rncddIavlland MANY CONSTRUCTION articles scale models warn prospective builder model experts author does believe theory observations relatively inexpe rienced modelers beginners have natural manual art skill some modelers years experience want build model think can go ahead build However sure have desire build Most scale projects time consuming de manding require months work Without burning desire create model builder will never finish project deHavilland Comet 88 unique airplane its time designed specif ically long-range racing aircraft intended solely McRobertsen air race England Australia 1934 Only three aircraft built aircraft red-and-white racer sponsored Grosvenor House London hotel winner aircraft later experienced succession owners modified craft various ways aircraft now exhibit Shuttleworth Museum England Comparison museum air craft photos taken craft first built flown indicate major changes made subsequent owners last renovation changes have deceived draftsmen model builders Comet 88 evidently based products Shuttleworth craft As result efforts depict aircraft existed McRobertsen race author researched aircraft three years before enough data gathered make scale project possible having sufficient fidelity scale Preparation three-view plan also necessary order avoid known errors available scale plans scale draw ing authenticated AMA Tech nical Director required AMA rules General Features model features retracting gear flaps throttle brakes Control devices including elevator control achieved three fly ing lines detailed plans An op tional fixed gear also shown plans model very fast twin 35s having clocked 53 mph con struction therefore rugged dont tempted cut corners save weight authors model weighed 7 lbs com plete rugged construction needed handle twin engines hard landings will also ensure contest seasons structural failure stress cracks particularly wing fillet area Engines smaller 35 recommended since model size weight will stay airborne smaller engine should engine fail flight common occurrence twins Detailed step-by-step instructions will described Rather key elements fabricating assembly well special parts will described order 12 Model Aviation good reason smile Ernie Violett poses Comet Mode/Aviation photographer Always great favorite modelers DH-88 beautiful today 1934 won England Australia air race Solid red coloring spectacular CameL 88 avoid major errors thorough study plans text however must chore after construction should no problem construction sequence too important except noted use cellulose-acetate type model airplane glues avoided planking exterior joints seams Glues type continue dry shrink over very long period causing telltale lines finish An aliphatic resin glue sug gested glue used must sandable therefore use white glues Money can saved planking planking strips cut sheets ever possible builder has access small table saw such Unimat other suitable devices Use medium-weight balsa structure members use soft light weight balsa planking Use light con test grade balsa tail surfaces plywood cores tail surfaces plywood inlay wing trailing edge permit sanding trailing edges sharp edge edge crumbling would occur balsa-only trail ing edge sharp edge scale thick edges balsa Wing Construction Wing construction should preceded fabrication landing gear cross shaft retraction counterbalance arm motor mounts landing gear bearers Part main plywood support connective member fixed gear arrangement chosen omit cross-shaft its associated parts motor mount bearing block landing gear bearers should jigdrilled cross-shaft bearing sleeve holes landing gear strut shaft ensure alignment freedom bind ing cross-shaft parts retracting gear must operate freely Slide motor bearers bearing block cross-shaft silver solder place end center retraction arms spring counterbalance arms jig rec ommended during soldering operation achieve proper positioning arms Jig assemble aforementioned members directly plans doublechecking alignments ascertaining freedom cross-shaft rotation before gluing Use epoxy glue flathead screws joints add wheel strut assemblies until after sanding complete wing constructed piece up side down utilizing jig ribs order create proper dihedral wing rib inci dence elevate wing above work surface clearance center retraction arm Start cutting out ribs jig ribs wing tips spars dihedral gussets leading trailing edges eight jig ribs sufficient support trailing edge regular ribs will have bench-supported withstand planking operation Use short length alsa vertical supports spot glued rib builder may opt make ribs jig ribs Refer jig base line shown front view de termine proper height jig ribs Mark parting line jig ribs before using Note left wing tip laminated bass plywood making tip epoxy glue aluminum guide tubes leadout wires leading edge should tapered slightly oversize shaped trailing edges should shaped prior attaching 1/32 ply trailing edge inlay Note 1/32 ply runs inboard edge aileron opening fuselage center line vicinity fuselage 1/32 ply forms base wing fillet added later Assemble two spar halves dihedral brace before wing assembly Erect jig ribs plan using temporary blocking bracing posi Nationals winner magnificent twin durable consistent flyer tion hold place Line up jig ribs straightedge Pin block leading trailing edge spar place Glue wing tips Glue rib pieces between nacelles outboard out board install Part A-motor mount-landing gear assembly Add re maining ribs glue Plank wing dont forget provide access hatches over bellerank area point juncture aileron torque tubes Con struct hatches 2 plies 3/32 hard balsa glued grain 90 de grees other Outline hatch opening hatch perimeter 1/32 ply prevent edge wear Let complete assembly dry least 48 hours before removal bench Remove jig portion ribs parting line sand rib edges Although complicated retractable landing gearof course works Iis fully detailed both text plan theres nothing like picture help clarify things Theres way make fuselage exact alignment build jig its assembly Heres authors simple jig semi-completed fuselage being worked October1975 13 deHavilland Comet 88 smooth Modify Roberts bellcrank described plans install Part blind nuts Install throttle flexible pushrods deadman crank stop pin over-travel arrangement throttle pushrod detailed plans permits activation landing gear switch after full throttle reached switch double-pole double-throw slide type tension spring shown ensures return slide down position takes place upon slight reduction throttle setting Install leadout cables wing weight brake flexible pushrod aluminum tubes running lights wiring aileron torque tubes Check items secure installation freedom moving parts electric continuity wiring satis fied everything place working order plank top wing Glue filler strip between aileron spar Make up aileron ply balsa sandwiches tack glue place nylon hinges should glued aile rons time Use balsa spacers spot glued achieve necessary clear ance between ailerons wing center ply core ailerons wing trailing edge wing tip dry sand wing proper airfoil section using templates check accuracy sanding com pleted cut ailerons loose tackglued balsa spacers store until finish ing begins Fuselage Constriwtion Begin cutting out formers fuselage sides part B two required Glue balsa fill piece outboard side two part B pieces Shape filler pieces according plan view Jig construction recom mended Build jig scrap balsa directly over plan will maintain vertical alignment fuselage sides estab lish fuselage width Glue fuselage sides part B dry insert sides fuselage jig wedging sides tight against jig frame insertion gluing fuselage formers forget insert flap deadman cranks cross-shaft sides placed jig Install some temporary diag onal braces between formers plan view prevent warps structure removed jig dry remove jig stall elevator pushrod tail skid wiring rudder elevator controls flap flexible pushrod flap cross-over arm bulkhead holes devices shown plans left builders choice routing Install retraction motor support time motor Construct battery case fiberglass cloth resin using dowel slightly larger battery diameter mold Install battery case required contacts connect wir ing Make fit dummy interior sides cockpit instrument panel cockpit floor install items Store until painting completed Check moving parts freedom wiring electrical continuity Plank top fuselage bottom Assemble fuselage wing inserting tabs projections part B part Glue tabs well after checking wing alignment fuse lage Plank bottom fuselage includ ing retraction gear access hatch area Fair bottom planking wing maintaining fuselage profile Sand planking using cross-section templates achieve proper shape Cut out access hatch install suitable formers hatch interior face maintain shape Line hatch opening hatch perimeter 1/32 ply protect edges against wear Begin wing fillet construction marking fillet outline fuselage side top wing Insert rectangular block wing leading edge root shown Cut fillet vertical laminations very soft 3/16 balsa pin glue place layer time dry carve sand fillet using templates achieve correct main retraction shaft made telescoping brass tubingtwo pieces inside other main landing gear struts Picture shows mechanism center fuselage r Above Landing gear extended position Right above landing gear strut pistons made 3/16 steel bolts Below Comet Sterling Models Award Outstanding Scale model Nationals irrespective event best show deHavilland Comet 88 shape Feather fillet edge fuselage wing surfaces until fillet outline marking just exposed Nacelles nacelles may either fiberglass balsa original model used latter either case check carefully required interior width needed accommodate engine landing gear assembly retractable fixed nacelle cross-sections shown plans true scale may have widened suit engine/gear set-up fiberglass chosen use two longitu dinal halves Include stiffening ribs necessary mold plywood nose ring behind spinner Also mold 1/32 ply piece around leading edge wing Use heavy cloth several layers light cloth After molding joining two halves cut two sections indi cated nacelle separation line Shim finished cowl away motor bearers bass stock trimmed fit epoxied place Fasten front half nacelle bass shims small flathead machine screws best epoxy matching nut bass block re ceive machine screw Locate screws coincide scale location cowling fasteners Cut out exhaust needle valve openings Fasten rear half nacelle shown plans balsa version constructed sheet sides balsa blocks fitted between sides blocks should divided two halves along nacelle longitud inal center spot glued separation Begin accurately cutting side pieces profile shape cut match curv ature wing Cut out position 1/32 ply piece around wing leading edge Insert glue blocks between sides holding rubber bands until dry Separate spot-glued points along centerline remove model rejoin spot gluing