SportAerobatics ORon VanPutte IT DOES us some good called carpet once turn carpet received fol lowing letter John Banas Warren Mass As mechanical engineer avid student aerodynamics am writing because comments aileron dif ferential Sept 1977 issue Model Aviation Pattern aircraft roll ax ially problem us time another non-axial roll has articles flying field discussions erroneously attributed phenomenon adverse yaw some loose definition could called adverse yaw ie 1 yaw 2 adverse helping way case true adverse yaw re sult differential drag can said question non-axial rolling does exist can remedied aileron differential whatever preferred method obtaining ad verse yaw ruining roll axiality logic behind fact true adverse yaw can remedied aile ron differential provided roll does exceed 9Q0 Beyond point rela tively deflected aileron now ex actly opposite situation flyer originally intended relatively less deflected aileron point true adverse yaw will exister greater magnitude would occur no differ ential yaw employed Case point deflection up right aileron right roll alleviates called adverse yaw once aircraft inverted wing right has less deflection up wing left Exactly opposite situation now exists aircraft upright bottom line aileron differential FIGURE 1 View instantaneous motion vertical fin during axial roll Arrows represent local fin velocity due roll rate roll Orrertion FICORE 2 Motion wing during axial roll causes local wing velocity due roll rate vary shown causes wing angle attack vary along wing though may improve axiality prop erly applied does eliminate true ad verse yaw per se unless aircraft rolled 900 Hopefully explanation will clear up common misinterpretation well intended poor application aerody namic principles comment caught trying give simple explanation about very complex dynamic situation definitely true aileron differential will cause ex actly opposite effect aircraft rolled inverted elevator applied maintain constant altitude roll However use aileron differential does improve axial rolls since alleviates adverse yaw very critical timeat initiation roll before aircraft can develop substantial roll rate Anyone has flown light aircraft Continued page 86 March 1978 21 p roll direction reea super plane tuned pipe retracts fly Nats Lonnie Roberts flew OS 40 Fun Two kitted John Garabidian Michael Balog about get going another good flight placed him 10th Novice Nats Plane T2A C designed Bob Smith Rossi engine/pipe Rev-Up 11/7-1/2 propeller Getting ready start up Nats IVOIKO noelner nina plane Saturn designed Ivan Kristensen Canada OS Schnuerle 60 [Au 111331 BOX 511E HIGGINSVILLE MO 64037 SERVICE TO THE R/C MODELER FORA 91 TER OF CENTURY Send revised 1978 catalog $1 Add $ 50 1st Class return Add $1 handling other orders uses including power supply small experimental circuts can rejuvenate flashlight batteries Use 3Oma until cell voltage reaches 1 5VDC again pen-cell battery box shown attached used purpose Fig 5 shows calculator charger box on-the-wall type simple adapter built pill bottle Fig 6 schematic Deans connector adapter reminds must very careful label adapters chargers Several manufacturers use Deans connectors Cit izenship Pro-Line ACE R/C Can non come mind immediately dont use pins same purposes Use voltmeter check out before turn charger perhaps some damage Ive confused please read col writing advertisers mention read about MA umn again Ive tried keep things simple possibleno chemistry no math just facts Ive tried show Rapid Charging safe used intelligence Examples shown demonstrate shouldnt play mixand-match components various manufacturers checking first see what Charger ratings ex plained help choose what need good general-purpose charger identified should prepared decision Happy Flying Keep cards letters coming Im very far behind right now expect catch up now winter has set Windlord/Bates continued page 20 adjusting CG small increments until stable floating glide achieved setting Towing accomplished bridle shown Figure E tie bridle snap swivel Pass through ring snap-swivel use large enough tow rings cannot pass through side bridle ring will stop snap swivel allow com plete tow One-side tows possible requiring about 100 rudder deflection correct yaw may substitute conventional hooks releasable capture hooks may necessary launching winch continuously pulse winch rapidly through early portion tow cluding tensioning line launch will maintain constant tension tow like hi-start run winch continuously until ship has - started rotate climb sud denly release pressure line may experience slight pitch up releasing tow bridle Efficient thermaling turns can made quite tightly penetration down elevator trim excellent Inverted flight almost good upright Windlord can made outside loop verted rudder does reverse Right still right Dont ask Dethermaliz ing done flaps shallow verted dive since upright dive builds speed rapidly speed does bleed off quickly Orientation has problem looks much like hawk distance dont recommend using dark color scheme Enjoy Windlord dont lose gaggle hawks RC Aerobatks/VanPutte continued page 21 very familiar necessity coordi nate application aileron rudder attempts roll light aircraft using aileron nose will generally yaw wrong direction before rolls Some airplanes like J-3 Cub will end up skid wing barely higher other important fact adverse yaw causes nose airplane move lat erally opposite direction roll before airplane really begins rol ling Consequently roll begun aircraft yawed condition what makes axial roll look bad Aile ron differential helps make axial rolls look better reducing initial adverse yaw other sources yaw roll require air plane must rolling order generate yawing moment causes yaw 86 Model Aviation FAMOUS BRITISH DIESELS DIC RAW * *NEWr * EATA LOG-DIESEL HANDBOOK $150 pp HOBBY H IDEAWAY DELAVMqILLe17a4 MORRISONSCALE DRAWINGS REPLA-TECH ntrfltIOfl@I CATALOG 25c vs 48500 McKenzie Hwy Vids Oregon 97488 George M Myers 70 Froehlich Farm Road Hicksville NY 11801 ACE R/C Inc metered van-charger can solve miscellaneous charging prob lems has handy indicator warn you should accidentaly connect backwards Two of common sources vertical fin wing itself sim plest visualize yaw generated vertical fin Visualize airplane rolling right clockwise viewed behind air plane vertical fin will moving right rolls see Fig 1 generating angle attack relative local air flow function far par ticular pint fin axis rotation angle attack will cause force fin direction opposite way rolling roll right force will left force will result yawing moment causes nose move right Since airplane rolling right yaw right called proverse yaw com pared adverse yaw Since yaw tendency will make axial rolls look bad aircraft designers try minimize fin proverse yaw lowering aerodynamic center vertical fin Placing sub-fin below fuselage having rudder extend bottom sub-fin helps move vertical fin aerodynamic center down Dirty Birdy good example technique yawing tendency wing rolls little tougher visualize Again consider airplane rolling right Fig 2 right wing will moving down left wing will obviously moving up roll velocity will cause increase local angles attack right wing corresponding reductions left wing actual angles tack will function fast air plane rolling aircraft speed distance particular wing station axis rotation wing generates lift also drag generated due lift drag is called induced drag right wing moves down roll lift increased wing because angle attack change caused roll rate increase lift right wing causes increase induced drag spanwise station right wing same way decrease lift left wing causes decrease induced drag spanwise station left wing effect drag changes nose-right yawmoment Like vertical fin effect also proverse