ONE seasons earliest all-scale contests 7th Annual Mint Julep meet Rough River Dam State Resort Park Kentucky sponsored Southern Indiana R/C Modelers site paved airstrip park complete camping facilities lodge cottages large meeting room Saturday evening banquet 38 entries meet has increased size Mint Julep contest directed Dale Arvin has innovative approach rules making Two basic groups Expert Sports man sub-divided Division mili tary civil planes retracting landing gears racing aircraft Division II light planes retracts Recognizing inadequate judging sore spots model contests sponsors decided something about run-away scoring Four judges used static flight scoring high low scores group being discarded remaining two scores added total score sum static score average best two flight scores four rounds flown Consis tency therefore required high place results Discarding high low scores well chosen device noted case high 45% above low Some clubs have initiated training programs help reduce wide spread scores tremendous increase scale activity certainly need pool trained judges especially knowledge full size aircraft construction Scale modeling directly related prototypes As could expected meet size some extraordinary models present Bob Underwoods new Petlyakov PE-2 USSR WW II twin-engine bomber outstanding its first place win spite some rather severe damage due capricious gust wind before round Fellow competitors helped reas semble fuselage tail surfaces time its first flight Bob used pair HP 40 engines 81-in model very light 125 pounds plane numerous operating features main tail wheels retracted operating doors flaps dive brakes two external bombs dropped high altitude amazing accuracy descended considerable thud lightweight bombs loaded clay prevent drift strong wind plane balsa construction covered e fiberglass cloth poly ester resin sanded metal-like surface before application weathered finish during Continued page 107 32 Model Aviation RUTflOfltIC5IIY UPllC8tOd Color scheme Hank Pohimans ... personal plane Webra 61 Blackhead powered 8-pound plane Sig will manufacture kit PumpIng pressure retract reservoir Petiya n u1u runway Daughter Cathy pit crew Highest flight stat, ores mui first Mint Julep MarIo YeaerIInIc team wltn /4 scale Aeronci thattool St Sportsman class MintJulep OS Max 60 4-cycie authentic sound prototype two-cylinder engine looking forperfection want see student flying airplane vice-versa 7 Landing pattern Start high 200 feet work down plan land Plan make airplane go supposed reference runway local obstructions Go up again 8 Landings plane properly trimmed will land itself have steer runway 9 Solo fast learner will get point afternoon instructor has time spend him supervised solo doesnt mean student ready go off himself unattended means student has mastered basics now ready learn fly George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 RC Scale/Wischers continued page 32 gusty winds Saturday air ground handling PE-2 excellent Modelers WW LI training planes may remember anti-spin strakes used some deHavilland Tiger Moths forward extensions horizontal stabilizer joins fuselage purpose being correction tendency flat spin Anti-spin strakes have reappeared Beech T-34 turboprop trainer model plane flown third place Bud Atkinson Buds Beech added nose length turboprop plane ideally proportioned modeling new plane made three flights before contest Bud yet determined effectiveness strakes Hank Pohlman again flown Iowa Cessna 172 Skyhawk carrying 65-in model Hawk specially constructed luggage compartment must ultimate scale documentation Victim high wind its first round flight hastily repaired ubiquitous instant glue going win first place Expert Division IL Hanks Skyhawk will released Sig kit later year complete foam wing formed molded ABS fuselage cowl pants windows corru gated control surfaces quarter-scale scratch-built Aeronca C-3 four Florida entrants Mario Yeder linics C-3 flown 0 S Max 60 fourcycle engine came surprisingly close authentic sound two-cylinder Aeronca E 113 engine apparent slow pace C-3 added considerably realism flight combin ing its high static score gain first place Sportsman Division II Mario also flew Hawker Hurricane Division Art Johnson also made thousand mile trip Florida renowned Lockheed P-38 Lightning Art sealed joints points P-38 assembled give plane overall smooth exterior large model needed transported piece just barely fitting capacious station wagon popularity Arts plane best evidenced spectator contestant reaction flies Absolutely everyone watches complete flight special attention instant droppable fuel tanks deployed Apair OS Max 60 Schnuerle engines supply energy Tip Stalls Again February column de scribed method preventing tip stalls tapered wing greater percentage thick ness toward tip Dan Parsons writes agree what said have question recommended methods preven ting tip stall increase percentage wing thickness tip over root have seen suggested over years other modelers wonder idea came According studies airfoil lift curves section lift coefficient vs section angle attack Theory Wing Sections Abbott Doenhoff just opposite