B AND B Special model shown threeview has racked up fair score itself Al though built various earlier versions 520 shown has built designer Bill Burks wife Carolyne far Cliff Cloud Climbers meet June racked up nine maxes first place Class Open Gas hightime award meet bad 50-yearold gal wed say NFFS International Planbook 1979 promises model aviation collectors item century judging present indica tions writing late July 96 drawings models intended flown World Champs have received according Planbook Editor Dave Linstrum almost volun teer draftsmen have lined up final drawings publication Planbook isnt merely book plans Some other items included Evolution FAI engines P G F Chinn evolution Nordic towline glider event early years Wakefield Trophy competition portfolio fa mous vintage Wakefield three-views Power photos models pen-pal address list fore word Frank Zinc some history started Model Aemnautics Yearbook series hold hats Aeromodelling Peking British spelling aeromodeling Offhand Id think Aeromodelling Pe king would suitable title booklet blank note paper Mainland China sending team participate World Champs wonder theyll show up staff built bamboo rice paper tied together reed thongs.. stuff made fiberglass carbon fibers Kevlar epoxy resins. e thing betveen Remember hehaws North Koreans got appeared list World Champs participants dont laugh much anymore about Mainly cry lot try harder Pinhole Turbulators want build model has competition potential about zero use airfoil rounded leading edge cover top surface least sheet use slick plastic film covering Most models arent built way employ some form turbulation sharp leading edge microscopically-fuzzy finish stick-n-paper con struction results discontinuity upper surface just aft leading-edge strip multiple top-surface spars employ honestto-goodness turbulators strips wood per haps thread glued upper surface turbulence wire out ahead leading edge usually monofilament nylon tennis racquet string strip rubber vibrates lets back up bit Whats wrong nice smoothly flowing air laminar boundary layer has less drag turbulent Thats fine bottom wing life isnt simple upper surface easier explain what happens regard wing fixed air moving rather other way around real life air right next wing stuck wing doesntmove Waxing wont help air perhaps 1/16 m I5 68%II F i IAL 520 9%tllIZ.S 0 Super Ti8re q-19 Cox &-4 8l 40dowv lLcfr Lt 19 0 ____________________7 40S 5 8 Super Monoiwte oit wine & stala 6 Model Aviation 251 amuOS am tu paid sic uuot La clcashima shows off Tadpole usa vvrnningest A-i glider designs west would believeInterstate 5 Meuser plc cLiItgdra inch away surface moving full speed betweenthe boundary layerthe speed flowing air increases zero full speed front part wings upper surface speed air higher speed main stream creates suction results lift air must slow down again join main stream after passes wing air some distance surface manages orderly fashion air right next surface already going very slowly main stream slows down some air within boundary layer brought dead standstill air closer surface moves forwarcL lied Such situation doesnt really occur except perhaps few mili-seconds unstable situation flow instead separates wing surface leaving thick separation region flow going way region pressure lowthe lift greatas flow followed wing contour solution make sure boundary layer turbulent turbulent boundary layer stagnant air next surface continu ously being mixed fast-moving main stream air less likely slow down reverse direction full-size aircraft no problem main-stream air moving fast enough wing chord great enough boundary layer almost certain turbulent almost allow very special laminar flow airfoils models both factorsair velocity chordwork against us must something convince boundary layer would rather turbulent An effective easily applied seldom seen method inducing turbulence use pinhole turbulators merely holes upper possibly lower surface wing near leading edge form turbula tor tested extensively Model Aero dynamics Research Project Engiand some 25 years ago special low-turbulence wind tunnel Four-inch-chord wings both built-up sheetcovered construction tested various hole configurations built-up wing holes 028-inch diameter pierced through paper just aft leading-edge strip 040inch diameter holes drilled through leading edge strip sheet-covered wing 020-inch diameter holes drilled through sheet covering just aft leading-edge strip what found span-wise hole spacing 25%-chordiinch spacing 4-inch chordis sufficient produce full effect adding holes helps very little greatest effect achieved sheetcovered surface merely because worst lot begin Critical Reynolds number Re cut half greatest effect achieved both top bottom surfaces pierced holes go through leading-edge strip Pre sumably air under pressure enters bottom jets out top holes Some effect achieved piercing upper surface either type wing just behind leading-edge strip Apparently combina tion hold volume air within wing sets up resonance alternately pumps air out holes Helmholtz resonator Reynolds numbers product air velocity chord above critical value no separa tion maximum lift drag unturbulated section somewhat less turbula ted section Lesson dont use larger turbulators closer hole spacing have So much wind-tunnel tests does work out field battle knows Ive seen absolutely nothing written subject POP DOWN OT FOR HIG yG,rvGuiI, 515 MUSIC NH/S HOLE OT LINE HOT STUFF BAKING SODA FILLET FUSELAGE PLYWOOD 1/32X1f8 X 1/4 PlywOod 1/3261/8 PLY STRIP SCOTCH TAPE HINGE / //DT POSITION 1/IS SO SPRUCE IE know Hank Cole used pinhole turbulators several Nordic A/2 towline giiders got still-air times well over 3 mm i used pinhole turbulators low-ceiling Indoor HandLaunch Glider beat Hines Wittman win USFF Champs couple years ago one-shot deal model never flown before hasnt since has never flown pinhole turbulators out reader-land try things know articles telling about Id really appreciate hearing NFFS World Champs Tech Project Another Wow NFFS goal project measurement performance critical observation technical tactical matters publication report covering whole works Project Manager Fred Pearce has spent third century doing related things recently NASA has already organized dozen helpers task teams key focal point project will altitude measurement models flight last perhaps well get some hard facts about altitudes attained FM Power Wakefield models about height gain achieved currently fashionable zoom launches Nordic giiders Homemade theodolitesmade home FAL Power man Tom McLaugh lanwill used applying technique devel oped over some 20 years model rocketry Hopefully still-air sink rates will measured too Also included addition para meters usually included published three-view drawings will measurements airfoilsnot merely statement builder what airfoil section thinks has intended have what really has unusual uses exotic materi als towhook hardware Wakefield front-end hardware zoom techniques tactics auto-surface mechanization winding protective systems stooges prop brakes structural control flutter Continued page 125 December1979 47 Ex-Indoor Champ ud Homak gets rimuns auring practice session forthcoming US team selection program isnt optical illusionprop really bends like thati Meuser pic equipped two synchronized 79-mm MG 17 guns fourth Ar 68 again powered BMW engine first actually identified Versuchs number being Ar 68V4 Following fifth machine powered Jumo 21ODa engine two-speed supercharger takeoff rating 680 hp being Ar 68V5 became production prototype Arado Ar 68E-1 Appearing definitive execution intended design concepts Arado Ar 68E1 conformance specifica tions shown chart Early 1936 no decision concerning produc tion Arado Ar 68 yet made Ernst Udet himself time Luftwaffe Inspector Fighter Pilots put test speak mock combat Jumo powered Ar 68 against top Luftwaffe fighter pilot flying Heinkel 51 easy victory over Heinkel precipitated immediate pro duction order Arado Ar 68E-1 However production tooling almost complete occurred drastic redirection priori ties application Junkers Jumo 210 engines certainly relation oncom ing Messerschmitt Bf 109 production per haps also relation other Luftwaffe projects resulted another redesign Ar 68 again incorporate BMW Vi 7 3ZuprightV 12 engine 51 engine Thus Arado Ar 68F-1 created fact Ar 68 model see front-line service after September 1 1939 Production Ar 68F did noi might have expected end Ar 68E means As events rapidly unfolded poor showing Heinkel 51 Spain motivated yet another change priorities Junkers Jumo 210 engines being massive produc tion Messerschmitt Bf 109 monoplanes still distant Thus fall 1936 Jumo 210 engines again made available Arado Ar 68E machines after became principal production examples last first-line biplane fighter deployed Luftwaffe Consequently occurred aboutmid 1937 tomid 1938 whenthenew eraof Bf 109 opened Arado Ar 68E principal first-line fighter Jagdgruppen Fighter Wings Luftwaffe Although some conflicting numbers records seem indicate approximately 500 Arado Ar 68 machines built Arado Ar 68 mixed-materials phi losophy execution aircraft construction reached high state perfection Basic internal fuselage truss welded steel tubing rectangular section accommodating connec