yaw However unlike vertical fin isnt much can done reduce yaw Consequently proverse yaw generated wing will al ways cause problems axial rolls bottom line will always some yaw during axial rolls aileron differential helps cut down initial yaw makes rolls look better Apparently lot people liked servo tester appeared December issue Model Aviation unfortunate schematic ser vo tester inadvertently omitted magazine published Editor got last issue Both maga CONTROL LINE KITS WEVE GOT EM STARTING AT $595 SiRingmaster S2FS1 Mustang S3YakS S5Ringmaster Jr S6Super Ringmaster S12Flying Funi S13Baby Ringmaster S15Ruffy SIlP38 Lightning 518Ringmaster Imper SiSSpitfire S22Ringmaster Spurts S27Skylark S28Sky Shark S29Ring Jr Flash S30Beginners Ring 1595 1695 1595 1095 1995 1695 195 2995 1695 2895 3595 1995 3495 1995 1295 595 S31Beginners Mustang595 S32Beg Ring Bipe695 S33Winder1395 S34Beginners Spitfire595 S35Beginners Thunder Jet595 S36Beginners Piper Cub595 S37Beginners Eindecker595 S38Beginners Shnestring595 S39Beginners Thunderhult595 S40Beginners Cherukee595 S41Beginners Fnkker 07695 S42Beginners Hellcat595 S43Beginners FuckeWnIf595 S44Beginners Zern595 S45Beginners Messerschmitt595 ClMunuceupe C3Mr Mulligan C4The Wace CBSE5 C8Fukker Dl C9Cersair ClONieupurt2B CliGrumman Gnardian C12Stearman PT17 C13Great takes STERLING MODELS G ST PHILA PA 19134 no dealer anallable direct orders accepted i5 addltioral charge handling shipping lkn ninlnun US 5125 nlninunr outside USl 0 Catalog 01 entire lIne airplane control line model kits R/C scale Trainer kits boat model kits accessories dc $00 enclosed C Secrals ot Model AIrplane BuIldIng Including design conStruction conering finIshing flying adlusling control systems etc 25c enclosed C Secrets Control Line Carrier Flying Including preflight soloing otunling Carrier roles regulations Carrier flying hints control lIne Installation instructions 256 enclosed No checks Only US maney orders currency accepted Name DU-BRO 7U1LFU FUEL PUMP NEW CONCEPT IN FUEL PUMPS ONLY ONE MOVING PART NOTHING TO BREAK OR WEAR OUT 0 0 S LIGHT COMPACT AND RUGGED ONLY2WIDEAND 2-7/8 INDIA HAND OPERATED AND REVER SIBLE S IN AND OUT HIGH VOLUME FLOW PUMP COMES ASSEMBLED AND MOUNTS ON GALLON CANS QUICK EASY INSTALLATION PUMP COMES COMPLETE WITH STEEL MOUNTING BRACKETS HARDWARE AND FUEL TUBINGNo191 PRODUCTS INCORPORATED 480 Bonner Road Wauconda IllinoIs 60064 USA March1978 87 1995 1995 2195 2295 2195 2395 2295 2895 2295 2495 Tho KINNER SPORTSTER 39 wrogopon 09 power op 3 channels nc great sport troiner 19300$1255 FAIRCHILD 22 8 Wingspan 09 to25 Power 02000 VA 00000000 0004* tAO*00 10* FOR 0000100*00 P007*5G see local hobby dealer AMERICANSee~3B CLASSICS worlds finest models Send free brochure Ti, AristocratFRO 0*00000700 *105Al WIOOSflM 040 P0000 FOR 000000020 FOROROCMSUIA *0000010000 AIR FOR 0000 000000100 FORE 0OA0 0000 lee 00L005 00 ELLANCAtel 702 272-9593 -00550 00000010 FOWER 101 8095 05 OIOOSFAN 020 P0000 FOR F0SE 000 SMALL kS&0k0000VT T1JP 0*2 SO FLOWN POE Fib ELS 2020 0000 AVEEALOFAX VA*2030 CUSTOM TUNED ENGINESI24 PLAN ARASOL COMPETITION ACCESSORIESI HEATH Cox 049Z051 Specialists brochure send 13 St amp to I Kustom Krattsmanship Brochure ALOG 25c Box 2699 Laguna Hills CA 92653 ERNISTIC MODELS 714 830-5162PO BOX6974ALBUO NM 87107 zinc office have received letters Editor phone calls requesting send copies schematic hope something like doesnt happen again because knows peo ple would have built tester schematic available article way learned 74121 inte grated circuit Radio Shack # 276-1814 available Radio Shack stores may have purchased other source few days ago received letter John Haumersen old friend used fly stationed An drews AFB Maryland near Washington DC John currently lives Bettendorf Iowa retired Army Colonel tank corps commander Any way excerpt Johns letter main purpose writing report use equations locating CG aircraft varying geo metry Ive lot fun using equations models past couple years finding always worked out improving CG location some kits about eight months ago got TI SR52 computor programed solve equations Works like charm pleased sent pro gram TI accepted publication Now modeling friends access TI SR52 can ob tain program TI fellow has already written has used program successfully several planes Ive tried make back Toledo show see old friends missed last year coming year Im going make bust Maybe Ill get chance see look forward equations talked about pub lished April 1976 Model Aviation work very well initial center mass determination new airplane sufficient interest Id glad re publish equations future column Ron Van Pune 12 Connie Drive Shal imar FL 32579 RC Scale/Wischers continued page 22 color half-tone type maga zines lacking detail necessary detail photos required judges accurately grade model lack documentation must have cost sta tic points otherwise excellent plane third place final standings PZL Wilga entered Phil Moore England fidelity standing elev enth indicating something lacking plane documentation Since plane masterpiece examined documentation found reason low score 3-view drawing good showed too variants plane no indication sketches judges follow scale rule furnished very small diffi cult read markings clear eleven color photos 3/2 X 5 size too small really helpful judges minimum number Better documentation could easily have given him six points needed put him second place prize would have $500 plane deserved better other English entry Dennis Bryant Bristol Bulldog came properly prepared scale rule finely mark ed made wood sliding caliper make judges job easy possible graduated frequent pencil markings Surprisingly 3-view rather muddy print good way fluence critics additional small 3-views book showing too variants confusing unnecessary must recognized plane vintage easy document few photos half tones Other photos RAF fighter book pages marked bad idea except photos doubtful value evident Dennis competed previously inter national meets cockpit photos sketches superior An example over-documentation two stuffed books 8 X 10 photos furnished George Rose except ional Curtiss Hawk P6-E George done praiseworthy job researching prototype reluctant give up valued information recorded photos actually too good showed such great detail judges able find fault sel dom sufficient time close scrutiny such vast quantities information confusion can detrimental 3-view large clear pair drawings pre pared Paul Matt published Historical viation Album excellent source George made rule yardstick easy use number contestants used photos model during construction practice some value similar photo prototype can used comparison Judges prefer photos full-size plane Model photos show construction methods quest genuity points generally consider ed acceptable least four contestants included model photos Another four contestants made own 3-view drawings requiring approval builder prototype National Scale Committee competitors skilled draftsmen Dave Platt published drawing making acceptable according rulesScale rulers varied simple short wood strips elaborate plastic six footers finely lined graduations press-type numerals simple rulers really ade quate did meet required FAI specifications respect AMA meet different short ruler necessary use drawing Documenting obscure aircraft would appear tougher assign ments scale modeling yet planes some builders find satisfing Granger Willims Curtiss F6C-4 Hawk falls class pro totype kind converted Hawk P-i information very diffi cult acquire Granger found excel lent 5X7 cut-away cockpit photos drawing classic William Wylam 3-views folding rule made thin plastic strips modelers aroused classic beauty planes era few will spend 88 Model Aviation
Edition: Model Aviation - 1978/03
