Old Timers 0 Clarence Haught KEEPING TRIM flying season officially Time get old birds out check trim initial trimming brand-new ship model has several successful seasons winter storage may take its toll form unwanted warps sticky timers congealed oil fuel system Better check out before big contest spend day troubleshooting retrim ming Trimming old-timer little differ ent checking out typical AMA power ship Start locating center gravity balance point old-timer plans indicate CG Generally speaking cabin ships balance 1/3 chord back leading edge Pylon models should balance 1/2 chord Next check model warps Any unwanted warps can removed twist ing opposite direction holding surface over steam pan boil ing water Eliminate tail surface warps Wing tips should washed out slightly trailing edge higher leading edge tips will stall before main panels induce spins About 3/32 inch OK plan glide turn same power turn inboard wing panel direction turn should washed slightly trailing edge lower leading edge/s inch average effective added incidence will assist slower flying inboard wing during climbing turn same added inci dence will create enough drag help duce gliding turn same direction wish glide opposite di rection power pattern would better advised keep main panels flat climb against opposite rud der tab hold inboard wing up glide rudder typical old days personally feel models tran sist better turns same di rection Stabilizer tilt widely used turn trim modern models seldom effective old-timers due small area com pared wing frequent use non-lifting stabilizer airfoils basic rule power turn pylon Continued page 99 MARK FECHNERS FUEL TEST RESULTS 1947 OSR SIDE PORT 19 Y8IO 10-4 PROP ALL FUELS MIXED 31 COMBUSTIBLESLUBRICANTSRPM WHITE GASKLOTZ OIL2OO WHITE GASSAE 70 L7600 COLEMAN FUELBLENZALL7300 COLEMAN FUELSAF 70 OIL7700 AVIATION GASKLOTZ OIL7400 AVIATION GASSAE 70 OIL8100 June 1977 39 nanamaas timer assemiies Dy ucnsner Lenter unit fits nya 1 y 19 Right unit Enya 09 Left unit miscellaneous Handmade ignition conversions McCoy 35 19 Hans Ochsner using points lawnmower engineis turns 9 1 1 M 9-4 prop Bill MclJow displays OT details Westerner Stab pivots center wire trailing edge wire maintains alignment Bob Stalick pic Spielmaker 60 sand cast one-piece head cylinder No head bolts Tank formed snowmobile windshield Vic Ferrarese photo test enables model set up re paired and/or re-aligned using exactly same fixtures built sur face Fig 5 model carrying box Since base fixture wide balsa strip pins work well building board home masking tape ideal contest Plan Ahead limitation Ive found own version devices de scribed future shock couldnt envision would ever need 7/2 wing chord wires adjustable stands 7 apart Oops Bud Tenny Box 545 Richardson TX 75080 FF Old-Timers/Haught continued page 39 right cabin left Some cabin ships will climb right just well would recommend left safe side Power turn usually induced engine side-thrust subject thrust adjustments old-timers need downthrust rarely called out plan About 2 degrees good starting point should now ready flight tests Hand glide ship wind check diving stalling tendencies Correct changing incidence either wing stab prefer make adjust ments stabilizer because changing wing incidence effectively changes thrust line Also turning tendencies should observed Due limited duration hand glide slight turn should apparent Begin power tests 5-second engine run shorter run will tell enough longer may prove disas trous trim far off engine should adjusted reasonable amount thrust Extremely low power wont really tell anything could lead stall As soon possible increase power normal models behave consider ably different power increases trim ming done low power will have re done anyhow Gradually lengthen engine run ob serving flight pattern Adjust climb pat tern thrust and/or incidence adjust ments Make adjustment time Dont worry too much about glide trim long its safe stage Once power pattern good can correct glide speed small shifts center gravity addition ballast Glide turn can also induced adding short approximately 6 piece Vi X 1 tapered trailing edge stock bot tom trailing edge inboard wing thin edge forward Some modelers prefer hinged drag flap purpose experience nil Ill mis direct score Transition power glide influ enced power turn having trouble transitions try tighter pow er turn will reduce effective cidence may have increase maintain climb angle Looping tenden cies can corrected down-thrust power turn Think out problem observe things arent going too well pack up go home can