Carve sand shape Separate halves once again hollow out interior Glue halves together cut along nacelle separation line Fasten motor mounts described fiberglass version Trim 1/32 off top edge nacelle glue 1/32 ply lip projecting 1/4 beyond cowling form base fillet Form fillet Epoxolite sand smooth Note vent openings cowl sides wing juncture ex treme rear nacelle must pro vided openings provide ex haust cooling air engine wheels retracted position also recommended fixed gear version Tail Surfaces tail surfaces similar ie 1/32 ply core faced soft balsa laminations Ply cores must have cut-outs made hinges control-horn arms mass balance BANK S TURN CLOCK OIL PRESSUREARTIFICIAL ICR TACHOMETERSAIRSPEED ROSSARACECANOPY FRAMEALTIMETER 3/64 BR ROD INSTRUMENT PANELFUEL GAUGES HEADREST I/B SUPPORT BLOCKPLASTIC FOAM COMPASS ON ALUMLEATHER COVEh BASE WITH WIRE STHROTTLE BMISLONG STRINGER I/3D PLY SEATSSWITCHES HAND BRAKERETRACTION RUDDER PEDALSWHEEL I/SD PLY SIDES --STRINGER ALUM TREADS 1/1K PLY FLOOR NEVEL GEAFSEEV PUSH ROD W/FPRTUNNEL1/16 PLY TUNNEL DO-AS MS FURIl 52MW PUSH ROD ALL PIVOTS CONNECT TO RUDDER FIRNOTES BASS W/ LEATHERUSE THIN ALUMINUM B PLASTIC SHEET & TUBE FOR PARTS COVERINSTRUMENTS ARE TATONE 5/16 B T/16 DIA CLEAR DOPE SEATS COCKPIT SIDES STRINGERS & TUNNEL SECTION BPAINT FLAT BLACK INSYR PANEL INSTRUMENTS GRIPS RETRACTION WHEEL TTLE QADRANT MINIATURE TOGGLE SWITCHES MAY BE CUT DOWN B USED IN INSTR PANEL FOR MODELS ELECTRICAL SYSTEM COMPASS CARD SECTION GRAPHIC SCALE 0I 53456 aluminum tubes prior lamination After lamination add spruce spars balsa fairings shown Fasten hinge fixed surface time thus permitting separation surfaces final shaping sanding finishing Add rear fuselage block slotted rudder ply projection Add fixed tail surfaces sand fuselage block shape add fillets using Epoxolite DEHAVILANO COMET 88 3/BI- 0 SCALE3 DESIGNED B DRAWN BY ERNIE VIOLET1IEof 3 Landing Gear retreacting gear simple appears self-locking type main retraction shaft made telescoping brass tubing two pieces inside other also main landing gear struts Easily available materials parts used machining held minimum continued page 66 October1975 17 Above Over three years research went project before work began Below engine nacelles made fiberglass balsa Only projecting needle valve knob betrays model Note righthand-turning props also scale Inboard prop has 1 pitch D H Comet 88 continued control travel third line indicator top handle Provide stop full-throttle position Movement beyond stop actuate retraction motor DPDT slide switch model virtue throttle overtravel arrange ment shown plans Provide second stop other end indicator travel throttle idle position Movement beyond stop actuate engine cut-off Both stops should hinged swing out way indicator hand can used swing stops out way gear operation engine shut-off someone help check operation flying lines stops throt tles DPDT switch gear retrac tion engines running flying lines under tension Repeat process engine running both running Make necessary adjustments line lengths handle stops throttle settings DPDT switch position gear operation fails erratic engines running problem likely intermittent complete loss electrical continuity caused vibration vibration loose connection whatever cause must eliminated first flight flights testing gear retraction fly nacelles wheel spats removed wheels-up belly landing needed model will land undamaged Otherwise nacelles would wiped out Some gb-plug damage may incurred minor matter Use little up right aileron achieve level flight Use masking tape hold aileron position Also tape canopy down precaution flights Use clear tape competition Pick smooth flying surface must since model will flip its nose easily rough surface Conduct successful pull-test youre ready maiden flight get engines running correctly start outboard engine tune best rpm ear reed tachometer Stop engine repeat operation inboard engine running smoothly restart outboard engine required tweaking needle valves sure engines synchronized closely possible helper hold ing plane reduce engine rpm control handle about 40% level release plane Hold plane ground gradually opening throt tle Dont lift plane offlet lift off used Contest Directors placing con tests Flyers will still fly together scoring awards will divided categories Bob Hunt NJ wrote state 55Flying Goombahs Eastern Controline Championships Mass expert advanced circle intermediate beginners another circle virtue sufficient flying speed rest easy plane fast grooves easily land reduce engine rpm slow ly let plane speed decrease plane flying slowly possible lose altitude slowly very close ground reduce throttle slightly model will set down reduce landing roll stop apply brake using full up elevator Move third-line control engine shut-off position Check aircraft thoroughly after first flight flight thereafter damage stress cracks loose nuts fittings wheels engines control surfaces reasonable care model capable five seven year competition life author wishes extend appre ciation Bill Harris Laurel Md skillful help preparing Comet competition acting pit man past Nationals Editors Note Extensive informationa Scale Information Sheetaccompanies plans does scale authentication drawing information thus provided consider entering model competitionsuch information required judging proof scale etc chief purpose provide begin ning competition new flyers competition top nationals caliber Lets face person starts out new situation likes see some material results progress Quite possibly some form categories stunt could help bring about tract flyers event address 1640 Maywick Drive Lexing ton Ky 40504 68 Model Aviation WHAT PRICE LLENCE Dave Brown Mark Rado lIt Ia SO- iJfr~Jj leg tat end 3rd Macto proven excellence ot EXPERT SERtES World Eng non w f7 continue ntvo R/C en uc pe 4 tsd V dottar Oflyona Ota. Dave 5 CH 4SERVOS~ 3MO rk DENGINES 8960 ROSSASH AVECINCINNATI OHIO 45236 VIXEN~ -/ze 2I95 VIXEN has edva,teg beog smell andeconoocal huId end opetete na I,, tedaee eqo,oga two-ohe,,eI edOoethSpet- ,oetue stows 50111 SatIety peck hitAea-t8Osq teetoen,clodepecision baodsaosedandeaodedWeigtt------21 pelts Ate t08, esiotend Cotoplete hedesaeEtgi~-Co ID 045-051 Coot olsA j cod Fopooptdelioeyteodoeshiesohett ononty ode, adding 5155 shipping a,d handling Wsoo,snesde,tsedd 4%seleeteo Sotty no COD odes CONCEPT MODELS ___ffi Xe Deal ot Dole Olteot Bob Emett holds Don Schultz Model FAI CL AerobaticsAvenger OS 3547 oX span 57 continued page 18
Edition: Model Aviation - 1975/10
Page Numbers: 12, 13, 15, 17, 68
rncddIavlland MANY CONSTRUCTION articles scale models warn prospective builder model experts author does believe theory observations relatively inexpe rienced modelers beginners have natural manual art skill some modelers years experience want build model think can go ahead build However sure have desire build Most scale projects time consuming de manding require months work Without burning desire create model builder will never finish project deHavilland Comet 88 unique airplane its time designed specif ically long-range racing aircraft intended solely McRobertsen air race England Australia 1934 Only three aircraft built aircraft red-and-white racer sponsored Grosvenor House London hotel winner aircraft later experienced succession owners modified craft various ways aircraft now exhibit Shuttleworth Museum England Comparison museum air craft photos taken craft first built flown indicate major changes made subsequent owners last renovation changes have deceived draftsmen model builders Comet 88 evidently based products Shuttleworth craft As result efforts depict aircraft existed McRobertsen race author researched aircraft three years before enough data gathered make scale project possible having sufficient fidelity scale Preparation three-view plan also necessary order avoid known errors available scale plans scale draw ing authenticated AMA Tech nical Director required AMA rules General Features model features retracting gear flaps throttle brakes Control devices including elevator control achieved three fly ing lines detailed plans An op tional fixed gear also shown plans model very fast twin 35s having clocked 53 mph con struction therefore rugged dont tempted cut corners save weight authors model weighed 7 lbs com plete rugged construction needed handle twin engines hard landings will also ensure contest seasons structural failure stress cracks particularly wing fillet area Engines smaller 35 recommended since model size weight will stay airborne smaller engine should engine fail flight common occurrence twins Detailed step-by-step instructions will described Rather key elements fabricating assembly well special parts will described order 12 Model Aviation good reason smile Ernie Violett poses Comet Mode/Aviation photographer Always great favorite modelers DH-88 beautiful today 1934 won England Australia air race Solid red coloring spectacular CameL 88 avoid major errors thorough study plans text however must chore after construction should no problem construction sequence too important except noted use cellulose-acetate type model airplane glues avoided planking exterior joints seams Glues type continue dry shrink over very long period causing telltale lines finish An aliphatic resin glue sug gested glue used must sandable therefore use white glues Money can saved planking planking strips cut sheets ever possible builder has access small table saw such Unimat other suitable devices Use medium-weight balsa structure members use soft light weight balsa planking Use light con test grade balsa tail surfaces plywood cores tail surfaces plywood inlay wing trailing edge permit sanding trailing edges sharp edge edge crumbling would occur balsa-only trail ing edge sharp edge scale thick edges balsa Wing Construction Wing construction should preceded fabrication landing gear cross shaft retraction counterbalance arm motor mounts landing gear bearers Part main plywood support connective member fixed gear arrangement chosen omit cross-shaft its associated parts motor mount bearing block landing gear bearers should jigdrilled cross-shaft bearing sleeve holes landing gear strut shaft ensure alignment freedom bind ing cross-shaft parts retracting gear must operate freely Slide motor bearers bearing block cross-shaft silver solder place end center retraction arms spring counterbalance arms jig rec ommended during soldering operation achieve proper positioning arms Jig assemble aforementioned members directly plans doublechecking alignments ascertaining freedom cross-shaft rotation before gluing Use epoxy glue flathead screws joints add wheel strut assemblies until after sanding complete wing constructed piece up side down utilizing jig ribs order create proper dihedral wing rib inci dence elevate wing above work surface clearance center retraction arm Start cutting out ribs jig ribs wing