Page Numbers: 21, 86, 87, 88
SportAerobatics ORon VanPutte IT DOES us some good called carpet once turn carpet received fol lowing letter John Banas Warren Mass As mechanical engineer avid student aerodynamics am writing because comments aileron dif ferential Sept 1977 issue Model Aviation Pattern aircraft roll ax ially problem us time another non-axial roll has articles flying field discussions erroneously attributed phenomenon adverse yaw some loose definition could called adverse yaw ie 1 yaw 2 adverse helping way case true adverse yaw re sult differential drag can said question non-axial rolling does exist can remedied aileron differential whatever preferred method obtaining ad verse yaw ruining roll axiality logic behind fact true adverse yaw can remedied aile ron differential provided roll does exceed 9Q0 Beyond point rela tively deflected aileron now ex actly opposite situation flyer originally intended relatively less deflected aileron point true adverse yaw will exister greater magnitude would occur no differ ential yaw employed Case point deflection up right aileron right roll alleviates called adverse yaw once aircraft inverted wing right has less deflection up wing left Exactly opposite situation now exists aircraft upright bottom line aileron differential FIGURE 1 View instantaneous motion vertical fin during axial roll Arrows represent local fin velocity due roll rate roll Orrertion FICORE 2 Motion wing during axial roll causes local wing velocity due roll rate vary shown causes wing angle attack vary along wing though may improve axiality prop erly applied does eliminate true ad verse yaw per se unless aircraft rolled 900 Hopefully explanation will clear up common misinterpretation well intended poor application aerody namic principles comment caught trying give simple explanation about very complex dynamic situation definitely true aileron differential will cause ex actly opposite effect aircraft rolled inverted elevator applied maintain constant altitude roll However use aileron differential does improve axial rolls since alleviates adverse yaw very critical timeat initiation roll before aircraft can develop substantial roll rate Anyone has flown light aircraft Continued page 86 March 1978 21 p roll direction reea super plane tuned pipe retracts fly Nats Lonnie Roberts flew OS 40 Fun Two kitted John Garabidian Michael Balog about get going another good flight placed him 10th Novice Nats Plane T2A C designed Bob Smith Rossi engine/pipe Rev-Up 11/7-1/2 propeller Getting ready start up Nats IVOIKO noelner nina plane Saturn designed Ivan Kristensen Canada OS Schnuerle 60 [Au 111331 BOX 511E HIGGINSVILLE MO 64037 SERVICE TO THE R/C MODELER FORA 91 TER OF CENTURY Send revised 1978 catalog $1 Add $ 50 1st Class return Add $1 handling other orders uses including power supply small experimental circuts can rejuvenate flashlight batteries Use 3Oma until cell voltage reaches 1 5VDC again pen-cell battery box shown attached used purpose Fig 5 shows calculator charger box on-the-wall type simple adapter built pill bottle Fig 6 schematic Deans connector adapter reminds must very careful label adapters chargers Several manufacturers use Deans connectors Cit izenship Pro-Line ACE R/C Can non come mind immediately dont use pins same purposes Use voltmeter check out before turn charger perhaps some damage Ive confused please read col writing advertisers mention read about MA umn again Ive tried keep things simple possibleno chemistry no math just facts Ive tried show Rapid Charging safe used intelligence Examples shown demonstrate shouldnt play mixand-match components various manufacturers checking first see what Charger ratings ex plained help choose what need good general-purpose charger identified should prepared decision Happy Flying Keep cards letters coming Im very far behind right now expect catch up now winter has set Windlord/Bates continued page 20 adjusting CG small increments until stable floating glide achieved setting Towing accomplished bridle shown Figure E tie bridle snap swivel Pass through ring snap-swivel use large enough tow rings cannot pass through side bridle ring will stop snap swivel allow com plete tow One-side tows possible requiring about 100 rudder deflection correct yaw may substitute conventional hooks releasable capture hooks may necessary launching winch continuously pulse winch rapidly through early portion tow cluding tensioning line launch will maintain constant tension tow like hi-start run winch continuously until ship has - started rotate climb sud denly release pressure line may experience slight pitch up releasing tow bridle Efficient thermaling turns can made quite tightly penetration down elevator trim excellent Inverted flight almost good upright Windlord can made outside loop verted rudder does reverse Right still right Dont ask Dethermaliz ing done flaps shallow verted dive since upright dive builds speed rapidly speed does bleed off quickly Orientation has problem looks much like hawk distance dont recommend using dark color scheme Enjoy Windlord dont lose gaggle hawks RC Aerobatks/VanPutte continued page 21 very familiar necessity coordi nate application aileron rudder attempts roll light aircraft using aileron nose will generally yaw wrong direction before rolls Some airplanes like J-3 Cub will end up skid wing barely higher other important fact adverse yaw causes nose airplane move lat erally opposite direction roll before airplane really begins rol ling Consequently roll begun aircraft yawed condition what makes axial roll look bad Aile ron differential helps make axial rolls look better reducing initial adverse yaw other sources yaw roll require air plane must rolling order generate yawing moment causes yaw 86 Model Aviation FAMOUS BRITISH DIESELS DIC RAW * *NEWr * EATA LOG-DIESEL HANDBOOK $150 pp HOBBY H IDEAWAY DELAVMqILLe17a4 MORRISONSCALE DRAWINGS REPLA-TECH ntrfltIOfl@I CATALOG 25c vs 48500 McKenzie Hwy Vids Oregon 97488 George M Myers 70 Froehlich Farm Road Hicksville NY 11801 ACE R/C Inc metered van-charger can solve miscellaneous charging prob lems has handy indicator warn you should accidentaly connect backwards Two of common sources vertical fin wing itself sim plest visualize yaw generated vertical fin Visualize airplane rolling right clockwise viewed behind air plane vertical fin will moving right rolls see Fig 1 generating angle attack relative local air flow function far par ticular pint fin axis rotation angle attack will cause force fin direction opposite way rolling roll right force will left force will result yawing moment causes nose move right Since airplane rolling right yaw right called proverse yaw com pared adverse yaw Since yaw tendency will make axial rolls look bad aircraft designers try minimize fin proverse yaw lowering aerodynamic center vertical fin Placing sub-fin below fuselage having rudder extend bottom sub-fin helps move vertical fin aerodynamic center down Dirty Birdy good example technique yawing tendency wing rolls little tougher visualize Again consider airplane rolling right Fig 2 right wing will moving down left wing will obviously moving up roll velocity will cause increase local angles attack right wing corresponding reductions left wing actual angles tack will function fast air plane rolling aircraft speed distance particular wing station axis rotation wing generates lift also drag generated due lift drag is called induced drag right wing moves down roll lift increased wing because angle attack change caused roll rate increase lift right wing causes increase induced drag spanwise station right wing same way decrease lift left wing causes decrease induced drag spanwise station left wing effect drag changes nose-right yawmoment Like vertical fin effect