LETS talk about forces particular forces act racing model flight need state couple laws physics try see apply model airplane flight Old Isaac Newton smart old cuss figured out some basic physical laws really explained lot things particular5 three laws mechanics stated 1 Motion constant velocity natural behavior bodies 2 The force acting body equal mass body times its acceleration 3 Whenever object exerts force second object second exerts equal force opposite direction first Lets restate three laws examples 1 When start object moving wants keep moving slowing due factors like wind resistance friction etc Similarly object rest zero velocity tends stay rest would throw ball some velocity ball affected air gravity other force-causing factor ball would continue off straight line would go forever 2 Newtons second law physics merely statement force product mass acceleration apply force object some mass object will accelerate direction force applied model engine produces thrust force applied airplane forward direction model accelerates due force up some velocity resistive force drag increases match thrust engine model stops accelerating achieving steady state conditions 3 A box sitting floor exerting force floor equal its mass times accelera tion due gravity floor pushing back same force since combination two forces zero no acceleration observed What does mean racing model aircraft Well interesting able calculate G forces function line length air speed able predict what effect G Ac VAg1O A11O 322R - 2164472 T2R T Time 1/2 mile seconds R length feet Al _________________ Ac $ Ag Ag itational acceleration Gs Al lift acceleration Gs Ac Centripetal acceleration Gs FIGURE 1 forces have fuel system have first understand what forces act model what magnitude what direction apply Really interested accelerations rather forces remembering Newtons se cond law mass missing between two worrying about mass great simplification Consider airplane flight What forces acting plane major ones 1 Thrust engine 2 Air resistance whatever source 3 Gravity 4 Lift forces acts different direction plane stable flight sum forces zero thrust has direction forward air drag rearward since assumed steady state must equal acceleration would occur Newtons second Similarly force due gravity exactly matched lift created wing thing constant steady plane flies straight line constant velocity no acceleration racing models dont fly straight line fly circle means some force must acting model causing turn course force due lines called centripetal force force pilot sees center rotation calledcentrifugal force Lets draw picture forces acting racing aircraft steady-state constant velocity constant height equal height handle will ignore thrust air drag forces will looking plane rear Fig 1 Now lets get little technical write some equations define forces MV2 Centripetal Force Fc velocity airplane feet/seconds R distance center rotation plane feet M mass plane better equation Centripetal Acceleration Ac al R ly conveys same information indepen dent mass airplane An better equation expresses centripetal acceleration multiple acceleration due gravity V2 Centripetal acceleration Gs Ac 22R Given approach Gravitational Ac celeration Gs Ag onstant Converted useful terms Centripetal acceleration Gs Ac2164472 T T2R time travel seconds R line length feet As example 100-mph Big Goodyear travels 18 seconds on6O feet control lines centripetal acceleration plane about 111 Gs Question What forces act fuel tank above example fuel accel erated about 11 Gs due horizontal centripetal force affected 10 G gravitational force result being slightly 11 Gs directed below horizontal about 5 degrees As speed increases angle decreases force seen fuel very nearly horizontaL Question What happens flying above handle height Examine Fig 2 Note lines make angle 0 horizontaL Also effective radius flight smaller FIGURE 2 L e H HANDLER H ht above handle feet L length feet R Radius circle flown feet R H2 e Angle lines make horizontal e xample H t L 60 ft thenO degrees R 581 ft Now consider Fig 3 Centripetal force situation can act horizontal direction airplane flying some altitude above handle some force must exist