshis own final touches 3/B BORE ALL SIZES IN18 S7 6 B & 10 PITCH 208 22 10 24 13 NEWSIZE SPITCH 26 $16 BROS GRISH ST JOHN INDIANA 46373 RC Aerobatics/Van Putte continued page 3 1 operate 12 volts will drive speakers can picked up used reasonable price 7 Start contest time few things annoying competitor contest finally gets cranked up two hours late takes no effort start timejust proper planning An nounce contestants club members contest will start timethen 8 The Contest Director responsible conducting contest according rules judges should know rule book better anyone except contest director Inform judges direct rule book interpretations contest director hassles 9 Have confidence people Make sure understand jobs leave alone will probably surprise well will does wonders egos 10 Finish contest early enough permit people get home reasonable hour good contest can spoiled having drive well wee hours next day hope guidelines will help interested detailed article let know Encouragement what need overcome procrastination Recently newsletters have contained rash announcements about club flying site losses Usually noise complaints sale property developers reasons loss sites However Eglin Aero Modellers lost flying site abandoned runway Eglin AFB Florida unusual reason seems Air Force wants blow up runway training unit USAF Civil Engineering Center involved training rapid runway repair will move site order teach airmen repair craters runway must first blow holes case Eglin Aero Modellers have lost flying site 19 years Have gotten new FCC license lately would pay check make sure FCC sent right license should have Radio Control Service Quite few people fly RC have received license Citizens Band voice Service mistake would good idea older licenses check make sure have Class C license Apparently FCC receives license applications Citizens Band use Radio Control use sometimes send wrong license RC fliers Pattern/Sport Problem Month came result flying field discus sion about wing versus tail incidence downthrust problem does flier determine much downthrust required Most airplanes require 2 3 degrees negative incidence horizontal tail relative wing order have zero elevator deflection trim glide case aircraft center mass about right simple test deter proper downthrust Fly air plane straight level full power suddenly cut power Determine care fully what happens pitch attitude airplane pitches up downthrust must reduced Correspondingly pitches down downthrust needed may take several observations sure exactly what airplane doing sometimes difficult determine air plane really pitching down just setting steady sink pitch up easier detect because pitching tendency will keep airplane same altitude longer time course after thrust changes made sure readjust elevator trim level flight full power before making further test Continue adjusting downthrust until no tendency airplane pitch power rapidly reduced Next month hope have good selection problems pick Pattern/Sport Problem Month Ron Van Putte 12 Connie Drive Shal imar FL 32579 Adjust/Prey continued page 35 ways loop caused either forward CO location too much decalage both Check out CO CG farther 110 Model Aviation 1 styles RIGHT HAND TRACTOR SAFE FLYING IS NO ACCIDENT THE chose Waco F-a biplane flagship because represents Golden Era 1930s flying adventure Add easy snag-tree building safe gentle flyingthe result ot thorough kit engineering caretul prototype development features Platt Kits have satisfying building flying experience ahead Kit featuresTop-quality diecut machined balsa plywood Full size plans Separate instruction book isometrics Decals Injection-moulded vacuum-formed plastic cowl cowl blisters wheel pants required nylon fittings Formed wire langing gear & struts Span 60Area 950 Sqi 4 6 channel Engine good 40 60 2657 N E 188th Street Miami Fiorida 33180 Telephone g35-1436 forward plans specifr shift CG rearward time towards correct location Also check decalage against plan decalage plans specify also have option reduce decalage However proceed very cautiously making adjustment time Dont exceed specified CG location trying other options also some cases plans may call thrust offset wash-in wash-out main wing panel Check adjust ments too neither correct have options consider Problem 5 Model starts steep right climb after 1-2 seconds dips right building up speed resumes steep right climb problem involves Vertical axis other aspect problem dip can due angle direction model launched launched near vertical steeper normal climb angle will dip right after launch Also launched crosswind wind strikes left half wing greater right would occur nose banked pointed right wind launch very important model should pointed up about 80-degree angle almost dead center wind slight right bank Never launch pylon model left wind few degrees right wind never bank model few degrees right launching launch correct dip right after launch due thrust offset pylon designs wash-in right main wing panel use right left thrust check thrust offset right thrust used reduce right thrust left thrust used increase left thrust pylon designs wash-out left main wing panel use right thrust reduce right thrust pylon designs no wash-in wash-out use left vertical fin rudder offset thrust offset crank left thrust high-thrust-line designs better watch launch else put left rudder tab offset never want climb right Problem 6 Model grooves full engine run transition satisfactory glide starts out turning desired glide direction slows down upwind starts turning opposite direction now speeds up downwind again starts change turn direction slowing down up wind repeating wandering prob lem involves Longitudinal axis pylon designs wash-in right main wing panel stabilizer tilted left turn wash-in too much causing drag drag increases upwind model slows down turns model right As speed builds up downwind drag decreases liftincreases turn ing model left process keeps repeating have several options first change glide circle left right Depending upon size stabilizer amount tilt model may glide right changing wash-in want stay left glide other option would reduce wash-in readjust climb Increasing left tilt will cause model unstable dive left speed increases glide reduced wash-in model will bank turn tighter right during climb Use left vertical fin rudder tab August 1979 111 SCALE CLASCICS 7-4 Plans & Construction Manual CURTISS HAWK POESTINSON RELIANT SR9 Scala 54o Span $220 /o Scale 126 Span250 2Scala 83 Span 12 2Scal BA Span1810 1 Scale 4713Span jQ8O uS Scala 63 Span1280 CURTISS GOSHAWK P1100 2 Scale 83 SpatSf590 CURTISS GULFHAWK lA . 