AEROBATICS Wynn Paul LINE tension problem Bob Green Boyertown PA writes problem line tension profile airplane using Fox 35 engine 10-6 prop five percent nitro fuel 60 ft lines engine offset shown plans says plane loses line tension especially vertical eights overhead eights solution simple First Bob should make certain has enough tip weight Most 35 size profiles require least ry ounce 125 oz see helps talking about wing Bob better make certain wing warped outboard wing may twisted down relative inboard panel maybe flap plane has same problem could try shorter lines would make plane respon sive cause fly lap faster same rpm engine could help line tension Actually 60 foot lines profile little long unless measuring handle center airplane line length same slow combat trying fly plane about 30 mph slower slow combat Make certain lines 015 diameter 018s used tip weight will definitely needed next trouble spot could engine attempting run too slow emulate expert fliers able run engines may just having too little power out engine Remember expert fliers now using muffler pressure pressurize fuel tank among other things helps give run insufficient rpm engine would account airplane falling out sky engines muffler pressure turning 7500 9000 rpm pressure may just setting needle too rich Dont concerned engine doesnt have significant break four cycle two cycle associated star fliers thing light plane will put load engine helps cause break Also probably has engine reworked meaning piston sleeve havent fitted lapped basic stock configuration Fox 35 will easily pull a35 oz profile through pattern heavier plane engine will probably break four two cycle case judging what put letter Bob probably running engine too slow must assume Bob performing maneuvers downwind Some fliers forget vitally important part setting up maneuvers Establish wind direction before starting en gine remember During flight look trees smoke etc see wind changes direction Fliers should develop art feeling wind direction faces Continued page 122 48 Model Aviation Engine room ship built Mike Grab Sulphur Springs TX Engine OS Max 4OFSR Bob Hunt muffler Clunk tank has uniflow venting Note wire tiedown scheme tank Wynn Paul nfluruvv VUFOId Idd rIdUUU CIIIIU III CUIIU engine us OS Max r photo shows nice detail Ia wheel wire/fairing construction Sharp photo shows drop ui muffler Larry Kruse Dhotos EU 330EU WV PROPS FOR BIGGIES Now can experience full thrust potential chain saw engine prop-drive new durable efficient glass-filled nylon pY NATNrati props Platt Seen QSAA Fun Flys Louisville Las Vegas Look us up WRAMS TOLEDO Direct Factory Introductory Prices New items biggies coming DYNAHUB easist safest way start big engines DYNATI-IRUST Prop Balancer Accurate Easy-to-use & inespensive Add 50 PER PROP shipping USA pay shipping charges orders 6 s Send CHECK MO VISA MC COD mounts place Cut holes bladder tube fuelproof its interior pouring about two ounces thinned white glue sloshing around pouring out excess Fuel-proof motor mount slow-curing epoxy glue last step before engine mounting check warps also im portant steps position full soft drink can four corners wing flat surface Put straight pins tip leading edge trailing edge four pins rest cans wing straight now time mount engine go flying yours fly good hope dont meet contest CL Scale/Gretz Continued page 47 fourth control line first Zlin Akrobat used standard G-S 3-line bellcrank system throttle control An inverted style bellcrank mounted fuselage solid music wire pushrod going Fox Eagle carburetor Rhom Air retract system am familiar IN STOCK NOW 186 188 208 2010 $700 700 900 900 COMING EARLY 1980 156$500 16550 166500 Dynathrust Props Inc 2541 NE 11th Court Pompano Beach FL 33062 Raymond Colelli 305 941 9119 having used since 1973 has 4-way switching valve actuate up down movements landing gears presume other pneumatic systems have similar valve valve basically junction box systems up down pressure air hoses valve has grooved sliding barrel inside routes pressurized air appropriate up down hose end barrels travel RC applications standard servo drives inner barrel end valve other Zlin use throttle pushrod same job As can see accompanying drawing spur wire wrapped soldered throttle pushrod spur wire two wheel collars small enough slide valve push barrel valve body itself securely fastened fuselage structure throttle pushrod moves forward open carburetor number 2 collar pushes barrel front valve thus connecting up air hose pressure hose bringing landing gear up Conversely throttle pushrod closes carb number 1 collar pushes barrel rear valve completes down circuit lowers landing gear use wheel collars spur wire makes exact timing retraction ex tension gears adjustable within power range engine number 2 collar adjusted gears came up absolute full high throttle Obviously makes necessary take offwith just slightly less full power avoid prematurely retracting gear ground doesnt present problem model adequately powered number 1 collar adjusted gear came down throttled back about /s-/z power setting Im sure sort