holding plane up force has Continued page 112 Mafch 1980 45 RACING Bill Lee appears ais really C looKing Rat urged along Supertigre 62-35 WWI MODEL ACCESSORIES FINE QUALITY MACHINE GUN KITS JLLOAJS mLINc class should go acquisition certain number first second third places contests should figure point award based number competitors contest place competitor finishes finally should continue attempt keep scoring average fliers Some systems rely someone keep records Can expect AMA headquarters what about numerous contest administrators never send results Stunt News can hope send results AMA headquarters final problem PAMPA categories whether should include Nationals categories Nationals utilized course last Nationals saw 46 Open entries nearly half qualifiers since 20 flew Finals day Yes thats right last day really called Finalfinals day Walker Cup day informaton stunt P4MPA write WvnnPauh 1640 Maywick Dr Lexington KY 40504 WHEELS TS INGS SEND 50t FOR COMPLETE CATALOG DEPT MA 0 181 PAWNEE STREET SAN MARCOS CALIFORNIA 9 BARRONS L E C ASS IC S CL Combat/Johnson continued page 44 rye hearing about new proposed event called Speed Pattern Oh God another event say Sounds less destructive Combat easier Speed precision maneuvers Aerobatics Bob Hunt Mike 1-loffelt promoting event think would good idea two promote years Nationals event goes something like uncowled 40-powered model circulating astounding speeds 60-foot lines signal judge ready model streaks downwind marker judge starts stopwatch As finish first timed lap three inside loops continue around level lap three outside loops same downwind area same level lap used between next three horizontal-eights vertical-eights watch being stopped marker following level lap after vertical-eights Dog FAI did course 24 seconds AMA plane 15 course FAI less distance travel maneuvers would done designated window downwind keep pilot flying over sky Horizontal placement critical whereas vertical framing isnt can fly maneuvers tall want Sounds would least make fun event club meetings Well let 135-mph fire-breathers take over becomes national event event would offer challenge engine man plane designer super pilot would try trim down elapsed time through area proficiency Lets encourage Mike Bob sponsor event year some club level give try figure have give try event worthwhile will perpetuate itself whereas no amount fiddling rules would thing aid its popularity Makes think about long-forgotten Texas combat flier 1952 invented mid-air collision look what thats done rules-making combat general Charlie Johnson 3716 Ingraham St San Diego C4 92109 CL Racing/Lee continued page 45 generated lift wings example Big Goodyear Ac= 115 Gs Accos145 115 x9681 111 Gs Alt in 145 115 x25 29 Gs FIGURE 3 Ac ripetal acceleration Gs Acceleration transmitted through lines Al AccosGAl Ac e AtAg Alt Lift acceleration keep plane altitude Ac sin cceleration balancing Ag Ag Acceleration due gravity e Angle lines make horizontal wing must produce 29 Gs lift just counteract component centripetal force cannot transmitted via lines addition lift necessary support aircraft Al s since lift created perpendicular wing lift neces sary produce 10 G ofvertical force 0/cos0 Hence total lift produced wing Lift 104 Gs almost four times much lift needed 15 feet above handle handle height Quite lot lift needed fly high lift creates drag causes airplane slow down rational explanation see speed fliers actually flying below level pylon going faster because What force acts fuel system flying above handle level Actually same conditions apply applied before slight changes quantity fuel tank sees force acting outward downward Using Big Goodyear example fuel sees about 115 Gs force acting about five degrees below horizon tal big change body tank 112 Model Aiiation ENGINE KITS & CYLINDERS Rosies D&R Fbwer Pod Fits CDX T- D & Med 049 051 Engs Rubber Band Screw Mounting Eng mts upright Inverted Running time appx 4 mm Nylon injection mouldedColors Power 3 lb airplanes total weight 3M OL$595RED BLACK WEYELLOW ALSOORANGE MAKE BANTAM ServosWrite D&R SticksFor Free Connectors Bulkhead SwitchCatalog mountsFin Products ch jeavy duty gear Woid oda *siua D otha fin