2Scal 63 Span S160O Scala 94/i Span S3OP pleas Add SISO P 00 Pstoead Ilandllog. 001500 US Add SOsMka eli PaymOOts tO Richard G Barron1213 Holly SprIng L Grand Blanc MIchIgan 46439 Sood 11cc COmplete I0t0atIc offset will help transition initiating left turn soon engine cuts will assist tilt left glide glide circle originally set right glide increase stabilizer tilt However may also necessary decrease wash-in stab tilt does make model turn right wash-in reduced readjust climb using right rudder required bank right climb pylon designs wash-out left main wing panel stabilizer tilt left glide turn wash-out becomes effec tive upwind due decreased speed stabilizer tilt trying overpower wing forces cant quite make fore increase stabilizer tilt left glide turn careful use too much tilt could cause model unstable glide turn Too much tilt would increase turn washed-out wing upset gust wind could cause dive left pylon designs no wash-in wash-out use left vertical fin rudder offset high-thrust-line designs stabilizer tilt enough keep model turning left right case may Also left rudder tab offsct may affecting turn speed increases downwind causing some wandering Increase tilt either left right turn case may Problem 7 Model grooves full engine run shallower angle like also makes about ht turn during full 12 seconds want least 1 1 turns transition good glide too fast nose down problem involves Lateral axis pylon models overall nosedown tendency caused insufficient de calage Increasing decalage de creasing positive angle incidence stabilizer will raise nose up climb glide decalage increased also increases tendency model turn right climb conversely decrease turn right left glide Therefore decreasing de calage will result increasing right turn climb desired ito 1 turns slow up sink rate glide Adjust glide turn stabilizer tilt Problem 8 Model grooves steep right climb transition perfect glide turn perfect occasional slight stall problem involves Lateral axis pylon designs high-thrust models easy problem cure however fliers fight cure Simply add little weight nose reduce stall Youd surprised alibis used keep adding weight weight will actually help model penetrate upwind improve glide sink rate Problem 9 Model grooves steeper climb want transition good glide perfect calm day climb pattern would alright However least bit increase wind could make model loop climb problem involves Lateral axis pylon designs high-thrust models too can easy problem cure again adding weight cure seems offensive Reduce decalage flatten climb add weight tail adjust glide decalage can reduced shims under leading edge stabilizer will bring nose down climb reduced decalage will speed up glide however added weight tail will restore perfect glide few grams added tail get glide adjusted perfectly wont add wing loading enough change glide hope above problems will give better insight adjusting new gener ation gas free-flight models mak ing adjustments mentioned above few dos donts also merit consideration adding incidence wing stabilizer dont use balsa wood shims Balsa wood compresses will change adjustment Use 1/64 1/32 1/16 plywood shims shims less 1/64 needed use brass shims Any auto parts store has brass shim stock various sizes vertical fin used offset instead rudder tab sure re key stabilizer fin stabilizer Again use hard woods metal engine mount used sure side thrust can added also adding down thrust example adding side thrust mount three mounting holes down thrust also added needed Re-drill mount four mounting holes dont use original center bottom hole mounting four holes can spaced side thrust needed dont get down thrust Use metal shims engine thrust adjust ments using metal mounts keep shim pressing plywood firewall use 020 aluminum spacer against firewall metal mount Insert metal shim between alu minum spacer mount Check DT line tension Too much tension can bow fuselage changing either de calage vertical fin rudder offset final thought Stand own decisions what adjustments make Its model decision dont let some bystander try con other adjustments against judgment Youve built design model things doesnt know about make mistake let decision Youll learn making own decisions sincerely hope information series will help make right decision continuously max dead air FF Old Timers/Haught continued page 37 interest Northwest well other areas us will no doubt pouring through magazine collec tions looking sure winner Square peg round hole Newly manu factured spark plugs 1/4 X 32 threadsize have available quite sometime up point new plugs have available 3/8 X 24 thread size options scarcer day old Champion V use adapter bushing smaller size plug suitable alternative available local small engine shop form Japanese NKG brand CM-6 chain saw 112 Model Aviation Af7 ASS/S 7w2k6rGff GRwZ4VC OAr ThrAe *V3
Edition: Model Aviation - 1979/08
Page Numbers: 32, 33, 34, 110, 111, 112
How toAd justThat High-Powered AMA Gas Free Flightpart2 Last months installment covered aerodynamic theory construction tech niques contest models Concluding series author now describes typical flight-test problems appropriate adjustmentsE Ralph Prey THERE three elements leading consistent max dead air namely fast steep climb smooth transition low sink-rate glide key success select ing trim adjustments harmony other launch enda max go about making selection Answer Fly try fly again main ingredients new genera tion free-ffight models high speed climb super engine power quick response adjustments makes sense concen trate adjusting techniques affecting climb pattern Once climb ad justed liking glide can ironed out glide adjustment also affects climb well have re-adjust climb again before proceeding glide seesaw procedure needed because adjusting techniques such shift ing Center Gravity CG decalage often used adjust both climb glide begin hand