technique should employed percentage wing thickness tip should decreased over root reason being type airfoils com monly used modelers 12% airfoil stalls higher angle attack 15% Thus wing tapering 15% root 12% tip have built washout having warp wing following table illus trates NACA * Stall Angle Max Lift Cocif 24121516 2415 2421 4412 4415 23012 23015 23024 14 14 13 12 165 15 14 14 125 152 143 162 153 120 As will note max lift coefficient also higher 12% thickness years modelers have thought thicker airfoil lift Taint according curves least September 1979 107 THE chose Waco F-3 biplane flagship because represents Golden Era 1930s flying adventure Add easy snag-free building safe gentle flyingthe result thorough kit engineering careful prototype development features Platt Kits have satisfying building flying experience ahead Kit featuresTop-quality diecut machined balsa plywood Full size plans Separate instruction book isometrics Decals Injection-moulded vacuum-formed plastic cowl cowl blisters wheel pants required nylon fittings Formed wire langing gear & struts Span 60 Area 950 Sq 4 6 channel Engine good 40 60 2657 NE 188th Street Miami Florida 33180 Telephone 935-1436 KELLY PROPS Winningest Fiberglas Graphite Propellers U S Nationals 10-6 9 7 Nashville Slow Rat 8- 8 Gillopt 8 8 Regular 8-7 Regular 7 6 7 55 $650 $650 $500 $475 $475 $375 Graphite $500 614 5% Willoughby $375 Graphite $500 6 7/8 52 Anderson Ballard Latest Version Mk-3 $375 Graphite $500 7 4 FAI Combat Prop $375 TEAM RACE PROPS DRAZEK NOVA JOHN GRAY Fiber $375 Graphite $500 ODDY ONE BLADE PROP w/out counter balence Fiber $400 Graphite $500 DIESEL HEADS fit 15 engines $18 ORDER DIRECT 72 hour shipping cashiers checks money orders 10-day person al checks Money promptly refunded prop stock KELLY PRODUCTS INC P0 Box 38 Western Springs IL 60558 108 Model Aviation Reynolds number region full-size aircraft rm assuming holds true Reynolds number region cant imagine effects reversing have recently built wings taper 15% root 12% tip Martin Baker MB-S uses 2301523012 airfoil 34 ounce per sq ft wing loading consider moderate after some 75 flights have yet suffer unwanted snap roll Ive made some poor takeoffs routinely make high G turns tight square loops feel tapered % airfoil working Another sport plane Ijust finished also has tapered percent airfoil have difficult time getting snap roll command Since full-size planes use decreasing percentage toward tip increasing percent tip thickness would non-scale would look like h- constant percentage wings used scale kits look bad enough would interested comments right Dan about non-scale appear ance wing tips noticeably too thick searching through information airfoils find list stall patterns indicates tapered wing wash-out twist reduced percentage thickness tip will experience tip stalls first because smaller Reynolds number thinner airfoil loss aileron control nearthe stall tendency roll near stall Another stall patterns tapered wing increase 12% root 18% tip Bede 5 plane indicates excellent stall pattern good lift distribution no adverse drag cruise speed Planes have sharply tapered wings use large amounts washout avoid tip stalls high angies attack Douglas A-20 example 4i degrees wash-out com pensate low Reynolds number short chord wing tips tapered portion Cessna wings also use wash-out Overweight underpowered scale models flown near stalled condition need help increase thickness toward tips need great unsightly An alternative wash-out though used prototype certainly employed required original Bob Underwood used wash-out extremely narrow tips deHavilland Comet racer desired results plane neither overweight nor underpowered though wing loading Dans MB-S moderately high likely under powered therefore flies through maneuvers occasional bad take-offs evidence tip stalls RC Aerobatics/Van Putte continued page 33 Master flier Jim Edwards won 1968 Masters Tournament Indianapolis Indiana suggested operating rudder using two thin cables filed suggestion away almost year until judges Kirkland Memorial noted during judges training session rudder getting pretty py After pondering what about week remem bered Jims suggestion less half hour later conversion cable-driven rudder complete used two Sullivan 030 cables tubes Rocket City long servo arm two IM control horns cut down use inside holes new Sullivan cable packages come small threaded couplers sweat solder neatly cable clevis end cable locked threaded coupler ajam nut preclude movement install cable system simply put new horns side rudder drilled extra hole fuselage installed cables adjusted cable tension entire rudder system now very precise slop caused gear backiash servos seems negative reaction manufacturers new Beginner Simple Novice whatever call events limit aircraft system retracts fuel pumps tuned pipes Schnuerle ported engines attitude appears imply something being taken away having such events Just what logic results such conclusion escapes basic events intended draw new competitors pattern flying promote orderly transition highly competitive Novice class seems manufacturers would welcome events technique develop new sources income competitor encouraged continue competition pattern reasonable transition scheme will soon buying exotic products make other classes competitive mail often brings suggestions other fliers recent letter R Gregg Lovick Grapevine Texas warmed cockies Scottish heart mother born Scotland went follows use conductors punch little plier-like affairs punch round holes paper cut small circles out little scraps trim MonoKote accrue put red green dots gel cell Bob andDolly Wischer Ri 1 S221 Lap ham Peak Rd Delafleld WI 53018