pveducu 3501-B W Moore St Santa Ana CA 92704 PLANS & cONsTR MANUAL Curtiss Hawk PGE Stinson Reliant SR9 I/4SCALE 94SSP $2250 SASCALE 126SP $2500 2SCALE B3SPAPE 51250 2SCALE S4SPAN $1500 23SCALE 47l/4SF$1050 15sCALr 6iSPAN $1250 Curtiss FIIC2 Curtiss Gulthawk IA ShScALE 54SSP $3000 1MSCALE 945SP $3000 2SCALE 03SP $1500 2SCALE C3SP $1500 PLEASE ADD *200 0RP/H USASEND $100 WRITE row MAE LINO IT7 t INrORMATION INCLUDE $100CATALOGE row CATALOOE 1213 HOLLY Spmoe LANE GRAND BLANC Mi 40439 SAFE FLYING IS NO ACCIDENT E}wL1 ATTACKER good-looking foam plane ex cellent fun-fly contests Big thick wing washout make docile yet maneuverable Illustrated plans much hardware & large full color decal sheet Wing Span 48 Construc tion All-Foam Radio 4 Channel Engine 19404495 SWEET STIK simple build & fun flying model Larger version popular Das Little Stik Full-size plans & much hardware cluding motor mounts & hinges Wing Span 54 Construction All-Balsa Ra dio 4 Channel Engine 1940 TAYLORCRAFT stand-off scale model offering best flight performance Kit builds quickly contains full-size plans de tailed instruction booklet vacuum formed cowl & wheel parts & much hardware Wing Span 55-1/2 Con struction Balsa Radio 4 42~Channel Engine 29455995 Send 50 complete catalog MIDWEST PRODUCTS COMPANY 400 S Indiana Street Hobart Indiana 46342 no longer same position tilted towards center circle angle 0 145 degrees Big Goodyear example tilting can cause rather significant changes fuel tank geometry taken account As example consider Fig 4 tank 3-in height fuel pickup bottom out UNIFLOW VENT II 75 HORIZONTAL 3FORCE IOs 1450 FUEL PICKUP FIGURE 4 PECKS MODEL MENAGERIE PEANUT SCALE KITS $395 P ETENPOL GIPSY MOTH PPER J3 CUR DR EAS ON TURBULENT GORIE MUSTANG UGAR ES ZERO MItCATALOG $100 COMPLETE GUIDE TO RUBBER MOOR SUPPLIES Jbe CuatThis P2490-MA LA MESA CALIF 92041 Peck-hlyauers PHONE7144698675o7141442-4636 board corner uniflow air vent top outboard corner tank tilted inboard 145 degrees erence horizontal direction between uniflow air vent pickup Add 5-degree angle due gravity have nearly 1 effective distance between vent pickup bottom line uniflow vent should placed near pickup avoid kind flight-attitude fuel feed variations JV R Lee 3522 Tamarisk Lane Missouri City TX 77459 March 1980 113 CNo aint kissing Just hectic moment Jim Ongs pitting routine Joe King helping Slow Rat Lincoln Nats Nonracing types will find interesting details hot hand flOdO WARE WORKING TURNBUCKLES RIGGING & CONTROL CABLE CONTROL HORNS UT FITTINGS eSHOCK CORD COCKPIT TRIM PULLEYS INSTRUMENT HOUSINGS a For information cataIogu end aioo Poar ENT CORP PO BOX 9641 SAN OIEGOCA92109 Just think hard would fly witI Ballard ever lit cigarette Using John pylon Stew Willoughbyi 979 Nats
Edition: Model Aviation - 1980/03
Page Numbers: 45, 112, 113
LETS talk about forces particular forces act racing model flight need state couple laws physics try see apply model airplane flight Old Isaac Newton smart old cuss figured out some basic physical laws really explained lot things particular5 three laws mechanics stated 1 Motion constant velocity natural behavior bodies 2 The force acting body equal mass body times its acceleration 3 Whenever object exerts force second object second exerts equal force opposite direction first Lets restate three laws examples 1 When start object moving wants keep moving slowing due factors like wind resistance friction etc Similarly object rest zero velocity tends stay rest would throw ball some velocity ball affected air gravity other force-causing factor ball would continue off straight line would go forever 2 Newtons second law physics merely statement force product mass acceleration apply force object some mass object will accelerate direction force applied model engine produces thrust force applied airplane forward direction model accelerates due force up some velocity resistive force drag increases match thrust engine model stops accelerating achieving steady state conditions 3 A box sitting floor exerting force floor equal its mass times accelera tion due gravity floor pushing back same force since combination two forces zero no acceleration observed What does mean racing