test gliding highpowered high-performance model useful verify CG location decalage test glide shows us CG suffi ciently forward enough decalage keep nose up during initial climb first flight CG shifted farther forward decalage increased assure nose up attitude Very little time spent hand test gliding adjust glide sink rate glide circle reason being very difficult duplicate actual flying speed hand test glides Significant too adjusting proce dure use short engine runs 3 seconds very near full power fol lowed quick DT Engine runs successively increased 1 2 seconds provided climb pattern previous flight safe Conversely engine runs reduced 1 2 seconds depending upon trim adjustments made following last test flight logic using short engine runs very near full power sound Fewer adjustments need made using high power example test flights using longer runs low power will have re adjusted time power speed increase use quick DT 2 3 seconds after engine shut off must safety factor well time saver chasing interval before quick DT varies test flights progress climb transition eventual glide adjustment Lets consider some typical flight test problems select trim adjustments options available particular design design model must taken consideration because de sign has flight characteristics peculiar itself make matters complicated 32 Model Aviation - Illustrations Jim Newman \ \ N Problem 1 I\ \ K N N N Problem2N no two models same design will fly exactly alike same flight trim adjustments Thats name game fly try fly again Fortunately adjustments can used safely models compar able design planforms described following problems ones youll likely encounter careful application adjustment techniques explained should help adjust comparable modeL Problem 1 Model grooves steep right climb 6-8 seconds after right wing starts raise up turn begins straighten towards left climb atti tude remains steep Any further engine run would result climbing left roll problem involves Longitudinal Ver tical axes pylon designs wash-in right main wing panel use right left thrust raising right wing after 6-8 seconds due wash-in becoming effective speed eventual left roll Thrust effectiveness decreases speed cause reduce left roll decrease wash-in slightly Make no other adjustments pylon designs wash-out left main wing panel use right thrust wash-out left wing panel becomes effective speed raising right wing speed builds up 6-8 seconds rolling model left Some designs also use left fm rudder offset wash-out control right bank Fin II-\ August 1979 33 LI K Problem 4 Problem 3 / Problem 5 / K Problem 6 f / rudder tab effectiveness increase speed case have option reduce left rudder tab washout reduce left roll Increasing right thrust last chance option pylon designs no wing wash-in wash-out use left vertical fin rudder offset thrust offset raising right wing after 6-8 seconds due increased effectiveness left fin rudder offset speed creased Thrust looses effectiveness speed cause Decrease left fin rudder offset make no other adjustments high-thrust-line designs model climbing wrong direction Check carefully wing warps should no washin left main panel wash out right main panel Also check thrust offset should no right thrust Use rudder tab offset left control model climbing left turn Problem 2 Model grooves steep right climb 9-10 seconds after climb angle increased slightly turn started straighten towards left right wing starting raise Another few seconds full 12 seconds engine run wing would almost level horizon steep climb angle problem volves Longitudinal Vettical axes pylon designs wash-in right main wing panel use right left thrust wash-in still reason changes last few seconds Dont change wash-in Instead add very small amount right rudder-tab offset right tab will start become effective speed builds up 6-8 seconds will keep model grooving overpowering wash-in full run Moreover model set glide right preferred safest direction right tab will help transition holding model right turn As speed decreases right tab looses effectiveness stabilizer tilt takes over glide turn Make no other adjustments model set glide left small amount right-rudder tab should adversely affect transi tion glide dies dont use right tab offset reduce wash-in traditional right climb left glide pattern using stabilizer tilt wash-in right wing wash-out left wing could result model diving glide Particularly glide speed increases due upset gust wind increased speed increases effectiveness wash-in wash-out resulting left rolling dive pylon designs wash-out left main wing panel use right thrust designs also using left rudder wash-out left rudder still reason changes last few seconds 34 Model Aviation \ I II / / / Problem 7 / Problem 8 junior Joey Foster gets off perfect launch feet airof dads National Record Holder Class A-B called Buck powered Schnuerle K&B 325 35 nitro-breathing engines Again note steep angle barely perceptible right bank Sophisticated gimmickry Dad once world champ Wakefield leading Pylon flier struggling find time com plete article Buck future MA None other C berg making last check engine timer before launching latest high-thrust Skyrocket design Note forthcoming steep launch angle See text details ibt-fldidO PROPELLERS polyester boil color Go GRISH propeller True helical pitch airfoil win-power 2 BladeTractor 5-3each 5-45%35--4304 6364384 74 7-678504 84 8688654 94 969-7 9-810-410-6854needs 11-411611-8Si 12-412-512-6$150 2 Blade PusherAT YOUR DEALER 5A3 54-4 6-36-4354 8-6854 9610-6SiJ 3 Blade Tractor2 53 6364504 3 BladePushe 635043 -I -BIade Metallic Aluminum Color Tractor 1678Si 8688$125 96106104$150 Pusher106$150 Sizes pitches dations 5 Washers will used screws holding servos mounting trays also screws holding tray rails washers will approximately same diameter grommets Servos mounted directly rails will also have washers mounting screws addition servo trays will have least extra safety screw necessarily turned down tightly placed between grommets rear tray prevent tray slipping out grommets flight 6 A keeper collar will used pushrods have right-angle bend connects servos S-bends acceptable clevis used both ends pushrod clevis will secured will turn 7 All control surfaces will firm hinge