actuating arrangement would work equally well model size wing loading range Zlin years flew particular model including two Nationals never reason wish could operate retracts independently throttle fact might consider using extra pneumatic air cylinder operate flaps tailhook etc conjunction retracts throttle could simply plug extra cylinder retract system same way done retractable tailwheel nose gear Mike Gretz Box 162 Montezuma IA 501 71 CL Aerobatics/Paul Con finued page 48 ears Lastly Bob said engine offset called plans might try some shims under front engine see helps line tension might also have move leadouts back forward change amount line tension Most profile kits built leadouts position Bob may have move around see helps summary good order trouble shooting case would 1 wing alignment including flaps also see stabilizer matched up line wing 2 wind direction 3 tip weight 4 engine Bob might want try entirely different engine same make another make see original just plain worn out 5 engine offset 6 leadout variation Sam Howard Quebec Canada wrote asking about banded crankshaft ST 46 Some RC friends told him imperative remove Actually have heard instance band coming loose subscribe Murphys Law would probably want remove However since operating stunt engines 7000 9500 rpm range less chance band coming loose RC fraternity usually run engines top end rpm range 15000 17000 Some people feel keeping band adds little bit crankcase packing helps performance Now time planning contest next summer use P AM P categories has become quite widespread area contest has started using method should promote P M P categories 1 Expert average AMA score 500 over 2 Advanced average score 400 499 3 Intermediate average score 300 399 4 Beginner average score under 300 Most fliers should have idea what average score dont can make educated guess after first round flying can change categories need areas stunt turnout large contest administrators have combined two classes based 122 Model Aviation IN STOCK FOR IMMEDIATE SHIPMENT QUADRAS $8995 QUADRA REPAIR- $1000 plus parts Jim Messers ERCOUPE KIT- $19500* Concepts BIG FLEET KIT-$17995* Barkleys TIGER MOTH KIT- $24995* *includes FREE Du-Bro Wheels /4-SCALE PLANS FOR QUADRA ERCOUPE SKYBOLT- $2000 Ca SUPER STEARMAN- $2495 ZINGER & TOP FLITE PROPS- 10% off BALSA & SPRUCE sizes- 45% off COCKPIT KIT Ercoupe- $1500 Stearman $1800 Fleet- $1800 RADIAL ENGINESfor Fleet- $3000 COVERITE 15 rolls- 20% off 24-Hour Service. Add $200 postage Send Bank Check Money Order JIM MESSERS QUALITY MODEL PRODUCTS 196 Valley View DrAllegany NY 14706 Heres equipment yeu need give props toe very Sent balance--balance directions Carefully crafted free top grade materials BUBBLE BALANCER accomodates 3/161/49/32 prop holes Other sizes available special order Dealers invited $1495 Add $150 HOWARD B HUEBL SEPT 005 postage handling iz Mion add 4% sales tan No CODs Boo 193 Reule 4 Mankato Mn 5011111 Bucker Bu-133 Jungmeister new Bucker Jungmeister 1/5 scale de signed give maximum aerobatic performance 60 engine kit documentation will illus trate 3 4 different versions famed German biplane appropriate 3-viewsThe model also convertible Jungmann version Its very versatile airplanel Construction all-wood wing structure comparable famed Wacos sequential photo-illustrated instruction manual makes putting together snap bipe youll enjoy building much flyingl FEATURES Mylar decals 60 span Complete hardware pkg 1030 sq area Builds 3 versions 49 length Modifiable Jungmann Weight 8-9 lbs Illustrated instruc 60 engine vacu-formed cowl rice $9995 2657 NE 188th Street Miami Florida 33180 Telephone 305 935-1436 previous turnouts fliers general abilities instance contest has drawn approximately 15 fliers past Beginners Intermediates Advanced contest could advertised having PA NIPA categoriea Beginner Intermediate combined Advanced Expert keeps number trophy sets three same required traditional AMA three divisions practice fliers voluntarily placing themselves cate gories seems have worked quite well over past couple years Only very few instances sandbagging have come light cases through ignorance scoring abilities rather anything else areas PAMPA categories have tried usually takes just few voices stunt fliers get contest director go ahead P NI P classes Once instituted use P AM P cate gories seems help drawing out stunt fliers some instances AMA Novice pattern has used P NI P begin ner category help get new fliers stunt flying handout sheet complete instruc tions holding P AM P category stunt contest available Keep clean English stunt newslet ter Claptrap comes suggestion Robert King periodically clean both muffler pressure fitting remove residue numerous flights experiencing lean runs some engine stopping mid-flight After changing engines tanks filter fuel lines thing left muffler pressure fitting surmised partial blocking pressure fitting residue causing lean runs info rmation Ofl Stunt orP 4 MP 4 write Wynn Pau 1640 Maywick Drive Lexington KY 40504 CL Carrier/Perry Continued page 49 wing outboard flap/aileron Leadouts