also proverse yaw However unlike vertical fin isnt much can done reduce yaw Consequently proverse yaw generated wing will al ways cause problems axial rolls bottom line will always some yaw during axial rolls aileron differential helps cut down initial yaw makes rolls look better Apparently lot people liked servo tester appeared December issue Model Aviation unfortunate schematic ser vo tester inadvertently omitted magazine published Editor got last issue Both maga CONTROL LINE KITS WEVE GOT EM STARTING AT $595 SiRingmaster S2FS1 Mustang S3YakS S5Ringmaster Jr S6Super Ringmaster S12Flying Funi S13Baby Ringmaster S15Ruffy SIlP38 Lightning 518Ringmaster Imper SiSSpitfire S22Ringmaster Spurts S27Skylark S28Sky Shark S29Ring Jr Flash S30Beginners Ring 1595 1695 1595 1095 1995 1695 195 2995 1695 2895 3595 1995 3495 1995 1295 595 S31Beginners Mustang595 S32Beg Ring Bipe695 S33Winder1395 S34Beginners Spitfire595 S35Beginners Thunder Jet595 S36Beginners Piper Cub595 S37Beginners Eindecker595 S38Beginners Shnestring595 S39Beginners Thunderhult595 S40Beginners Cherukee595 S41Beginners Fnkker 07695 S42Beginners Hellcat595 S43Beginners FuckeWnIf595 S44Beginners Zern595 S45Beginners Messerschmitt595 ClMunuceupe C3Mr Mulligan C4The Wace CBSE5 C8Fukker Dl C9Cersair ClONieupurt2B CliGrumman Gnardian C12Stearman PT17 C13Great takes STERLING MODELS G ST PHILA PA 19134 no dealer anallable direct orders accepted i5 addltioral charge handling shipping lkn ninlnun US 5125 nlninunr outside USl 0 Catalog 01 entire lIne airplane control line model kits R/C scale Trainer kits boat model kits accessories dc $00 enclosed C Secrals ot Model AIrplane BuIldIng Including design conStruction conering finIshing flying adlusling control systems etc 25c enclosed C Secrets Control Line Carrier Flying Including preflight soloing otunling Carrier roles regulations Carrier flying hints control lIne Installation instructions 256 enclosed No checks Only US maney orders currency accepted Name DU-BRO 7U1LFU FUEL PUMP NEW CONCEPT IN FUEL PUMPS ONLY ONE MOVING PART NOTHING TO BREAK OR WEAR OUT 0 0 S LIGHT COMPACT AND RUGGED ONLY2WIDEAND 2-7/8 INDIA HAND OPERATED AND REVER SIBLE S IN AND OUT HIGH VOLUME FLOW PUMP COMES ASSEMBLED AND MOUNTS ON GALLON CANS QUICK EASY INSTALLATION PUMP COMES COMPLETE WITH STEEL MOUNTING BRACKETS HARDWARE AND FUEL TUBINGNo191 PRODUCTS INCORPORATED 480 Bonner Road Wauconda IllinoIs 60064 USA March1978 87 1995 1995 2195 2295 2195 2395 2295 2895 2295 2495 Tho KINNER SPORTSTER 39 wrogopon 09 power op 3 channels nc great sport troiner 19300$1255 FAIRCHILD 22 8 Wingspan 09 to25 Power 02000 VA 00000000 0004* tAO*00 10* FOR 0000100*00 P007*5G see local hobby dealer AMERICANSee~3B CLASSICS worlds finest models Send free brochure Ti, AristocratFRO 0*00000700 *105Al WIOOSflM 040 P0000 FOR 000000020 FOROROCMSUIA *0000010000 AIR FOR 0000 000000100 FORE 0OA0 0000 lee 00L005 00 ELLANCAtel 702 272-9593 -00550 00000010 FOWER 101 8095 05 OIOOSFAN 020 P0000 FOR F0SE 000 SMALL kS&0k0000VT T1JP 0*2 SO FLOWN POE Fib ELS 2020 0000 AVEEALOFAX VA*2030 CUSTOM TUNED ENGINESI24 PLAN ARASOL COMPETITION ACCESSORIESI HEATH Cox 049Z051 Specialists brochure send 13 St amp to I Kustom Krattsmanship Brochure ALOG 25c Box 2699 Laguna Hills CA 92653 ERNISTIC MODELS 714 830-5162PO BOX6974ALBUO NM 87107 zinc office have received letters Editor phone calls requesting send copies schematic hope something like doesnt happen again because knows peo ple would have built tester schematic available article way learned 74121 inte grated circuit Radio Shack # 276-1814 available Radio Shack stores may have purchased other source few days ago received letter John Haumersen old friend used fly stationed An drews AFB Maryland near Washington DC John currently lives Bettendorf Iowa retired Army Colonel tank corps commander Any way excerpt Johns letter main purpose writing report use equations locating CG aircraft varying geo metry Ive lot fun using equations models past couple years finding always worked out improving CG location some kits about eight months ago got TI SR52 computor programed solve equations Works like charm pleased sent pro gram TI accepted publication Now modeling friends access TI SR52 can ob tain program TI fellow has already written has used program successfully several planes Ive tried make back Toledo show see old friends missed last year coming year Im going make bust Maybe Ill get chance see look forward equations talked about pub lished April 1976 Model Aviation work very well initial center mass determination new airplane sufficient interest Id glad re publish equations future column Ron Van Pune 12 Connie Drive Shal imar FL 32579 RC Scale/Wischers continued page 22 color half-tone type maga zines lacking detail necessary detail photos required judges accurately grade model lack documentation must have cost sta tic points otherwise excellent plane third place final standings PZL Wilga entered Phil Moore England fidelity standing elev enth indicating something lacking plane documentation Since plane masterpiece examined documentation found reason low score 3-view drawing good showed too variants plane no indication sketches judges follow scale rule furnished very small diffi cult read markings clear eleven color photos 3/2 X 5 size too small really helpful judges minimum number Better documentation could easily have given him six points needed put him second place prize would have $500 plane deserved better other English entry Dennis Bryant Bristol Bulldog came properly prepared scale rule finely mark ed made wood sliding caliper make judges job easy possible graduated frequent pencil markings Surprisingly 3-view rather muddy print good way fluence critics additional small 3-views book showing too variants confusing unnecessary must recognized plane vintage easy document few photos half tones Other photos RAF fighter book pages marked bad idea except photos doubtful value evident Dennis competed previously inter national meets cockpit photos sketches superior An example over-documentation two stuffed books 8 X 10 photos furnished George Rose except ional Curtiss Hawk P6-E George done praiseworthy job researching prototype reluctant give up valued information recorded photos actually too good showed such great detail judges able find fault sel dom sufficient time close scrutiny such vast quantities information confusion can detrimental 3-view large clear pair drawings pre pared Paul Matt published Historical viation Album excellent source George made rule yardstick easy use number contestants used photos model during construction practice some value similar photo prototype can used comparison Judges prefer photos full-size plane Model photos show construction methods quest genuity points generally consider ed acceptable least four contestants included model photos Another four contestants made own 3-view drawings requiring approval builder prototype National Scale Committee competitors skilled draftsmen Dave Platt published drawing making acceptable according rulesScale rulers varied simple short wood strips elaborate plastic six footers finely lined graduations press-type numerals simple rulers really ade quate did meet required FAI specifications respect AMA meet different short ruler necessary use drawing Documenting obscure aircraft would appear tougher assign ments scale modeling yet planes some builders find satisfing Granger Willims Curtiss F6C-4 Hawk falls class pro totype kind converted Hawk P-i information very diffi cult acquire Granger found excel lent 5X7 cut-away cockpit photos drawing classic William Wylam 3-views folding rule made thin plastic strips modelers aroused classic beauty planes era few will spend 88 Model Aviation
Edition: Model Aviation - 1978/03