line excess slop dis cretion safety inspector 8 Positive thread-type wing bolts screws will secure wing place two-piece aircraft 9 A positive method holding wheel axle will used wheel shall bind 10 The entire aircraft shall inspected stress cracks have comments please let know have no way knowing what opinions unless speak up Write Bill Hager 4622 Bridgeport Drive Garland TX 75041 GRISH LARGE WOOD PROPELLERS HARDWOOD too hard minimizes costly plane engine damage True pitch airfoil fully carved Crafts man addshis own final touches 3/B BORE ALL SIZES IN18 S7 6 B & 10 PITCH 208 22 10 24 13 NEWSIZE SPITCH 26 $16 BROS GRISH ST JOHN INDIANA 46373 RC Aerobatics/Van Putte continued page 3 1 operate 12 volts will drive speakers can picked up used reasonable price 7 Start contest time few things annoying competitor contest finally gets cranked up two hours late takes no effort start timejust proper planning An nounce contestants club members contest will start timethen 8 The Contest Director responsible conducting contest according rules judges should know rule book better anyone except contest director Inform judges direct rule book interpretations contest director hassles 9 Have confidence people Make sure understand jobs leave alone will probably surprise well will does wonders egos 10 Finish contest early enough permit people get home reasonable hour good contest can spoiled having drive well wee hours next day hope guidelines will help interested detailed article let know Encouragement what need overcome procrastination Recently newsletters have contained rash announcements about club flying site losses Usually noise complaints sale property developers reasons loss sites However Eglin Aero Modellers lost flying site abandoned runway Eglin AFB Florida unusual reason seems Air Force wants blow up runway training unit USAF Civil Engineering Center involved training rapid runway repair will move site order teach airmen repair craters runway must first blow holes case Eglin Aero Modellers have lost flying site 19 years Have gotten new FCC license lately would pay check make sure FCC sent right license should have Radio Control Service Quite few people fly RC have received license Citizens Band voice Service mistake would good idea older licenses check make sure have Class C license Apparently FCC receives license applications Citizens Band use Radio Control use sometimes send wrong license RC fliers Pattern/Sport Problem Month came result flying field discus sion about wing versus tail incidence downthrust problem does flier determine much downthrust required Most airplanes require 2 3 degrees negative incidence horizontal tail relative wing order have zero elevator deflection trim glide case aircraft center mass about right simple test deter proper downthrust Fly air plane straight level full power suddenly cut power Determine care fully what happens pitch attitude airplane pitches up downthrust must reduced Correspondingly pitches down downthrust needed may take several observations sure exactly what airplane doing sometimes difficult determine air plane really pitching down just setting steady sink pitch up easier detect because pitching tendency will keep airplane same altitude longer time course after thrust changes made sure readjust elevator trim level flight full power before making further test Continue adjusting downthrust until no tendency airplane pitch power rapidly reduced Next month hope have good selection problems pick Pattern/Sport Problem Month Ron Van Putte 12 Connie Drive Shal imar FL 32579 Adjust/Prey continued page 35 ways loop caused either forward CO location too much decalage both Check out CO CG farther 110 Model Aviation 1 styles RIGHT HAND TRACTOR SAFE FLYING IS NO ACCIDENT THE chose Waco F-a biplane flagship because represents Golden Era 1930s flying adventure Add easy snag-tree building safe gentle flyingthe result ot thorough kit engineering caretul prototype development features Platt Kits have satisfying building flying experience ahead Kit featuresTop-quality diecut machined balsa plywood Full size plans Separate instruction book isometrics Decals Injection-moulded vacuum-formed plastic cowl cowl blisters wheel pants required nylon fittings Formed wire langing gear & struts Span 60Area 950 Sqi 4 6 channel Engine good 40 60 2657 N E 188th Street Miami Fiorida 33180 Telephone g35-1436 forward plans specifr shift CG rearward time towards correct location Also check decalage against plan decalage plans specify also have option reduce decalage However proceed very cautiously making adjustment time Dont exceed specified CG location trying other options also some cases plans may call thrust offset wash-in wash-out main wing panel Check adjust ments too neither correct have options consider Problem 5 Model starts steep right climb after 1-2 seconds dips right building up speed resumes steep right climb problem involves Vertical axis other aspect problem dip can due angle direction model launched launched near vertical steeper normal climb angle will dip right after launch Also launched crosswind wind strikes left half wing greater right would occur nose banked pointed right wind launch very important model should pointed up about 80-degree angle almost dead center wind slight right bank Never launch pylon model left wind few degrees right wind never bank model few degrees right launching launch correct dip right after launch due thrust offset pylon designs wash-in right main wing panel use right left thrust check thrust offset right thrust used reduce right thrust left thrust used increase left thrust pylon designs wash-out left main wing panel use right thrust reduce right thrust pylon designs no wash-in wash-out use left vertical fin rudder offset thrust offset crank left thrust high-thrust-line designs better watch launch else put left rudder tab offset never want climb right Problem 6 Model grooves full engine run transition satisfactory glide starts out turning desired glide direction slows down upwind starts turning opposite direction now speeds up downwind again starts change turn direction slowing down up wind repeating wandering prob lem involves Longitudinal axis pylon designs wash-in right main wing panel stabilizer tilted left turn wash-in too much causing drag drag increases upwind model slows down turns model right As speed builds up downwind drag decreases liftincreases turn ing model left process keeps repeating have several options first change glide circle left right Depending upon size stabilizer amount tilt model may glide right changing wash-in want stay left glide other option would reduce wash-in readjust climb Increasing left tilt will cause model unstable dive left speed increases glide reduced wash-in model will bank turn tighter right during climb Use left vertical fin rudder tab August 1979 111 SCALE CLASCICS 7-4 Plans & Construction Manual CURTISS HAWK POESTINSON RELIANT SR9 Scala 54o Span $220 /o Scale 126 Span250 2Scala 83 Span 12 2Scal BA Span1810 1 Scale 4713Span jQ8O uS Scala 63 Span1280 CURTISS GOSHAWK P1100 2 Scale 83 SpatSf590 CURTISS GULFHAWK lA . 