moveable rudder fixed thin low-aspect-ratio wing reduces frontal area increases Reynolds Number end result reduced profile drag high speed Induced drag high speed very small because relatively light wing loadings Profile class models low speed induced drag increases compared model higher aspect ratio wing produces gentle stall because low-aspectratio planform has affect lift does airfoil section high angles attack Thus thin airfoil no penalty low speed outboard wing has flap/aileron mounted inboard two thirds span deflects up low speed providing rolling moment Out circle addition flap causes pitchup moment Mariah transitions full stall very easily quite stable 45-degree nosehigh attitude Tonys engine converted K&B 58 Speed control Supertigre carburetor rotary exhaust restrictor fuel tank uniflow type prop Rev-Up 8-8 Tony has scoring 240s combination scale bonus points Richard L Perry 416 Woodhill Dr Golds boro NC 27530 CL Speed/Hempel Continued page 50 stock preferably 2024 T6 should available hardware store metal shop Drill way through glow plug hole using #3 drill tap hole using ap Check local hardware store tap chamber use ball-end mill run up until touches tapped hole Bore out additional 115 depth develop problems check drawings clarification Ma chine button head per drawing external dimensions Now necessary machine work fin ished can start reassembling engine height clearance between button head piston Top Dead Center should no 003 may have use brass shims achieve dimension Also very careful pull binds engine tightening bolts part causes engine bind remove part check what causing problem next installmentJune issue will cover modification venturi run tank set up plus what type fuel works best suction system pipe set up Gene Hempe 301 N Yale Dr Garlana TX 75042 Fairey/Berliner Continued page 53 crew decided play safe landed Karachi India 100 gallons gas left world record flight 4130 miles first non-stop Britain India lot learned flight least important being need make crew comfortable simple lack arm rests forced pilots trade off two hours instead planned five hours FIt Lt N H Jenkins Sqdr Ldr G JonesWilliams proved basic concept Fairey LRM good Less five months after its first flight made sec ond longest aviation history Dec 16 1929 second try record begun time distance beaten 4975 set September Costes Bellonte flying Breguet XIX Ques tion Mark Paris Manchuria About 12 hours after takeoff South Africa Fairey LRM NIk 1 slammed side mountain south Tunis near Mediter ranean coast North Africa Both pilots killed airplane demolished accident investigation pointed toward weather pilot error likely con tributing factors airplane being given clean bill health July 1930 Air Ministry decided build second Long Range Monoplane changes planned addition landing gear fairings complete instrumentation two-axis gyroscopic auto-pilot being developed Royal Aeronautical Establishment new machine Mk2 K1991 flown June 30 1931 RAF tests completed early autumn proving flight made Sqdr Ldr 0 R Gayford FIt Lt D L G Bett took off Cranwell Oct 27 arrived late next day Egypt after flight 2857 miles airplane worked quite satisfactorily trip out leisurely trip back until ar rived home dense fog forced landing field England did enough damage put LRM Mk2 repair shop several months Finally ready go record April 1980 123
Edition: Model Aviation - 1980/04
Page Numbers: 48, 122, 123
AEROBATICS Wynn Paul LINE tension problem Bob Green Boyertown PA writes problem line tension profile airplane using Fox 35 engine 10-6 prop five percent nitro fuel 60 ft lines engine offset shown plans says plane loses line tension especially vertical eights overhead eights solution simple First Bob should make certain has enough tip weight Most 35 size profiles require least ry ounce 125 oz see helps talking about wing Bob better make certain wing warped outboard wing may twisted down relative inboard panel maybe flap plane has same problem could try shorter lines would make plane respon sive cause fly lap faster same rpm engine could help line tension Actually 60 foot lines profile little long unless measuring handle center airplane line length same slow combat trying fly plane about 30 mph slower slow combat Make certain lines 015 diameter 018s used tip weight will definitely needed next trouble spot could engine attempting run too slow emulate expert fliers able run engines may just having too little power out engine Remember expert fliers now using muffler pressure pressurize fuel tank among other things helps give run insufficient rpm engine would account airplane falling out sky engines muffler pressure turning 7500 9000 rpm pressure may just setting needle too rich Dont concerned engine doesnt have significant break four cycle two cycle associated star fliers thing light plane will put load engine helps cause break Also probably has engine reworked meaning piston sleeve havent fitted lapped basic stock configuration Fox 35 will easily pull a35 oz profile through pattern heavier plane engine will probably break four two cycle case judging