Page Numbers: 21, 86, 87, 88
SportAerobatics ORon VanPutte IT DOES us some good called carpet once turn carpet received fol lowing letter John Banas Warren Mass As mechanical engineer avid student aerodynamics am writing because comments aileron dif ferential Sept 1977 issue Model Aviation Pattern aircraft roll ax ially problem us time another non-axial roll has articles flying field discussions erroneously attributed phenomenon adverse yaw some loose definition could called adverse yaw ie 1 yaw 2 adverse helping way case true adverse yaw re sult differential drag can said question non-axial rolling does exist can remedied aileron differential whatever preferred method obtaining ad verse yaw ruining roll axiality logic behind fact true adverse yaw can remedied aile ron differential provided roll does exceed 9Q0 Beyond point rela tively deflected aileron now ex actly opposite situation flyer originally intended relatively less deflected aileron point true adverse yaw will exister greater magnitude would occur no differ ential yaw employed Case point deflection up right aileron right roll alleviates called adverse yaw once aircraft inverted wing right has less deflection up wing left Exactly opposite situation now exists aircraft upright bottom line aileron differential FIGURE 1 View instantaneous motion vertical fin during axial roll Arrows represent local fin velocity due roll rate roll Orrertion FICORE 2 Motion wing during axial roll causes local wing velocity due roll rate vary shown causes wing angle attack vary along wing though may improve axiality prop erly applied does eliminate true ad verse yaw per se unless aircraft rolled 900 Hopefully explanation will clear up common misinterpretation well intended poor application aerody namic principles comment caught trying give simple explanation about very complex dynamic situation definitely true aileron differential will cause ex actly opposite effect aircraft rolled inverted elevator applied maintain constant altitude roll However use aileron differential does improve axial rolls since alleviates adverse yaw very critical timeat initiation roll before aircraft can develop substantial roll rate Anyone has flown light aircraft Continued page 86 March 1978 21 p roll direction reea super plane tuned pipe retracts fly Nats Lonnie Roberts flew OS 40 Fun Two kitted John Garabidian Michael Balog about get going another good flight placed him 10th Novice Nats Plane T2A C designed Bob Smith Rossi engine/pipe Rev-Up 11/7-1/2 propeller Getting ready start up Nats IVOIKO noelner nina plane Saturn designed Ivan Kristensen Canada OS Schnuerle 60 [Au 111331 BOX 511E HIGGINSVILLE MO 64037 SERVICE TO THE R/C MODELER FORA 91 TER OF CENTURY Send revised 1978 catalog $1 Add $ 50 1st Class return Add $1 handling other orders uses including power supply small experimental circuts can rejuvenate flashlight batteries Use 3Oma until cell voltage reaches 1 5VDC again pen-cell battery box shown attached used purpose Fig 5 shows calculator charger box on-the-wall type simple adapter built pill bottle Fig 6 schematic Deans connector adapter reminds must very careful label adapters chargers Several manufacturers use Deans connectors Cit izenship Pro-Line ACE R/C Can non come mind immediately dont use pins same purposes Use voltmeter check out before turn charger perhaps some damage Ive confused please read col writing advertisers mention read about MA umn again Ive tried keep things simple possibleno chemistry no math just facts Ive tried show Rapid Charging safe used intelligence Examples shown demonstrate shouldnt play mixand-match components various manufacturers checking first see what Charger ratings ex plained help choose what need good general-purpose charger identified should prepared decision Happy Flying Keep cards letters coming Im very far behind right now expect catch up now winter has set Windlord/Bates continued page 20 adjusting CG small increments until stable floating glide achieved setting Towing accomplished bridle shown Figure E tie bridle snap swivel Pass through ring snap-swivel use large enough tow rings cannot pass through side bridle ring will stop snap swivel allow com plete tow One-side tows possible requiring about 100 rudder deflection correct yaw may substitute conventional hooks releasable capture hooks may necessary launching winch continuously pulse winch rapidly through early portion tow cluding tensioning line launch will maintain constant tension tow like hi-start run winch continuously until ship has - started rotate climb sud denly release pressure line may experience slight pitch up releasing tow bridle Efficient thermaling turns can made quite tightly penetration down elevator trim excellent Inverted flight almost good upright Windlord can made outside loop verted rudder does reverse Right still right Dont ask Dethermaliz ing done flaps shallow verted dive since upright dive builds speed rapidly speed does bleed off quickly Orientation has problem looks much like hawk distance dont recommend using dark color scheme Enjoy Windlord dont lose gaggle hawks RC Aerobatks/VanPutte continued page 21 very familiar necessity coordi nate application aileron rudder attempts roll light aircraft using aileron nose will generally yaw wrong direction before rolls Some airplanes like J-3 Cub will end up skid wing barely higher other important fact adverse yaw causes nose airplane move lat erally opposite direction roll before airplane really begins rol ling Consequently roll begun aircraft yawed condition what makes axial roll look bad Aile ron differential helps make axial rolls look better reducing initial adverse yaw other sources yaw roll require air plane must rolling order generate yawing moment causes yaw 86 Model Aviation FAMOUS BRITISH DIESELS DIC RAW * *NEWr * EATA LOG-DIESEL HANDBOOK $150 pp HOBBY H IDEAWAY DELAVMqILLe17a4 MORRISONSCALE DRAWINGS REPLA-TECH ntrfltIOfl@I CATALOG 25c vs 48500 McKenzie Hwy Vids Oregon 97488 George M Myers 70 Froehlich Farm Road Hicksville NY 11801 ACE R/C Inc metered van-charger can solve miscellaneous charging prob lems has handy indicator warn you should accidentaly connect backwards Two of common sources vertical fin wing itself sim plest visualize yaw generated vertical fin Visualize airplane rolling right clockwise viewed behind air plane vertical fin will moving right rolls see Fig 1 generating angle attack relative local air flow function far par ticular pint fin axis rotation angle attack will cause force fin direction opposite way rolling roll right force will left force will result yawing moment causes nose move right Since airplane rolling right yaw right called proverse yaw com pared adverse yaw Since yaw tendency will make axial rolls look bad aircraft designers try minimize fin proverse yaw lowering aerodynamic center vertical fin Placing sub-fin below fuselage having rudder extend bottom sub-fin helps move vertical fin aerodynamic center down Dirty Birdy good example technique yawing tendency wing rolls little tougher visualize Again consider airplane rolling right Fig 2 right wing will moving down left wing will obviously moving up roll velocity will cause increase local angles attack right wing corresponding reductions left wing actual angles tack will function fast air plane rolling aircraft speed distance particular wing station axis rotation wing generates lift also drag generated due lift drag is called induced drag right wing moves down roll lift increased wing because angle attack change caused roll rate increase lift right wing causes increase induced drag spanwise station right wing same way decrease lift left wing causes decrease induced drag spanwise station left wing effect drag changes nose-right yawmoment Like