2Scal 63 Span S160O Scala 94/i Span S3OP pleas Add SISO P 00 Pstoead Ilandllog. 001500 US Add SOsMka eli PaymOOts tO Richard G Barron1213 Holly SprIng L Grand Blanc MIchIgan 46439 Sood 11cc COmplete I0t0atIc offset will help transition initiating left turn soon engine cuts will assist tilt left glide glide circle originally set right glide increase stabilizer tilt However may also necessary decrease wash-in stab tilt does make model turn right wash-in reduced readjust climb using right rudder required bank right climb pylon designs wash-out left main wing panel stabilizer tilt left glide turn wash-out becomes effec tive upwind due decreased speed stabilizer tilt trying overpower wing forces cant quite make fore increase stabilizer tilt left glide turn careful use too much tilt could cause model unstable glide turn Too much tilt would increase turn washed-out wing upset gust wind could cause dive left pylon designs no wash-in wash-out use left vertical fin rudder offset high-thrust-line designs stabilizer tilt enough keep model turning left right case may Also left rudder tab offsct may affecting turn speed increases downwind causing some wandering Increase tilt either left right turn case may Problem 7 Model grooves full engine run shallower angle like also makes about ht turn during full 12 seconds want least 1 1 turns transition good glide too fast nose down problem involves Lateral axis pylon models overall nosedown tendency caused insufficient de calage Increasing decalage de creasing positive angle incidence stabilizer will raise nose up climb glide decalage increased also increases tendency model turn right climb conversely decrease turn right left glide Therefore decreasing de calage will result increasing right turn climb desired ito 1 turns slow up sink rate glide Adjust glide turn stabilizer tilt Problem 8 Model grooves steep right climb transition perfect glide turn perfect occasional slight stall problem involves Lateral axis pylon designs high-thrust models easy problem cure however fliers fight cure Simply add little weight nose reduce stall Youd surprised alibis used keep adding weight weight will actually help model penetrate upwind improve glide sink rate Problem 9 Model grooves steeper climb want transition good glide perfect calm day climb pattern would alright However least bit increase wind could make model loop climb problem involves Lateral axis pylon designs high-thrust models too can easy problem cure again adding weight cure seems offensive Reduce decalage flatten climb add weight tail adjust glide decalage can reduced shims under leading edge stabilizer will bring nose down climb reduced decalage will speed up glide however added weight tail will restore perfect glide few grams added tail get glide adjusted perfectly wont add wing loading enough change glide hope above problems will give better insight adjusting new gener ation gas free-flight models mak ing adjustments mentioned above few dos donts also merit consideration adding incidence wing stabilizer dont use balsa wood shims Balsa wood compresses will change adjustment Use 1/64 1/32 1/16 plywood shims shims less 1/64 needed use brass shims Any auto parts store has brass shim stock various sizes vertical fin used offset instead rudder tab sure re key stabilizer fin stabilizer Again use hard woods metal engine mount used sure side thrust can added also adding down thrust example adding side thrust mount three mounting holes down thrust also added needed Re-drill mount four mounting holes dont use original center bottom hole mounting four holes can spaced side thrust needed dont get down thrust Use metal shims engine thrust adjust ments using metal mounts keep shim pressing plywood firewall use 020 aluminum spacer against firewall metal mount Insert metal shim between alu minum spacer mount Check DT line tension Too much tension can bow fuselage changing either de calage vertical fin rudder offset final thought Stand own decisions what adjustments make Its model decision dont let some bystander try con other adjustments against judgment Youve built design model things doesnt know about make mistake let decision Youll learn making own decisions sincerely hope information series will help make right decision continuously max dead air FF Old Timers/Haught continued page 37 interest Northwest well other areas us will no doubt pouring through magazine collec tions looking sure winner Square peg round hole Newly manu factured spark plugs 1/4 X 32 threadsize have available quite sometime up point new plugs have available 3/8 X 24 thread size options scarcer day old Champion V use adapter bushing smaller size plug suitable alternative available local small engine shop form Japanese NKG brand CM-6 chain saw 112 Model Aviation Af7 ASS/S 7w2k6rGff GRwZ4VC OAr ThrAe *V3
Edition: Model Aviation - 1979/08
Page Numbers: 32, 33, 34, 110, 111, 112