what put letter Bob probably running engine too slow must assume Bob performing maneuvers downwind Some fliers forget vitally important part setting up maneuvers Establish wind direction before starting en gine remember During flight look trees smoke etc see wind changes direction Fliers should develop art feeling wind direction faces Continued page 122 48 Model Aviation Engine room ship built Mike Grab Sulphur Springs TX Engine OS Max 4OFSR Bob Hunt muffler Clunk tank has uniflow venting Note wire tiedown scheme tank Wynn Paul nfluruvv VUFOId Idd rIdUUU CIIIIU III CUIIU engine us OS Max r photo shows nice detail Ia wheel wire/fairing construction Sharp photo shows drop ui muffler Larry Kruse Dhotos EU 330EU WV PROPS FOR BIGGIES Now can experience full thrust potential chain saw engine prop-drive new durable efficient glass-filled nylon pY NATNrati props Platt Seen QSAA Fun Flys Louisville Las Vegas Look us up WRAMS TOLEDO Direct Factory Introductory Prices New items biggies coming DYNAHUB easist safest way start big engines DYNATI-IRUST Prop Balancer Accurate Easy-to-use & inespensive Add 50 PER PROP shipping USA pay shipping charges orders 6 s Send CHECK MO VISA MC COD mounts place Cut holes bladder tube fuelproof its interior pouring about two ounces thinned white glue sloshing around pouring out excess Fuel-proof motor mount slow-curing epoxy glue last step before engine mounting check warps also im portant steps position full soft drink can four corners wing flat surface Put straight pins tip leading edge trailing edge four pins rest cans wing straight now time mount engine go flying yours fly good hope dont meet contest CL Scale/Gretz Continued page 47 fourth control line first Zlin Akrobat used standard G-S 3-line bellcrank system throttle control An inverted style bellcrank mounted fuselage solid music wire pushrod going Fox Eagle carburetor Rhom Air retract system am familiar IN STOCK NOW 186 188 208 2010 $700 700 900 900 COMING EARLY 1980 156$500 16550 166500 Dynathrust Props Inc 2541 NE 11th Court Pompano Beach FL 33062 Raymond Colelli 305 941 9119 having used since 1973 has 4-way switching valve actuate up down movements landing gears presume other pneumatic systems have similar valve valve basically junction box systems up down pressure air hoses valve has grooved sliding barrel inside routes pressurized air appropriate up down hose end barrels travel RC applications standard servo drives inner barrel end valve other Zlin use throttle pushrod same job As can see accompanying drawing spur wire wrapped soldered throttle pushrod spur wire two wheel collars small enough slide valve push barrel valve body itself securely fastened fuselage structure throttle pushrod moves forward open carburetor number 2 collar pushes barrel front valve thus connecting up air hose pressure hose bringing landing gear up Conversely throttle pushrod closes carb number 1 collar pushes barrel rear valve completes down circuit lowers landing gear use wheel collars spur wire makes exact timing retraction ex tension gears adjustable within power range engine number 2 collar adjusted gears came up absolute full high throttle Obviously makes necessary take offwith just slightly less full power avoid prematurely retracting gear ground doesnt present problem model adequately powered number 1 collar adjusted gear came down throttled back about /s-/z power setting Im sure sort actuating arrangement would work equally well model size wing loading range Zlin years flew particular model including two Nationals never reason wish could operate retracts independently throttle fact might consider using extra pneumatic air cylinder operate flaps tailhook etc conjunction retracts throttle could simply plug extra cylinder retract system same way done retractable tailwheel nose gear Mike Gretz Box 162 Montezuma IA 501 71 CL Aerobatics/Paul Con finued page 48 ears Lastly Bob said engine offset called plans might try some shims under front engine see helps line tension might also have move leadouts back forward change amount line tension Most profile kits built leadouts position Bob may have move around see helps summary good order trouble shooting case would 1 wing alignment including flaps also see stabilizer matched up line wing 2 wind direction 3 tip weight 4 engine Bob might want try entirely different engine same make another make see original just plain worn out 5 engine offset 6 leadout variation Sam Howard Quebec Canada wrote asking about banded crankshaft ST 46 Some RC friends told him imperative remove Actually have heard instance band coming loose subscribe Murphys Law would probably want remove However since operating stunt engines 7000 9500 rpm range less chance band coming loose RC fraternity usually run engines top end rpm range 15000 17000 Some people feel keeping band adds little bit crankcase packing helps performance Now time planning contest next summer use P AM P categories has become quite widespread area contest has started using method should promote P M P categories 1 Expert average AMA score 500 over 2 