vertical fin effect also proverse yaw However unlike vertical fin isnt much can done reduce yaw Consequently proverse yaw generated wing will al ways cause problems axial rolls bottom line will always some yaw during axial rolls aileron differential helps cut down initial yaw makes rolls look better Apparently lot people liked servo tester appeared December issue Model Aviation unfortunate schematic ser vo tester inadvertently omitted magazine published Editor got last issue Both maga CONTROL LINE KITS WEVE GOT EM STARTING AT $595 SiRingmaster S2FS1 Mustang S3YakS S5Ringmaster Jr S6Super Ringmaster S12Flying Funi S13Baby Ringmaster S15Ruffy SIlP38 Lightning 518Ringmaster Imper SiSSpitfire S22Ringmaster Spurts S27Skylark S28Sky Shark S29Ring Jr Flash S30Beginners Ring 1595 1695 1595 1095 1995 1695 195 2995 1695 2895 3595 1995 3495 1995 1295 595 S31Beginners Mustang595 S32Beg Ring Bipe695 S33Winder1395 S34Beginners Spitfire595 S35Beginners Thunder Jet595 S36Beginners Piper Cub595 S37Beginners Eindecker595 S38Beginners Shnestring595 S39Beginners Thunderhult595 S40Beginners Cherukee595 S41Beginners Fnkker 07695 S42Beginners Hellcat595 S43Beginners FuckeWnIf595 S44Beginners Zern595 S45Beginners Messerschmitt595 ClMunuceupe C3Mr Mulligan C4The Wace CBSE5 C8Fukker Dl C9Cersair ClONieupurt2B CliGrumman Gnardian C12Stearman PT17 C13Great takes STERLING MODELS G ST PHILA PA 19134 no dealer anallable direct orders accepted i5 addltioral charge handling shipping lkn ninlnun US 5125 nlninunr outside USl 0 Catalog 01 entire lIne airplane control line model kits R/C scale Trainer kits boat model kits accessories dc $00 enclosed C Secrals ot Model AIrplane BuIldIng Including design conStruction conering finIshing flying adlusling control systems etc 25c enclosed C Secrets Control Line Carrier Flying Including preflight soloing otunling Carrier roles regulations Carrier flying hints control lIne Installation instructions 256 enclosed No checks Only US maney orders currency accepted Name DU-BRO 7U1LFU FUEL PUMP NEW CONCEPT IN FUEL PUMPS ONLY ONE MOVING PART NOTHING TO BREAK OR WEAR OUT 0 0 S LIGHT COMPACT AND RUGGED ONLY2WIDEAND 2-7/8 INDIA HAND OPERATED AND REVER SIBLE S IN AND OUT HIGH VOLUME FLOW PUMP COMES ASSEMBLED AND MOUNTS ON GALLON CANS QUICK EASY INSTALLATION PUMP COMES COMPLETE WITH STEEL MOUNTING BRACKETS HARDWARE AND FUEL TUBINGNo191 PRODUCTS INCORPORATED 480 Bonner Road Wauconda IllinoIs 60064 USA March1978 87 1995 1995 2195 2295 2195 2395 2295 2895 2295 2495 Tho KINNER SPORTSTER 39 wrogopon 09 power op 3 channels nc great sport troiner 19300$1255 FAIRCHILD 22 8 Wingspan 09 to25 Power 02000 VA 00000000 0004* tAO*00 10* FOR 0000100*00 P007*5G see local hobby dealer AMERICANSee~3B CLASSICS worlds finest models Send free brochure Ti, AristocratFRO 0*00000700 *105Al WIOOSflM 040 P0000 FOR 000000020 FOROROCMSUIA *0000010000 AIR FOR 0000 000000100 FORE 0OA0 0000 lee 00L005 00 ELLANCAtel 702 272-9593 -00550 00000010 FOWER 101 8095 05 OIOOSFAN 020 P0000 FOR F0SE 000 SMALL kS&0k0000VT T1JP 0*2 SO FLOWN POE Fib ELS 2020 0000 AVEEALOFAX VA*2030 CUSTOM TUNED ENGINESI24 PLAN ARASOL COMPETITION ACCESSORIESI HEATH Cox 049Z051 Specialists brochure send 13 St amp to I Kustom Krattsmanship Brochure ALOG 25c Box 2699 Laguna Hills CA 92653 ERNISTIC MODELS 714 830-5162PO BOX6974ALBUO NM 87107 zinc office have received letters Editor phone calls requesting send copies schematic hope something like doesnt happen again because knows peo ple would have built tester schematic available article way learned 74121 inte grated circuit Radio Shack # 276-1814 available Radio Shack stores may have purchased other source few days ago received letter John Haumersen old friend used fly stationed An drews AFB Maryland near Washington DC John currently lives Bettendorf Iowa retired Army Colonel tank corps commander Any way excerpt Johns letter main purpose writing report use equations locating CG aircraft varying geo metry Ive lot fun using equations models past couple years finding always worked out improving CG location some kits about eight months ago got TI SR52 computor programed solve equations Works like charm pleased sent pro gram TI accepted publication Now modeling friends access TI SR52 can ob tain program TI fellow has already written has used program successfully several planes Ive tried make back Toledo show see old friends missed last year coming year Im going make bust Maybe Ill get chance see look forward equations talked about pub lished April 1976 Model Aviation work very well initial center mass determination new airplane sufficient interest Id glad re publish equations future column Ron Van Pune 12 Connie Drive Shal imar FL 32579 RC Scale/Wischers continued page 22 color half-tone type maga zines lacking detail necessary detail photos required judges accurately grade model lack documentation must have cost sta tic points otherwise excellent plane third place final standings PZL Wilga entered Phil Moore England fidelity standing elev enth indicating something lacking plane documentation Since plane masterpiece examined documentation found reason low score 3-view drawing good showed too variants plane no indication sketches judges follow scale rule furnished very small diffi cult read markings clear eleven color photos 3/2 X 5 size too small really helpful judges minimum number Better documentation could easily have given him six points needed put him second place prize would have $500 plane deserved better other English entry Dennis Bryant Bristol Bulldog came properly prepared scale rule finely mark ed made wood sliding caliper make judges job easy possible graduated frequent pencil markings Surprisingly 3-view rather muddy print good way fluence critics additional small 3-views book showing too variants confusing unnecessary must recognized plane vintage easy document few photos half tones Other photos RAF fighter book pages marked bad idea except photos doubtful value evident Dennis competed previously inter national meets cockpit photos sketches superior An example over-documentation two stuffed books 8 X 10 photos furnished George Rose except ional Curtiss Hawk P6-E George done praiseworthy job researching prototype reluctant give up valued information recorded photos actually too good showed such great detail judges able find fault sel dom sufficient time close scrutiny such vast quantities information confusion can detrimental 3-view large clear pair drawings pre pared Paul Matt published Historical viation Album excellent source George made rule yardstick easy use number contestants used photos model during construction practice some value similar photo prototype can used comparison Judges prefer photos full-size plane Model photos show construction methods quest genuity points generally consider ed acceptable least four contestants included model photos Another four contestants made own 3-view drawings requiring approval builder prototype National Scale Committee competitors skilled draftsmen Dave Platt published drawing making acceptable according rulesScale rulers varied simple short wood strips elaborate plastic six footers finely lined graduations press-type numerals simple rulers really ade quate did meet required FAI specifications respect AMA meet different short ruler necessary use drawing Documenting obscure aircraft would appear tougher assign ments scale modeling yet planes some builders find satisfing Granger Willims Curtiss F6C-4 Hawk falls class pro totype kind converted Hawk P-i information very diffi cult acquire Granger found excel lent 5X7 cut-away cockpit photos drawing classic William Wylam 3-views folding rule made thin plastic strips modelers aroused classic beauty planes era few will spend 88 Model Aviation