devote unpressured thought prob lem Never rush flight trimming proce dures Fuel Tests mail indicates testing various fuels improved serv ice life better power Phil Mahony Lime Rock CT has experimenting Castrol R-40 Phil claims less heat oil uses Amoco high-test no-lead gasoline Phil didnt indicate mixing ratio 3 1 would good start Mark Fechner oit Salt Lake way has run some interesting tests using O&R 19 side-port engine Y&O 10-4 prop using various oils combustibles always comparing back good old SAE 70 oil accompanying chart shows results Marks tests Mark accomplished engine conversion spe cialist plan obtain Marks Continued page 100 June 1977 99 dollarthats need send big EAA info pack shown above Tells about EAA benefits EAA membership will mean Send buck today Includes recent issue SPORT AVIATION Experimental Aircraft Association Inc ~~ EAAAVIATIQN PO Box 229 Hales Corners Wis 53130 A Milwaukee Suburb \HAS MY Phone 414-425-4860 W Airplanes thing Want find out what real world sport aviation about youll want information EAA homebuilts antiques classics warbirds gliders rotary wing aerobatics other type sport aircraft turn Find out what takes build aircraftor design can join EAA chapter near benefit experience skills other builders EAA membership $2000 per year includes monthly SPORT AVIATION Junior membership 18 younger $1000 Information pack $150 Continued page 99 Kiondyke engines test future col umn list parts services en gines write him 4456 W 3145 S Salt Lake City UT 84120 Incidentally Mark has available excel lent reproduction Super Cyclone manuals very interesting bit out past Engines My mail also indicates consider able interest engine conversion work Hans Ochsner Detroit has working McCoy Enya engines con verting using hand tools Hans utilizes readily available chainsaw lawnmower point assemblies reworks model use engines far converted have good power handling qualities Hans competition flier has flown Brooklyn Dodger Enya 19 conversion Hans also has running some interesting comparisons engine dimensions combustion chamber vol umes Write him 19195 McCormick Detroit MI 48224 Clarence Haught Route 5 Box 16 Coeur dAlene ID 83814 Seen Nurnberg/Moulton continued page 45 Robbe have less shattering Rasant racer electric sport plus yet another scale Piper Cub Super Cruiser variant Milan Circe sailplanes elegant lines Lanzet delta calls mixer controls Aeronaut have gone Cessna 172 ever popular twoway electric glow BD5 caricature wings Looks good scale really fell Udets Flamingo created elec tric glowvintage bipe late 1970s power Knck add latest Fournier RF7 quality scale range Karl Heinz Denzin has done again ideal combo detail plus GF fuselage model offers fun flying strict con test prospects Topp GF specialist Buyers get shell plans what subjects latest DO 17 Pencil Bomber MRCA Tornado Strangely conventional Topps Tweety yet another 2-way electro-glow using full range balsa GF/foam assy make latter day H-Ray Rogallo Flexwing autogiro sail plus tail sight see Thrust moments drag factors could make Langley field blink sure Big models continue Bauer have chunky Auster Wik Hummel either can anything slow cruise glider tow haul cameras Schiuter represents real progress beauty new case Heli Baby make Hughes 500 also Bell 222 incorporates lessons maestro rotorplanes has gleaned Kompletta Dieters finished 3-meter sail plane work wanted Fohn 2-meter kit slope tow-launch sail plane Siniprop enter smaller RC 20 Boxflynuff sed two l/2A Ministhe Bird Devil 09 Cessna 177 among other imports Simprop inven tory huge though Kavans breakaway must have some effect Simprop bank ing SSM contest system RC units ring bells competitive sector Webras tie Becker market 433 MHz well 27 35 40 equipment drew constant dealer attention too big 91 joins successful 61 marine aero versions Webra family riding crest proving highrev noise-makers dont necessarily win boat game 18 cc Euro pean marine classes plus 20 build range bigger Sad news Helmut Bernhard died new Cessna Stationair testing eve show put cloud announcements HB engines PDP pumps carhs understand Helmuts death will affect immediate production must recall mans genius built up fastest growing model manufacturing unit Europe make Veco first confused HP Austria played cool year UC40 sandblasted 61 re-appearance 40 61 twins being showpieces OPS re vived 19 proto coming closer reality MVVS produced new 40 plus 027 C02 buyers queue alas no production till next year Rudi Cerny heads Czech kit firm now 100 Model Aviation U
Edition: Model Aviation - 1977/06