Edition: Model Aviation - 1979/09
Page Numbers: 32, 107, 108
ONE seasons earliest all-scale contests 7th Annual Mint Julep meet Rough River Dam State Resort Park Kentucky sponsored Southern Indiana R/C Modelers site paved airstrip park complete camping facilities lodge cottages large meeting room Saturday evening banquet 38 entries meet has increased size Mint Julep contest directed Dale Arvin has innovative approach rules making Two basic groups Expert Sports man sub-divided Division mili tary civil planes retracting landing gears racing aircraft Division II light planes retracts Recognizing inadequate judging sore spots model contests sponsors decided something about run-away scoring Four judges used static flight scoring high low scores group being discarded remaining two scores added total score sum static score average best two flight scores four rounds flown Consis tency therefore required high place results Discarding high low scores well chosen device noted case high 45% above low Some clubs have initiated training programs help reduce wide spread scores tremendous increase scale activity certainly need pool trained judges especially knowledge full size aircraft construction Scale modeling directly related prototypes As could expected meet size some extraordinary models present Bob Underwoods new Petlyakov PE-2 USSR WW II twin-engine bomber outstanding its first place win spite some rather severe damage due capricious gust wind before round Fellow competitors helped reas semble fuselage tail surfaces time its first flight Bob used pair HP 40 engines 81-in model very light 125 pounds plane numerous operating features main tail wheels retracted operating doors flaps dive brakes two external bombs dropped high altitude amazing accuracy descended considerable thud lightweight bombs loaded clay prevent drift strong wind plane balsa construction covered e fiberglass cloth poly ester resin sanded metal-like surface before application weathered finish during Continued page 107 32 Model Aviation RUTflOfltIC5IIY UPllC8tOd Color scheme Hank Pohimans ... personal plane Webra 61 Blackhead powered 8-pound plane Sig will manufacture kit PumpIng pressure retract reservoir Petiya n u1u runway Daughter Cathy pit crew Highest flight stat, ores mui first Mint Julep MarIo YeaerIInIc team wltn /4 scale Aeronci thattool St Sportsman class MintJulep OS Max 60 4-cycie authentic sound prototype two-cylinder engine looking forperfection want see student flying airplane vice-versa 7 Landing pattern Start high 200 feet work down plan land Plan make airplane go supposed reference runway local obstructions Go up again 8 Landings plane properly trimmed will land itself have steer runway 9 Solo fast learner will get point afternoon instructor has time spend him supervised solo doesnt mean student ready go off himself unattended means student has mastered basics now ready learn fly George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 RC Scale/Wischers continued page 32 gusty winds Saturday air ground handling PE-2 excellent Modelers WW LI training planes may remember anti-spin strakes used some deHavilland Tiger Moths forward extensions horizontal stabilizer joins fuselage purpose being correction tendency flat spin Anti-spin strakes have reappeared Beech T-34 turboprop trainer model plane flown third place Bud Atkinson Buds Beech added nose length turboprop plane ideally proportioned modeling new plane made three flights before contest Bud yet determined effectiveness strakes Hank Pohlman again flown Iowa Cessna 172 Skyhawk carrying 65-in model Hawk specially constructed luggage compartment must ultimate scale documentation Victim high wind its first round flight hastily repaired ubiquitous instant glue going win first place Expert Division IL Hanks Skyhawk will released Sig kit later year complete foam wing formed molded ABS fuselage cowl pants windows corru gated control surfaces quarter-scale scratch-built Aeronca C-3 four Florida entrants Mario Yeder linics C-3 flown 0 S Max 60 fourcycle engine came surprisingly close authentic sound two-cylinder Aeronca E 113 engine apparent slow pace C-3 added considerably realism flight combin ing its high static score gain first place Sportsman Division II Mario also flew Hawker Hurricane Division Art Johnson also made thousand mile trip Florida renowned Lockheed P-38 Lightning Art sealed joints points P-38 assembled give plane overall smooth exterior large model needed transported piece just barely fitting capacious station wagon popularity Arts plane best evidenced spectator contestant reaction flies Absolutely everyone