tips spars dihedral gussets leading trailing edges eight jig ribs sufficient support trailing edge regular ribs will have bench-supported withstand planking operation Use short length alsa vertical supports spot glued rib builder may opt make ribs jig ribs Refer jig base line shown front view de termine proper height jig ribs Mark parting line jig ribs before using Note left wing tip laminated bass plywood making tip epoxy glue aluminum guide tubes leadout wires leading edge should tapered slightly oversize shaped trailing edges should shaped prior attaching 1/32 ply trailing edge inlay Note 1/32 ply runs inboard edge aileron opening fuselage center line vicinity fuselage 1/32 ply forms base wing fillet added later Assemble two spar halves dihedral brace before wing assembly Erect jig ribs plan using temporary blocking bracing posi Nationals winner magnificent twin durable consistent flyer tion hold place Line up jig ribs straightedge Pin block leading trailing edge spar place Glue wing tips Glue rib pieces between nacelles outboard out board install Part A-motor mount-landing gear assembly Add re maining ribs glue Plank wing dont forget provide access hatches over bellerank area point juncture aileron torque tubes Con struct hatches 2 plies 3/32 hard balsa glued grain 90 de grees other Outline hatch opening hatch perimeter 1/32 ply prevent edge wear Let complete assembly dry least 48 hours before removal bench Remove jig portion ribs parting line sand rib edges Although complicated retractable landing gearof course works Iis fully detailed both text plan theres nothing like picture help clarify things Theres way make fuselage exact alignment build jig its assembly Heres authors simple jig semi-completed fuselage being worked October1975 13 deHavilland Comet 88 smooth Modify Roberts bellcrank described plans install Part blind nuts Install throttle flexible pushrods deadman crank stop pin over-travel arrangement throttle pushrod detailed plans permits activation landing gear switch after full throttle reached switch double-pole double-throw slide type tension spring shown ensures return slide down position takes place upon slight reduction throttle setting Install leadout cables wing weight brake flexible pushrod aluminum tubes running lights wiring aileron torque tubes Check items secure installation freedom moving parts electric continuity wiring satis fied everything place working order plank top wing Glue filler strip between aileron spar Make up aileron ply balsa sandwiches tack glue place nylon hinges should glued aile rons time Use balsa spacers spot glued achieve necessary clear ance between ailerons wing center ply core ailerons wing trailing edge wing tip dry sand wing proper airfoil section using templates check accuracy sanding com pleted cut ailerons loose tackglued balsa spacers store until finish ing begins Fuselage Constriwtion Begin cutting out formers fuselage sides part B two required Glue balsa fill piece outboard side two part B pieces Shape filler pieces according plan view Jig construction recom mended Build jig scrap balsa directly over plan will maintain vertical alignment fuselage sides estab lish fuselage width Glue fuselage sides part B dry insert sides fuselage jig wedging sides tight against jig frame insertion gluing fuselage formers forget insert flap deadman cranks cross-shaft sides placed jig Install some temporary diag onal braces between formers plan view prevent warps structure removed jig dry remove jig stall elevator pushrod tail skid wiring rudder elevator controls flap flexible pushrod flap cross-over arm bulkhead holes devices shown plans left builders choice routing Install retraction motor support time motor Construct battery case fiberglass cloth resin using dowel slightly larger battery diameter mold Install battery case required contacts connect wir ing Make fit dummy interior sides cockpit instrument panel cockpit floor install items Store until painting completed Check moving parts freedom wiring electrical continuity Plank top fuselage bottom Assemble fuselage wing inserting tabs projections part B part Glue tabs well after checking wing alignment fuse lage Plank bottom fuselage includ ing retraction gear access hatch area Fair bottom planking wing maintaining fuselage profile Sand planking using cross-section templates achieve proper shape Cut out access hatch install suitable formers hatch interior face maintain shape Line hatch opening hatch perimeter 1/32 ply protect edges against wear Begin wing fillet construction marking fillet outline fuselage side top wing Insert rectangular block wing leading edge root shown Cut fillet vertical laminations very soft 3/16 balsa pin glue place layer time dry carve sand fillet using templates achieve correct main retraction shaft made telescoping brass tubingtwo pieces inside other main landing gear struts Picture shows mechanism center fuselage r Above Landing gear extended position Right above landing gear strut pistons made 3/16 steel bolts Below Comet Sterling Models Award Outstanding Scale model Nationals irrespective event best show deHavilland Comet 88 shape Feather fillet edge fuselage wing surfaces until fillet outline marking just exposed Nacelles nacelles may either fiberglass balsa original model used latter either case check carefully required interior width needed accommodate engine landing gear assembly retractable fixed nacelle cross-sections shown plans true scale may have widened suit engine/gear set-up fiberglass chosen use two longitu dinal halves Include stiffening ribs necessary mold plywood nose ring behind spinner Also mold 1/32 ply piece around leading edge wing Use heavy cloth several layers light cloth After molding joining two halves cut two sections indi cated nacelle separation line Shim finished cowl away motor bearers bass stock trimmed fit epoxied place Fasten front half nacelle bass shims small flathead machine screws best epoxy matching nut bass block re ceive machine screw Locate screws coincide scale location cowling fasteners Cut out exhaust needle valve openings Fasten rear half nacelle shown plans balsa version constructed sheet sides balsa blocks fitted between sides blocks should divided two halves along nacelle longitud inal center spot glued separation Begin accurately cutting side pieces profile shape cut match curv ature wing Cut out position 1/32 ply piece around wing leading edge Insert glue blocks between sides holding rubber bands until dry Separate spot-glued points along centerline remove model rejoin spot gluing Carve sand shape Separate halves once again hollow out interior Glue halves together cut along nacelle separation line Fasten motor mounts described fiberglass version Trim 1/32 off top edge nacelle glue 1/32 ply lip projecting 1/4 beyond cowling form base fillet Form fillet Epoxolite sand smooth Note vent openings cowl sides wing juncture ex treme rear nacelle must pro vided openings provide ex haust cooling air engine wheels retracted position also recommended fixed gear version Tail Surfaces tail surfaces similar ie 1/32 ply core faced soft balsa laminations Ply cores must have cut-outs made hinges control-horn arms mass balance BANK S TURN CLOCK OIL PRESSUREARTIFICIAL ICR TACHOMETERSAIRSPEED ROSSARACECANOPY FRAMEALTIMETER 3/64 BR ROD INSTRUMENT PANELFUEL GAUGES HEADREST I/B SUPPORT BLOCKPLASTIC FOAM COMPASS ON ALUMLEATHER COVEh BASE WITH WIRE STHROTTLE BMISLONG STRINGER I/3D PLY SEATSSWITCHES HAND BRAKERETRACTION RUDDER PEDALSWHEEL I/SD PLY SIDES --STRINGER ALUM TREADS 1/1K PLY FLOOR NEVEL GEAFSEEV PUSH ROD W/FPRTUNNEL1/16 PLY TUNNEL DO-AS MS FURIl 52MW PUSH ROD ALL PIVOTS CONNECT TO RUDDER FIRNOTES BASS W/ LEATHERUSE THIN ALUMINUM B PLASTIC SHEET & TUBE FOR PARTS COVERINSTRUMENTS ARE TATONE 5/16 B T/16 DIA CLEAR DOPE SEATS COCKPIT SIDES STRINGERS & TUNNEL SECTION BPAINT FLAT BLACK INSYR PANEL INSTRUMENTS GRIPS RETRACTION WHEEL TTLE QADRANT MINIATURE TOGGLE SWITCHES MAY BE CUT DOWN B USED IN INSTR PANEL FOR MODELS ELECTRICAL SYSTEM COMPASS CARD SECTION GRAPHIC SCALE 0I 53456 aluminum tubes prior lamination After lamination add spruce spars balsa fairings shown Fasten hinge fixed surface time thus permitting separation surfaces final shaping sanding finishing Add rear fuselage block slotted rudder ply projection Add fixed tail surfaces sand fuselage block shape add fillets using Epoxolite DEHAVILANO COMET 88 3/BI- 0 SCALE3 DESIGNED B DRAWN BY ERNIE VIOLET1IEof 3 Landing Gear retreacting gear simple appears self-locking type main retraction shaft made telescoping brass tubing two pieces inside other also main landing gear struts Easily available materials parts used machining held minimum continued page 66 October1975 17 Above Over three years research went project before work began Below engine nacelles made fiberglass balsa Only projecting needle valve knob betrays model Note righthand-turning props also scale Inboard prop has 1 pitch D H Comet 88 continued control travel third line indicator top handle Provide stop full-throttle position Movement beyond stop actuate retraction motor DPDT slide switch model virtue throttle overtravel arrange ment shown plans Provide second stop other end indicator travel throttle idle position Movement beyond stop actuate engine cut-off Both stops should hinged swing out way indicator hand can used swing stops out way gear operation engine shut-off someone help check operation flying lines stops throt tles DPDT switch gear retrac tion engines running flying lines under tension Repeat process engine running both running Make necessary adjustments line lengths handle stops throttle settings DPDT switch position gear operation fails erratic engines running problem likely intermittent complete loss electrical continuity caused vibration vibration loose connection whatever cause must eliminated first flight flights testing gear retraction fly nacelles wheel spats removed wheels-up belly landing needed model will land undamaged Otherwise nacelles would wiped out Some gb-plug damage may incurred minor matter Use little up right aileron achieve level flight Use masking tape hold aileron position Also tape canopy down precaution flights Use clear tape competition Pick smooth flying surface must since model will flip its nose easily rough surface Conduct successful pull-test youre ready maiden flight get engines running correctly start outboard engine tune best rpm ear reed tachometer Stop engine repeat operation inboard engine running smoothly restart outboard engine required tweaking needle valves sure engines synchronized closely possible helper hold ing plane reduce engine rpm control handle about 40% level release plane Hold plane ground gradually opening throt tle Dont lift plane offlet lift off used Contest Directors placing con tests Flyers will still fly together scoring awards will divided categories Bob Hunt NJ wrote state 55Flying Goombahs