Page Numbers: 39, 99, 100
Old Timers 0 Clarence Haught KEEPING TRIM flying season officially Time get old birds out check trim initial trimming brand-new ship model has several successful seasons winter storage may take its toll form unwanted warps sticky timers congealed oil fuel system Better check out before big contest spend day troubleshooting retrim ming Trimming old-timer little differ ent checking out typical AMA power ship Start locating center gravity balance point old-timer plans indicate CG Generally speaking cabin ships balance 1/3 chord back leading edge Pylon models should balance 1/2 chord Next check model warps Any unwanted warps can removed twist ing opposite direction holding surface over steam pan boil ing water Eliminate tail surface warps Wing tips should washed out slightly trailing edge higher leading edge tips will stall before main panels induce spins About 3/32 inch OK plan glide turn same power turn inboard wing panel direction turn should washed slightly trailing edge lower leading edge/s inch average effective added incidence will assist slower flying inboard wing during climbing turn same added inci dence will create enough drag help duce gliding turn same direction wish glide opposite di rection power pattern would better advised keep main panels flat climb against opposite rud der tab hold inboard wing up glide rudder typical old days personally feel models tran sist better turns same di rection Stabilizer tilt widely used turn trim modern models seldom effective old-timers due small area com pared wing frequent use non-lifting stabilizer airfoils basic rule power turn pylon Continued page 99 MARK FECHNERS FUEL TEST RESULTS 1947 OSR SIDE PORT 19 Y8IO 10-4 PROP ALL FUELS MIXED 31 COMBUSTIBLESLUBRICANTSRPM WHITE GASKLOTZ OIL2OO WHITE GASSAE 70 L7600 COLEMAN FUELBLENZALL7300 COLEMAN FUELSAF 70 OIL7700 AVIATION GASKLOTZ OIL7400 AVIATION GASSAE 70 OIL8100 June 1977 39 nanamaas timer assemiies Dy ucnsner Lenter unit fits nya 1 y 19 Right unit Enya 09 Left unit miscellaneous Handmade ignition conversions McCoy 35 19 Hans Ochsner using points lawnmower engineis turns 9 1 1 M 9-4 prop Bill MclJow displays OT details Westerner Stab pivots center wire trailing edge wire maintains alignment Bob Stalick pic Spielmaker 60 sand cast one-piece head cylinder No head bolts Tank formed snowmobile windshield Vic Ferrarese photo test enables model set up re paired and/or re-aligned using exactly same fixtures built sur face Fig 5 model carrying box Since base fixture wide balsa strip pins work well building board home masking tape ideal contest Plan Ahead limitation Ive found own version devices de scribed future shock couldnt envision would ever need 7/2 wing chord wires adjustable stands 7 apart Oops Bud Tenny Box 545 Richardson TX 75080 FF Old-Timers/Haught continued page 39 right cabin left Some cabin ships will climb right just well would recommend left safe side Power turn usually induced engine side-thrust subject thrust adjustments old-timers need downthrust rarely called out plan About 2 degrees good starting point should now ready flight tests Hand glide ship wind check diving stalling tendencies Correct changing incidence either wing stab prefer make adjust ments stabilizer because changing wing incidence effectively changes thrust line Also turning tendencies should observed Due limited duration hand glide slight turn should apparent Begin power tests 5-second engine run shorter run will tell enough longer may prove disas trous trim far off engine should adjusted reasonable amount thrust Extremely low power wont really tell anything could lead stall As soon possible increase power normal models behave consider ably different power increases trim ming done low power will have re done anyhow Gradually lengthen engine run ob serving flight pattern Adjust climb pat tern thrust and/or incidence adjust ments Make adjustment time Dont worry too much about glide trim long its safe stage Once power pattern good can correct glide speed small shifts center gravity addition ballast Glide turn can also induced adding short approximately 6 piece Vi X 1 tapered trailing edge stock bot tom trailing edge inboard wing thin edge forward Some modelers prefer hinged drag flap purpose experience nil Ill mis direct score Transition power glide influ enced power turn having trouble transitions try tighter pow er turn will reduce effective cidence may have increase maintain climb angle Looping tenden cies can corrected down-thrust power turn Think out problem observe things arent going too well