How toAd justThat High-Powered AMA Gas Free Flightpart2 Last months installment covered aerodynamic theory construction tech niques contest models Concluding series author now describes typical flight-test problems appropriate adjustmentsE Ralph Prey THERE three elements leading consistent max dead air namely fast steep climb smooth transition low sink-rate glide key success select ing trim adjustments harmony other launch enda max go about making selection Answer Fly try fly again main ingredients new genera tion free-ffight models high speed climb super engine power quick response adjustments makes sense concen trate adjusting techniques affecting climb pattern Once climb ad justed liking glide can ironed out glide adjustment also affects climb well have re-adjust climb again before proceeding glide seesaw procedure needed because adjusting techniques such shift ing Center Gravity CG decalage often used adjust both climb glide begin hand test gliding highpowered high-performance model useful verify CG location decalage test glide shows us CG suffi ciently forward enough decalage keep nose up during initial climb first flight CG shifted farther forward decalage increased assure nose up attitude Very little time spent hand test gliding adjust glide sink rate glide circle reason being very difficult duplicate actual flying speed hand test glides Significant too adjusting proce dure use short engine runs 3 seconds very near full power fol lowed quick DT Engine runs successively increased 1 2 seconds provided climb pattern previous flight safe Conversely engine runs reduced 1 2 seconds depending upon trim adjustments made following last test flight logic using short engine runs very near full power sound Fewer adjustments need made using high power example test flights using longer runs low power will have re adjusted time power speed increase use quick DT 2 3 seconds after engine shut off must safety factor well time saver chasing interval before quick DT varies test flights progress climb transition eventual glide adjustment Lets consider some typical flight test problems select trim adjustments options available particular design design model must taken consideration because de sign has flight characteristics peculiar itself make matters complicated 32 Model Aviation - Illustrations Jim Newman \ \ N Problem 1 I\ \ K N N N Problem2N no two models same design will fly exactly alike same flight trim adjustments Thats name game fly try fly again Fortunately adjustments can used safely models compar able design planforms described following problems ones youll likely encounter careful application adjustment techniques explained should help adjust comparable modeL Problem 1 Model grooves steep right climb 6-8 seconds after right wing starts raise up turn begins straighten towards left climb atti tude remains steep Any further engine run would result climbing left roll problem involves Longitudinal Ver tical axes pylon designs wash-in right main wing panel use right left thrust raising right wing after 6-8 seconds due wash-in becoming effective speed eventual left roll Thrust effectiveness decreases speed cause reduce left roll decrease wash-in slightly Make no other adjustments pylon designs wash-out left main wing panel use right thrust wash-out left wing panel becomes effective speed raising right wing speed builds up 6-8 seconds rolling model left Some designs also use left fm rudder offset wash-out control right bank Fin II-\ August 1979 33 LI K Problem 4 Problem 3 / Problem 5 / K Problem 6 f / rudder tab effectiveness increase speed case have option reduce left rudder tab washout reduce left roll Increasing right thrust last chance option pylon designs no wing wash-in wash-out use left vertical fin rudder offset thrust offset raising right wing after 6-8 seconds due increased effectiveness left fin rudder offset speed creased Thrust looses effectiveness speed cause Decrease left fin rudder offset make no other adjustments high-thrust-line designs model climbing wrong direction Check carefully wing warps should no washin left main panel wash out right main panel Also check thrust offset should no right thrust Use rudder tab offset left control model climbing left turn Problem 2 Model grooves steep right climb 9-10 seconds after climb angle increased slightly turn started straighten towards left right wing starting raise Another few seconds full 12 seconds engine run wing would almost level horizon steep climb angle problem volves Longitudinal Vettical axes pylon designs wash-in right main wing panel use right left thrust wash-in still reason changes last few seconds Dont change wash-in Instead add very small amount right rudder-tab offset right tab will start become effective speed builds up 6-8 seconds will keep model grooving overpowering wash-in full run Moreover model set glide right preferred safest direction right tab will help transition holding model right turn As speed decreases right tab looses effectiveness stabilizer tilt takes over glide turn Make no other adjustments model set glide left small amount right-rudder tab should adversely affect transi tion glide dies dont use right tab offset reduce wash-in traditional right climb left glide pattern using stabilizer tilt wash-in right wing wash-out left wing could result model diving glide Particularly glide speed increases due upset gust wind increased speed increases effectiveness wash-in wash-out resulting left rolling dive pylon designs wash-out left main wing panel use right thrust designs also using left rudder wash-out left rudder still reason changes last few seconds 34 Model Aviation \ I II / / / Problem 7 / Problem 8 junior Joey Foster gets off perfect launch feet airof dads National Record Holder Class A-B called Buck powered Schnuerle K&B 325 35 nitro-breathing engines Again note steep angle barely perceptible right bank Sophisticated gimmickry Dad once world champ Wakefield leading Pylon flier struggling find time com plete article Buck future MA None other C berg making last check engine timer before launching latest high-thrust Skyrocket design Note forthcoming steep launch angle See text details ibt-fldidO PROPELLERS polyester boil color Go GRISH propeller True helical pitch airfoil win-power 2 BladeTractor 5-3each 5-45%35--4304 6364384 74 7-678504 84 8688654 94 969-7 9-810-410-6854needs 11-411611-8Si 12-412-512-6$150 2 Blade PusherAT YOUR DEALER 5A3 54-4 6-36-4354 8-6854 9610-6SiJ 3 Blade Tractor2 53 6364504 3 BladePushe 635043 -I -BIade Metallic Aluminum Color Tractor 1678Si 8688$125 96106104$150 Pusher106$150 Sizes pitches dations 5 Washers will used screws holding servos mounting