watches complete flight special attention instant droppable fuel tanks deployed Apair OS Max 60 Schnuerle engines supply energy Tip Stalls Again February column de scribed method preventing tip stalls tapered wing greater percentage thick ness toward tip Dan Parsons writes agree what said have question recommended methods preven ting tip stall increase percentage wing thickness tip over root have seen suggested over years other modelers wonder idea came According studies airfoil lift curves section lift coefficient vs section angle attack Theory Wing Sections Abbott Doenhoff just opposite technique should employed percentage wing thickness tip should decreased over root reason being type airfoils com monly used modelers 12% airfoil stalls higher angle attack 15% Thus wing tapering 15% root 12% tip have built washout having warp wing following table illus trates NACA * Stall Angle Max Lift Cocif 24121516 2415 2421 4412 4415 23012 23015 23024 14 14 13 12 165 15 14 14 125 152 143 162 153 120 As will note max lift coefficient also higher 12% thickness years modelers have thought thicker airfoil lift Taint according curves least September 1979 107 THE chose Waco F-3 biplane flagship because represents Golden Era 1930s flying adventure Add easy snag-free building safe gentle flyingthe result thorough kit engineering careful prototype development features Platt Kits have satisfying building flying experience ahead Kit featuresTop-quality diecut machined balsa plywood Full size plans Separate instruction book isometrics Decals Injection-moulded vacuum-formed plastic cowl cowl blisters wheel pants required nylon fittings Formed wire langing gear & struts Span 60 Area 950 Sq 4 6 channel Engine good 40 60 2657 NE 188th Street Miami Florida 33180 Telephone 935-1436 KELLY PROPS Winningest Fiberglas Graphite Propellers U S Nationals 10-6 9 7 Nashville Slow Rat 8- 8 Gillopt 8 8 Regular 8-7 Regular 7 6 7 55 $650 $650 $500 $475 $475 $375 Graphite $500 614 5% Willoughby $375 Graphite $500 6 7/8 52 Anderson Ballard Latest Version Mk-3 $375 Graphite $500 7 4 FAI Combat Prop $375 TEAM RACE PROPS DRAZEK NOVA JOHN GRAY Fiber $375 Graphite $500 ODDY ONE BLADE PROP w/out counter balence Fiber $400 Graphite $500 DIESEL HEADS fit 15 engines $18 ORDER DIRECT 72 hour shipping cashiers checks money orders 10-day person al checks Money promptly refunded prop stock KELLY PRODUCTS INC P0 Box 38 Western Springs IL 60558 108 Model Aviation Reynolds number region full-size aircraft rm assuming holds true Reynolds number region cant imagine effects reversing have recently built wings taper 15% root 12% tip Martin Baker MB-S uses 2301523012 airfoil 34 ounce per sq ft wing loading consider moderate after some 75 flights have yet suffer unwanted snap roll Ive made some poor takeoffs routinely make high G turns tight square loops feel tapered % airfoil working Another sport plane Ijust finished also has tapered percent airfoil have difficult time getting snap roll command Since full-size planes use decreasing percentage toward tip increasing percent tip thickness would non-scale would look like h- constant percentage wings used scale kits look bad enough would interested comments right Dan about non-scale appear ance wing tips noticeably too thick searching through information airfoils find list stall patterns indicates tapered wing wash-out twist reduced percentage thickness tip will experience tip stalls first because smaller Reynolds number thinner airfoil loss aileron control nearthe stall tendency roll near stall Another stall patterns tapered wing increase 12% root 18% tip Bede 5 plane indicates excellent stall pattern good lift distribution no adverse drag cruise speed Planes have sharply tapered wings use large amounts washout avoid tip stalls high angies attack Douglas A-20 example 4i degrees wash-out com pensate low Reynolds number short chord wing tips tapered portion Cessna wings also use wash-out Overweight underpowered scale models flown near stalled condition need help increase thickness toward tips need great unsightly An alternative wash-out though used prototype certainly employed required original Bob Underwood used wash-out extremely narrow tips deHavilland Comet racer desired results plane neither overweight nor underpowered though wing loading Dans MB-S moderately high likely under powered therefore flies through maneuvers occasional bad take-offs evidence tip stalls RC Aerobatics/Van Putte continued page 33 Master flier Jim Edwards won 1968 Masters Tournament Indianapolis Indiana suggested operating rudder using two thin cables filed suggestion away almost year until judges Kirkland Memorial noted during judges training session rudder getting pretty py After pondering what about week remem bered Jims suggestion less half hour later conversion cable-driven rudder complete used two Sullivan 030 cables tubes Rocket City long servo arm two IM control horns cut down use inside holes new Sullivan cable packages come small threaded couplers sweat solder neatly cable clevis end cable locked threaded coupler ajam nut preclude movement install cable system simply put new horns side rudder drilled