pack up go home can devote unpressured thought prob lem Never rush flight trimming proce dures Fuel Tests mail indicates testing various fuels improved serv ice life better power Phil Mahony Lime Rock CT has experimenting Castrol R-40 Phil claims less heat oil uses Amoco high-test no-lead gasoline Phil didnt indicate mixing ratio 3 1 would good start Mark Fechner oit Salt Lake way has run some interesting tests using O&R 19 side-port engine Y&O 10-4 prop using various oils combustibles always comparing back good old SAE 70 oil accompanying chart shows results Marks tests Mark accomplished engine conversion spe cialist plan obtain Marks Continued page 100 June 1977 99 dollarthats need send big EAA info pack shown above Tells about EAA benefits EAA membership will mean Send buck today Includes recent issue SPORT AVIATION Experimental Aircraft Association Inc ~~ EAAAVIATIQN PO Box 229 Hales Corners Wis 53130 A Milwaukee Suburb \HAS MY Phone 414-425-4860 W Airplanes thing Want find out what real world sport aviation about youll want information EAA homebuilts antiques classics warbirds gliders rotary wing aerobatics other type sport aircraft turn Find out what takes build aircraftor design can join EAA chapter near benefit experience skills other builders EAA membership $2000 per year includes monthly SPORT AVIATION Junior membership 18 younger $1000 Information pack $150 Continued page 99 Kiondyke engines test future col umn list parts services en gines write him 4456 W 3145 S Salt Lake City UT 84120 Incidentally Mark has available excel lent reproduction Super Cyclone manuals very interesting bit out past Engines My mail also indicates consider able interest engine conversion work Hans Ochsner Detroit has working McCoy Enya engines con verting using hand tools Hans utilizes readily available chainsaw lawnmower point assemblies reworks model use engines far converted have good power handling qualities Hans competition flier has flown Brooklyn Dodger Enya 19 conversion Hans also has running some interesting comparisons engine dimensions combustion chamber vol umes Write him 19195 McCormick Detroit MI 48224 Clarence Haught Route 5 Box 16 Coeur dAlene ID 83814 Seen Nurnberg/Moulton continued page 45 Robbe have less shattering Rasant racer electric sport plus yet another scale Piper Cub Super Cruiser variant Milan Circe sailplanes elegant lines Lanzet delta calls mixer controls Aeronaut have gone Cessna 172 ever popular twoway electric glow BD5 caricature wings Looks good scale really fell Udets Flamingo created elec tric glowvintage bipe late 1970s power Knck add latest Fournier RF7 quality scale range Karl Heinz Denzin has done again ideal combo detail plus GF fuselage model offers fun flying strict con test prospects Topp GF specialist Buyers get shell plans what subjects latest DO 17 Pencil Bomber MRCA Tornado Strangely conventional Topps Tweety yet another 2-way electro-glow using full range balsa GF/foam assy make latter day H-Ray Rogallo Flexwing autogiro sail plus tail sight see Thrust moments drag factors could make Langley field blink sure Big models continue Bauer have chunky Auster Wik Hummel either can anything slow cruise glider tow haul cameras Schiuter represents real progress beauty new case Heli Baby make Hughes 500 also Bell 222 incorporates lessons maestro rotorplanes has gleaned Kompletta Dieters finished 3-meter sail plane work wanted Fohn 2-meter kit slope tow-launch sail plane Siniprop enter smaller RC 20 Boxflynuff sed two l/2A Ministhe Bird Devil 09 Cessna 177 among other imports Simprop inven tory huge though Kavans breakaway must have some effect Simprop bank ing SSM contest system RC units ring bells competitive sector Webras tie Becker market 433 MHz well 27 35 40 equipment drew constant dealer attention too big 91 joins successful 61 marine aero versions Webra family riding crest proving highrev noise-makers dont necessarily win boat game 18 cc Euro pean marine classes plus 20 build range bigger Sad news Helmut Bernhard died new Cessna Stationair testing eve show put cloud announcements HB engines PDP pumps carhs understand Helmuts death will affect immediate production must recall mans genius built up fastest growing model manufacturing unit Europe make Veco first confused HP Austria played cool year UC40 sandblasted 61 re-appearance 40 61 twins being showpieces OPS re vived 19 proto coming closer reality MVVS produced new 40 plus 027 C02 buyers queue alas no production till next year Rudi Cerny heads Czech kit firm now 100 Model Aviation U
Edition: Model Aviation - 1977/06