model aircraft Well interesting able calculate G forces function line length air speed able predict what effect G Ac VAg1O A11O 322R - 2164472 T2R T Time 1/2 mile seconds R length feet Al _________________ Ac $ Ag Ag itational acceleration Gs Al lift acceleration Gs Ac Centripetal acceleration Gs FIGURE 1 forces have fuel system have first understand what forces act model what magnitude what direction apply Really interested accelerations rather forces remembering Newtons se cond law mass missing between two worrying about mass great simplification Consider airplane flight What forces acting plane major ones 1 Thrust engine 2 Air resistance whatever source 3 Gravity 4 Lift forces acts different direction plane stable flight sum forces zero thrust has direction forward air drag rearward since assumed steady state must equal acceleration would occur Newtons second Similarly force due gravity exactly matched lift created wing thing constant steady plane flies straight line constant velocity no acceleration racing models dont fly straight line fly circle means some force must acting model causing turn course force due lines called centripetal force force pilot sees center rotation calledcentrifugal force Lets draw picture forces acting racing aircraft steady-state constant velocity constant height equal height handle will ignore thrust air drag forces will looking plane rear Fig 1 Now lets get little technical write some equations define forces MV2 Centripetal Force Fc velocity airplane feet/seconds R distance center rotation plane feet M mass plane better equation Centripetal Acceleration Ac al R ly conveys same information indepen dent mass airplane An better equation expresses centripetal acceleration multiple acceleration due gravity V2 Centripetal acceleration Gs Ac 22R Given approach Gravitational Ac celeration Gs Ag onstant Converted useful terms Centripetal acceleration Gs Ac2164472 T T2R time travel seconds R line length feet As example 100-mph Big Goodyear travels 18 seconds on6O feet control lines centripetal acceleration plane about 111 Gs Question What forces act fuel tank above example fuel accel erated about 11 Gs due horizontal centripetal force affected 10 G gravitational force result being slightly 11 Gs directed below horizontal about 5 degrees As speed increases angle decreases force seen fuel very nearly horizontaL Question What happens flying above handle height Examine Fig 2 Note lines make angle 0 horizontaL Also effective radius flight smaller FIGURE 2 L e H HANDLER H ht above handle feet L length feet R Radius circle flown feet R H2 e Angle lines make horizontal e xample H t L 60 ft thenO degrees R 581 ft Now consider Fig 3 Centripetal force situation can act horizontal direction airplane flying some altitude above handle some force must exist holding plane up force has Continued page 112 Mafch 1980 45 RACING Bill Lee appears ais really C looKing Rat urged along Supertigre 62-35 WWI MODEL ACCESSORIES FINE QUALITY MACHINE GUN KITS JLLOAJS mLINc class should go acquisition certain number first second third places contests should figure point award based number competitors contest place competitor finishes finally should continue attempt keep scoring average fliers Some systems rely someone keep records Can expect AMA headquarters what about numerous contest administrators never send results Stunt News can hope send results AMA headquarters final problem PAMPA categories whether should include Nationals categories Nationals utilized course last Nationals saw 46 Open entries nearly half qualifiers since 20 flew Finals day Yes thats right last day really called Finalfinals day Walker Cup day informaton stunt P4MPA write WvnnPauh 1640 Maywick Dr Lexington KY 40504 WHEELS TS INGS SEND 50t FOR COMPLETE CATALOG DEPT MA 0 181 PAWNEE STREET SAN MARCOS CALIFORNIA 9 BARRONS L E C ASS IC S CL Combat/Johnson continued page 44 rye hearing about new proposed event called Speed Pattern Oh God another event say Sounds less destructive Combat easier Speed precision maneuvers Aerobatics Bob Hunt Mike 1-loffelt promoting event think would good idea two promote years Nationals event goes something like uncowled 40-powered