Eastern Controline Championships Mass expert advanced circle intermediate beginners another circle virtue sufficient flying speed rest easy plane fast grooves easily land reduce engine rpm slow ly let plane speed decrease plane flying slowly possible lose altitude slowly very close ground reduce throttle slightly model will set down reduce landing roll stop apply brake using full up elevator Move third-line control engine shut-off position Check aircraft thoroughly after first flight flight thereafter damage stress cracks loose nuts fittings wheels engines control surfaces reasonable care model capable five seven year competition life author wishes extend appre ciation Bill Harris Laurel Md skillful help preparing Comet competition acting pit man past Nationals Editors Note Extensive informationa Scale Information Sheetaccompanies plans does scale authentication drawing information thus provided consider entering model competitionsuch information required judging proof scale etc chief purpose provide begin ning competition new flyers competition top nationals caliber Lets face person starts out new situation likes see some material results progress Quite possibly some form categories stunt could help bring about tract flyers event address 1640 Maywick Drive Lexing ton Ky 40504 68 Model Aviation WHAT PRICE LLENCE Dave Brown Mark Rado lIt Ia SO- iJfr~Jj leg tat end 3rd Macto proven excellence ot EXPERT SERtES World Eng non w f7 continue ntvo R/C en uc pe 4 tsd V dottar Oflyona Ota. Dave 5 CH 4SERVOS~ 3MO rk DENGINES 8960 ROSSASH AVECINCINNATI OHIO 45236 VIXEN~ -/ze 2I95 VIXEN has edva,teg beog smell andeconoocal huId end opetete na I,, tedaee eqo,oga two-ohe,,eI edOoethSpet- ,oetue stows 50111 SatIety peck hitAea-t8Osq teetoen,clodepecision baodsaosedandeaodedWeigtt------21 pelts Ate t08, esiotend Cotoplete hedesaeEtgi~-Co ID 045-051 Coot olsA j cod Fopooptdelioeyteodoeshiesohett ononty ode, adding 5155 shipping a,d handling Wsoo,snesde,tsedd 4%seleeteo Sotty no COD odes CONCEPT MODELS ___ffi Xe Deal ot Dole Olteot Bob Emett holds Don Schultz Model FAI CL AerobaticsAvenger OS 3547 oX span 57 continued page 18
Edition: Model Aviation - 1975/10
Page Numbers: 12, 13, 15, 17, 68
rncddIavlland MANY CONSTRUCTION articles scale models warn prospective builder model experts author does believe theory observations relatively inexpe rienced modelers beginners have natural manual art skill some modelers years experience want build model think can go ahead build However sure have desire build Most scale projects time consuming de manding require months work Without burning desire create model builder will never finish project deHavilland Comet 88 unique airplane its time designed specif ically long-range racing aircraft intended solely McRobertsen air race England Australia 1934 Only three aircraft built aircraft red-and-white racer sponsored Grosvenor House London hotel winner aircraft later experienced succession owners modified craft various ways aircraft now exhibit Shuttleworth Museum England Comparison museum air craft photos taken craft first built flown indicate major changes made subsequent owners last renovation changes have deceived draftsmen model builders Comet 88 evidently based products Shuttleworth craft As result efforts depict aircraft existed McRobertsen race author researched aircraft three years before enough data gathered make scale project possible having sufficient fidelity scale Preparation three-view plan also necessary order avoid known errors available scale plans scale draw ing authenticated AMA Tech nical Director required AMA rules General Features model features retracting gear flaps throttle brakes Control devices including elevator control achieved three fly ing lines detailed plans An op tional fixed gear also shown plans model very fast twin 35s having clocked 53 mph con struction therefore rugged dont tempted cut corners save weight authors model weighed 7 lbs com plete rugged construction needed handle twin engines hard landings will also ensure contest seasons structural failure stress cracks particularly wing fillet area Engines smaller 35 recommended since model size weight will stay airborne smaller engine should engine fail flight common occurrence twins Detailed step-by-step instructions will described Rather key elements fabricating assembly well special parts will described order 12 Model Aviation good reason smile Ernie Violett poses Comet Mode/Aviation photographer Always great favorite modelers DH-88 beautiful today 1934 won England Australia air race Solid red coloring spectacular CameL 88 avoid major errors thorough study plans text however must chore after construction should no problem construction sequence too important except noted use cellulose-acetate type model airplane glues avoided planking exterior joints seams Glues type continue dry shrink over very long period causing telltale lines finish An aliphatic resin glue sug gested glue used must sandable therefore use white glues Money can saved planking planking strips cut sheets ever possible builder has access small table saw such Unimat other suitable devices Use medium-weight balsa structure members use soft light weight balsa planking Use light con test grade balsa tail surfaces plywood cores tail surfaces plywood inlay wing trailing edge permit sanding trailing edges sharp edge edge crumbling would occur balsa-only trail ing edge sharp edge scale thick edges balsa Wing Construction Wing construction should preceded fabrication landing gear cross shaft retraction counterbalance arm motor mounts landing gear bearers Part main plywood support connective member fixed gear arrangement chosen omit cross-shaft its associated parts motor mount bearing block landing gear bearers should jigdrilled cross-shaft bearing sleeve holes landing gear strut shaft ensure alignment freedom bind ing cross-shaft parts retracting gear must operate freely Slide motor bearers bearing block cross-shaft silver solder place end center retraction arms spring counterbalance arms jig rec ommended during soldering operation achieve proper positioning arms Jig assemble aforementioned members directly plans doublechecking alignments ascertaining freedom cross-shaft rotation before gluing Use epoxy glue flathead screws joints add wheel strut assemblies until after sanding complete wing constructed piece up side down utilizing jig ribs order create proper dihedral wing rib inci dence elevate wing above work surface clearance center retraction arm Start cutting out ribs jig ribs wing tips spars dihedral gussets leading trailing edges eight jig ribs sufficient support trailing edge regular ribs will have bench-supported withstand planking operation Use short length alsa vertical supports spot glued rib builder may opt make ribs jig ribs Refer jig base line shown front view de termine proper height jig ribs Mark parting line jig ribs before using Note left wing tip laminated bass plywood making tip epoxy glue aluminum guide tubes leadout wires leading edge should tapered slightly oversize shaped trailing edges should shaped prior attaching 1/32 ply trailing edge inlay Note 1/32 ply runs inboard edge aileron opening fuselage center line vicinity fuselage 1/32 ply forms base wing fillet added later Assemble two spar halves dihedral brace before wing assembly Erect jig ribs plan using temporary blocking bracing posi Nationals winner magnificent twin durable consistent flyer tion hold place Line up jig ribs straightedge Pin block leading trailing edge spar place Glue wing tips Glue rib pieces between nacelles outboard out board install Part A-motor mount-landing gear assembly Add re maining ribs glue Plank wing dont forget provide access hatches over bellerank area point juncture aileron torque tubes Con struct hatches 2 plies 3/32 hard balsa glued grain 90 de grees other Outline hatch opening hatch perimeter 1/32 ply prevent edge wear Let complete assembly dry least 48 hours before removal bench Remove jig portion ribs parting line sand rib edges Although complicated retractable landing gearof course works Iis fully detailed both text plan theres nothing like picture help clarify things Theres way make fuselage exact alignment build jig its assembly Heres authors simple jig semi-completed fuselage being worked October1975 13 deHavilland Comet 88 smooth Modify Roberts bellcrank described plans install Part blind nuts Install throttle flexible pushrods deadman crank stop pin over-travel arrangement throttle pushrod detailed plans permits activation landing gear switch after full throttle reached switch double-pole double-throw slide type tension spring shown ensures return slide down position takes place upon slight reduction throttle setting Install leadout cables wing weight brake flexible pushrod aluminum tubes running lights wiring aileron torque tubes Check items secure installation freedom moving parts electric continuity wiring satis fied everything place working order plank top wing Glue filler strip between aileron spar Make up aileron ply balsa sandwiches tack glue place nylon hinges should glued aile rons time Use balsa spacers spot glued achieve necessary clear ance between ailerons wing center ply core ailerons wing trailing edge wing tip dry sand wing proper airfoil section using templates check accuracy sanding com pleted cut ailerons loose tackglued balsa spacers store until finish ing begins Fuselage Constriwtion Begin cutting out formers fuselage sides part B two required Glue balsa fill piece outboard side two part B pieces Shape filler pieces according plan view Jig construction recom mended Build jig scrap balsa directly over plan will maintain vertical alignment fuselage sides estab lish fuselage width Glue fuselage sides part B dry insert sides fuselage jig wedging sides tight against jig frame insertion gluing fuselage formers forget insert flap deadman cranks cross-shaft sides placed jig Install some temporary diag onal braces between formers plan view prevent warps structure removed jig dry remove jig stall elevator pushrod tail skid wiring rudder elevator controls flap flexible pushrod flap cross-over arm bulkhead holes devices shown plans left builders choice routing Install retraction motor support time motor Construct battery case fiberglass cloth resin using dowel slightly larger battery diameter mold Install battery case required contacts connect wir ing Make fit dummy interior sides cockpit instrument panel cockpit floor install items Store until painting completed Check moving parts freedom wiring electrical continuity Plank top fuselage bottom Assemble fuselage wing inserting tabs projections part B part Glue tabs well after checking wing alignment fuse lage Plank bottom fuselage includ ing retraction gear access hatch area Fair bottom planking wing maintaining fuselage profile Sand planking using cross-section templates achieve proper