tions cabane struts integral engine mount structure lower wing roots gun mounts very robust landing gear Geometrical fuselage sec tion essentially oval maintained stringers aft cockpit below light metal rear deck light metal forward engine cowling also light metal Wings wood plywood construction upper wing plywood fabric covering lower wing panels plywood covering Light metal tail surfaces structure fabric covered aft fuselage below rear deck Propeller usually utilized two-blade fixed-pitch wooden Heine Final development Arado Ar68 Ar 68H prototype completed spring 1937 machine redesign incorporate BMW 1 32Da nine-cylinder radial air-cooled engine 850 hp takeoff featured enclosed cockpit four 79-mm MG 17 guns two upper wing Top speed 250 mph service ceiling about 30000 feet Few biplane fighters beyond Fiat CR42 first flown early 1939 immediately recalled Max/speed 274 mph 20000 feet Recalling reactivation Arado Ar 68E production motivated inade quacy Heinkel 51 Spain involved re-reallocation some Junkers Jumo 210 engines Ar 68 machines would have otherwise gone Messerschmitt Bf 109 production interest note two Arado Ar 68E fighters actually reached Spain As events ultimately transpired suffi cient number Messerschmitt fighters assure Condor Legion air superiority supplied Bayerische Flugzeugwerke des pite simultaneous production Ar 68E Arado course possible expansion production Jumo 210 engines Beyond Bf 109E machines sent Spain near end conflict powered later Daimler-Benz DB 601A inverted V-i 2 engines 1050 hp September 11939 amongthe hundreds Messerschmitt fighters first-line operational service yet remained 28 Arado Ar 68E-1 biplanes same status operating south-western region Reich after Ar 68F-l machines deployed night fighters year 1940 Thereafter biplane fighters Arados Heinkels some others relegated training schools some surviving until 1945 No recount Luftwaffe biplane fighters however brief complete some mention excellent Avia B-S 34 biplane fighters German origin acquired annexation Czechoslovakia appear last biplane fighters deployed Luftwaffe under combat conditions First applied training schools desperate days late war compelled deployment some Avia BS 34 machines defense Balkan petroleum region SAFE FLYING IS NO ACCIDENT FF Duration/Meuser continued page 47 thermal-detection devices techniques team organization management cheat getting caught oh gosh could write book will Model Models An article May issue SportAviation byTakashi Araki tells small simply built all-balsa gliders can used predict stability characteristics proposed full-size aircraft Strangely enough simple flat wing sections work well accurately formed airfoils profile fuselage works well three-dimensional relative weight wing loading model make little difference purposes Apparently spin characteris tics can rather accurately predicted too high-power flight characteristics can simu December 1979 125 IF R EALIS N/iSCALE ACCESSORIES WILLIAMS BROTHERS RADIO CONTROL SCALE PILOTS E WHEELS CONTROL-LINECYLINDERS ENGINE KITS MACHINE GUN KITS FREE-FLIGHT TIC DISPLAY MODELS SEND 5O FOR COMPLETE ILLUSTRATED CATALOG DEPT MA 181 PAWNEE STREET SAN MARCOS CA 9 BROWN CO-2 ENGINES ENGINES ARE IN STOCK NEW CHARGER AND 5 SIZES OF TANKS BROWN ENGINES COMPLETE CATALOG $100 HARD TO FIND ACCESSORIES KITE AND PLANS FOR RUBBER POWERED MODELS PHONE 17141 4698675 Peck-Pelymeis W BOX 2498-AM LA MESA CALIF 92041 CUSTOM TUNED ENGINES COMPETITION ACCESSORIES Cox 049L051 Specialists brochure send 1 5c stamp Kustom Krattsmanship Brochure Box 2699 Laguna Hills CA 92653 714 830-5162 Diesel Conversion Kits e Power Quiet Smooth Economical Send 30 & Stamped Addressed Envelope Dealer Inquiry InvIted Davis Diesel Development Inc Box 141 Mllford CT 06460 Winning Ideas FOURMOST FUEL FITTING SETS Large Fuel Fitting Set cSize % IDPRICE S150 1 Tee 1 Elbow 1 Union 1 Plug Both Made Fuel Proof Polyethylene Small Fuel Fitting Set Size A6 10PRICE S125 1 Tee 2 Elbows 1 Pen Bladder Tee FUEL MANIFOLD This Manifold Provides Convenient Method Tank Filling Draining Priming %2 10PRICE 95 1 Scale 1931 Gee Bee Super Sportster IGeneral Arrange ment Drawing Catalog 25cBy W T Bill Given ERNISTIC MODELS PO BOX 6974 ALBUQ NM 87197 lated mild chuck article claims control characteristics can simulated too cutting away control surface taping back deflected position author cites cases unusual characteristics cures predicted small chuck-glider tests later confirmed expensive wind-tunnel tests RC model programs course models must accurately constructed attention must paid accuracy incidence angles CG positions model must launched proper flight attitude speed wonder dont use technique design aid free-flight competition sport models has done course isnt done very often reason bunch copy cats Basic area ratios moment arms dihedral angles CG positions have pretty well standardized before trying something really newa T-tail negative dihe dral stab canard winglets whateverwouldnt pay spend hour two doing bit cutand-try chuck glider first Certainly FF Scale modelers should able profit technique except perhaps few blessed nack being able make fool thing fly Hello Bill Warner course technique shouldnt work Reynolds Number thatbut ap parently does recently built model absolutely unstable Perhaps bi-stable would accurate description perfectly stable either normal glide near-vertical dive model wasnt far out should have flown well didnt might have profited technique shouldnt work does OHLG DT forms dethermalizers have 0491051 AIR FLO ENGINE MOUNT REDUCES DRAG VIBRATION FREE PRICE 250 FUEL SHUTOFF Can Used Control Fuel Flow Starting jPositive Airborn Shutoff PRICE 350 C FLASH STARTING SUNEXCELLER POWER S LONGER LIFE SLOWEST DRAIN GLOW PLUGS SWANSON ASSOCIATES gte P0 309 SI WAYNE N W JERSEY 69 ROUTE 29PEOIJANROcE 9W IERS used outdoor hand-launch gliders cluding drag brakes fold-down rudder drop-off nose weight pop-up stab popularized Bill Blanchard See Polly article May issue Bills scheme employed him others decade works just great some fliers prefer mount stabilizer bottom fuselage such designs pop-up stab wont work Orbiteer Gerry Giles comes rescue pop-down stab reported Torbellino sketch shows basic tail-end hardware front end can fuse burner such Polly Gerry reports prototype works very well does appear vulnerable damage feared Addition 1/16-sq spruce leading edge will help drawback compared pop-up lack adjusting screw trim However find once adjust ments warped little need ever change Note Blanchards version pop-up DT employs shims rather adjust ing screw Bob Meuser 4200 Gregory St Oakland CA 94619 FF Indoor/Tenny continued page 48 done yet another fun model idea glven specified set materials can build glider 30 minutes set rules specified contestant would furnished 6-in long piece 1/16X1/8 balsa 2X6X1/32 balsa sheet No other materials except choice adhesive permitted includes nose weight must derived balsa glue idea provides interesting challenge should thought out well advance contest Styrofoam prop blocla Bob Lieber has sug gested expensive balsa blocks no longer need invested prop blocks photo shows styrofoam block used forming balsa blades Coupe dHiver models also can used Easy B Pennyplane props Two precautions necessary first blades must air dried since baking oven would melt deform styrofoam second work sur face should protected rubbing epoxy glue foam Bob uses expanded bead foam material offers following advice about cutting helix Thin plywood some other hard material glued uncut block both top bottom gnide hot wire cutter top guide visible photo cutter wire must parallel end planes block during whole cut cut surface needs no sanding care applying epoxy glue will preserve smooth surface Bud Tenny PO Box 545 Richardson TX 75080 Junior/Hartmangruber continued page 57 once week Boys Club starters use Comet Fly Boy Cloud Buster kits because two kits excellent teaching fundamentals built up wing fuselage construction finer points model adjustments best flights After boys have mastered two models encouraged make own selections building proj ects have several have gone advanced free flight control line engine-powered models needs done ignite spark interest help grow Now must say should club club member volunteer conduct model group anywhere make one-time thing Continuous instruction flying operations necessary keep up develop interest boy Boys Club always influx new members time goes find boy often will show real interest educational value art model building really rest life others time may seem just something Boys Club knows maybe later life will remember enjoyed modeling resume building flying Editors Note numerous flying sessions localities have impressed enthralled kidsof ageswho ask models can befoun4 tofly Letters magazine reflect same needfor information So Wyoufree-flighters will bear us month wed like render much-needed service author outstand ing rubber-model expert familiar market availabiliiy invited MA share us experience building flying hund reds interesting aircraft Although talking scale will find included meaningful coverage non-scale items trainer intermediate categoriesgreat lead-ins tackling real scale stuff SAFE FLYING IS NO ACCIDENT 126 Model Aviation
Edition: Model Aviation - 1979/12