Advanced average score 400 499 3 Intermediate average score 300 399 4 Beginner average score under 300 Most fliers should have idea what average score dont can make educated guess after first round flying can change categories need areas stunt turnout large contest administrators have combined two classes based 122 Model Aviation IN STOCK FOR IMMEDIATE SHIPMENT QUADRAS $8995 QUADRA REPAIR- $1000 plus parts Jim Messers ERCOUPE KIT- $19500* Concepts BIG FLEET KIT-$17995* Barkleys TIGER MOTH KIT- $24995* *includes FREE Du-Bro Wheels /4-SCALE PLANS FOR QUADRA ERCOUPE SKYBOLT- $2000 Ca SUPER STEARMAN- $2495 ZINGER & TOP FLITE PROPS- 10% off BALSA & SPRUCE sizes- 45% off COCKPIT KIT Ercoupe- $1500 Stearman $1800 Fleet- $1800 RADIAL ENGINESfor Fleet- $3000 COVERITE 15 rolls- 20% off 24-Hour Service. Add $200 postage Send Bank Check Money Order JIM MESSERS QUALITY MODEL PRODUCTS 196 Valley View DrAllegany NY 14706 Heres equipment yeu need give props toe very Sent balance--balance directions Carefully crafted free top grade materials BUBBLE BALANCER accomodates 3/161/49/32 prop holes Other sizes available special order Dealers invited $1495 Add $150 HOWARD B HUEBL SEPT 005 postage handling iz Mion add 4% sales tan No CODs Boo 193 Reule 4 Mankato Mn 5011111 Bucker Bu-133 Jungmeister new Bucker Jungmeister 1/5 scale de signed give maximum aerobatic performance 60 engine kit documentation will illus trate 3 4 different versions famed German biplane appropriate 3-viewsThe model also convertible Jungmann version Its very versatile airplanel Construction all-wood wing structure comparable famed Wacos sequential photo-illustrated instruction manual makes putting together snap bipe youll enjoy building much flyingl FEATURES Mylar decals 60 span Complete hardware pkg 1030 sq area Builds 3 versions 49 length Modifiable Jungmann Weight 8-9 lbs Illustrated instruc 60 engine vacu-formed cowl rice $9995 2657 NE 188th Street Miami Florida 33180 Telephone 305 935-1436 previous turnouts fliers general abilities instance contest has drawn approximately 15 fliers past Beginners Intermediates Advanced contest could advertised having PA NIPA categoriea Beginner Intermediate combined Advanced Expert keeps number trophy sets three same required traditional AMA three divisions practice fliers voluntarily placing themselves cate gories seems have worked quite well over past couple years Only very few instances sandbagging have come light cases through ignorance scoring abilities rather anything else areas PAMPA categories have tried usually takes just few voices stunt fliers get contest director go ahead P NI P classes Once instituted use P AM P cate gories seems help drawing out stunt fliers some instances AMA Novice pattern has used P NI P begin ner category help get new fliers stunt flying handout sheet complete instruc tions holding P AM P category stunt contest available Keep clean English stunt newslet ter Claptrap comes suggestion Robert King periodically clean both muffler pressure fitting remove residue numerous flights experiencing lean runs some engine stopping mid-flight After changing engines tanks filter fuel lines thing left muffler pressure fitting surmised partial blocking pressure fitting residue causing lean runs info rmation Ofl Stunt orP 4 MP 4 write Wynn Pau 1640 Maywick Drive Lexington KY 40504 CL Carrier/Perry Continued page 49 wing outboard flap/aileron Leadouts moveable rudder fixed thin low-aspect-ratio wing reduces frontal area increases Reynolds Number end result reduced profile drag high speed Induced drag high speed very small because relatively light wing loadings Profile class models low speed induced drag increases compared model higher aspect ratio wing produces gentle stall because low-aspectratio planform has affect lift does airfoil section high angles attack Thus thin airfoil no penalty low speed outboard wing has flap/aileron mounted inboard two thirds span deflects up low speed providing rolling moment Out circle addition flap causes pitchup moment Mariah transitions full stall very easily quite stable 45-degree nosehigh attitude Tonys engine converted K&B 58 Speed control Supertigre carburetor rotary exhaust restrictor fuel tank uniflow type prop Rev-Up 8-8 Tony has scoring 240s combination scale bonus points Richard L Perry 416 Woodhill Dr Golds boro NC 27530 CL Speed/Hempel Continued page 50 stock preferably 2024 T6 should available hardware store metal shop Drill way through glow plug hole using #3 drill tap hole using ap Check local hardware store tap chamber use ball-end mill run up until touches tapped hole Bore out additional 115 depth develop problems check drawings clarification Ma chine button head per drawing external dimensions Now necessary machine work fin ished can start reassembling engine height clearance between button head piston Top Dead Center should no 003 may have use brass shims achieve dimension Also very careful pull binds engine tightening bolts part causes engine bind remove part check what causing problem next installmentJune issue will cover modification