Edition: Model Aviation - 1978/03
Page Numbers: 21, 86, 87, 88
SportAerobatics ORon VanPutte IT DOES us some good called carpet once turn carpet received fol lowing letter John Banas Warren Mass As mechanical engineer avid student aerodynamics am writing because comments aileron dif ferential Sept 1977 issue Model Aviation Pattern aircraft roll ax ially problem us time another non-axial roll has articles flying field discussions erroneously attributed phenomenon adverse yaw some loose definition could called adverse yaw ie 1 yaw 2 adverse helping way case true adverse yaw re sult differential drag can said question non-axial rolling does exist can remedied aileron differential whatever preferred method obtaining ad verse yaw ruining roll axiality logic behind fact true adverse yaw can remedied aile ron differential provided roll does exceed 9Q0 Beyond point rela tively deflected aileron now ex actly opposite situation flyer originally intended relatively less deflected aileron point true adverse yaw will exister greater magnitude would occur no differ ential yaw employed Case point deflection up right aileron right roll alleviates called adverse yaw once aircraft inverted wing right has less deflection up wing left Exactly opposite situation now exists aircraft upright bottom line aileron differential FIGURE 1 View instantaneous motion vertical fin during axial roll Arrows represent local fin velocity due roll rate roll Orrertion FICORE 2 Motion wing during axial roll causes local wing velocity due roll rate vary shown causes wing angle attack vary along wing though may improve axiality prop erly applied does eliminate true ad verse yaw per se unless aircraft rolled 900 Hopefully explanation will clear up common misinterpretation well intended poor application aerody namic principles comment caught trying give simple explanation about very complex dynamic situation definitely true aileron differential will cause ex actly opposite effect aircraft rolled inverted elevator applied maintain constant altitude roll However use aileron differential does improve axial rolls since alleviates adverse yaw very critical timeat initiation roll before aircraft can develop substantial roll rate Anyone has flown light aircraft Continued page 86 March 1978 21 p roll direction reea super plane tuned pipe retracts fly Nats Lonnie Roberts flew OS 40 Fun Two kitted John Garabidian Michael Balog about get going another good flight placed him 10th Novice Nats Plane T2A C designed Bob Smith Rossi engine/pipe Rev-Up 11/7-1/2 propeller Getting ready start up Nats IVOIKO noelner nina plane Saturn designed Ivan Kristensen Canada OS Schnuerle 60 [Au 111331 BOX 511E HIGGINSVILLE MO 64037 SERVICE TO THE R/C MODELER FORA 91 TER OF CENTURY Send revised 1978 catalog $1 Add $ 50 1st Class return Add $1 handling other orders uses including power supply small experimental circuts can rejuvenate flashlight batteries Use 3Oma until cell voltage reaches 1 5VDC again pen-cell battery box shown attached used purpose Fig 5 shows calculator charger box on-the-wall type simple adapter built pill bottle Fig 6 schematic Deans connector adapter reminds must very careful label adapters chargers Several manufacturers use Deans connectors Cit izenship Pro-Line ACE R/C Can non come mind immediately dont use pins same purposes Use voltmeter check out before turn charger perhaps some damage Ive confused please read col writing advertisers mention read about MA umn again Ive tried keep things simple possibleno chemistry no math just facts Ive tried show Rapid Charging safe used intelligence Examples shown demonstrate shouldnt play mixand-match components various manufacturers checking first see what Charger ratings ex plained help choose what need good general-purpose charger identified should prepared decision Happy Flying Keep cards letters coming Im very far behind right now expect catch up now winter has set Windlord/Bates continued page 20 adjusting CG small increments until stable floating glide achieved setting Towing accomplished bridle shown Figure E tie bridle snap swivel Pass through ring snap-swivel use large enough tow rings cannot pass through side bridle ring will stop snap swivel allow com plete tow One-side tows possible requiring about 100 rudder deflection correct yaw may substitute conventional hooks releasable capture hooks may necessary launching winch continuously pulse winch rapidly through early portion tow cluding tensioning line launch will maintain constant tension tow like hi-start run winch continuously until ship has - started rotate climb sud denly release pressure line may experience slight pitch up releasing tow bridle Efficient thermaling turns can made quite tightly penetration down elevator trim excellent Inverted flight almost good upright Windlord can made outside loop verted rudder does reverse Right still right Dont ask Dethermaliz ing done flaps shallow verted dive since upright dive builds speed rapidly speed does bleed off quickly Orientation has problem looks much like hawk distance dont recommend using dark color scheme Enjoy Windlord dont lose gaggle hawks RC Aerobatks/VanPutte continued page 21 very familiar necessity coordi nate application aileron rudder attempts roll light aircraft using aileron nose will generally yaw wrong direction before rolls Some airplanes like J-3 Cub will end up skid wing barely higher other important fact adverse yaw causes nose airplane move lat erally opposite direction roll before airplane really begins rol ling Consequently roll begun aircraft yawed condition what makes axial roll look bad Aile ron differential helps make axial rolls look better reducing initial adverse yaw other sources yaw roll require air plane must rolling order generate yawing moment causes yaw 86 Model Aviation FAMOUS BRITISH DIESELS DIC RAW * *NEWr * EATA LOG-DIESEL HANDBOOK $150 pp HOBBY H IDEAWAY DELAVMqILLe17a4 MORRISONSCALE DRAWINGS REPLA-TECH ntrfltIOfl@I CATALOG 25c vs 48500 McKenzie Hwy Vids Oregon 97488 George M Myers 70 Froehlich Farm Road Hicksville NY 11801 ACE R/C Inc metered van-charger can solve miscellaneous charging prob lems has handy indicator warn you should accidentaly connect backwards Two of common sources vertical fin wing itself sim plest visualize yaw generated vertical fin Visualize airplane rolling right clockwise viewed behind air plane vertical fin will moving right rolls see Fig 1 generating angle attack relative local air flow function far par ticular pint fin axis rotation angle attack will cause force fin direction opposite way rolling roll right force will left force will result yawing moment causes nose move right Since airplane rolling right yaw right called proverse yaw com pared adverse yaw Since yaw tendency will make axial rolls look bad aircraft designers try minimize fin proverse yaw lowering aerodynamic center vertical fin Placing sub-fin below fuselage having rudder extend bottom sub-fin helps move vertical fin aerodynamic center down Dirty Birdy good example technique yawing tendency wing rolls little tougher visualize Again consider airplane rolling right Fig 2 right wing will moving down left wing will obviously moving up roll velocity will cause increase local angles attack right wing corresponding reductions left wing actual angles tack will function fast air plane rolling aircraft speed distance particular wing station axis rotation wing generates lift also drag generated due lift drag is called induced drag right wing moves down roll lift increased wing because angle attack change caused roll rate increase lift right wing causes increase induced drag spanwise station right wing same way decrease lift left wing causes decrease induced drag spanwise station left wing effect drag changes nose-right