Page Numbers: 46, 47, 125, 126
B AND B Special model shown threeview has racked up fair score itself Al though built various earlier versions 520 shown has built designer Bill Burks wife Carolyne far Cliff Cloud Climbers meet June racked up nine maxes first place Class Open Gas hightime award meet bad 50-yearold gal wed say NFFS International Planbook 1979 promises model aviation collectors item century judging present indica tions writing late July 96 drawings models intended flown World Champs have received according Planbook Editor Dave Linstrum almost volun teer draftsmen have lined up final drawings publication Planbook isnt merely book plans Some other items included Evolution FAI engines P G F Chinn evolution Nordic towline glider event early years Wakefield Trophy competition portfolio fa mous vintage Wakefield three-views Power photos models pen-pal address list fore word Frank Zinc some history started Model Aemnautics Yearbook series hold hats Aeromodelling Peking British spelling aeromodeling Offhand Id think Aeromodelling Pe king would suitable title booklet blank note paper Mainland China sending team participate World Champs wonder theyll show up staff built bamboo rice paper tied together reed thongs.. stuff made fiberglass carbon fibers Kevlar epoxy resins. e thing betveen Remember hehaws North Koreans got appeared list World Champs participants dont laugh much anymore about Mainly cry lot try harder Pinhole Turbulators want build model has competition potential about zero use airfoil rounded leading edge cover top surface least sheet use slick plastic film covering Most models arent built way employ some form turbulation sharp leading edge microscopically-fuzzy finish stick-n-paper con struction results discontinuity upper surface just aft leading-edge strip multiple top-surface spars employ honestto-goodness turbulators strips wood per haps thread glued upper surface turbulence wire out ahead leading edge usually monofilament nylon tennis racquet string strip rubber vibrates lets back up bit Whats wrong nice smoothly flowing air laminar boundary layer has less drag turbulent Thats fine bottom wing life isnt simple upper surface easier explain what happens regard wing fixed air moving rather other way around real life air right next wing stuck wing doesntmove Waxing wont help air perhaps 1/16 m I5 68%II F i IAL 520 9%tllIZ.S 0 Super Ti8re q-19 Cox &-4 8l 40dowv lLcfr Lt 19 0 ____________________7 40S 5 8 Super Monoiwte oit wine & stala 6 Model Aviation 251 amuOS am tu paid sic uuot La clcashima shows off Tadpole usa vvrnningest A-i glider designs west would believeInterstate 5 Meuser plc cLiItgdra inch away surface moving full speed betweenthe boundary layerthe speed flowing air increases zero full speed front part wings upper surface speed air higher speed main stream creates suction results lift air must slow down again join main stream after passes wing air some distance surface manages orderly fashion air right next surface already going very slowly main stream slows down some air within boundary layer brought dead standstill air closer surface moves forwarcL lied Such situation doesnt really occur except perhaps few mili-seconds unstable situation flow instead separates wing surface leaving thick separation region flow going way region pressure lowthe lift greatas flow followed wing contour solution make sure boundary layer turbulent turbulent boundary layer stagnant air next surface continu ously being mixed fast-moving main stream air less likely slow down reverse direction full-size aircraft no problem main-stream air moving fast enough wing chord great enough boundary layer almost certain turbulent almost allow very special laminar flow airfoils models both factorsair velocity chordwork against us must something convince boundary layer would rather turbulent An effective easily applied seldom seen method inducing turbulence use pinhole turbulators merely holes upper possibly lower surface wing near leading edge form turbula tor tested extensively Model Aero dynamics Research Project Engiand some 25 years ago special low-turbulence wind tunnel Four-inch-chord wings both built-up sheetcovered construction tested various hole configurations built-up wing holes 028-inch diameter pierced through paper just aft leading-edge strip 040inch diameter holes drilled through leading edge strip sheet-covered wing 020-inch diameter holes drilled through sheet covering just aft leading-edge strip what found span-wise hole spacing 25%-chordiinch spacing 4-inch chordis sufficient produce full effect adding holes helps very little greatest effect achieved sheetcovered surface merely because worst lot begin Critical Reynolds number Re cut half greatest effect achieved both top bottom surfaces pierced holes go through leading-edge strip Pre sumably air under pressure enters bottom jets out top holes Some effect achieved piercing upper surface either type wing just behind leading-edge strip Apparently combina tion hold volume air within wing sets up resonance alternately pumps air out holes Helmholtz resonator Reynolds numbers product air velocity chord above critical value no separa tion maximum lift drag unturbulated section somewhat less turbula ted section Lesson dont use larger turbulators closer hole spacing have So much wind-tunnel tests does work out field battle knows Ive seen absolutely nothing written subject POP DOWN OT FOR HIG yG,rvGuiI, 515 MUSIC NH/S HOLE OT LINE HOT STUFF BAKING SODA FILLET FUSELAGE PLYWOOD 1/32X1f8 X 1/4 PlywOod 1/3261/8 PLY STRIP SCOTCH TAPE HINGE / //DT POSITION 1/IS SO SPRUCE IE know Hank Cole used pinhole turbulators several Nordic A/2 towline giiders got still-air times well over 3 mm i used pinhole turbulators low-ceiling Indoor HandLaunch Glider beat Hines Wittman win USFF Champs couple years ago one-shot deal model never flown before hasnt since has never flown pinhole turbulators out reader-land try things know articles telling about Id really appreciate hearing NFFS World Champs Tech Project Another Wow NFFS goal project measurement performance critical observation technical tactical matters publication report covering whole works Project Manager Fred Pearce has spent third century doing related things recently NASA has already organized dozen helpers task teams key focal point project will altitude measurement models flight last perhaps well get some hard facts about altitudes attained FM Power Wakefield models about height gain achieved currently fashionable zoom launches Nordic giiders Homemade theodolitesmade home FAL Power man Tom McLaugh lanwill used applying technique devel oped over some 20 years model rocketry Hopefully still-air sink rates will measured too Also included addition para meters usually included published three-view drawings will measurements airfoilsnot merely statement builder what airfoil section thinks has intended have what really has unusual uses exotic materi als towhook hardware Wakefield front-end hardware zoom techniques tactics auto-surface mechanization winding protective systems stooges prop brakes structural control flutter Continued page 125 December1979 47 Ex-Indoor Champ ud Homak gets rimuns auring practice session forthcoming US team selection program isnt optical illusionprop really bends like thati Meuser pic equipped two synchronized 79-mm MG 17 guns fourth Ar 68 again powered BMW engine first actually identified Versuchs number being Ar 68V4 Following fifth machine powered Jumo 21ODa engine two-speed supercharger takeoff rating 680 hp being Ar 68V5 became production prototype Arado Ar 68E-1 Appearing definitive execution intended design concepts Arado Ar 68E1 conformance specifica tions shown chart Early 1936 no decision concerning produc tion Arado Ar 68 yet made Ernst Udet himself time Luftwaffe Inspector Fighter Pilots put test speak mock combat Jumo powered Ar 68 against top Luftwaffe fighter pilot flying Heinkel 51 easy victory over Heinkel precipitated immediate pro duction order Arado Ar 68E-1 However production tooling almost complete occurred drastic redirection priori ties application Junkers Jumo 210 engines certainly relation oncom ing Messerschmitt Bf 109 production per haps also relation other Luftwaffe projects resulted another redesign Ar 68 again incorporate BMW Vi 7 3ZuprightV 12 engine 51 engine Thus Arado Ar 68F-1 created fact Ar 68 model see front-line service after September 1 1939 Production Ar 68F did noi might have expected end Ar 68E means As events rapidly unfolded poor showing Heinkel 51 Spain motivated yet another change priorities Junkers Jumo 210 engines being massive produc tion Messerschmitt Bf 109 monoplanes still distant Thus fall 1936 Jumo 210 engines again made available Arado Ar 68E machines after became principal production examples last first-line biplane fighter deployed Luftwaffe Consequently occurred aboutmid 1937 tomid 1938 whenthenew eraof Bf 109 opened Arado Ar 68E principal first-line fighter Jagdgruppen Fighter Wings Luftwaffe Although some conflicting numbers records seem indicate approximately 500 Arado Ar 68 machines built Arado Ar 68 mixed-materials phi losophy execution aircraft construction reached high state perfection Basic internal fuselage truss welded steel tubing rectangular section