trays also screws holding tray rails washers will approximately same diameter grommets Servos mounted directly rails will also have washers mounting screws addition servo trays will have least extra safety screw necessarily turned down tightly placed between grommets rear tray prevent tray slipping out grommets flight 6 A keeper collar will used pushrods have right-angle bend connects servos S-bends acceptable clevis used both ends pushrod clevis will secured will turn 7 All control surfaces will firm hinge line excess slop dis cretion safety inspector 8 Positive thread-type wing bolts screws will secure wing place two-piece aircraft 9 A positive method holding wheel axle will used wheel shall bind 10 The entire aircraft shall inspected stress cracks have comments please let know have no way knowing what opinions unless speak up Write Bill Hager 4622 Bridgeport Drive Garland TX 75041 GRISH LARGE WOOD PROPELLERS HARDWOOD too hard minimizes costly plane engine damage True pitch airfoil fully carved Crafts man addshis own final touches 3/B BORE ALL SIZES IN18 S7 6 B & 10 PITCH 208 22 10 24 13 NEWSIZE SPITCH 26 $16 BROS GRISH ST JOHN INDIANA 46373 RC Aerobatics/Van Putte continued page 3 1 operate 12 volts will drive speakers can picked up used reasonable price 7 Start contest time few things annoying competitor contest finally gets cranked up two hours late takes no effort start timejust proper planning An nounce contestants club members contest will start timethen 8 The Contest Director responsible conducting contest according rules judges should know rule book better anyone except contest director Inform judges direct rule book interpretations contest director hassles 9 Have confidence people Make sure understand jobs leave alone will probably surprise well will does wonders egos 10 Finish contest early enough permit people get home reasonable hour good contest can spoiled having drive well wee hours next day hope guidelines will help interested detailed article let know Encouragement what need overcome procrastination Recently newsletters have contained rash announcements about club flying site losses Usually noise complaints sale property developers reasons loss sites However Eglin Aero Modellers lost flying site abandoned runway Eglin AFB Florida unusual reason seems Air Force wants blow up runway training unit USAF Civil Engineering Center involved training rapid runway repair will move site order teach airmen repair craters runway must first blow holes case Eglin Aero Modellers have lost flying site 19 years Have gotten new FCC license lately would pay check make sure FCC sent right license should have Radio Control Service Quite few people fly RC have received license Citizens Band voice Service mistake would good idea older licenses check make sure have Class C license Apparently FCC receives license applications Citizens Band use Radio Control use sometimes send wrong license RC fliers Pattern/Sport Problem Month came result flying field discus sion about wing versus tail incidence downthrust problem does flier determine much downthrust required Most airplanes require 2 3 degrees negative incidence horizontal tail relative wing order have zero elevator deflection trim glide case aircraft center mass about right simple test deter proper downthrust Fly air plane straight level full power suddenly cut power Determine care fully what happens pitch attitude airplane pitches up downthrust must reduced Correspondingly pitches down downthrust needed may take several observations sure exactly what airplane doing sometimes difficult determine air plane really pitching down just setting steady sink pitch up easier detect because pitching tendency will keep airplane same altitude longer time course after thrust changes made sure readjust elevator trim level flight full power before making further test Continue adjusting downthrust until no tendency airplane pitch power rapidly reduced Next month hope have good selection problems pick Pattern/Sport Problem Month Ron Van Putte 12 Connie Drive Shal imar FL 32579 Adjust/Prey continued page 35 ways loop caused either forward CO location too much decalage both Check out CO CG farther 110 Model Aviation 1 styles RIGHT HAND TRACTOR SAFE FLYING IS NO ACCIDENT THE chose Waco F-a biplane flagship because represents Golden Era 1930s flying adventure Add easy snag-tree building safe gentle flyingthe result ot thorough kit engineering caretul prototype development features Platt Kits have satisfying building flying experience ahead Kit featuresTop-quality diecut machined balsa plywood Full size plans Separate instruction book isometrics Decals Injection-moulded vacuum-formed plastic cowl cowl blisters wheel pants required nylon fittings Formed wire langing gear & struts Span 60Area 950 Sqi 4 6 channel Engine good 40 60 2657 N E 188th Street Miami Fiorida 33180 Telephone g35-1436 forward plans specifr shift CG rearward time towards correct location Also check decalage against plan decalage plans specify also have option reduce decalage However proceed very cautiously making adjustment time Dont exceed specified CG location trying other options also some cases plans may call thrust offset wash-in wash-out main wing panel Check adjust ments too neither correct have options consider Problem 5 Model starts steep right climb after 1-2 seconds dips right building up speed resumes steep right climb problem involves Vertical axis other aspect problem dip can due angle direction model launched launched near vertical steeper normal climb angle will dip right after launch Also launched crosswind wind strikes left half wing greater right would occur nose banked pointed right wind launch very important model should pointed up about 80-degree angle almost dead center wind slight right bank Never launch pylon model left wind few degrees right wind never bank model few degrees right launching launch correct dip right after launch due thrust offset pylon designs wash-in right main wing panel use right left thrust check thrust offset right thrust used reduce right thrust left thrust used increase left thrust pylon designs wash-out left main wing panel use right thrust reduce right thrust pylon designs no