shape Cut out access hatch install suitable formers hatch interior face maintain shape Line hatch opening hatch perimeter 1/32 ply protect edges against wear Begin wing fillet construction marking fillet outline fuselage side top wing Insert rectangular block wing leading edge root shown Cut fillet vertical laminations very soft 3/16 balsa pin glue place layer time dry carve sand fillet using templates achieve correct main retraction shaft made telescoping brass tubingtwo pieces inside other main landing gear struts Picture shows mechanism center fuselage r Above Landing gear extended position Right above landing gear strut pistons made 3/16 steel bolts Below Comet Sterling Models Award Outstanding Scale model Nationals irrespective event best show deHavilland Comet 88 shape Feather fillet edge fuselage wing surfaces until fillet outline marking just exposed Nacelles nacelles may either fiberglass balsa original model used latter either case check carefully required interior width needed accommodate engine landing gear assembly retractable fixed nacelle cross-sections shown plans true scale may have widened suit engine/gear set-up fiberglass chosen use two longitu dinal halves Include stiffening ribs necessary mold plywood nose ring behind spinner Also mold 1/32 ply piece around leading edge wing Use heavy cloth several layers light cloth After molding joining two halves cut two sections indi cated nacelle separation line Shim finished cowl away motor bearers bass stock trimmed fit epoxied place Fasten front half nacelle bass shims small flathead machine screws best epoxy matching nut bass block re ceive machine screw Locate screws coincide scale location cowling fasteners Cut out exhaust needle valve openings Fasten rear half nacelle shown plans balsa version constructed sheet sides balsa blocks fitted between sides blocks should divided two halves along nacelle longitud inal center spot glued separation Begin accurately cutting side pieces profile shape cut match curv ature wing Cut out position 1/32 ply piece around wing leading edge Insert glue blocks between sides holding rubber bands until dry Separate spot-glued points along centerline remove model rejoin spot gluing Carve sand shape Separate halves once again hollow out interior Glue halves together cut along nacelle separation line Fasten motor mounts described fiberglass version Trim 1/32 off top edge nacelle glue 1/32 ply lip projecting 1/4 beyond cowling form base fillet Form fillet Epoxolite sand smooth Note vent openings cowl sides wing juncture ex treme rear nacelle must pro vided openings provide ex haust cooling air engine wheels retracted position also recommended fixed gear version Tail Surfaces tail surfaces similar ie 1/32 ply core faced soft balsa laminations Ply cores must have cut-outs made hinges control-horn arms mass balance BANK S TURN CLOCK OIL PRESSUREARTIFICIAL ICR TACHOMETERSAIRSPEED ROSSARACECANOPY FRAMEALTIMETER 3/64 BR ROD INSTRUMENT PANELFUEL GAUGES HEADREST I/B SUPPORT BLOCKPLASTIC FOAM COMPASS ON ALUMLEATHER COVEh BASE WITH WIRE STHROTTLE BMISLONG STRINGER I/3D PLY SEATSSWITCHES HAND BRAKERETRACTION RUDDER PEDALSWHEEL I/SD PLY SIDES --STRINGER ALUM TREADS 1/1K PLY FLOOR NEVEL GEAFSEEV PUSH ROD W/FPRTUNNEL1/16 PLY TUNNEL DO-AS MS FURIl 52MW PUSH ROD ALL PIVOTS CONNECT TO RUDDER FIRNOTES BASS W/ LEATHERUSE THIN ALUMINUM B PLASTIC SHEET & TUBE FOR PARTS COVERINSTRUMENTS ARE TATONE 5/16 B T/16 DIA CLEAR DOPE SEATS COCKPIT SIDES STRINGERS & TUNNEL SECTION BPAINT FLAT BLACK INSYR PANEL INSTRUMENTS GRIPS RETRACTION WHEEL TTLE QADRANT MINIATURE TOGGLE SWITCHES MAY BE CUT DOWN B USED IN INSTR PANEL FOR MODELS ELECTRICAL SYSTEM COMPASS CARD SECTION GRAPHIC SCALE 0I 53456 aluminum tubes prior lamination After lamination add spruce spars balsa fairings shown Fasten hinge fixed surface time thus permitting separation surfaces final shaping sanding finishing Add rear fuselage block slotted rudder ply projection Add fixed tail surfaces sand fuselage block shape add fillets using Epoxolite DEHAVILANO COMET 88 3/BI- 0 SCALE3 DESIGNED B DRAWN BY ERNIE VIOLET1IEof 3 Landing Gear retreacting gear simple appears self-locking type main retraction shaft made telescoping brass tubing two pieces inside other also main landing gear struts Easily available materials parts used machining held minimum continued page 66 October1975 17 Above Over three years research went project before work began Below engine nacelles made fiberglass balsa Only projecting needle valve knob betrays model Note righthand-turning props also scale Inboard prop has 1 pitch D H Comet 88 continued control travel third line indicator top handle Provide stop full-throttle position Movement beyond stop actuate retraction motor DPDT slide switch model virtue throttle overtravel arrange ment shown plans Provide second stop other end indicator travel throttle idle position Movement beyond stop actuate engine cut-off Both stops should hinged swing out way indicator hand can used swing stops out way gear operation engine shut-off someone help check operation flying lines stops throt tles DPDT switch gear retrac tion engines running flying lines under tension Repeat process engine running both running Make necessary adjustments line lengths handle stops throttle settings DPDT switch position gear operation fails erratic engines running problem likely intermittent complete loss electrical continuity caused vibration vibration loose connection whatever cause must eliminated first flight flights testing gear retraction fly nacelles wheel spats removed wheels-up belly landing needed model will land undamaged Otherwise nacelles would wiped out Some gb-plug damage may incurred minor matter Use little up right aileron achieve level flight Use masking tape hold aileron position Also tape canopy down precaution flights Use clear tape competition Pick smooth flying surface must since model will flip its nose easily rough surface Conduct successful pull-test youre ready maiden flight get engines running correctly start outboard engine tune best rpm ear reed tachometer Stop engine repeat operation inboard engine running smoothly restart outboard engine required tweaking needle valves sure engines synchronized closely possible helper hold ing plane reduce engine rpm control handle about 40% level release plane Hold plane ground gradually opening throt tle Dont lift plane offlet lift off used Contest Directors placing con tests Flyers will still fly together scoring awards will divided categories Bob Hunt NJ wrote state 55Flying Goombahs Eastern Controline Championships Mass expert advanced circle intermediate beginners another circle virtue sufficient flying speed rest easy plane fast grooves easily land reduce engine rpm slow ly let plane speed decrease plane flying slowly possible lose altitude slowly very close ground reduce throttle slightly model will set down reduce landing roll stop apply brake using full up elevator Move third-line control engine shut-off position Check aircraft thoroughly after first flight flight thereafter damage stress cracks loose nuts fittings wheels engines control surfaces reasonable care model capable five seven year competition life author wishes extend appre ciation Bill Harris Laurel Md skillful help preparing Comet competition acting pit man past Nationals Editors Note Extensive informationa Scale Information Sheetaccompanies plans does scale authentication drawing information thus provided consider entering model competitionsuch information required judging proof scale etc chief purpose provide begin ning competition new flyers competition top nationals caliber Lets face person starts out new situation likes see some material results progress Quite possibly some form categories stunt could help bring about tract flyers event address 1640 Maywick Drive Lexing ton Ky 40504 68 Model Aviation WHAT PRICE LLENCE Dave Brown Mark Rado lIt Ia SO- iJfr~Jj leg tat end 3rd Macto proven excellence ot EXPERT SERtES World Eng non w f7 continue ntvo R/C en uc pe 4 tsd V dottar Oflyona Ota. Dave 5 CH 4SERVOS~ 3MO rk DENGINES 8960 ROSSASH AVECINCINNATI OHIO 45236 VIXEN~ -/ze 2I95 VIXEN has edva,teg beog smell andeconoocal huId end opetete na I,, tedaee eqo,oga two-ohe,,eI edOoethSpet- ,oetue stows 50111 SatIety peck hitAea-t8Osq teetoen,clodepecision baodsaosedandeaodedWeigtt------21 pelts Ate t08, esiotend Cotoplete hedesaeEtgi~-Co ID 045-051 Coot olsA j cod Fopooptdelioeyteodoeshiesohett ononty ode, adding 5155 shipping a,d handling Wsoo,snesde,tsedd 4%seleeteo Sotty no COD odes CONCEPT MODELS ___ffi Xe Deal ot Dole Olteot Bob Emett holds Don Schultz Model FAI CL AerobaticsAvenger OS 3547 oX span 57 continued page 18
Edition: Model Aviation - 1975/10
Page Numbers: 12, 13, 15, 17, 68
rncddIavlland MANY CONSTRUCTION articles scale models warn prospective builder model experts author does believe theory observations relatively inexpe rienced modelers beginners have natural manual art skill some modelers years experience want build model think can go ahead build However sure have desire build Most scale projects time consuming de manding require months work Without burning desire create model builder will never finish project deHavilland Comet 88 unique airplane its time designed specif ically long-range racing aircraft intended solely McRobertsen air race England Australia 1934 Only three aircraft built aircraft red-and-white racer sponsored Grosvenor House London hotel winner aircraft later experienced succession owners modified craft various ways aircraft now exhibit Shuttleworth Museum England Comparison museum air craft photos taken craft first built flown indicate major changes made subsequent owners last renovation changes have deceived draftsmen model builders Comet 88 evidently based products Shuttleworth craft As result efforts depict aircraft existed McRobertsen race author researched aircraft three years before enough data gathered make scale project possible having sufficient fidelity scale Preparation three-view plan also necessary order avoid known errors available scale plans scale draw ing authenticated AMA Tech nical Director required AMA rules General Features model features retracting gear flaps throttle brakes Control devices including elevator control achieved three fly ing lines detailed plans An op tional fixed gear also shown plans model very fast twin 35s having clocked 53 mph con struction therefore rugged dont tempted cut corners save weight authors model weighed 7 lbs com plete rugged construction needed handle twin engines hard landings will also ensure contest seasons structural failure stress cracks particularly wing fillet area Engines smaller 35 recommended since model size weight will stay airborne smaller engine should engine fail flight common occurrence twins Detailed step-by-step instructions will described Rather key elements fabricating assembly well