accommodating connec tions cabane struts integral engine mount structure lower wing roots gun mounts very robust landing gear Geometrical fuselage sec tion essentially oval maintained stringers aft cockpit below light metal rear deck light metal forward engine cowling also light metal Wings wood plywood construction upper wing plywood fabric covering lower wing panels plywood covering Light metal tail surfaces structure fabric covered aft fuselage below rear deck Propeller usually utilized two-blade fixed-pitch wooden Heine Final development Arado Ar68 Ar 68H prototype completed spring 1937 machine redesign incorporate BMW 1 32Da nine-cylinder radial air-cooled engine 850 hp takeoff featured enclosed cockpit four 79-mm MG 17 guns two upper wing Top speed 250 mph service ceiling about 30000 feet Few biplane fighters beyond Fiat CR42 first flown early 1939 immediately recalled Max/speed 274 mph 20000 feet Recalling reactivation Arado Ar 68E production motivated inade quacy Heinkel 51 Spain involved re-reallocation some Junkers Jumo 210 engines Ar 68 machines would have otherwise gone Messerschmitt Bf 109 production interest note two Arado Ar 68E fighters actually reached Spain As events ultimately transpired suffi cient number Messerschmitt fighters assure Condor Legion air superiority supplied Bayerische Flugzeugwerke des pite simultaneous production Ar 68E Arado course possible expansion production Jumo 210 engines Beyond Bf 109E machines sent Spain near end conflict powered later Daimler-Benz DB 601A inverted V-i 2 engines 1050 hp September 11939 amongthe hundreds Messerschmitt fighters first-line operational service yet remained 28 Arado Ar 68E-1 biplanes same status operating south-western region Reich after Ar 68F-l machines deployed night fighters year 1940 Thereafter biplane fighters Arados Heinkels some others relegated training schools some surviving until 1945 No recount Luftwaffe biplane fighters however brief complete some mention excellent Avia B-S 34 biplane fighters German origin acquired annexation Czechoslovakia appear last biplane fighters deployed Luftwaffe under combat conditions First applied training schools desperate days late war compelled deployment some Avia BS 34 machines defense Balkan petroleum region SAFE FLYING IS NO ACCIDENT FF Duration/Meuser continued page 47 thermal-detection devices techniques team organization management cheat getting caught oh gosh could write book will Model Models An article May issue SportAviation byTakashi Araki tells small simply built all-balsa gliders can used predict stability characteristics proposed full-size aircraft Strangely enough simple flat wing sections work well accurately formed airfoils profile fuselage works well three-dimensional relative weight wing loading model make little difference purposes Apparently spin characteris tics can rather accurately predicted too high-power flight characteristics can simu December 1979 125 IF R EALIS N/iSCALE ACCESSORIES WILLIAMS BROTHERS RADIO CONTROL SCALE PILOTS E WHEELS CONTROL-LINECYLINDERS ENGINE KITS MACHINE GUN KITS FREE-FLIGHT TIC DISPLAY MODELS SEND 5O FOR COMPLETE ILLUSTRATED CATALOG DEPT MA 181 PAWNEE STREET SAN MARCOS CA 9 BROWN CO-2 ENGINES ENGINES ARE IN STOCK NEW CHARGER AND 5 SIZES OF TANKS BROWN ENGINES COMPLETE CATALOG $100 HARD TO FIND ACCESSORIES KITE AND PLANS FOR RUBBER POWERED MODELS PHONE 17141 4698675 Peck-Pelymeis W BOX 2498-AM LA MESA CALIF 92041 CUSTOM TUNED ENGINES COMPETITION ACCESSORIES Cox 049L051 Specialists brochure send 1 5c stamp Kustom Krattsmanship Brochure Box 2699 Laguna Hills CA 92653 714 830-5162 Diesel Conversion Kits e Power Quiet Smooth Economical Send 30 & Stamped Addressed Envelope Dealer Inquiry InvIted Davis Diesel Development Inc Box 141 Mllford CT 06460 Winning Ideas FOURMOST FUEL FITTING SETS Large Fuel Fitting Set cSize % IDPRICE S150 1 Tee 1 Elbow 1 Union 1 Plug Both Made Fuel Proof Polyethylene Small Fuel Fitting Set Size A6 10PRICE S125 1 Tee 2 Elbows 1 Pen Bladder Tee FUEL MANIFOLD This Manifold Provides Convenient Method Tank Filling Draining Priming %2 10PRICE 95 1 Scale 1931 Gee Bee Super Sportster IGeneral Arrange ment Drawing Catalog 25cBy W T Bill Given ERNISTIC MODELS PO BOX 6974 ALBUQ NM 87197 lated mild chuck article claims control characteristics can simulated too cutting away control surface taping back deflected position author cites cases unusual characteristics cures predicted small chuck-glider tests later confirmed expensive wind-tunnel tests RC model programs course models must accurately constructed attention must paid accuracy incidence angles CG positions model must launched proper flight attitude speed wonder dont use technique design aid free-flight competition sport models has done course isnt done very often reason bunch copy cats Basic area ratios moment arms dihedral angles CG positions have pretty well standardized before trying something really newa T-tail negative dihe dral stab canard winglets whateverwouldnt pay spend hour two doing bit cutand-try chuck glider first Certainly FF Scale modelers should able profit technique except perhaps few blessed nack being able make fool thing fly Hello Bill Warner course technique shouldnt work Reynolds Number thatbut ap parently does recently built model absolutely unstable Perhaps bi-stable would accurate description perfectly stable either normal glide near-vertical dive model wasnt far out should have flown well didnt might have profited technique shouldnt work does OHLG DT forms dethermalizers have 0491051 AIR FLO ENGINE MOUNT REDUCES DRAG VIBRATION FREE PRICE 250 FUEL SHUTOFF Can Used Control Fuel Flow Starting jPositive Airborn Shutoff PRICE 350 C FLASH STARTING SUNEXCELLER POWER S LONGER LIFE SLOWEST DRAIN GLOW PLUGS SWANSON ASSOCIATES gte P0 309 SI WAYNE N W JERSEY 69 ROUTE 29PEOIJANROcE 9W IERS used outdoor hand-launch gliders cluding drag brakes fold-down rudder drop-off nose weight pop-up stab popularized Bill Blanchard See Polly article May issue Bills scheme employed him others decade works just great some fliers prefer mount stabilizer bottom fuselage such designs pop-up stab wont work Orbiteer Gerry Giles comes rescue pop-down stab reported Torbellino sketch shows basic tail-end hardware front end can fuse burner such Polly Gerry reports prototype works very well does appear vulnerable damage feared Addition 1/16-sq spruce leading edge will help drawback compared pop-up lack adjusting screw trim However find once adjust ments warped little need ever change Note Blanchards version pop-up DT employs shims rather adjust ing screw Bob Meuser 4200 Gregory St Oakland CA 94619 FF Indoor/Tenny continued page 48 done yet another fun model idea glven specified set materials can build glider 30 minutes set rules specified contestant would furnished 6-in long piece 1/16X1/8 balsa 2X6X1/32 balsa sheet No other materials except choice adhesive permitted includes nose weight must derived balsa glue idea provides interesting challenge should thought out well advance contest Styrofoam prop blocla Bob Lieber has sug gested expensive balsa blocks no longer need invested prop blocks photo shows styrofoam block used forming balsa blades Coupe dHiver models also can used Easy B Pennyplane props Two precautions necessary first blades must air dried since baking oven would melt deform styrofoam second work sur face should protected rubbing epoxy glue foam Bob uses expanded bead foam material offers following advice about cutting helix Thin plywood some other hard material glued uncut block both top bottom gnide hot wire cutter top guide visible photo cutter wire must parallel end planes block during whole cut cut surface needs no sanding care applying epoxy glue will preserve smooth surface Bud Tenny PO Box 545 Richardson TX 75080 Junior/Hartmangruber continued page 57 once week Boys Club starters use Comet Fly Boy Cloud Buster kits because two kits excellent teaching fundamentals built up wing fuselage construction finer points model adjustments best flights After boys have mastered two models encouraged make own selections building proj ects have several have gone advanced free flight control line engine-powered models needs done ignite spark interest help grow Now must say should club club member volunteer conduct model group anywhere make one-time thing Continuous instruction flying operations necessary keep up develop interest boy Boys Club always influx new members time goes find boy often will show real interest educational value art model building really rest life others time may seem just something Boys Club knows maybe later life will remember enjoyed modeling resume building flying Editors Note numerous flying sessions localities have impressed enthralled kidsof ageswho ask models can befoun4 tofly Letters magazine reflect same needfor information So Wyoufree-flighters will bear us month wed like render much-needed service author outstand ing rubber-model expert familiar market availabiliiy invited MA share us experience building flying hund reds interesting aircraft Although talking scale will find included meaningful coverage non-scale items trainer intermediate categoriesgreat lead-ins tackling real scale stuff SAFE FLYING IS NO ACCIDENT 126 Model Aviation
Edition: Model Aviation - 1979/12