model circulating astounding speeds 60-foot lines signal judge ready model streaks downwind marker judge starts stopwatch As finish first timed lap three inside loops continue around level lap three outside loops same downwind area same level lap used between next three horizontal-eights vertical-eights watch being stopped marker following level lap after vertical-eights Dog FAI did course 24 seconds AMA plane 15 course FAI less distance travel maneuvers would done designated window downwind keep pilot flying over sky Horizontal placement critical whereas vertical framing isnt can fly maneuvers tall want Sounds would least make fun event club meetings Well let 135-mph fire-breathers take over becomes national event event would offer challenge engine man plane designer super pilot would try trim down elapsed time through area proficiency Lets encourage Mike Bob sponsor event year some club level give try figure have give try event worthwhile will perpetuate itself whereas no amount fiddling rules would thing aid its popularity Makes think about long-forgotten Texas combat flier 1952 invented mid-air collision look what thats done rules-making combat general Charlie Johnson 3716 Ingraham St San Diego C4 92109 CL Racing/Lee continued page 45 generated lift wings example Big Goodyear Ac= 115 Gs Accos145 115 x9681 111 Gs Alt in 145 115 x25 29 Gs FIGURE 3 Ac ripetal acceleration Gs Acceleration transmitted through lines Al AccosGAl Ac e AtAg Alt Lift acceleration keep plane altitude Ac sin cceleration balancing Ag Ag Acceleration due gravity e Angle lines make horizontal wing must produce 29 Gs lift just counteract component centripetal force cannot transmitted via lines addition lift necessary support aircraft Al s since lift created perpendicular wing lift neces sary produce 10 G ofvertical force 0/cos0 Hence total lift produced wing Lift 104 Gs almost four times much lift needed 15 feet above handle handle height Quite lot lift needed fly high lift creates drag causes airplane slow down rational explanation see speed fliers actually flying below level pylon going faster because What force acts fuel system flying above handle level Actually same conditions apply applied before slight changes quantity fuel tank sees force acting outward downward Using Big Goodyear example fuel sees about 115 Gs force acting about five degrees below horizon tal big change body tank 112 Model Aiiation ENGINE KITS & CYLINDERS Rosies D&R Fbwer Pod Fits CDX T- D & Med 049 051 Engs Rubber Band Screw Mounting Eng mts upright Inverted Running time appx 4 mm Nylon injection mouldedColors Power 3 lb airplanes total weight 3M OL$595RED BLACK WEYELLOW ALSOORANGE MAKE BANTAM ServosWrite D&R SticksFor Free Connectors Bulkhead SwitchCatalog mountsFin Products ch jeavy duty gear Woid oda *siua D otha fin pveducu 3501-B W Moore St Santa Ana CA 92704 PLANS & cONsTR MANUAL Curtiss Hawk PGE Stinson Reliant SR9 I/4SCALE 94SSP $2250 SASCALE 126SP $2500 2SCALE B3SPAPE 51250 2SCALE S4SPAN $1500 23SCALE 47l/4SF$1050 15sCALr 6iSPAN $1250 Curtiss FIIC2 Curtiss Gulthawk IA ShScALE 54SSP $3000 1MSCALE 945SP $3000 2SCALE 03SP $1500 2SCALE C3SP $1500 PLEASE ADD *200 0RP/H USASEND $100 WRITE row MAE LINO IT7 t INrORMATION INCLUDE $100CATALOGE row CATALOOE 1213 HOLLY Spmoe LANE GRAND BLANC Mi 40439 SAFE FLYING IS NO ACCIDENT E}wL1 ATTACKER good-looking foam plane ex cellent fun-fly contests Big thick wing washout make docile yet maneuverable Illustrated plans much hardware & large full color decal sheet Wing Span 48 Construc tion All-Foam Radio 4 Channel Engine 19404495 SWEET STIK simple build & fun flying model Larger version popular Das Little Stik Full-size plans & much hardware cluding motor mounts & hinges Wing Span 54 Construction All-Balsa Ra dio 4 Channel Engine 1940 TAYLORCRAFT stand-off scale model offering best flight performance Kit builds quickly contains full-size plans de tailed instruction booklet vacuum formed cowl & wheel parts & much hardware Wing Span 55-1/2 Con struction Balsa Radio 4 42~Channel Engine 29455995 Send 50 complete catalog MIDWEST PRODUCTS COMPANY 400 S Indiana Street Hobart Indiana 46342 no longer same position tilted towards center circle