venturi run tank set up plus what type fuel works best suction system pipe set up Gene Hempe 301 N Yale Dr Garlana TX 75042 Fairey/Berliner Continued page 53 crew decided play safe landed Karachi India 100 gallons gas left world record flight 4130 miles first non-stop Britain India lot learned flight least important being need make crew comfortable simple lack arm rests forced pilots trade off two hours instead planned five hours FIt Lt N H Jenkins Sqdr Ldr G JonesWilliams proved basic concept Fairey LRM good Less five months after its first flight made sec ond longest aviation history Dec 16 1929 second try record begun time distance beaten 4975 set September Costes Bellonte flying Breguet XIX Ques tion Mark Paris Manchuria About 12 hours after takeoff South Africa Fairey LRM NIk 1 slammed side mountain south Tunis near Mediter ranean coast North Africa Both pilots killed airplane demolished accident investigation pointed toward weather pilot error likely con tributing factors airplane being given clean bill health July 1930 Air Ministry decided build second Long Range Monoplane changes planned addition landing gear fairings complete instrumentation two-axis gyroscopic auto-pilot being developed Royal Aeronautical Establishment new machine Mk2 K1991 flown June 30 1931 RAF tests completed early autumn proving flight made Sqdr Ldr 0 R Gayford FIt Lt D L G Bett took off Cranwell Oct 27 arrived late next day Egypt after flight 2857 miles airplane worked quite satisfactorily trip out leisurely trip back until ar rived home dense fog forced landing field England did enough damage put LRM Mk2 repair shop several months Finally ready go record April 1980 123
Edition: Model Aviation - 1980/04
Page Numbers: 48, 122, 123
AEROBATICS Wynn Paul LINE tension problem Bob Green Boyertown PA writes problem line tension profile airplane using Fox 35 engine 10-6 prop five percent nitro fuel 60 ft lines engine offset shown plans says plane loses line tension especially vertical eights overhead eights solution simple First Bob should make certain has enough tip weight Most 35 size profiles require least ry ounce 125 oz see helps talking about wing Bob better make certain wing warped outboard wing may twisted down relative inboard panel maybe flap plane has same problem could try shorter lines would make plane respon sive cause fly lap faster same rpm engine could help line tension Actually 60 foot lines profile little long unless measuring handle center airplane line length same slow combat trying fly plane about 30 mph slower slow combat Make certain lines 015 diameter 018s used tip weight will definitely needed next trouble spot could engine attempting run too slow emulate expert fliers able run engines may just having too little power out engine Remember expert fliers now using muffler pressure pressurize fuel tank among other things helps give run insufficient rpm engine would account airplane falling out sky engines muffler pressure turning 7500 9000 rpm pressure may just setting needle too rich Dont concerned engine doesnt have significant break four cycle two cycle associated star fliers thing light plane will put load engine helps cause break Also probably has engine reworked meaning piston sleeve havent fitted lapped basic stock configuration Fox 35 will easily pull a35 oz profile through pattern heavier plane engine will probably break four two cycle case judging what put letter Bob probably running engine too slow must assume Bob performing maneuvers downwind Some fliers forget vitally important part setting up maneuvers Establish wind direction before starting en gine remember During flight look trees smoke etc see wind changes direction Fliers should develop art feeling wind direction faces Continued page 122 48 Model Aviation Engine room ship built Mike Grab Sulphur Springs TX Engine OS Max 4OFSR Bob Hunt muffler Clunk tank has uniflow venting Note wire tiedown scheme tank Wynn Paul nfluruvv VUFOId Idd rIdUUU CIIIIU III CUIIU engine us OS Max r photo shows nice detail Ia wheel wire/fairing construction Sharp photo shows drop ui muffler Larry Kruse Dhotos EU 330EU WV PROPS FOR BIGGIES Now can experience full thrust potential chain saw engine prop-drive new durable efficient glass-filled nylon pY NATNrati props Platt Seen QSAA Fun Flys Louisville Las Vegas Look us up WRAMS TOLEDO Direct Factory Introductory Prices New items biggies coming DYNAHUB easist safest way start big engines DYNATI-IRUST Prop Balancer Accurate Easy-to-use & inespensive Add 50 PER PROP shipping USA pay shipping charges orders 6 s Send CHECK MO VISA MC COD mounts place Cut holes bladder tube fuelproof its interior pouring about two ounces thinned white glue sloshing around pouring out excess Fuel-proof motor mount slow-curing epoxy glue last step before engine mounting check warps also im portant steps position full soft drink can four corners wing flat surface Put straight pins tip leading edge trailing edge four pins rest cans wing straight now time mount engine go flying yours fly good hope dont meet contest CL Scale/Gretz Continued