Page Numbers: 46, 47, 125, 126
B AND B Special model shown threeview has racked up fair score itself Al though built various earlier versions 520 shown has built designer Bill Burks wife Carolyne far Cliff Cloud Climbers meet June racked up nine maxes first place Class Open Gas hightime award meet bad 50-yearold gal wed say NFFS International Planbook 1979 promises model aviation collectors item century judging present indica tions writing late July 96 drawings models intended flown World Champs have received according Planbook Editor Dave Linstrum almost volun teer draftsmen have lined up final drawings publication Planbook isnt merely book plans Some other items included Evolution FAI engines P G F Chinn evolution Nordic towline glider event early years Wakefield Trophy competition portfolio fa mous vintage Wakefield three-views Power photos models pen-pal address list fore word Frank Zinc some history started Model Aemnautics Yearbook series hold hats Aeromodelling Peking British spelling aeromodeling Offhand Id think Aeromodelling Pe king would suitable title booklet blank note paper Mainland China sending team participate World Champs wonder theyll show up staff built bamboo rice paper tied together reed thongs.. stuff made fiberglass carbon fibers Kevlar epoxy resins. e thing betveen Remember hehaws North Koreans got appeared list World Champs participants dont laugh much anymore about Mainly cry lot try harder Pinhole Turbulators want build model has competition potential about zero use airfoil rounded leading edge cover top surface least sheet use slick plastic film covering Most models arent built way employ some form turbulation sharp leading edge microscopically-fuzzy finish stick-n-paper con struction results discontinuity upper surface just aft leading-edge strip multiple top-surface spars employ honestto-goodness turbulators strips wood per haps thread glued upper surface turbulence wire out ahead leading edge usually monofilament nylon tennis racquet string strip rubber vibrates lets back up bit Whats wrong nice smoothly flowing air laminar boundary layer has less drag turbulent Thats fine bottom wing life isnt simple upper surface easier explain what happens regard wing fixed air moving rather other way around real life air right next wing stuck wing doesntmove Waxing wont help air perhaps 1/16 m I5 68%II F i IAL 520 9%tllIZ.S 0 Super Ti8re q-19 Cox &-4 8l 40dowv lLcfr Lt 19 0 ____________________7 40S 5 8 Super Monoiwte oit wine & stala 6 Model Aviation 251 amuOS am tu paid sic uuot La clcashima shows off Tadpole usa vvrnningest A-i glider designs west would believeInterstate 5 Meuser plc cLiItgdra inch away surface moving full speed betweenthe boundary layerthe speed flowing air increases zero full speed front part wings upper surface speed air higher speed main stream creates suction results lift air must slow down again join main stream after passes wing air some distance surface manages orderly fashion air right next surface already going very slowly main stream slows down some air within boundary layer brought dead standstill air closer surface moves forwarcL lied Such situation doesnt really occur except perhaps few mili-seconds unstable situation flow instead separates wing surface leaving thick separation region flow going way region pressure lowthe lift greatas flow followed wing contour solution make sure boundary layer turbulent turbulent boundary layer stagnant air next surface continu ously being mixed fast-moving main stream air less likely slow down reverse direction full-size aircraft no problem main-stream air moving fast enough wing chord great enough boundary layer almost certain turbulent almost allow very special laminar flow airfoils models both factorsair velocity chordwork against us must something convince boundary layer would rather turbulent An effective easily applied seldom seen method inducing turbulence use pinhole turbulators merely holes upper possibly lower surface wing near leading edge form turbula tor tested extensively Model Aero dynamics Research Project Engiand some 25 years ago special low-turbulence wind tunnel Four-inch-chord wings both built-up sheetcovered construction tested various hole configurations built-up wing holes 028-inch diameter pierced through paper just aft leading-edge strip 040inch diameter holes drilled through leading edge strip sheet-covered wing 020-inch diameter holes drilled through sheet covering just aft leading-edge strip what found span-wise hole spacing 25%-chordiinch spacing 4-inch chordis sufficient produce full effect adding holes helps very little greatest effect achieved sheetcovered surface merely because worst lot begin Critical Reynolds number Re cut half greatest effect achieved both top bottom surfaces pierced holes go through leading-edge strip Pre sumably air under pressure enters bottom jets out top holes Some effect achieved piercing upper surface either type wing just behind leading-edge strip Apparently combina tion hold volume air within wing sets up resonance alternately pumps air out holes Helmholtz resonator Reynolds numbers product air velocity chord above critical value no separa tion maximum lift drag unturbulated section somewhat less turbula ted section Lesson dont use larger turbulators closer hole spacing have So much wind-tunnel tests does work out field battle knows Ive seen absolutely nothing written subject POP DOWN OT FOR HIG yG,rvGuiI, 515 MUSIC NH/S HOLE OT LINE HOT STUFF BAKING SODA FILLET FUSELAGE PLYWOOD 1/32X1f8 X 1/4 PlywOod 1/3261/8 PLY STRIP SCOTCH TAPE HINGE / //DT POSITION 1/IS SO SPRUCE IE know Hank Cole used pinhole turbulators several Nordic A/2 towline giiders got still-air times well over 3 mm i used pinhole turbulators low-ceiling Indoor HandLaunch Glider beat Hines Wittman win USFF Champs couple years ago one-shot deal model never flown before hasnt since has never flown pinhole turbulators out reader-land try things know articles telling about Id really appreciate hearing NFFS World Champs Tech Project Another Wow NFFS goal project measurement performance critical observation technical tactical matters publication report covering whole works Project Manager Fred Pearce has spent third century doing related things recently NASA has already organized dozen helpers task teams key focal point project will altitude measurement models flight last perhaps well get some hard facts about altitudes attained FM Power Wakefield models about height gain achieved currently fashionable zoom launches Nordic giiders Homemade theodolitesmade home FAL Power man Tom McLaugh lanwill used applying technique devel oped over some 20 years model rocketry Hopefully still-air sink rates will measured too Also included addition para meters usually included published three-view drawings will measurements airfoilsnot merely statement builder what airfoil section thinks has intended have what really has unusual uses exotic materi als towhook hardware Wakefield front-end hardware zoom techniques tactics auto-surface mechanization winding protective systems stooges prop brakes structural control flutter Continued page 125 December1979 47 Ex-Indoor Champ ud Homak gets rimuns auring practice session forthcoming US team selection program isnt optical illusionprop really bends like thati Meuser pic equipped two synchronized 79-mm MG 17 guns fourth Ar 68 again powered BMW engine first actually identified Versuchs number being Ar 68V4 Following fifth machine powered Jumo 21ODa engine two-speed supercharger takeoff rating 680 hp being Ar 68V5 became production prototype Arado Ar 68E-1 Appearing definitive execution intended design concepts Arado Ar 68E1 conformance specifica tions shown chart Early 1936 no decision concerning produc tion Arado Ar 68 yet made Ernst Udet himself time Luftwaffe Inspector Fighter Pilots put test speak mock combat Jumo powered Ar 68 against top Luftwaffe fighter pilot flying Heinkel 51 easy victory over Heinkel precipitated immediate pro duction order Arado Ar 68E-1 However production tooling almost complete occurred drastic redirection priori ties application Junkers Jumo 210 engines certainly relation oncom ing Messerschmitt Bf 109 production per haps also relation other Luftwaffe projects resulted another redesign Ar 68 again incorporate BMW Vi 7 3ZuprightV 12 engine 51 engine Thus Arado Ar 68F-1 created fact Ar 68 model see front-line service after September 1 1939 Production Ar 68F did noi might have expected end Ar 68E means As events rapidly unfolded poor showing Heinkel 51 Spain motivated yet another change priorities Junkers Jumo 210 engines being massive produc tion Messerschmitt Bf 109 monoplanes still distant Thus fall 1936 Jumo 210 engines again made available Arado Ar 68E machines after became principal production examples last first-line biplane fighter deployed Luftwaffe Consequently occurred aboutmid 1937 tomid 1938 whenthenew eraof Bf 109 opened Arado Ar 68E principal first-line fighter Jagdgruppen Fighter Wings Luftwaffe Although some conflicting numbers records seem indicate approximately 500 Arado Ar 68 machines built Arado Ar 68 mixed-materials phi losophy execution aircraft construction reached high state perfection Basic internal fuselage truss welded steel tubing rectangular