Page Numbers: 39, 99, 100
Old Timers 0 Clarence Haught KEEPING TRIM flying season officially Time get old birds out check trim initial trimming brand-new ship model has several successful seasons winter storage may take its toll form unwanted warps sticky timers congealed oil fuel system Better check out before big contest spend day troubleshooting retrim ming Trimming old-timer little differ ent checking out typical AMA power ship Start locating center gravity balance point old-timer plans indicate CG Generally speaking cabin ships balance 1/3 chord back leading edge Pylon models should balance 1/2 chord Next check model warps Any unwanted warps can removed twist ing opposite direction holding surface over steam pan boil ing water Eliminate tail surface warps Wing tips should washed out slightly trailing edge higher leading edge tips will stall before main panels induce spins About 3/32 inch OK plan glide turn same power turn inboard wing panel direction turn should washed slightly trailing edge lower leading edge/s inch average effective added incidence will assist slower flying inboard wing during climbing turn same added inci dence will create enough drag help duce gliding turn same direction wish glide opposite di rection power pattern would better advised keep main panels flat climb against opposite rud der tab hold inboard wing up glide rudder typical old days personally feel models tran sist better turns same di rection Stabilizer tilt widely used turn trim modern models seldom effective old-timers due small area com pared wing frequent use non-lifting stabilizer airfoils basic rule power turn pylon Continued page 99 MARK FECHNERS FUEL TEST RESULTS 1947 OSR SIDE PORT 19 Y8IO 10-4 PROP ALL FUELS MIXED 31 COMBUSTIBLESLUBRICANTSRPM WHITE GASKLOTZ OIL2OO WHITE GASSAE 70 L7600 COLEMAN FUELBLENZALL7300 COLEMAN FUELSAF 70 OIL7700 AVIATION GASKLOTZ OIL7400 AVIATION GASSAE 70 OIL8100 June 1977 39 nanamaas timer assemiies Dy ucnsner Lenter unit fits nya 1 y 19 Right unit Enya 09 Left unit miscellaneous Handmade ignition conversions McCoy 35 19 Hans Ochsner using points lawnmower engineis turns 9 1 1 M 9-4 prop Bill MclJow displays OT details Westerner Stab pivots center wire trailing edge wire maintains alignment Bob Stalick pic Spielmaker 60 sand cast one-piece head cylinder No head bolts Tank formed snowmobile windshield Vic Ferrarese photo test enables model set up re paired and/or re-aligned using exactly same fixtures built sur face Fig 5 model carrying box Since base fixture wide balsa strip pins work well building board home masking tape ideal contest Plan Ahead limitation Ive found own version devices de scribed future shock couldnt envision would ever need 7/2 wing chord wires adjustable stands 7 apart Oops Bud Tenny Box 545 Richardson TX 75080 FF Old-Timers/Haught continued page 39 right cabin left Some cabin ships will climb right just well would recommend left safe side Power turn usually induced engine side-thrust subject thrust adjustments old-timers need downthrust rarely called out plan About 2 degrees good starting point should now ready flight tests Hand glide ship wind check diving stalling tendencies Correct changing incidence either wing stab prefer make adjust ments stabilizer because changing wing incidence effectively changes thrust line Also turning tendencies should observed Due limited duration hand glide slight turn should apparent Begin power tests 5-second engine run shorter run will tell enough longer may prove disas trous trim far off engine should adjusted reasonable amount thrust Extremely low power wont really tell anything could lead stall As soon possible increase power normal models behave consider ably different power increases trim ming done low power will have re done anyhow Gradually lengthen engine run ob serving flight pattern Adjust climb pat tern thrust and/or incidence adjust ments Make adjustment time Dont worry too much about glide trim long its safe stage Once power pattern good can correct glide speed small shifts center gravity addition ballast Glide turn can also induced adding short approximately 6 piece Vi X 1 tapered trailing edge stock bot tom trailing edge inboard wing thin edge forward Some modelers prefer hinged drag flap purpose experience nil Ill mis direct score Transition power glide influ enced power turn having trouble transitions try tighter pow er turn will reduce effective cidence may have increase maintain climb angle Looping tenden cies can corrected down-thrust power turn Think out problem observe things