angle 0 145 degrees Big Goodyear example tilting can cause rather significant changes fuel tank geometry taken account As example consider Fig 4 tank 3-in height fuel pickup bottom out UNIFLOW VENT II 75 HORIZONTAL 3FORCE IOs 1450 FUEL PICKUP FIGURE 4 PECKS MODEL MENAGERIE PEANUT SCALE KITS $395 P ETENPOL GIPSY MOTH PPER J3 CUR DR EAS ON TURBULENT GORIE MUSTANG UGAR ES ZERO MItCATALOG $100 COMPLETE GUIDE TO RUBBER MOOR SUPPLIES Jbe CuatThis P2490-MA LA MESA CALIF 92041 Peck-hlyauers PHONE7144698675o7141442-4636 board corner uniflow air vent top outboard corner tank tilted inboard 145 degrees erence horizontal direction between uniflow air vent pickup Add 5-degree angle due gravity have nearly 1 effective distance between vent pickup bottom line uniflow vent should placed near pickup avoid kind flight-attitude fuel feed variations JV R Lee 3522 Tamarisk Lane Missouri City TX 77459 March 1980 113 CNo aint kissing Just hectic moment Jim Ongs pitting routine Joe King helping Slow Rat Lincoln Nats Nonracing types will find interesting details hot hand flOdO WARE WORKING TURNBUCKLES RIGGING & CONTROL CABLE CONTROL HORNS UT FITTINGS eSHOCK CORD COCKPIT TRIM PULLEYS INSTRUMENT HOUSINGS a For information cataIogu end aioo Poar ENT CORP PO BOX 9641 SAN OIEGOCA92109 Just think hard would fly witI Ballard ever lit cigarette Using John pylon Stew Willoughbyi 979 Nats
Edition: Model Aviation - 1980/03
Page Numbers: 45, 112, 113
LETS talk about forces particular forces act racing model flight need state couple laws physics try see apply model airplane flight Old Isaac Newton smart old cuss figured out some basic physical laws really explained lot things particular5 three laws mechanics stated 1 Motion constant velocity natural behavior bodies 2 The force acting body equal mass body times its acceleration 3 Whenever object exerts force second object second exerts equal force opposite direction first Lets restate three laws examples 1 When start object moving wants keep moving slowing due factors like wind resistance friction etc Similarly object rest zero velocity tends stay rest would throw ball some velocity ball affected air gravity other force-causing factor ball would continue off straight line would go forever 2 Newtons second law physics merely statement force product mass acceleration apply force object some mass object will accelerate direction force applied model engine produces thrust force applied airplane forward direction model accelerates due force up some velocity resistive force drag increases match thrust engine model stops accelerating achieving steady state conditions 3 A box sitting floor exerting force floor equal its mass times accelera tion due gravity floor pushing back same force since combination two forces zero no acceleration observed What does mean racing model aircraft Well interesting able calculate G forces function line length air speed able predict what effect G Ac VAg1O A11O 322R - 2164472 T2R T Time 1/2 mile seconds R length feet Al _________________ Ac $ Ag Ag itational acceleration Gs Al lift acceleration Gs Ac Centripetal acceleration Gs FIGURE 1 forces have fuel system have first understand what forces act model what magnitude what direction apply Really interested accelerations rather forces remembering Newtons se cond law mass missing between two worrying about mass great simplification Consider airplane flight What forces acting plane major ones 1 Thrust engine 2 Air resistance whatever source 3 Gravity 4 Lift forces acts different direction plane stable flight sum forces zero thrust has direction forward air drag rearward since assumed steady state must equal acceleration would occur Newtons second Similarly force due gravity exactly matched lift created wing thing constant steady plane flies straight line constant velocity no acceleration racing models dont fly straight line fly circle means some force must acting model causing turn course force due lines called centripetal force force pilot sees center rotation calledcentrifugal force Lets draw picture forces acting racing aircraft steady-state constant velocity constant height equal height handle will ignore thrust air drag forces will