section accommodating connec tions cabane struts integral engine mount structure lower wing roots gun mounts very robust landing gear Geometrical fuselage sec tion essentially oval maintained stringers aft cockpit below light metal rear deck light metal forward engine cowling also light metal Wings wood plywood construction upper wing plywood fabric covering lower wing panels plywood covering Light metal tail surfaces structure fabric covered aft fuselage below rear deck Propeller usually utilized two-blade fixed-pitch wooden Heine Final development Arado Ar68 Ar 68H prototype completed spring 1937 machine redesign incorporate BMW 1 32Da nine-cylinder radial air-cooled engine 850 hp takeoff featured enclosed cockpit four 79-mm MG 17 guns two upper wing Top speed 250 mph service ceiling about 30000 feet Few biplane fighters beyond Fiat CR42 first flown early 1939 immediately recalled Max/speed 274 mph 20000 feet Recalling reactivation Arado Ar 68E production motivated inade quacy Heinkel 51 Spain involved re-reallocation some Junkers Jumo 210 engines Ar 68 machines would have otherwise gone Messerschmitt Bf 109 production interest note two Arado Ar 68E fighters actually reached Spain As events ultimately transpired suffi cient number Messerschmitt fighters assure Condor Legion air superiority supplied Bayerische Flugzeugwerke des pite simultaneous production Ar 68E Arado course possible expansion production Jumo 210 engines Beyond Bf 109E machines sent Spain near end conflict powered later Daimler-Benz DB 601A inverted V-i 2 engines 1050 hp September 11939 amongthe hundreds Messerschmitt fighters first-line operational service yet remained 28 Arado Ar 68E-1 biplanes same status operating south-western region Reich after Ar 68F-l machines deployed night fighters year 1940 Thereafter biplane fighters Arados Heinkels some others relegated training schools some surviving until 1945 No recount Luftwaffe biplane fighters however brief complete some mention excellent Avia B-S 34 biplane fighters German origin acquired annexation Czechoslovakia appear last biplane fighters deployed Luftwaffe under combat conditions First applied training schools desperate days late war compelled deployment some Avia BS 34 machines defense Balkan petroleum region SAFE FLYING IS NO ACCIDENT FF Duration/Meuser continued page 47 thermal-detection devices techniques team organization management cheat getting caught oh gosh could write book will Model Models An article May issue SportAviation byTakashi Araki tells small simply built all-balsa gliders can used predict stability characteristics proposed full-size aircraft Strangely enough simple flat wing sections work well accurately formed airfoils profile fuselage works well three-dimensional relative weight wing loading model make little difference purposes Apparently spin characteris tics can rather accurately predicted too high-power flight characteristics can simu December 1979 125 IF R EALIS N/iSCALE ACCESSORIES WILLIAMS BROTHERS RADIO CONTROL SCALE PILOTS E WHEELS CONTROL-LINECYLINDERS ENGINE KITS MACHINE GUN KITS FREE-FLIGHT TIC DISPLAY MODELS SEND 5O FOR COMPLETE ILLUSTRATED CATALOG DEPT MA 181 PAWNEE STREET SAN MARCOS CA 9 BROWN CO-2 ENGINES ENGINES ARE IN STOCK NEW CHARGER AND 5 SIZES OF TANKS BROWN ENGINES COMPLETE CATALOG $100 HARD TO FIND ACCESSORIES KITE AND PLANS FOR RUBBER POWERED MODELS PHONE 17141 4698675 Peck-Pelymeis W BOX 2498-AM LA MESA CALIF 92041 CUSTOM TUNED ENGINES COMPETITION ACCESSORIES Cox 049L051 Specialists brochure send 1 5c stamp Kustom Krattsmanship Brochure Box 2699 Laguna Hills CA 92653 714 830-5162 Diesel Conversion Kits e Power Quiet Smooth Economical Send 30 & Stamped Addressed Envelope Dealer Inquiry InvIted Davis Diesel Development Inc Box 141 Mllford CT 06460 Winning Ideas FOURMOST FUEL FITTING SETS Large Fuel Fitting Set cSize % IDPRICE S150 1 Tee 1 Elbow 1 Union 1 Plug Both Made Fuel Proof Polyethylene Small Fuel Fitting Set Size A6 10PRICE S125 1 Tee 2 Elbows 1 Pen Bladder Tee FUEL MANIFOLD This Manifold Provides Convenient Method Tank Filling Draining Priming %2 10PRICE 95 1 Scale 1931 Gee Bee Super Sportster IGeneral Arrange ment Drawing Catalog 25cBy W T Bill Given ERNISTIC MODELS PO BOX 6974 ALBUQ NM 87197 lated mild chuck article claims control characteristics can simulated too cutting away control surface taping back deflected position author cites cases unusual characteristics cures predicted small chuck-glider tests later confirmed expensive wind-tunnel tests RC model programs course models must accurately constructed attention must paid accuracy incidence angles CG positions model must launched proper flight attitude speed wonder dont use technique design aid free-flight competition sport models has done course isnt done very often reason bunch copy cats Basic area ratios moment arms dihedral angles CG positions have pretty well standardized before trying something really newa T-tail negative dihe dral stab canard winglets whateverwouldnt pay spend hour two doing bit cutand-try chuck glider first Certainly FF Scale modelers should able profit technique except perhaps few blessed nack being able make fool thing fly Hello Bill Warner course technique shouldnt work Reynolds Number thatbut ap parently does recently built model absolutely unstable Perhaps bi-stable would accurate description perfectly stable either normal glide near-vertical dive model wasnt far out should have flown well didnt might have profited technique shouldnt work does OHLG DT forms dethermalizers have 0491051 AIR FLO ENGINE MOUNT REDUCES DRAG VIBRATION FREE PRICE 250 FUEL SHUTOFF Can Used Control Fuel Flow Starting jPositive Airborn Shutoff PRICE 350 C FLASH STARTING SUNEXCELLER POWER S LONGER LIFE SLOWEST DRAIN GLOW PLUGS SWANSON ASSOCIATES gte P0 309 SI WAYNE N W JERSEY 69 ROUTE 29PEOIJANROcE 9W IERS used outdoor hand-launch gliders cluding drag brakes fold-down rudder drop-off nose weight pop-up stab popularized Bill Blanchard See Polly article May issue Bills scheme employed him others decade works just great some fliers prefer mount stabilizer bottom fuselage such designs pop-up stab wont work Orbiteer Gerry Giles comes rescue pop-down stab reported Torbellino sketch shows basic tail-end hardware front end can fuse burner such Polly Gerry reports prototype works very well does appear vulnerable damage feared Addition 1/16-sq spruce leading edge will help drawback compared pop-up lack adjusting screw trim However find once adjust ments warped little need ever change Note Blanchards version pop-up DT employs shims rather adjust ing screw Bob Meuser 4200 Gregory St Oakland CA 94619 FF Indoor/Tenny continued page 48 done yet another fun model idea glven specified set materials can build glider 30 minutes set rules specified contestant would furnished 6-in long piece 1/16X1/8 balsa 2X6X1/32 balsa sheet No other materials except choice adhesive permitted includes nose weight must derived balsa glue idea provides interesting challenge should thought out well advance contest Styrofoam prop blocla Bob Lieber has sug gested expensive balsa blocks no longer need invested prop blocks photo shows styrofoam block used forming balsa blades Coupe dHiver models also can used Easy B Pennyplane props Two precautions necessary first blades must air dried since baking oven would melt deform styrofoam second work sur face should protected rubbing epoxy glue foam Bob uses expanded bead foam material offers following advice about cutting helix Thin plywood some other hard material glued uncut block both top bottom gnide hot wire cutter top guide visible photo cutter wire must parallel end planes block during whole cut cut surface needs no sanding care applying epoxy glue will preserve smooth surface Bud Tenny PO Box 545 Richardson TX 75080 Junior/Hartmangruber continued page 57 once week Boys Club starters use Comet Fly Boy Cloud Buster kits because two kits excellent teaching fundamentals built up wing fuselage construction finer points model adjustments best flights After boys have mastered two models encouraged make own selections building proj ects have several have gone advanced free flight control line engine-powered models needs done ignite spark interest help grow Now must say should club club member volunteer conduct model group anywhere make one-time thing Continuous instruction flying operations necessary keep up develop interest boy Boys Club always influx new members time goes find boy often will show real interest educational value art model building really rest life others time may seem just something Boys Club knows maybe later life will remember enjoyed modeling resume building flying Editors Note numerous flying sessions localities have impressed enthralled kidsof ageswho ask models can befoun4 tofly Letters magazine reflect same needfor information So Wyoufree-flighters will bear us month wed like render much-needed service author outstand ing rubber-model expert familiar market availabiliiy invited MA share us experience building flying hund reds interesting aircraft Although talking scale will find included meaningful coverage non-scale items trainer intermediate categoriesgreat lead-ins tackling real scale stuff SAFE FLYING IS NO ACCIDENT 126 Model Aviation