page 47 fourth control line first Zlin Akrobat used standard G-S 3-line bellcrank system throttle control An inverted style bellcrank mounted fuselage solid music wire pushrod going Fox Eagle carburetor Rhom Air retract system am familiar IN STOCK NOW 186 188 208 2010 $700 700 900 900 COMING EARLY 1980 156$500 16550 166500 Dynathrust Props Inc 2541 NE 11th Court Pompano Beach FL 33062 Raymond Colelli 305 941 9119 having used since 1973 has 4-way switching valve actuate up down movements landing gears presume other pneumatic systems have similar valve valve basically junction box systems up down pressure air hoses valve has grooved sliding barrel inside routes pressurized air appropriate up down hose end barrels travel RC applications standard servo drives inner barrel end valve other Zlin use throttle pushrod same job As can see accompanying drawing spur wire wrapped soldered throttle pushrod spur wire two wheel collars small enough slide valve push barrel valve body itself securely fastened fuselage structure throttle pushrod moves forward open carburetor number 2 collar pushes barrel front valve thus connecting up air hose pressure hose bringing landing gear up Conversely throttle pushrod closes carb number 1 collar pushes barrel rear valve completes down circuit lowers landing gear use wheel collars spur wire makes exact timing retraction ex tension gears adjustable within power range engine number 2 collar adjusted gears came up absolute full high throttle Obviously makes necessary take offwith just slightly less full power avoid prematurely retracting gear ground doesnt present problem model adequately powered number 1 collar adjusted gear came down throttled back about /s-/z power setting Im sure sort actuating arrangement would work equally well model size wing loading range Zlin years flew particular model including two Nationals never reason wish could operate retracts independently throttle fact might consider using extra pneumatic air cylinder operate flaps tailhook etc conjunction retracts throttle could simply plug extra cylinder retract system same way done retractable tailwheel nose gear Mike Gretz Box 162 Montezuma IA 501 71 CL Aerobatics/Paul Con finued page 48 ears Lastly Bob said engine offset called plans might try some shims under front engine see helps line tension might also have move leadouts back forward change amount line tension Most profile kits built leadouts position Bob may have move around see helps summary good order trouble shooting case would 1 wing alignment including flaps also see stabilizer matched up line wing 2 wind direction 3 tip weight 4 engine Bob might want try entirely different engine same make another make see original just plain worn out 5 engine offset 6 leadout variation Sam Howard Quebec Canada wrote asking about banded crankshaft ST 46 Some RC friends told him imperative remove Actually have heard instance band coming loose subscribe Murphys Law would probably want remove However since operating stunt engines 7000 9500 rpm range less chance band coming loose RC fraternity usually run engines top end rpm range 15000 17000 Some people feel keeping band adds little bit crankcase packing helps performance Now time planning contest next summer use P AM P categories has become quite widespread area contest has started using method should promote P M P categories 1 Expert average AMA score 500 over 2 Advanced average score 400 499 3 Intermediate average score 300 399 4 Beginner average score under 300 Most fliers should have idea what average score dont can make educated guess after first round flying can change categories need areas stunt turnout large contest administrators have combined two classes based 122 Model Aviation IN STOCK FOR IMMEDIATE SHIPMENT QUADRAS $8995 QUADRA REPAIR- $1000 plus parts Jim Messers ERCOUPE KIT- $19500* Concepts BIG FLEET KIT-$17995* Barkleys TIGER MOTH KIT- $24995* *includes FREE Du-Bro Wheels /4-SCALE PLANS FOR QUADRA ERCOUPE SKYBOLT- $2000 Ca SUPER STEARMAN- $2495 ZINGER & TOP FLITE PROPS- 10% off BALSA & SPRUCE sizes- 45% off COCKPIT KIT Ercoupe- $1500 Stearman $1800 Fleet- $1800 RADIAL ENGINESfor Fleet- $3000 COVERITE 15 rolls- 20% off 24-Hour Service. Add $200 postage Send Bank Check Money Order JIM MESSERS QUALITY MODEL PRODUCTS 196 Valley View DrAllegany NY 14706 Heres equipment yeu need give props toe very Sent balance--balance directions Carefully crafted free top grade materials BUBBLE BALANCER accomodates 3/161/49/32 prop holes Other sizes available special order Dealers invited $1495 Add $150 HOWARD B HUEBL SEPT 005 postage handling iz Mion add 4% sales tan No CODs Boo 193 Reule 4 Mankato Mn 5011111 Bucker Bu-133 Jungmeister new Bucker Jungmeister 1/5 scale de signed give maximum aerobatic performance 60 engine kit documentation will illus trate 3 4 different versions famed German biplane appropriate 3-viewsThe model also convertible Jungmann version Its very versatile airplanel Construction all-wood wing structure comparable famed Wacos sequential photo-illustrated instruction manual makes putting