looking plane rear Fig 1 Now lets get little technical write some equations define forces MV2 Centripetal Force Fc velocity airplane feet/seconds R distance center rotation plane feet M mass plane better equation Centripetal Acceleration Ac al R ly conveys same information indepen dent mass airplane An better equation expresses centripetal acceleration multiple acceleration due gravity V2 Centripetal acceleration Gs Ac 22R Given approach Gravitational Ac celeration Gs Ag onstant Converted useful terms Centripetal acceleration Gs Ac2164472 T T2R time travel seconds R line length feet As example 100-mph Big Goodyear travels 18 seconds on6O feet control lines centripetal acceleration plane about 111 Gs Question What forces act fuel tank above example fuel accel erated about 11 Gs due horizontal centripetal force affected 10 G gravitational force result being slightly 11 Gs directed below horizontal about 5 degrees As speed increases angle decreases force seen fuel very nearly horizontaL Question What happens flying above handle height Examine Fig 2 Note lines make angle 0 horizontaL Also effective radius flight smaller FIGURE 2 L e H HANDLER H ht above handle feet L length feet R Radius circle flown feet R H2 e Angle lines make horizontal e xample H t L 60 ft thenO degrees R 581 ft Now consider Fig 3 Centripetal force situation can act horizontal direction airplane flying some altitude above handle some force must exist holding plane up force has Continued page 112 Mafch 1980 45 RACING Bill Lee appears ais really C looKing Rat urged along Supertigre 62-35 WWI MODEL ACCESSORIES FINE QUALITY MACHINE GUN KITS JLLOAJS mLINc class should go acquisition certain number first second third places contests should figure point award based number competitors contest place competitor finishes finally should continue attempt keep scoring average fliers Some systems rely someone keep records Can expect AMA headquarters what about numerous contest administrators never send results Stunt News can hope send results AMA headquarters final problem PAMPA categories whether should include Nationals categories Nationals utilized course last Nationals saw 46 Open entries nearly half qualifiers since 20 flew Finals day Yes thats right last day really called Finalfinals day Walker Cup day informaton stunt P4MPA write WvnnPauh 1640 Maywick Dr Lexington KY 40504 WHEELS TS INGS SEND 50t FOR COMPLETE CATALOG DEPT MA 0 181 PAWNEE STREET SAN MARCOS CALIFORNIA 9 BARRONS L E C ASS IC S CL Combat/Johnson continued page 44 rye hearing about new proposed event called Speed Pattern Oh God another event say Sounds less destructive Combat easier Speed precision maneuvers Aerobatics Bob Hunt Mike 1-loffelt promoting event think would good idea two promote years Nationals event goes something like uncowled 40-powered model circulating astounding speeds 60-foot lines signal judge ready model streaks downwind marker judge starts stopwatch As finish first timed lap three inside loops continue around level lap three outside loops same downwind area same level lap used between next three horizontal-eights vertical-eights watch being stopped marker following level lap after vertical-eights Dog FAI did course 24 seconds AMA plane 15 course FAI less distance travel maneuvers would done designated window downwind keep pilot flying over sky Horizontal placement critical whereas vertical framing isnt can fly maneuvers tall want Sounds would least make fun event club meetings Well let 135-mph fire-breathers take over becomes national event event would offer challenge engine man plane designer super pilot would try trim down elapsed time through area proficiency Lets encourage Mike Bob sponsor event year some club level give try figure have give try event worthwhile will perpetuate itself whereas no amount fiddling rules would thing aid its popularity Makes think about long-forgotten Texas combat flier 1952 invented mid-air collision look what thats done rules-making combat general Charlie Johnson 3716 Ingraham St San Diego C4 92109 CL Racing/Lee continued page 45 generated lift wings example Big Goodyear Ac= 115 Gs Accos145 115 x9681 111 Gs Alt in 145 115 x25 29 Gs FIGURE 3 Ac