Edition: Model Aviation - 1979/12
Page Numbers: 46, 47, 125, 126
B AND B Special model shown threeview has racked up fair score itself Al though built various earlier versions 520 shown has built designer Bill Burks wife Carolyne far Cliff Cloud Climbers meet June racked up nine maxes first place Class Open Gas hightime award meet bad 50-yearold gal wed say NFFS International Planbook 1979 promises model aviation collectors item century judging present indica tions writing late July 96 drawings models intended flown World Champs have received according Planbook Editor Dave Linstrum almost volun teer draftsmen have lined up final drawings publication Planbook isnt merely book plans Some other items included Evolution FAI engines P G F Chinn evolution Nordic towline glider event early years Wakefield Trophy competition portfolio fa mous vintage Wakefield three-views Power photos models pen-pal address list fore word Frank Zinc some history started Model Aemnautics Yearbook series hold hats Aeromodelling Peking British spelling aeromodeling Offhand Id think Aeromodelling Pe king would suitable title booklet blank note paper Mainland China sending team participate World Champs wonder theyll show up staff built bamboo rice paper tied together reed thongs.. stuff made fiberglass carbon fibers Kevlar epoxy resins. e thing betveen Remember hehaws North Koreans got appeared list World Champs participants dont laugh much anymore about Mainly cry lot try harder Pinhole Turbulators want build model has competition potential about zero use airfoil rounded leading edge cover top surface least sheet use slick plastic film covering Most models arent built way employ some form turbulation sharp leading edge microscopically-fuzzy finish stick-n-paper con struction results discontinuity upper surface just aft leading-edge strip multiple top-surface spars employ honestto-goodness turbulators strips wood per haps thread glued upper surface turbulence wire out ahead leading edge usually monofilament nylon tennis racquet string strip rubber vibrates lets back up bit Whats wrong nice smoothly flowing air laminar boundary layer has less drag turbulent Thats fine bottom wing life isnt simple upper surface easier explain what happens regard wing fixed air moving rather other way around real life air right next wing stuck wing doesntmove Waxing wont help air perhaps 1/16 m I5 68%II F i IAL 520 9%tllIZ.S 0 Super Ti8re q-19 Cox &-4 8l 40dowv lLcfr Lt 19 0 ____________________7 40S 5 8 Super Monoiwte oit wine & stala 6 Model Aviation 251 amuOS am tu paid sic uuot La clcashima shows off Tadpole usa vvrnningest A-i glider designs west would believeInterstate 5 Meuser plc cLiItgdra inch away surface moving full speed betweenthe boundary layerthe speed flowing air increases zero full speed front part wings upper surface speed air higher speed main stream creates suction results lift air must slow down again join main stream after passes wing air some distance surface manages orderly fashion air right next surface already going very slowly main stream slows down some air within boundary layer brought dead standstill air closer surface moves forwarcL lied Such situation doesnt really occur except perhaps few mili-seconds unstable situation flow instead separates wing surface leaving thick separation region flow going way region pressure lowthe lift greatas flow followed wing contour solution make sure boundary layer turbulent turbulent boundary layer stagnant air next surface continu ously being mixed fast-moving main stream air less likely slow down reverse direction full-size aircraft no problem main-stream air moving fast enough wing chord great enough boundary layer almost certain turbulent almost allow very special laminar flow airfoils models both factorsair velocity chordwork against us must something convince boundary layer would rather turbulent An effective easily applied seldom seen method inducing turbulence use pinhole turbulators merely holes upper possibly lower surface wing near leading edge form turbula tor tested extensively Model Aero dynamics Research Project Engiand some 25 years ago special low-turbulence wind tunnel Four-inch-chord wings both built-up sheetcovered construction tested various hole configurations built-up wing holes 028-inch diameter pierced through paper just aft leading-edge strip 040inch diameter holes drilled through leading edge strip sheet-covered wing 020-inch diameter holes drilled through sheet covering just aft leading-edge strip what found span-wise hole spacing 25%-chordiinch spacing 4-inch chordis sufficient produce full effect adding holes helps very little greatest effect achieved sheetcovered surface merely because worst lot begin Critical Reynolds number Re cut half greatest effect achieved both top bottom surfaces pierced holes go through leading-edge strip Pre sumably air under pressure enters bottom jets out top holes Some effect achieved piercing upper surface either type wing just behind leading-edge strip Apparently combina tion hold volume air within wing sets up resonance alternately pumps air out holes Helmholtz resonator Reynolds numbers product air velocity chord above critical value no separa tion maximum lift drag unturbulated section somewhat less turbula ted section Lesson dont use larger turbulators closer hole spacing have So much wind-tunnel tests does work out field battle knows Ive seen absolutely nothing written subject POP DOWN OT FOR HIG yG,rvGuiI, 515 MUSIC NH/S HOLE OT LINE HOT STUFF BAKING SODA FILLET FUSELAGE PLYWOOD 1/32X1f8 X 1/4 PlywOod 1/3261/8 PLY STRIP SCOTCH TAPE HINGE / //DT POSITION 1/IS SO SPRUCE IE know Hank Cole used pinhole turbulators several Nordic A/2 towline giiders got still-air times well over 3 mm i used pinhole turbulators low-ceiling Indoor HandLaunch Glider beat Hines Wittman win USFF Champs couple years ago one-shot deal model never flown before hasnt since has never flown pinhole turbulators out reader-land try things know articles telling about Id really appreciate hearing NFFS World Champs Tech Project Another Wow NFFS goal project measurement performance critical observation technical tactical matters publication report covering whole works Project Manager Fred Pearce has spent third century doing related things recently NASA has already organized dozen helpers task teams key focal point project will altitude measurement models flight last perhaps well get some hard facts about altitudes attained FM Power Wakefield models about height gain achieved currently fashionable zoom launches Nordic giiders Homemade theodolitesmade home FAL Power man Tom McLaugh lanwill used applying technique devel oped over some 20 years model rocketry Hopefully still-air sink rates will measured too Also included addition para meters usually included published three-view drawings will measurements airfoilsnot merely statement builder what airfoil section thinks has intended have what really has unusual uses exotic materi als towhook hardware Wakefield front-end hardware zoom techniques tactics auto-surface mechanization winding protective systems stooges prop brakes structural control flutter Continued page 125 December1979 47 Ex-Indoor Champ ud Homak gets rimuns auring practice session forthcoming US team selection program isnt optical illusionprop really bends like thati Meuser pic equipped two synchronized 79-mm MG 17 guns fourth Ar 68 again powered BMW engine first actually identified Versuchs number being Ar 68V4 Following fifth machine powered Jumo 21ODa engine two-speed supercharger takeoff rating 680 hp being Ar 68V5 became production prototype Arado Ar 68E-1 Appearing definitive execution intended design concepts Arado Ar 68E1 conformance specifica tions shown chart Early 1936 no decision concerning produc tion Arado Ar 68 yet made Ernst Udet himself time Luftwaffe Inspector Fighter Pilots put test speak mock combat Jumo powered Ar 68 against top Luftwaffe fighter pilot flying Heinkel 51 easy victory over Heinkel precipitated immediate pro duction order Arado Ar 68E-1 However production tooling almost complete occurred drastic redirection priori ties application Junkers Jumo 210 engines certainly relation oncom ing Messerschmitt Bf 109 production per haps also relation other Luftwaffe projects resulted another redesign Ar 68 again incorporate BMW Vi 7 3ZuprightV 12 engine 51 engine Thus Arado Ar 68F-1 created fact Ar 68 model see front-line service after September 1 1939 Production Ar 68F did noi might have expected end Ar 68E means As events rapidly unfolded poor showing Heinkel 51 Spain motivated yet another change priorities Junkers Jumo 210 engines being massive produc tion Messerschmitt Bf 109 monoplanes still distant Thus fall 1936 Jumo 210 engines again made available Arado Ar 68E machines after became principal production examples last first-line biplane fighter deployed Luftwaffe Consequently occurred aboutmid 1937 tomid 1938 whenthenew eraof Bf 109 opened Arado Ar 68E principal first-line fighter Jagdgruppen Fighter Wings Luftwaffe Although some conflicting numbers records seem indicate approximately 500 Arado Ar 68 machines built Arado Ar 68 mixed-materials phi losophy execution aircraft construction reached high state perfection Basic internal fuselage truss welded steel