Control Line: Aerobatics

Control Line AEROBA TICS Wynn Paul HOW LIGHT light good light Stunt freaks talk about building all-time light plane will win Nationals what happens finally get super-light airplane Lets look plane pictured month belongs Larry Robertson Louis ville KY. Larry has flying Stunt since early Sixties usually finishes high standings around Midwest contest circuit hasjust missed qualifying couple times Nationals good builder think anyone knows Larry will attest serious Stunt flier knows build fly H 1982 ships basic statistics 750 sq wing area 62-in-span I-beam wing fuselage length 49 rather long moment arms 105 18 uses Super tigre 46 engine power uni-flow muffler-pressure tank off very light Bob Paul muffler plane very light finish described below 3/4 oz sip weight came unbelievable 4676 oz big plane although basic clear finish small trim panels doesnt appear painted white would look gigantic may may part Larrys scheme things Lets start wing I-beam consists -in balsa spar 1/16-in plywood stiffeners I-beam middle wing out about inch beyond fuselage sides used two-in unequal-panel scheme has three-in leading edge sweepback ribs conventional I-beam type leading edge stock trailing edge stock Larrys flaps made 3-in balsa stock holes cut has built four I-beam wings feels wing although no apparent warps needs additional spar midway between I-beam trailing edge help prevent structural flexing Several observers told Larry appeared wing flexing hard corners 1983 ship now under way has extra spar Larry said recently wing seems quite strong now fuselage 1982 plane 3/32-in sides / 32-in plywood doublers up front engine bearers Textilite composition board epoxy resin spliced wood bearers rear fuselage flaps back has liberally drilled lightening holes turtle deck 1/16-in balsa sheet wet-formed over 16-in formers Unfortu nately Larry found fuselage flexing during maneuvers cut bottom block way piece 3/ 16-in balsa block hollowed-out place two /s stiffeners along fuselage side flap back stab stabilizer built up using l/ -in spar 1/16-in ribs diagonal bracing / 16 goes through center ribs leading trailing edges originally trips formed hollowed Out inside Dremel tool after Hot Stuff sprayed along inside Once again stab flexing under stress Larry forced place some oval aluminum tube struts bottom fuse lage seen picture also remove warp elevators sun hitting dope caused shrinkage washed elevator tips down used boiling-waterand-hot-towels method removing warp finish used chosen maximum light ness used medium GM silkspan tinted Rit yellow dye before application bare wood no paint planes surface used Aero Gloss clear over paper Aero Gloss colors trim made light finish although no doubt will give up few appearance points having fullcolored paint job Larry also uses unique side panel inside forward part fuselage remove tank can beseen accompanying picture Continued page 143 March 1983 65 Larry Robertson Louisville KY went great lengths get really lightweight modelthe Golden Bantam Wynn devotes lot column describing Larrys experiences first left work bench 62-in-span I-beam-winged Supertigre 46-powered model weighed about 46/i oz Progressive structural mods increased 1049 oZ Photo right above shows removable side panel allows access fuel tank Note Robert Paul lightweight muffler tank-pressure line tapped Below left tail assembly showing mucho lightening holes oval aluminum-tube struts needed brace stab reminds us All-American Stunter deBolt Photo right below shows unique cowl modelallows maximum cooling air sweep over engine Note plastic venturi parts wont have slice op plan show lot thought especially like Supermarine Sparrow Peanut can yours two bucks postpaid list heavy round WW II types hit above beginner level war buff shoot Dave off SASE plan list Handy hints department Dick Smith Garden Grove CA has winner little tool making round balsa strip out square type drills series holes piece brass plate such might glean old trophy starting diameter begins take corners off square stick being pushed through getting smaller until push-thru last hole gives desired diameter sharp edge can easily obtained brass filing top bottom surfaces flat after drilling care fully touching up burr pushed hole Scale documentation next superscaler might easier find using Dale Willoughbys Scale Model Research service catalog goes usual dollar Dale describes what offers foto paak [sic] down quality interior-view shot Also has Xerox 3-view hell make copy Write Dale PO Box 573 Anza CA 92306 Until next time keep tight capon diesel fuel can Pirelli rubber out sunlight Bill Warner 423-C San Vicente Blvd