yawmoment Like vertical fin effect also proverse yaw However unlike vertical fin isnt much can done reduce yaw Consequently proverse yaw generated wing will al ways cause problems axial rolls bottom line will always some yaw during axial rolls aileron differential helps cut down initial yaw makes rolls look better Apparently lot people liked servo tester appeared December issue Model Aviation unfortunate schematic ser vo tester inadvertently omitted magazine published Editor got last issue Both maga CONTROL LINE KITS WEVE GOT EM STARTING AT $595 SiRingmaster S2FS1 Mustang S3YakS S5Ringmaster Jr S6Super Ringmaster S12Flying Funi S13Baby Ringmaster S15Ruffy SIlP38 Lightning 518Ringmaster Imper SiSSpitfire S22Ringmaster Spurts S27Skylark S28Sky Shark S29Ring Jr Flash S30Beginners Ring 1595 1695 1595 1095 1995 1695 195 2995 1695 2895 3595 1995 3495 1995 1295 595 S31Beginners Mustang595 S32Beg Ring Bipe695 S33Winder1395 S34Beginners Spitfire595 S35Beginners Thunder Jet595 S36Beginners Piper Cub595 S37Beginners Eindecker595 S38Beginners Shnestring595 S39Beginners Thunderhult595 S40Beginners Cherukee595 S41Beginners Fnkker 07695 S42Beginners Hellcat595 S43Beginners FuckeWnIf595 S44Beginners Zern595 S45Beginners Messerschmitt595 ClMunuceupe C3Mr Mulligan C4The Wace CBSE5 C8Fukker Dl C9Cersair ClONieupurt2B CliGrumman Gnardian C12Stearman PT17 C13Great takes STERLING MODELS G ST PHILA PA 19134 no dealer anallable direct orders accepted i5 addltioral charge handling shipping lkn ninlnun US 5125 nlninunr outside USl 0 Catalog 01 entire lIne airplane control line model kits R/C scale Trainer kits boat model kits accessories dc $00 enclosed C Secrals ot Model AIrplane BuIldIng Including design conStruction conering finIshing flying adlusling control systems etc 25c enclosed C Secrets Control Line Carrier Flying Including preflight soloing otunling Carrier roles regulations Carrier flying hints control lIne Installation instructions 256 enclosed No checks Only US maney orders currency accepted Name DU-BRO 7U1LFU FUEL PUMP NEW CONCEPT IN FUEL PUMPS ONLY ONE MOVING PART NOTHING TO BREAK OR WEAR OUT 0 0 S LIGHT COMPACT AND RUGGED ONLY2WIDEAND 2-7/8 INDIA HAND OPERATED AND REVER SIBLE S IN AND OUT HIGH VOLUME FLOW PUMP COMES ASSEMBLED AND MOUNTS ON GALLON CANS QUICK EASY INSTALLATION PUMP COMES COMPLETE WITH STEEL MOUNTING BRACKETS HARDWARE AND FUEL TUBINGNo191 PRODUCTS INCORPORATED 480 Bonner Road Wauconda IllinoIs 60064 USA March1978 87 1995 1995 2195 2295 2195 2395 2295 2895 2295 2495 Tho KINNER SPORTSTER 39 wrogopon 09 power op 3 channels nc great sport troiner 19300$1255 FAIRCHILD 22 8 Wingspan 09 to25 Power 02000 VA 00000000 0004* tAO*00 10* FOR 0000100*00 P007*5G see local hobby dealer AMERICANSee~3B CLASSICS worlds finest models Send free brochure Ti, AristocratFRO 0*00000700 *105Al WIOOSflM 040 P0000 FOR 000000020 FOROROCMSUIA *0000010000 AIR FOR 0000 000000100 FORE 0OA0 0000 lee 00L005 00 ELLANCAtel 702 272-9593 -00550 00000010 FOWER 101 8095 05 OIOOSFAN 020 P0000 FOR F0SE 000 SMALL kS&0k0000VT T1JP 0*2 SO FLOWN POE Fib ELS 2020 0000 AVEEALOFAX VA*2030 CUSTOM TUNED ENGINESI24 PLAN ARASOL COMPETITION ACCESSORIESI HEATH Cox 049Z051 Specialists brochure send 13 St amp to I Kustom Krattsmanship Brochure ALOG 25c Box 2699 Laguna Hills CA 92653 ERNISTIC MODELS 714 830-5162PO BOX6974ALBUO NM 87107 zinc office have received letters Editor phone calls requesting send copies schematic hope something like doesnt happen again because knows peo ple would have built tester schematic available article way learned 74121 inte grated circuit Radio Shack # 276-1814 available Radio Shack stores may have purchased other source few days ago received letter John Haumersen old friend used fly stationed An drews AFB Maryland near Washington DC John currently lives Bettendorf Iowa retired Army Colonel tank corps commander Any way excerpt Johns letter main purpose writing report use equations locating CG aircraft varying geo metry Ive lot fun using equations models past couple years finding always worked out improving CG location some kits about eight months ago got TI SR52 computor programed solve equations Works like charm pleased sent pro gram TI accepted publication Now modeling friends access TI SR52 can ob tain program TI fellow has already written has used program successfully several planes Ive tried make back Toledo show see old friends missed last year coming year Im going make bust Maybe Ill get chance see look forward equations talked about pub lished April 1976 Model Aviation work very well initial center mass determination new airplane sufficient interest Id glad re publish equations future column Ron Van Pune 12 Connie Drive Shal imar FL 32579 RC Scale/Wischers continued page 22 color half-tone type maga zines lacking detail necessary detail photos required judges accurately grade model lack documentation must have cost sta tic points otherwise excellent plane third place final standings PZL Wilga entered Phil Moore England fidelity standing elev enth indicating something lacking plane documentation Since plane masterpiece examined documentation found reason low score 3-view drawing good showed too variants plane no indication sketches judges follow scale rule furnished very small diffi cult read markings clear eleven color photos 3/2 X 5 size too small really helpful judges minimum number Better documentation could easily have given him six points needed put him second place prize would have $500 plane deserved better other English entry Dennis Bryant Bristol Bulldog came properly prepared scale rule finely mark ed made wood sliding caliper make judges job easy possible graduated frequent pencil markings Surprisingly 3-view rather muddy print good way fluence critics additional small 3-views book showing too variants confusing unnecessary must recognized plane vintage easy document few photos half tones Other photos RAF fighter book pages marked bad idea except photos doubtful value evident Dennis competed previously inter national meets cockpit photos sketches superior An example over-documentation two stuffed books 8 X 10 photos furnished George Rose except ional Curtiss Hawk P6-E George done praiseworthy job researching prototype reluctant give up valued information recorded photos actually too good showed such great detail judges able find fault sel dom sufficient time close scrutiny such vast quantities information confusion can detrimental 3-view large clear pair drawings pre pared Paul Matt published Historical viation Album excellent source George made rule yardstick easy use number contestants used photos model during construction practice some value similar photo prototype can used comparison Judges prefer photos full-size plane Model photos show construction methods quest genuity points generally consider ed acceptable least four contestants included model photos Another four contestants made own 3-view drawings requiring approval builder prototype National Scale Committee competitors skilled draftsmen Dave Platt published drawing making acceptable according rulesScale rulers varied simple short wood strips elaborate plastic six footers finely lined graduations press-type numerals simple rulers really ade quate did meet required FAI specifications respect AMA meet different short ruler necessary use drawing Documenting obscure aircraft would appear tougher assign ments scale modeling yet planes some builders find satisfing Granger Willims Curtiss F6C-4 Hawk falls class pro totype kind converted Hawk P-i information very diffi cult acquire Granger found excel lent 5X7 cut-away cockpit photos drawing classic William Wylam 3-views folding rule made thin plastic strips modelers aroused classic beauty planes era few will spend 88 Model Aviation