tubing rectangular section accommodating connec tions cabane struts integral engine mount structure lower wing roots gun mounts very robust landing gear Geometrical fuselage sec tion essentially oval maintained stringers aft cockpit below light metal rear deck light metal forward engine cowling also light metal Wings wood plywood construction upper wing plywood fabric covering lower wing panels plywood covering Light metal tail surfaces structure fabric covered aft fuselage below rear deck Propeller usually utilized two-blade fixed-pitch wooden Heine Final development Arado Ar68 Ar 68H prototype completed spring 1937 machine redesign incorporate BMW 1 32Da nine-cylinder radial air-cooled engine 850 hp takeoff featured enclosed cockpit four 79-mm MG 17 guns two upper wing Top speed 250 mph service ceiling about 30000 feet Few biplane fighters beyond Fiat CR42 first flown early 1939 immediately recalled Max/speed 274 mph 20000 feet Recalling reactivation Arado Ar 68E production motivated inade quacy Heinkel 51 Spain involved re-reallocation some Junkers Jumo 210 engines Ar 68 machines would have otherwise gone Messerschmitt Bf 109 production interest note two Arado Ar 68E fighters actually reached Spain As events ultimately transpired suffi cient number Messerschmitt fighters assure Condor Legion air superiority supplied Bayerische Flugzeugwerke des pite simultaneous production Ar 68E Arado course possible expansion production Jumo 210 engines Beyond Bf 109E machines sent Spain near end conflict powered later Daimler-Benz DB 601A inverted V-i 2 engines 1050 hp September 11939 amongthe hundreds Messerschmitt fighters first-line operational service yet remained 28 Arado Ar 68E-1 biplanes same status operating south-western region Reich after Ar 68F-l machines deployed night fighters year 1940 Thereafter biplane fighters Arados Heinkels some others relegated training schools some surviving until 1945 No recount Luftwaffe biplane fighters however brief complete some mention excellent Avia B-S 34 biplane fighters German origin acquired annexation Czechoslovakia appear last biplane fighters deployed Luftwaffe under combat conditions First applied training schools desperate days late war compelled deployment some Avia BS 34 machines defense Balkan petroleum region SAFE FLYING IS NO ACCIDENT FF Duration/Meuser continued page 47 thermal-detection devices techniques team organization management cheat getting caught oh gosh could write book will Model Models An article May issue SportAviation byTakashi Araki tells small simply built all-balsa gliders can used predict stability characteristics proposed full-size aircraft Strangely enough simple flat wing sections work well accurately formed airfoils profile fuselage works well three-dimensional relative weight wing loading model make little difference purposes Apparently spin characteris tics can rather accurately predicted too high-power flight characteristics can simu December 1979 125 IF R EALIS N/iSCALE ACCESSORIES WILLIAMS BROTHERS RADIO CONTROL SCALE PILOTS E WHEELS CONTROL-LINECYLINDERS ENGINE KITS MACHINE GUN KITS FREE-FLIGHT TIC DISPLAY MODELS SEND 5O FOR COMPLETE ILLUSTRATED CATALOG DEPT MA 181 PAWNEE STREET SAN MARCOS CA 9 BROWN CO-2 ENGINES ENGINES ARE IN STOCK NEW CHARGER AND 5 SIZES OF TANKS BROWN ENGINES COMPLETE CATALOG $100 HARD TO FIND ACCESSORIES KITE AND PLANS FOR RUBBER POWERED MODELS PHONE 17141 4698675 Peck-Pelymeis W BOX 2498-AM LA MESA CALIF 92041 CUSTOM TUNED ENGINES COMPETITION ACCESSORIES Cox 049L051 Specialists brochure send 1 5c stamp Kustom Krattsmanship Brochure Box 2699 Laguna Hills CA 92653 714 830-5162 Diesel Conversion Kits e Power Quiet Smooth Economical Send 30 & Stamped Addressed Envelope Dealer Inquiry InvIted Davis Diesel Development Inc Box 141 Mllford CT 06460 Winning Ideas FOURMOST FUEL FITTING SETS Large Fuel Fitting Set cSize % IDPRICE S150 1 Tee 1 Elbow 1 Union 1 Plug Both Made Fuel Proof Polyethylene Small Fuel Fitting Set Size A6 10PRICE S125 1 Tee 2 Elbows 1 Pen Bladder Tee FUEL MANIFOLD This Manifold Provides Convenient Method Tank Filling Draining Priming %2 10PRICE 95 1 Scale 1931 Gee Bee Super Sportster IGeneral Arrange ment Drawing Catalog 25cBy W T Bill Given ERNISTIC MODELS PO BOX 6974 ALBUQ NM 87197 lated mild chuck article claims control characteristics can simulated too cutting away control surface taping back deflected position author cites cases unusual characteristics cures predicted small chuck-glider tests later confirmed expensive wind-tunnel tests RC model programs course models must accurately constructed attention must paid accuracy incidence angles CG positions model must launched proper flight attitude speed wonder dont use technique design aid free-flight competition sport models has done course isnt done very often reason bunch copy cats Basic area ratios moment arms dihedral angles CG positions have pretty well standardized before trying something really newa T-tail negative dihe dral stab canard winglets whateverwouldnt pay spend hour two doing bit cutand-try chuck glider first Certainly FF Scale modelers should able profit technique except perhaps few blessed nack being able make fool thing fly Hello Bill Warner course technique shouldnt work Reynolds Number thatbut ap parently does recently built model absolutely unstable Perhaps bi-stable would accurate description perfectly stable either normal glide near-vertical dive model wasnt far out should have flown well didnt might have profited technique shouldnt work does OHLG DT forms dethermalizers have 0491051 AIR FLO ENGINE MOUNT REDUCES DRAG VIBRATION FREE PRICE 250 FUEL SHUTOFF Can Used Control Fuel Flow Starting jPositive Airborn Shutoff PRICE 350 C FLASH STARTING SUNEXCELLER POWER S LONGER LIFE SLOWEST DRAIN GLOW PLUGS SWANSON ASSOCIATES gte P0 309 SI WAYNE N W JERSEY 69 ROUTE 29PEOIJANROcE 9W IERS used outdoor hand-launch gliders cluding drag brakes fold-down rudder drop-off nose weight pop-up stab popularized Bill Blanchard See Polly article May issue Bills scheme employed him others decade works just great some fliers prefer mount stabilizer bottom fuselage such designs pop-up stab wont work Orbiteer Gerry Giles comes rescue pop-down stab reported Torbellino sketch shows basic tail-end hardware front end can fuse burner such Polly Gerry reports prototype works very well does appear vulnerable damage feared Addition 1/16-sq spruce leading edge will help drawback compared pop-up lack adjusting screw trim However find once adjust ments warped little need ever change Note Blanchards version pop-up DT employs shims rather adjust ing screw Bob Meuser 4200 Gregory St Oakland CA 94619 FF Indoor/Tenny continued page 48 done yet another fun model idea glven specified set materials can build glider 30 minutes set rules specified contestant would furnished 6-in long piece 1/16X1/8 balsa 2X6X1/32 balsa sheet No other materials except choice adhesive permitted includes nose weight must derived balsa glue idea provides interesting challenge should thought out well advance contest Styrofoam prop blocla Bob Lieber has sug gested expensive balsa blocks no longer need invested prop blocks photo shows styrofoam block used forming balsa blades Coupe dHiver models also can used Easy B Pennyplane props Two precautions necessary first blades must air dried since baking oven would melt deform styrofoam second work sur face should protected rubbing epoxy glue foam Bob uses expanded bead foam material offers following advice about cutting helix Thin plywood some other hard material glued uncut block both top bottom gnide hot wire cutter top guide visible photo cutter wire must parallel end planes block during whole cut cut surface needs no sanding care applying epoxy glue will preserve smooth surface Bud Tenny PO Box 545 Richardson TX 75080 Junior/Hartmangruber continued page 57 once week Boys Club starters use Comet Fly Boy Cloud Buster kits because two kits excellent teaching fundamentals built up wing fuselage construction finer points model adjustments best flights After boys have mastered two models encouraged make own selections building proj ects have several have gone advanced free flight control line engine-powered models needs done ignite spark interest help grow Now must say should club club member volunteer conduct model group anywhere make one-time thing Continuous instruction flying operations necessary keep up develop interest boy Boys Club always influx new members time goes find boy often will show real interest educational value art model building really rest life others time may seem just something Boys Club knows maybe later life will remember enjoyed modeling resume building flying Editors Note numerous flying sessions localities have impressed enthralled kidsof ageswho ask models can befoun4 tofly Letters magazine reflect same needfor information So Wyoufree-flighters will bear us month wed like render much-needed service author outstand ing rubber-model expert familiar market availabiliiy invited MA share us experience building flying hund reds interesting aircraft Although talking scale will find included meaningful coverage non-scale items trainer intermediate categoriesgreat lead-ins tackling real scale stuff SAFE FLYING IS NO ACCIDENT 126 Model Aviation