Santa Monica CA 90402 hottest fuel newest prop its good working combination original model weighs 139 ounces ready fly could easily built lighter wouldnt worth effort doubt trim would consistent would make model fast enough potentially dangerousits plenty fast enough exact number turns climb diameter glide circle nearly important establishing trim consistent comfortable using Its important both model flier able repeat perform ances time after time model trimmed too close its performance limits will almost never win because smallest error made disaster will strike Thats simply gamble worth taking Practice model until sure what can youre ready consistent winner CL Aerobatics/Paul Continued page 65 experienced some cracking around nose fuselage sides starting come loose right rear engine-mounting holes Epoxy used glue fuselage sides doublers plywood bulkheads together Continued page 151 CAP 21*Flown Miles Reed air show IMAA Nationals Ida Grove IA 88wing span 1232 sq 16-18 lbs engine 20-31 Plans S20 CAP 20L84 wing span 1272 sq 16-18 lbs engine 20-31Plans S20 TEMPEST86 wing span 1420 sq 18-20 lbs engine 2 4-3 7Plans S25 RV-3 *86 wing span 1638 sq 17-19 lbs engine 2 0-3 1Plans S20 R C Garmhausen 2715 Maple Ave NE Canton OH 44714 *RV3 CAP 21 pre-assembled kits available write information March 1983 143 Royal Lancer/Haught Continued page 64 SAFE FLYING IS NO ACCIDENT combination fuel vibration taking its toll After some repairs outboard wing broke half after some hard landings leading trailing edges fractured whole wing folded after stiffening fuselage stabilizer etc plane now weighs whopping 49 oz As Larry free admit went out get super-light plane some inherent difficulties very very light construc tion attempted Admittedly has spent lot time summer 1982 repairing plane could have Out practicing pat tern indeed difficult trim airplane because wing flex stabilizer flex fuselage flex So what can learned analysis super-light airplane 750 sq wing Keep mind wing loading air plane right 1085 az/sq ft compared typical Genesis Bob Hunt about 1235 oz/sq ft typical Gieseke Nobler 1120 oz/sq ft Supertigre able pull airplane relative ease However Larry admits maybe went too far striving light airplane stresses strains airplane performing Stunt pattern just may too much airplane such Golden Bantam Larry feels new 1983 plane added wing spar A-in fuselage sides stiffer stabilizer construction will have problems time writing 1983 airplane about five oz heavier 1982 plane intends use same type finish could come out 750-sq-in airplane weighs about 54 55 oz would still competitive also has built six mounting holes engines can interchange Supertigre OS Max 45 have unsightly gap nose ring Well see new plane Larrys works summer 1983 information Stunt PA MPA contact Wynn Paul 1640 Maywick Dr Lexington KY 40504 CL Racing/Ballard Continued page 66 directed Gary Frost 28 entries Sport Race predom inant engine Supertigre 35 plain-bearing engine airplane speeds 195 23 tee range Heats flown 100 laps three pilots circle large amount racing saw no line tanglements problems pitting Obviously first glance can see difference between reduced Slow Rat time 1415 see Sport Race time around 2023 sec means enormous difference airspeed increases maneuverability Sport Race aircraft certainly makes fun event Several opinions have offered reason popularity event stage development event unwritten law professional people generally enter evens think event ever made official pro visional AMA event expert professional flier must eliminated competing limitation should certainly promote event since average modeler could con struct fly airplanes too much difficulty addition would good learning-ground people wanted move up pro ranks think everyone unanimous opinion concerning need bring new blood new competitors field Racing certainly eliminating entry professional ranks event would maintained training ground new pilots pit men Quite frankly believe what originally intended Slow Rat event However short amount time professionals took over saw entries dropping 25 U-L P0 Box 3957 Torrance CA 90510 March 1983 151 CUSTOM FOAM WINGS d TAILS CUSTOM SAILPLANE WINGS d TAILS SPRAY ADHESIVES FIBERGLASS FUSELAGES HI STARTS BALSA d PLYWOOD SEND 5O d 10 SASE FOR INFO ESS BOX 437 LEMONT PA 16851 KITs 21 Old Time Gas 12 HL Gliders 11 Contest Rubber Send 50C for4 Satellite Kits 82/83 casalog3 Nastalgia Power Padfiers 6t LOTS OF GOOD STUFF FAI Model Supply P-40 CARD KIT FULL COLOR EXACT REPRODUCTION 4 NOW$rOO REMEMBER HOW ON YWELL THEY FLEW SpeII off IneIsd. soepo, eIolng bolone sot blt pAce Send 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