together snap bipe youll enjoy building much flyingl FEATURES Mylar decals 60 span Complete hardware pkg 1030 sq area Builds 3 versions 49 length Modifiable Jungmann Weight 8-9 lbs Illustrated instruc 60 engine vacu-formed cowl rice $9995 2657 NE 188th Street Miami Florida 33180 Telephone 305 935-1436 previous turnouts fliers general abilities instance contest has drawn approximately 15 fliers past Beginners Intermediates Advanced contest could advertised having PA NIPA categoriea Beginner Intermediate combined Advanced Expert keeps number trophy sets three same required traditional AMA three divisions practice fliers voluntarily placing themselves cate gories seems have worked quite well over past couple years Only very few instances sandbagging have come light cases through ignorance scoring abilities rather anything else areas PAMPA categories have tried usually takes just few voices stunt fliers get contest director go ahead P NI P classes Once instituted use P AM P cate gories seems help drawing out stunt fliers some instances AMA Novice pattern has used P NI P begin ner category help get new fliers stunt flying handout sheet complete instruc tions holding P AM P category stunt contest available Keep clean English stunt newslet ter Claptrap comes suggestion Robert King periodically clean both muffler pressure fitting remove residue numerous flights experiencing lean runs some engine stopping mid-flight After changing engines tanks filter fuel lines thing left muffler pressure fitting surmised partial blocking pressure fitting residue causing lean runs info rmation Ofl Stunt orP 4 MP 4 write Wynn Pau 1640 Maywick Drive Lexington KY 40504 CL Carrier/Perry Continued page 49 wing outboard flap/aileron Leadouts moveable rudder fixed thin low-aspect-ratio wing reduces frontal area increases Reynolds Number end result reduced profile drag high speed Induced drag high speed very small because relatively light wing loadings Profile class models low speed induced drag increases compared model higher aspect ratio wing produces gentle stall because low-aspectratio planform has affect lift does airfoil section high angles attack Thus thin airfoil no penalty low speed outboard wing has flap/aileron mounted inboard two thirds span deflects up low speed providing rolling moment Out circle addition flap causes pitchup moment Mariah transitions full stall very easily quite stable 45-degree nosehigh attitude Tonys engine converted K&B 58 Speed control Supertigre carburetor rotary exhaust restrictor fuel tank uniflow type prop Rev-Up 8-8 Tony has scoring 240s combination scale bonus points Richard L Perry 416 Woodhill Dr Golds boro NC 27530 CL Speed/Hempel Continued page 50 stock preferably 2024 T6 should available hardware store metal shop Drill way through glow plug hole using #3 drill tap hole using ap Check local hardware store tap chamber use ball-end mill run up until touches tapped hole Bore out additional 115 depth develop problems check drawings clarification Ma chine button head per drawing external dimensions Now necessary machine work fin ished can start reassembling engine height clearance between button head piston Top Dead Center should no 003 may have use brass shims achieve dimension Also very careful pull binds engine tightening bolts part causes engine bind remove part check what causing problem next installmentJune issue will cover modification venturi run tank set up plus what type fuel works best suction system pipe set up Gene Hempe 301 N Yale Dr Garlana TX 75042 Fairey/Berliner Continued page 53 crew decided play safe landed Karachi India 100 gallons gas left world record flight 4130 miles first non-stop Britain India lot learned flight least important being need make crew comfortable simple lack arm rests forced pilots trade off two hours instead planned five hours FIt Lt N H Jenkins Sqdr Ldr G JonesWilliams proved basic concept Fairey LRM good Less five months after its first flight made sec ond longest aviation history Dec 16 1929 second try record begun time distance beaten 4975 set September Costes Bellonte flying Breguet XIX Ques tion Mark Paris Manchuria About 12 hours after takeoff South Africa Fairey LRM NIk 1 slammed side mountain south Tunis near Mediter ranean coast North Africa Both pilots killed airplane demolished accident investigation pointed toward weather pilot error likely con tributing factors airplane being given clean bill health July 1930 Air Ministry decided build second Long Range Monoplane changes planned addition landing gear fairings complete instrumentation two-axis gyroscopic auto-pilot being developed Royal Aeronautical Establishment new machine Mk2 K1991 flown June 30 1931 RAF tests completed early autumn proving flight made Sqdr Ldr 0 R Gayford FIt Lt D L G Bett took off Cranwell Oct 27 arrived late next day Egypt after flight 2857 miles airplane worked quite satisfactorily trip out leisurely trip back until ar rived home dense fog forced landing field England did enough damage put LRM Mk2 repair shop several months Finally ready go record April 1980 123