special parts will described order 12 Model Aviation good reason smile Ernie Violett poses Comet Mode/Aviation photographer Always great favorite modelers DH-88 beautiful today 1934 won England Australia air race Solid red coloring spectacular CameL 88 avoid major errors thorough study plans text however must chore after construction should no problem construction sequence too important except noted use cellulose-acetate type model airplane glues avoided planking exterior joints seams Glues type continue dry shrink over very long period causing telltale lines finish An aliphatic resin glue sug gested glue used must sandable therefore use white glues Money can saved planking planking strips cut sheets ever possible builder has access small table saw such Unimat other suitable devices Use medium-weight balsa structure members use soft light weight balsa planking Use light con test grade balsa tail surfaces plywood cores tail surfaces plywood inlay wing trailing edge permit sanding trailing edges sharp edge edge crumbling would occur balsa-only trail ing edge sharp edge scale thick edges balsa Wing Construction Wing construction should preceded fabrication landing gear cross shaft retraction counterbalance arm motor mounts landing gear bearers Part main plywood support connective member fixed gear arrangement chosen omit cross-shaft its associated parts motor mount bearing block landing gear bearers should jigdrilled cross-shaft bearing sleeve holes landing gear strut shaft ensure alignment freedom bind ing cross-shaft parts retracting gear must operate freely Slide motor bearers bearing block cross-shaft silver solder place end center retraction arms spring counterbalance arms jig rec ommended during soldering operation achieve proper positioning arms Jig assemble aforementioned members directly plans doublechecking alignments ascertaining freedom cross-shaft rotation before gluing Use epoxy glue flathead screws joints add wheel strut assemblies until after sanding complete wing constructed piece up side down utilizing jig ribs order create proper dihedral wing rib inci dence elevate wing above work surface clearance center retraction arm Start cutting out ribs jig ribs wing tips spars dihedral gussets leading trailing edges eight jig ribs sufficient support trailing edge regular ribs will have bench-supported withstand planking operation Use short length alsa vertical supports spot glued rib builder may opt make ribs jig ribs Refer jig base line shown front view de termine proper height jig ribs Mark parting line jig ribs before using Note left wing tip laminated bass plywood making tip epoxy glue aluminum guide tubes leadout wires leading edge should tapered slightly oversize shaped trailing edges should shaped prior attaching 1/32 ply trailing edge inlay Note 1/32 ply runs inboard edge aileron opening fuselage center line vicinity fuselage 1/32 ply forms base wing fillet added later Assemble two spar halves dihedral brace before wing assembly Erect jig ribs plan using temporary blocking bracing posi Nationals winner magnificent twin durable consistent flyer tion hold place Line up jig ribs straightedge Pin block leading trailing edge spar place Glue wing tips Glue rib pieces between nacelles outboard out board install Part A-motor mount-landing gear assembly Add re maining ribs glue Plank wing dont forget provide access hatches over bellerank area point juncture aileron torque tubes Con struct hatches 2 plies 3/32 hard balsa glued grain 90 de grees other Outline hatch opening hatch perimeter 1/32 ply prevent edge wear Let complete assembly dry least 48 hours before removal bench Remove jig portion ribs parting line sand rib edges Although complicated retractable landing gearof course works Iis fully detailed both text plan theres nothing like picture help clarify things Theres way make fuselage exact alignment build jig its assembly Heres authors simple jig semi-completed fuselage being worked October1975 13 deHavilland Comet 88 smooth Modify Roberts bellcrank described plans install Part blind nuts Install throttle flexible pushrods deadman crank stop pin over-travel arrangement throttle pushrod detailed plans permits activation landing gear switch after full throttle reached switch double-pole double-throw slide type tension spring shown ensures return slide down position takes place upon slight reduction throttle setting Install leadout cables wing weight brake flexible pushrod aluminum tubes running lights wiring aileron torque tubes Check items secure installation freedom moving parts electric continuity wiring satis fied everything place working order plank top wing Glue filler strip between aileron spar Make up aileron ply balsa sandwiches tack glue place nylon hinges should glued aile rons time Use balsa spacers spot glued achieve necessary clear ance between ailerons wing center ply core ailerons wing trailing edge wing tip dry sand wing proper airfoil section using templates check accuracy sanding com pleted cut ailerons loose tackglued balsa spacers store until finish ing begins Fuselage Constriwtion Begin cutting out formers fuselage sides part B two required Glue balsa fill piece outboard side two part B pieces Shape filler pieces according plan view Jig construction recom mended Build jig scrap balsa directly over plan will maintain vertical alignment fuselage sides estab lish fuselage width Glue fuselage sides part B dry insert sides fuselage jig wedging sides tight against jig frame insertion gluing fuselage formers forget insert flap deadman cranks cross-shaft sides placed jig Install some temporary diag onal braces between formers plan view prevent warps structure removed jig dry remove jig stall elevator pushrod tail skid wiring rudder elevator controls flap flexible pushrod flap cross-over arm bulkhead holes devices shown plans left builders choice routing Install retraction motor support time motor Construct battery case fiberglass cloth resin using dowel slightly larger battery diameter mold Install battery case required contacts connect wir ing Make fit dummy interior sides cockpit instrument panel cockpit floor install items Store until painting completed Check moving parts freedom wiring electrical continuity Plank top fuselage bottom Assemble fuselage wing inserting tabs projections part B part Glue tabs well after checking wing alignment fuse lage Plank bottom fuselage includ ing retraction gear access hatch area Fair bottom planking wing maintaining fuselage profile Sand planking using cross-section templates achieve proper shape Cut out access hatch install suitable formers hatch interior face maintain shape Line hatch opening hatch perimeter 1/32 ply protect edges against wear Begin wing fillet construction marking fillet outline fuselage side top wing Insert rectangular block wing leading edge root shown Cut fillet vertical laminations very soft 3/16 balsa pin glue place layer time dry carve sand fillet using templates achieve correct main retraction shaft made telescoping brass tubingtwo pieces inside other main landing gear struts Picture shows mechanism center fuselage r Above Landing gear extended position Right above landing gear strut pistons made 3/16 steel bolts Below Comet Sterling Models Award Outstanding Scale model Nationals irrespective event best show deHavilland Comet 88 shape Feather fillet edge fuselage wing surfaces until fillet outline marking just exposed Nacelles nacelles may either fiberglass balsa original model used latter either case check carefully required interior width needed accommodate engine landing gear assembly retractable fixed nacelle cross-sections shown plans true scale may have widened suit engine/gear set-up fiberglass chosen use two longitu dinal halves Include stiffening ribs necessary mold plywood nose ring behind spinner Also mold 1/32 ply piece around leading edge wing Use heavy cloth several layers light cloth After molding joining two halves cut two sections indi cated nacelle separation line Shim finished cowl away motor bearers bass stock trimmed fit epoxied place Fasten front half nacelle bass shims small flathead machine screws best epoxy matching nut bass block re ceive machine screw Locate screws coincide scale location cowling fasteners Cut out exhaust needle valve openings Fasten rear half nacelle shown plans balsa version constructed sheet sides balsa blocks fitted between sides blocks should divided two halves along nacelle longitud inal center spot glued separation Begin accurately cutting side pieces profile shape cut match curv ature wing Cut out position 1/32 ply piece around wing leading edge Insert glue blocks between sides holding rubber bands until dry Separate spot-glued points along centerline remove model rejoin spot gluing Carve sand shape Separate halves once again hollow out interior Glue halves together cut along nacelle separation line Fasten motor mounts described fiberglass version Trim 1/32 off top edge nacelle glue 1/32 ply lip projecting 1/4 beyond cowling form base fillet Form fillet Epoxolite sand smooth Note vent openings cowl sides wing juncture ex treme rear nacelle must pro vided openings provide ex haust cooling air engine wheels retracted position also recommended fixed gear version Tail Surfaces tail surfaces similar ie 1/32 ply core faced soft balsa laminations Ply cores must have cut-outs made hinges control-horn arms mass balance BANK S TURN CLOCK OIL PRESSUREARTIFICIAL ICR TACHOMETERSAIRSPEED ROSSARACECANOPY FRAMEALTIMETER 3/64 BR ROD INSTRUMENT PANELFUEL GAUGES HEADREST I/B SUPPORT BLOCKPLASTIC FOAM COMPASS ON ALUMLEATHER COVEh BASE WITH WIRE STHROTTLE BMISLONG STRINGER I/3D PLY SEATSSWITCHES HAND BRAKERETRACTION RUDDER PEDALSWHEEL I/SD PLY SIDES --STRINGER ALUM TREADS 1/1K PLY FLOOR NEVEL GEAFSEEV PUSH ROD W/FPRTUNNEL1/16 PLY TUNNEL DO-AS MS FURIl 52MW PUSH ROD ALL PIVOTS CONNECT TO RUDDER FIRNOTES BASS W/ LEATHERUSE THIN ALUMINUM B PLASTIC SHEET & TUBE FOR PARTS COVERINSTRUMENTS ARE TATONE 5/16 B T/16 DIA CLEAR DOPE SEATS COCKPIT SIDES STRINGERS & TUNNEL SECTION BPAINT FLAT BLACK INSYR PANEL INSTRUMENTS GRIPS RETRACTION WHEEL TTLE QADRANT MINIATURE TOGGLE SWITCHES MAY BE CUT DOWN B USED IN INSTR PANEL FOR MODELS ELECTRICAL SYSTEM COMPASS CARD SECTION GRAPHIC SCALE 0I 53456 aluminum tubes prior lamination After lamination add spruce spars balsa fairings shown Fasten hinge fixed surface time thus permitting separation surfaces final shaping sanding finishing Add rear fuselage block slotted rudder ply projection Add fixed tail surfaces sand fuselage block shape add fillets using Epoxolite DEHAVILANO COMET 88 3/BI- 0 SCALE3 DESIGNED B DRAWN BY ERNIE VIOLET1IEof 3 Landing Gear retreacting gear simple appears self-locking type main retraction shaft made telescoping brass tubing two pieces inside other also main landing gear struts Easily available materials parts used machining held minimum continued page 