ripetal acceleration Gs Acceleration transmitted through lines Al AccosGAl Ac e AtAg Alt Lift acceleration keep plane altitude Ac sin cceleration balancing Ag Ag Acceleration due gravity e Angle lines make horizontal wing must produce 29 Gs lift just counteract component centripetal force cannot transmitted via lines addition lift necessary support aircraft Al s since lift created perpendicular wing lift neces sary produce 10 G ofvertical force 0/cos0 Hence total lift produced wing Lift 104 Gs almost four times much lift needed 15 feet above handle handle height Quite lot lift needed fly high lift creates drag causes airplane slow down rational explanation see speed fliers actually flying below level pylon going faster because What force acts fuel system flying above handle level Actually same conditions apply applied before slight changes quantity fuel tank sees force acting outward downward Using Big Goodyear example fuel sees about 115 Gs force acting about five degrees below horizon tal big change body tank 112 Model Aiiation ENGINE KITS & CYLINDERS Rosies D&R Fbwer Pod Fits CDX T- D & Med 049 051 Engs Rubber Band Screw Mounting Eng mts upright Inverted Running time appx 4 mm Nylon injection mouldedColors Power 3 lb airplanes total weight 3M OL$595RED BLACK WEYELLOW ALSOORANGE MAKE BANTAM ServosWrite D&R SticksFor Free Connectors Bulkhead SwitchCatalog mountsFin Products ch jeavy duty gear Woid oda *siua D otha fin pveducu 3501-B W Moore St Santa Ana CA 92704 PLANS & cONsTR MANUAL Curtiss Hawk PGE Stinson Reliant SR9 I/4SCALE 94SSP $2250 SASCALE 126SP $2500 2SCALE B3SPAPE 51250 2SCALE S4SPAN $1500 23SCALE 47l/4SF$1050 15sCALr 6iSPAN $1250 Curtiss FIIC2 Curtiss Gulthawk IA ShScALE 54SSP $3000 1MSCALE 945SP $3000 2SCALE 03SP $1500 2SCALE C3SP $1500 PLEASE ADD *200 0RP/H USASEND $100 WRITE row MAE LINO IT7 t INrORMATION INCLUDE $100CATALOGE row CATALOOE 1213 HOLLY Spmoe LANE GRAND BLANC Mi 40439 SAFE FLYING IS NO ACCIDENT E}wL1 ATTACKER good-looking foam plane ex cellent fun-fly contests Big thick wing washout make docile yet maneuverable Illustrated plans much hardware & large full color decal sheet Wing Span 48 Construc tion All-Foam Radio 4 Channel Engine 19404495 SWEET STIK simple build & fun flying model Larger version popular Das Little Stik Full-size plans & much hardware cluding motor mounts & hinges Wing Span 54 Construction All-Balsa Ra dio 4 Channel Engine 1940 TAYLORCRAFT stand-off scale model offering best flight performance Kit builds quickly contains full-size plans de tailed instruction booklet vacuum formed cowl & wheel parts & much hardware Wing Span 55-1/2 Con struction Balsa Radio 4 42~Channel Engine 29455995 Send 50 complete catalog MIDWEST PRODUCTS COMPANY 400 S Indiana Street Hobart Indiana 46342 no longer same position tilted towards center circle angle 0 145 degrees Big Goodyear example tilting can cause rather significant changes fuel tank geometry taken account As example consider Fig 4 tank 3-in height fuel pickup bottom out UNIFLOW VENT II 75 HORIZONTAL 3FORCE IOs 1450 FUEL PICKUP FIGURE 4 PECKS MODEL MENAGERIE PEANUT SCALE KITS $395 P ETENPOL GIPSY MOTH PPER J3 CUR DR EAS ON TURBULENT GORIE MUSTANG UGAR ES ZERO MItCATALOG $100 COMPLETE GUIDE TO RUBBER MOOR SUPPLIES Jbe CuatThis P2490-MA LA MESA CALIF 92041 Peck-hlyauers PHONE7144698675o7141442-4636 board corner uniflow air vent top outboard corner tank tilted inboard 145 degrees erence horizontal direction between uniflow air vent pickup Add 5-degree angle due gravity have nearly 1 effective distance between vent pickup bottom line uniflow vent should placed near pickup avoid kind flight-attitude fuel feed variations JV R Lee 3522 Tamarisk Lane Missouri City TX 77459 March 1980 113 CNo aint kissing Just hectic moment Jim Ongs pitting routine Joe King helping Slow Rat Lincoln Nats Nonracing types will find interesting details hot hand flOdO WARE WORKING TURNBUCKLES RIGGING & CONTROL CABLE CONTROL HORNS UT FITTINGS eSHOCK CORD COCKPIT TRIM PULLEYS INSTRUMENT HOUSINGS a For information cataIogu end aioo Poar ENT CORP PO BOX 9641 SAN OIEGOCA92109 Just think hard would fly witI Ballard ever lit cigarette Using John pylon Stew Willoughbyi 979 Nats