wash-in wash-out use left vertical fin rudder offset thrust offset crank left thrust high-thrust-line designs better watch launch else put left rudder tab offset never want climb right Problem 6 Model grooves full engine run transition satisfactory glide starts out turning desired glide direction slows down upwind starts turning opposite direction now speeds up downwind again starts change turn direction slowing down up wind repeating wandering prob lem involves Longitudinal axis pylon designs wash-in right main wing panel stabilizer tilted left turn wash-in too much causing drag drag increases upwind model slows down turns model right As speed builds up downwind drag decreases liftincreases turn ing model left process keeps repeating have several options first change glide circle left right Depending upon size stabilizer amount tilt model may glide right changing wash-in want stay left glide other option would reduce wash-in readjust climb Increasing left tilt will cause model unstable dive left speed increases glide reduced wash-in model will bank turn tighter right during climb Use left vertical fin rudder tab August 1979 111 SCALE CLASCICS 7-4 Plans & Construction Manual CURTISS HAWK POESTINSON RELIANT SR9 Scala 54o Span $220 /o Scale 126 Span250 2Scala 83 Span 12 2Scal BA Span1810 1 Scale 4713Span jQ8O uS Scala 63 Span1280 CURTISS GOSHAWK P1100 2 Scale 83 SpatSf590 CURTISS GULFHAWK lA . 2Scal 63 Span S160O Scala 94/i Span S3OP pleas Add SISO P 00 Pstoead Ilandllog. 001500 US Add SOsMka eli PaymOOts tO Richard G Barron1213 Holly SprIng L Grand Blanc MIchIgan 46439 Sood 11cc COmplete I0t0atIc offset will help transition initiating left turn soon engine cuts will assist tilt left glide glide circle originally set right glide increase stabilizer tilt However may also necessary decrease wash-in stab tilt does make model turn right wash-in reduced readjust climb using right rudder required bank right climb pylon designs wash-out left main wing panel stabilizer tilt left glide turn wash-out becomes effec tive upwind due decreased speed stabilizer tilt trying overpower wing forces cant quite make fore increase stabilizer tilt left glide turn careful use too much tilt could cause model unstable glide turn Too much tilt would increase turn washed-out wing upset gust wind could cause dive left pylon designs no wash-in wash-out use left vertical fin rudder offset high-thrust-line designs stabilizer tilt enough keep model turning left right case may Also left rudder tab offsct may affecting turn speed increases downwind causing some wandering Increase tilt either left right turn case may Problem 7 Model grooves full engine run shallower angle like also makes about ht turn during full 12 seconds want least 1 1 turns transition good glide too fast nose down problem involves Lateral axis pylon models overall nosedown tendency caused insufficient de calage Increasing decalage de creasing positive angle incidence stabilizer will raise nose up climb glide decalage increased also increases tendency model turn right climb conversely decrease turn right left glide Therefore decreasing de calage will result increasing right turn climb desired ito 1 turns slow up sink rate glide Adjust glide turn stabilizer tilt Problem 8 Model grooves steep right climb transition perfect glide turn perfect occasional slight stall problem involves Lateral axis pylon designs high-thrust models easy problem cure however fliers fight cure Simply add little weight nose reduce stall Youd surprised alibis used keep adding weight weight will actually help model penetrate upwind improve glide sink rate Problem 9 Model grooves steeper climb want transition good glide perfect calm day climb pattern would alright However least bit increase wind could make model loop climb problem involves Lateral axis pylon designs high-thrust models too can easy problem cure again adding weight cure seems offensive Reduce decalage flatten climb add weight tail adjust glide decalage can reduced shims under leading edge stabilizer will bring nose down climb reduced decalage will speed up glide however added weight tail will restore perfect glide few grams added tail get glide adjusted perfectly wont add wing loading enough change glide hope above problems will give better insight adjusting new gener ation gas free-flight models mak ing adjustments mentioned above few dos donts also merit consideration adding incidence wing stabilizer dont use balsa wood shims Balsa wood compresses will change adjustment Use 1/64 1/32 1/16 plywood shims shims less 1/64 needed use brass shims Any auto parts store has brass shim stock various sizes vertical fin used offset instead rudder tab sure re key stabilizer fin stabilizer Again use hard woods metal engine mount used sure side thrust can added also adding down thrust example adding side thrust mount three mounting holes down thrust also added needed Re-drill mount four mounting holes dont use original center bottom hole mounting four holes can spaced side thrust needed dont get down thrust Use metal shims engine thrust adjust ments using metal mounts keep shim pressing plywood firewall use 020 aluminum spacer against firewall metal mount Insert metal shim between alu minum spacer mount Check DT line tension Too much tension can bow fuselage changing either de calage vertical fin rudder offset final thought Stand own decisions what adjustments make Its model decision dont let some bystander try con other adjustments against judgment Youve built design model things doesnt know about make mistake let decision Youll learn making own decisions sincerely hope information series will help make right decision continuously max dead air FF Old Timers/Haught continued page 37 interest Northwest well other areas us will no doubt pouring through magazine collec tions looking sure winner Square peg round hole Newly manu factured spark plugs 1/4 X 32 threadsize have available quite sometime up point new plugs have available 3/8 X 24 thread size options scarcer day old Champion V use adapter bushing smaller size plug suitable alternative available local small engine shop form Japanese NKG brand CM-6 chain saw 112 Model Aviation Af7 ASS/S 7w2k6rGff GRwZ4VC OAr ThrAe *V3