66 October1975 17 Above Over three years research went project before work began Below engine nacelles made fiberglass balsa Only projecting needle valve knob betrays model Note righthand-turning props also scale Inboard prop has 1 pitch D H Comet 88 continued control travel third line indicator top handle Provide stop full-throttle position Movement beyond stop actuate retraction motor DPDT slide switch model virtue throttle overtravel arrange ment shown plans Provide second stop other end indicator travel throttle idle position Movement beyond stop actuate engine cut-off Both stops should hinged swing out way indicator hand can used swing stops out way gear operation engine shut-off someone help check operation flying lines stops throt tles DPDT switch gear retrac tion engines running flying lines under tension Repeat process engine running both running Make necessary adjustments line lengths handle stops throttle settings DPDT switch position gear operation fails erratic engines running problem likely intermittent complete loss electrical continuity caused vibration vibration loose connection whatever cause must eliminated first flight flights testing gear retraction fly nacelles wheel spats removed wheels-up belly landing needed model will land undamaged Otherwise nacelles would wiped out Some gb-plug damage may incurred minor matter Use little up right aileron achieve level flight Use masking tape hold aileron position Also tape canopy down precaution flights Use clear tape competition Pick smooth flying surface must since model will flip its nose easily rough surface Conduct successful pull-test youre ready maiden flight get engines running correctly start outboard engine tune best rpm ear reed tachometer Stop engine repeat operation inboard engine running smoothly restart outboard engine required tweaking needle valves sure engines synchronized closely possible helper hold ing plane reduce engine rpm control handle about 40% level release plane Hold plane ground gradually opening throt tle Dont lift plane offlet lift off used Contest Directors placing con tests Flyers will still fly together scoring awards will divided categories Bob Hunt NJ wrote state 55Flying Goombahs Eastern Controline Championships Mass expert advanced circle intermediate beginners another circle virtue sufficient flying speed rest easy plane fast grooves easily land reduce engine rpm slow ly let plane speed decrease plane flying slowly possible lose altitude slowly very close ground reduce throttle slightly model will set down reduce landing roll stop apply brake using full up elevator Move third-line control engine shut-off position Check aircraft thoroughly after first flight flight thereafter damage stress cracks loose nuts fittings wheels engines control surfaces reasonable care model capable five seven year competition life author wishes extend appre ciation Bill Harris Laurel Md skillful help preparing Comet competition acting pit man past Nationals Editors Note Extensive informationa Scale Information Sheetaccompanies plans does scale authentication drawing information thus provided consider entering model competitionsuch information required judging proof scale etc chief purpose provide begin ning competition new flyers competition top nationals caliber Lets face person starts out new situation likes see some material results progress Quite possibly some form categories stunt could help bring about tract flyers event address 1640 Maywick Drive Lexing ton Ky 40504 68 Model Aviation WHAT PRICE LLENCE Dave Brown Mark Rado lIt Ia SO- iJfr~Jj leg tat end 3rd Macto proven excellence ot EXPERT SERtES World Eng non w f7 continue ntvo R/C en uc pe 4 tsd V dottar Oflyona Ota. Dave 5 CH 4SERVOS~ 3MO rk DENGINES 8960 ROSSASH AVECINCINNATI OHIO 45236 VIXEN~ -/ze 2I95 VIXEN has edva,teg beog smell andeconoocal huId end opetete na I,, tedaee eqo,oga two-ohe,,eI edOoethSpet- ,oetue stows 50111 SatIety peck hitAea-t8Osq teetoen,clodepecision baodsaosedandeaodedWeigtt------21 pelts Ate t08, esiotend Cotoplete hedesaeEtgi~-Co ID 045-051 Coot olsA j cod Fopooptdelioeyteodoeshiesohett ononty ode, adding 5155 shipping a,d handling Wsoo,snesde,tsedd 4%seleeteo Sotty no COD odes CONCEPT MODELS ___ffi Xe Deal ot Dole Olteot Bob Emett holds Don Schultz Model FAI CL AerobaticsAvenger OS 3547 oX span 57 continued page 18
Edition: Model Aviation - 1975/10
Page Numbers: 12, 13, 15, 17, 68
rncddIavlland MANY CONSTRUCTION articles scale models warn prospective builder model experts author does believe theory observations relatively inexpe rienced modelers beginners have natural manual art skill some modelers years experience want build model think can go ahead build However sure have desire build Most scale projects time consuming de manding require months work Without burning desire create model builder will never finish project deHavilland Comet 88 unique airplane its time designed specif ically long-range racing aircraft intended solely McRobertsen air race England Australia 1934 Only three aircraft built aircraft red-and-white racer sponsored Grosvenor House London hotel winner aircraft later experienced succession owners modified craft various ways aircraft now exhibit Shuttleworth Museum England Comparison museum air craft photos taken craft first built flown indicate major changes made subsequent owners last renovation changes have deceived draftsmen model builders Comet 88 evidently based products Shuttleworth craft As result efforts depict aircraft existed McRobertsen race author researched aircraft three years before enough data gathered make scale project possible having sufficient fidelity scale Preparation three-view plan also necessary order avoid known errors available scale plans scale draw ing authenticated AMA Tech nical Director required AMA rules General Features model features retracting gear flaps throttle brakes Control devices including elevator control achieved three fly ing lines detailed plans An op tional fixed gear also shown plans model very fast twin 35s having clocked 53 mph con struction therefore rugged dont tempted cut corners save weight authors model weighed 7 lbs com plete rugged construction needed handle twin engines hard landings will also ensure contest seasons structural failure stress cracks particularly wing fillet area Engines smaller 35 recommended since model size weight will stay airborne smaller engine should engine fail flight common occurrence twins Detailed step-by-step instructions will described Rather key elements fabricating assembly well special parts will described order 12 Model Aviation good reason smile Ernie Violett poses Comet Mode/Aviation photographer Always great favorite modelers DH-88 beautiful today 1934 won England Australia air race Solid red coloring spectacular CameL 88 avoid major errors thorough study plans text however must chore after construction should no problem construction sequence too important except noted use cellulose-acetate type model airplane glues avoided planking exterior joints seams Glues type continue dry shrink over very long period causing telltale lines finish An aliphatic resin glue sug gested glue used must sandable therefore use white glues Money can saved planking planking strips cut sheets ever possible builder has access small table saw such Unimat other suitable devices Use medium-weight balsa structure members use soft light weight balsa planking Use light con test grade balsa tail surfaces plywood cores tail surfaces plywood inlay wing trailing edge permit sanding trailing edges sharp edge edge crumbling would occur balsa-only trail ing edge sharp edge scale thick edges balsa Wing Construction Wing construction should preceded fabrication landing gear cross shaft retraction counterbalance arm motor mounts landing gear bearers Part main plywood support connective member fixed gear arrangement chosen omit cross-shaft its associated parts motor mount bearing block landing gear bearers should jigdrilled cross-shaft bearing sleeve holes landing gear strut shaft ensure alignment freedom bind ing cross-shaft parts retracting gear must operate freely Slide motor bearers bearing block cross-shaft silver solder place end center retraction arms spring counterbalance arms jig rec ommended during soldering operation achieve proper positioning arms Jig assemble aforementioned members directly plans doublechecking alignments ascertaining freedom cross-shaft rotation before gluing Use epoxy glue flathead screws joints add wheel strut assemblies until after sanding complete wing constructed piece up side down utilizing jig ribs order create proper dihedral wing rib inci dence elevate wing above work surface clearance center retraction arm Start cutting out ribs jig ribs wing tips spars dihedral gussets leading trailing edges eight jig ribs sufficient support trailing edge regular ribs will have bench-supported withstand planking operation Use short length alsa vertical supports spot glued rib builder may opt make ribs jig ribs Refer jig base line shown front view de termine proper height jig ribs Mark parting line jig ribs before using Note left wing tip laminated bass plywood making tip epoxy glue aluminum guide tubes leadout wires leading edge should tapered slightly oversize shaped trailing edges should shaped prior attaching 1/32 ply trailing edge inlay Note 1/32 ply runs inboard edge aileron opening fuselage center line vicinity fuselage 1/32 ply forms base wing fillet added later Assemble two spar halves dihedral brace before wing assembly Erect jig ribs plan using temporary blocking bracing posi Nationals winner magnificent twin durable consistent flyer tion hold place Line up jig ribs straightedge Pin block leading trailing edge spar place Glue wing tips Glue rib pieces between nacelles outboard out board install Part A-motor mount-landing gear assembly Add re maining ribs glue Plank wing dont forget provide access hatches over bellerank area point juncture aileron torque tubes Con struct hatches 2 plies 3/32 hard balsa glued grain 90 de grees other Outline hatch opening hatch perimeter 1/32 ply prevent edge wear Let complete assembly dry least 48 hours before removal bench Remove jig portion ribs parting line sand rib edges Although complicated retractable landing gearof course works Iis fully detailed both text plan theres nothing like picture help clarify things Theres way make fuselage exact alignment build jig its assembly Heres authors simple jig semi-completed fuselage being worked October1975 13 deHavilland Comet 88 smooth Modify Roberts bellcrank described plans install Part blind nuts Install throttle flexible pushrods deadman crank stop pin over-travel arrangement throttle pushrod detailed plans permits activation landing gear switch after full throttle reached switch double-pole double-throw slide type tension spring shown ensures return slide down position takes