arent going too well pack up go home can devote unpressured thought prob lem Never rush flight trimming proce dures Fuel Tests mail indicates testing various fuels improved serv ice life better power Phil Mahony Lime Rock CT has experimenting Castrol R-40 Phil claims less heat oil uses Amoco high-test no-lead gasoline Phil didnt indicate mixing ratio 3 1 would good start Mark Fechner oit Salt Lake way has run some interesting tests using O&R 19 side-port engine Y&O 10-4 prop using various oils combustibles always comparing back good old SAE 70 oil accompanying chart shows results Marks tests Mark accomplished engine conversion spe cialist plan obtain Marks Continued page 100 June 1977 99 dollarthats need send big EAA info pack shown above Tells about EAA benefits EAA membership will mean Send buck today Includes recent issue SPORT AVIATION Experimental Aircraft Association Inc ~~ EAAAVIATIQN PO Box 229 Hales Corners Wis 53130 A Milwaukee Suburb \HAS MY Phone 414-425-4860 W Airplanes thing Want find out what real world sport aviation about youll want information EAA homebuilts antiques classics warbirds gliders rotary wing aerobatics other type sport aircraft turn Find out what takes build aircraftor design can join EAA chapter near benefit experience skills other builders EAA membership $2000 per year includes monthly SPORT AVIATION Junior membership 18 younger $1000 Information pack $150 Continued page 99 Kiondyke engines test future col umn list parts services en gines write him 4456 W 3145 S Salt Lake City UT 84120 Incidentally Mark has available excel lent reproduction Super Cyclone manuals very interesting bit out past Engines My mail also indicates consider able interest engine conversion work Hans Ochsner Detroit has working McCoy Enya engines con verting using hand tools Hans utilizes readily available chainsaw lawnmower point assemblies reworks model use engines far converted have good power handling qualities Hans competition flier has flown Brooklyn Dodger Enya 19 conversion Hans also has running some interesting comparisons engine dimensions combustion chamber vol umes Write him 19195 McCormick Detroit MI 48224 Clarence Haught Route 5 Box 16 Coeur dAlene ID 83814 Seen Nurnberg/Moulton continued page 45 Robbe have less shattering Rasant racer electric sport plus yet another scale Piper Cub Super Cruiser variant Milan Circe sailplanes elegant lines Lanzet delta calls mixer controls Aeronaut have gone Cessna 172 ever popular twoway electric glow BD5 caricature wings Looks good scale really fell Udets Flamingo created elec tric glowvintage bipe late 1970s power Knck add latest Fournier RF7 quality scale range Karl Heinz Denzin has done again ideal combo detail plus GF fuselage model offers fun flying strict con test prospects Topp GF specialist Buyers get shell plans what subjects latest DO 17 Pencil Bomber MRCA Tornado Strangely conventional Topps Tweety yet another 2-way electro-glow using full range balsa GF/foam assy make latter day H-Ray Rogallo Flexwing autogiro sail plus tail sight see Thrust moments drag factors could make Langley field blink sure Big models continue Bauer have chunky Auster Wik Hummel either can anything slow cruise glider tow haul cameras Schiuter represents real progress beauty new case Heli Baby make Hughes 500 also Bell 222 incorporates lessons maestro rotorplanes has gleaned Kompletta Dieters finished 3-meter sail plane work wanted Fohn 2-meter kit slope tow-launch sail plane Siniprop enter smaller RC 20 Boxflynuff sed two l/2A Ministhe Bird Devil 09 Cessna 177 among other imports Simprop inven tory huge though Kavans breakaway must have some effect Simprop bank ing SSM contest system RC units ring bells competitive sector Webras tie Becker market 433 MHz well 27 35 40 equipment drew constant dealer attention too big 91 joins successful 61 marine aero versions Webra family riding crest proving highrev noise-makers dont necessarily win boat game 18 cc Euro pean marine classes plus 20 build range bigger Sad news Helmut Bernhard died new Cessna Stationair testing eve show put cloud announcements HB engines PDP pumps carhs understand Helmuts death will affect immediate production must recall mans genius built up fastest growing model manufacturing unit Europe make Veco first confused HP Austria played cool year UC40 sandblasted 61 re-appearance 40 61 twins being showpieces OPS re vived 19 proto coming closer reality MVVS produced new 40 plus 027 C02 buyers queue alas no production till next year Rudi Cerny heads Czech kit firm now 100 Model Aviation U