place upon slight reduction throttle setting Install leadout cables wing weight brake flexible pushrod aluminum tubes running lights wiring aileron torque tubes Check items secure installation freedom moving parts electric continuity wiring satis fied everything place working order plank top wing Glue filler strip between aileron spar Make up aileron ply balsa sandwiches tack glue place nylon hinges should glued aile rons time Use balsa spacers spot glued achieve necessary clear ance between ailerons wing center ply core ailerons wing trailing edge wing tip dry sand wing proper airfoil section using templates check accuracy sanding com pleted cut ailerons loose tackglued balsa spacers store until finish ing begins Fuselage Constriwtion Begin cutting out formers fuselage sides part B two required Glue balsa fill piece outboard side two part B pieces Shape filler pieces according plan view Jig construction recom mended Build jig scrap balsa directly over plan will maintain vertical alignment fuselage sides estab lish fuselage width Glue fuselage sides part B dry insert sides fuselage jig wedging sides tight against jig frame insertion gluing fuselage formers forget insert flap deadman cranks cross-shaft sides placed jig Install some temporary diag onal braces between formers plan view prevent warps structure removed jig dry remove jig stall elevator pushrod tail skid wiring rudder elevator controls flap flexible pushrod flap cross-over arm bulkhead holes devices shown plans left builders choice routing Install retraction motor support time motor Construct battery case fiberglass cloth resin using dowel slightly larger battery diameter mold Install battery case required contacts connect wir ing Make fit dummy interior sides cockpit instrument panel cockpit floor install items Store until painting completed Check moving parts freedom wiring electrical continuity Plank top fuselage bottom Assemble fuselage wing inserting tabs projections part B part Glue tabs well after checking wing alignment fuse lage Plank bottom fuselage includ ing retraction gear access hatch area Fair bottom planking wing maintaining fuselage profile Sand planking using cross-section templates achieve proper shape Cut out access hatch install suitable formers hatch interior face maintain shape Line hatch opening hatch perimeter 1/32 ply protect edges against wear Begin wing fillet construction marking fillet outline fuselage side top wing Insert rectangular block wing leading edge root shown Cut fillet vertical laminations very soft 3/16 balsa pin glue place layer time dry carve sand fillet using templates achieve correct main retraction shaft made telescoping brass tubingtwo pieces inside other main landing gear struts Picture shows mechanism center fuselage r Above Landing gear extended position Right above landing gear strut pistons made 3/16 steel bolts Below Comet Sterling Models Award Outstanding Scale model Nationals irrespective event best show deHavilland Comet 88 shape Feather fillet edge fuselage wing surfaces until fillet outline marking just exposed Nacelles nacelles may either fiberglass balsa original model used latter either case check carefully required interior width needed accommodate engine landing gear assembly retractable fixed nacelle cross-sections shown plans true scale may have widened suit engine/gear set-up fiberglass chosen use two longitu dinal halves Include stiffening ribs necessary mold plywood nose ring behind spinner Also mold 1/32 ply piece around leading edge wing Use heavy cloth several layers light cloth After molding joining two halves cut two sections indi cated nacelle separation line Shim finished cowl away motor bearers bass stock trimmed fit epoxied place Fasten front half nacelle bass shims small flathead machine screws best epoxy matching nut bass block re ceive machine screw Locate screws coincide scale location cowling fasteners Cut out exhaust needle valve openings Fasten rear half nacelle shown plans balsa version constructed sheet sides balsa blocks fitted between sides blocks should divided two halves along nacelle longitud inal center spot glued separation Begin accurately cutting side pieces profile shape cut match curv ature wing Cut out position 1/32 ply piece around wing leading edge Insert glue blocks between sides holding rubber bands until dry Separate spot-glued points along centerline remove model rejoin spot gluing Carve sand shape Separate halves once again hollow out interior Glue halves together cut along nacelle separation line Fasten motor mounts described fiberglass version Trim 1/32 off top edge nacelle glue 1/32 ply lip projecting 1/4 beyond cowling form base fillet Form fillet Epoxolite sand smooth Note vent openings cowl sides wing juncture ex treme rear nacelle must pro vided openings provide ex haust cooling air engine wheels retracted position also recommended fixed gear version Tail Surfaces tail surfaces similar ie 1/32 ply core faced soft balsa laminations Ply cores must have cut-outs made hinges control-horn arms mass balance BANK S TURN CLOCK OIL PRESSUREARTIFICIAL ICR TACHOMETERSAIRSPEED ROSSARACECANOPY FRAMEALTIMETER 3/64 BR ROD INSTRUMENT PANELFUEL GAUGES HEADREST I/B SUPPORT BLOCKPLASTIC FOAM COMPASS ON ALUMLEATHER COVEh BASE WITH WIRE STHROTTLE BMISLONG STRINGER I/3D PLY SEATSSWITCHES HAND BRAKERETRACTION RUDDER PEDALSWHEEL I/SD PLY SIDES --STRINGER ALUM TREADS 1/1K PLY FLOOR NEVEL GEAFSEEV PUSH ROD W/FPRTUNNEL1/16 PLY TUNNEL DO-AS MS FURIl 52MW PUSH ROD ALL PIVOTS CONNECT TO RUDDER FIRNOTES BASS W/ LEATHERUSE THIN ALUMINUM B PLASTIC SHEET & TUBE FOR PARTS COVERINSTRUMENTS ARE TATONE 5/16 B T/16 DIA CLEAR DOPE SEATS COCKPIT SIDES STRINGERS & TUNNEL SECTION BPAINT FLAT BLACK INSYR PANEL INSTRUMENTS GRIPS RETRACTION WHEEL TTLE QADRANT MINIATURE TOGGLE SWITCHES MAY BE CUT DOWN B USED IN INSTR PANEL FOR MODELS ELECTRICAL SYSTEM COMPASS CARD SECTION GRAPHIC SCALE 0I 53456 aluminum tubes prior lamination After lamination add spruce spars balsa fairings shown Fasten hinge fixed surface time thus permitting separation surfaces final shaping sanding finishing Add rear fuselage block slotted rudder ply projection Add fixed tail surfaces sand fuselage block shape add fillets using Epoxolite DEHAVILANO COMET 88 3/BI- 0 SCALE3 DESIGNED B DRAWN BY ERNIE VIOLET1IEof 3 Landing Gear retreacting gear simple appears self-locking type main retraction shaft made telescoping brass tubing two pieces inside other also main landing gear struts Easily available materials parts used machining held minimum continued page 66 October1975 17 Above Over three years research went project before work began Below engine nacelles made fiberglass balsa Only projecting needle valve knob betrays model Note righthand-turning props also scale Inboard prop has 1 pitch D H Comet 88 continued control travel third line indicator top handle Provide stop full-throttle position Movement beyond stop actuate retraction motor DPDT slide switch model virtue throttle overtravel arrange ment shown plans Provide second stop other end indicator travel throttle idle position Movement beyond stop actuate engine cut-off Both stops should hinged swing out way indicator hand can used swing stops out way gear operation engine shut-off someone help check operation flying lines stops throt tles DPDT switch gear retrac tion engines running flying lines under tension Repeat process engine running both running Make necessary adjustments line lengths handle stops throttle settings DPDT switch position gear operation fails erratic engines running problem likely intermittent complete loss electrical continuity caused vibration vibration loose connection whatever cause must eliminated first flight flights testing gear retraction fly nacelles wheel spats removed wheels-up belly landing needed model will land undamaged Otherwise nacelles would wiped out Some gb-plug damage may incurred minor matter Use little up right aileron achieve level flight Use masking tape hold aileron position Also tape canopy down precaution flights Use clear tape competition Pick smooth flying surface must since model will flip its nose easily rough surface Conduct successful pull-test youre ready maiden flight get engines running correctly start outboard engine tune best rpm ear reed tachometer Stop engine repeat operation inboard engine running smoothly restart outboard engine required tweaking needle valves sure engines synchronized closely possible helper hold ing plane reduce engine rpm control handle about 40% level release plane Hold plane ground gradually opening throt tle Dont lift plane offlet lift off used Contest Directors placing con tests Flyers will still fly together scoring awards will divided categories Bob Hunt NJ wrote state 55Flying Goombahs Eastern Controline Championships Mass expert advanced circle intermediate beginners another circle virtue sufficient flying speed rest easy plane fast grooves easily land reduce engine rpm slow ly let plane speed decrease plane flying slowly possible lose altitude slowly very close ground reduce throttle slightly model will set down reduce landing roll stop apply brake using full up elevator Move third-line control engine shut-off position Check aircraft thoroughly after first flight flight thereafter damage stress cracks loose nuts fittings wheels engines control surfaces reasonable care model capable five seven year competition life author wishes extend appre ciation Bill Harris Laurel Md skillful help preparing Comet competition acting pit man past Nationals Editors Note Extensive informationa Scale Information Sheetaccompanies plans does scale authentication drawing information thus provided consider entering model competitionsuch information required judging proof scale etc chief purpose provide begin ning competition new flyers competition top nationals caliber Lets face person starts out new situation likes see some material results progress Quite possibly some form categories stunt could help bring about tract flyers event address 1640 Maywick Drive Lexing ton Ky 40504 68 Model Aviation WHAT PRICE LLENCE Dave Brown Mark Rado lIt Ia SO- iJfr~Jj leg tat end 3rd Macto proven excellence ot EXPERT SERtES World Eng non w f7 continue ntvo R/C en uc pe 4 tsd V dottar Oflyona Ota. Dave 5 CH 4SERVOS~ 3MO rk DENGINES 8960 ROSSASH AVECINCINNATI OHIO 45236 VIXEN~ -/ze 2I95 VIXEN has edva,teg beog smell andeconoocal huId end opetete na I,, tedaee eqo,oga two-ohe,,eI edOoethSpet- ,oetue stows 50111 SatIety peck hitAea-t8Osq teetoen,clodepecision baodsaosedandeaodedWeigtt------21 pelts Ate t08, esiotend Cotoplete hedesaeEtgi~-Co ID 045-051 Coot olsA j cod Fopooptdelioeyteodoeshiesohett ononty ode, adding 5155 shipping a,d handling Wsoo,snesde,tsedd 4%seleeteo Sotty no COD odes CONCEPT MODELS ___ffi Xe Deal ot Dole Olteot Bob Emett holds Don Schultz Model FAI CL AerobaticsAvenger OS 3547 oX span 57 continued page 18