extra hole fuselage installed cables adjusted cable tension entire rudder system now very precise slop caused gear backiash servos seems negative reaction manufacturers new Beginner Simple Novice whatever call events limit aircraft system retracts fuel pumps tuned pipes Schnuerle ported engines attitude appears imply something being taken away having such events Just what logic results such conclusion escapes basic events intended draw new competitors pattern flying promote orderly transition highly competitive Novice class seems manufacturers would welcome events technique develop new sources income competitor encouraged continue competition pattern reasonable transition scheme will soon buying exotic products make other classes competitive mail often brings suggestions other fliers recent letter R Gregg Lovick Grapevine Texas warmed cockies Scottish heart mother born Scotland went follows use conductors punch little plier-like affairs punch round holes paper cut small circles out little scraps trim MonoKote accrue put red green dots gel cell Bob andDolly Wischer Ri 1 S221 Lap ham Peak Rd Delafleld WI 53018
Edition: Model Aviation - 1979/09
Page Numbers: 32, 107, 108
ONE seasons earliest all-scale contests 7th Annual Mint Julep meet Rough River Dam State Resort Park Kentucky sponsored Southern Indiana R/C Modelers site paved airstrip park complete camping facilities lodge cottages large meeting room Saturday evening banquet 38 entries meet has increased size Mint Julep contest directed Dale Arvin has innovative approach rules making Two basic groups Expert Sports man sub-divided Division mili tary civil planes retracting landing gears racing aircraft Division II light planes retracts Recognizing inadequate judging sore spots model contests sponsors decided something about run-away scoring Four judges used static flight scoring high low scores group being discarded remaining two scores added total score sum static score average best two flight scores four rounds flown Consis tency therefore required high place results Discarding high low scores well chosen device noted case high 45% above low Some clubs have initiated training programs help reduce wide spread scores tremendous increase scale activity certainly need pool trained judges especially knowledge full size aircraft construction Scale modeling directly related prototypes As could expected meet size some extraordinary models present Bob Underwoods new Petlyakov PE-2 USSR WW II twin-engine bomber outstanding its first place win spite some rather severe damage due capricious gust wind before round Fellow competitors helped reas semble fuselage tail surfaces time its first flight Bob used pair HP 40 engines 81-in model very light 125 pounds plane numerous operating features main tail wheels retracted operating doors flaps dive brakes two external bombs dropped high altitude amazing accuracy descended considerable thud lightweight bombs loaded clay prevent drift strong wind plane balsa construction covered e fiberglass cloth poly ester resin sanded metal-like surface before application weathered finish during Continued page 107 32 Model Aviation RUTflOfltIC5IIY UPllC8tOd Color scheme Hank Pohimans ... personal plane Webra 61 Blackhead powered 8-pound plane Sig will manufacture kit PumpIng pressure retract reservoir Petiya n u1u runway Daughter Cathy pit crew Highest flight stat, ores mui first Mint Julep MarIo YeaerIInIc team wltn /4 scale Aeronci thattool St Sportsman class MintJulep OS Max 60 4-cycie authentic sound prototype two-cylinder engine looking forperfection want see student flying airplane vice-versa 7 Landing pattern Start high 200 feet work down plan land Plan make airplane go supposed reference runway local obstructions Go up again 8 Landings plane properly trimmed will land itself have steer runway 9 Solo fast learner will get point afternoon instructor has time spend him supervised solo doesnt mean student ready go off himself unattended means student has mastered basics now ready learn fly George M Myers 70 Froehlich Farm Rd Hicksville NY 11801 RC Scale/Wischers continued page 32 gusty winds Saturday air ground handling PE-2 excellent Modelers WW LI training planes may remember anti-spin strakes used some deHavilland Tiger Moths forward extensions horizontal stabilizer joins fuselage purpose being correction tendency flat spin Anti-spin strakes have reappeared Beech T-34 turboprop trainer model plane flown third place Bud Atkinson Buds Beech added nose length turboprop plane ideally proportioned modeling new plane made three flights before contest Bud yet determined effectiveness strakes Hank Pohlman again flown Iowa Cessna 172 Skyhawk carrying 65-in model Hawk specially constructed luggage compartment must ultimate scale documentation Victim high wind its first round flight hastily repaired ubiquitous instant glue going win first place Expert Division IL Hanks Skyhawk will released Sig kit later year complete foam wing formed molded ABS fuselage cowl pants windows corru gated control surfaces quarter-scale scratch-built Aeronca C-3 four Florida entrants Mario Yeder linics C-3 flown 0 S Max 60 fourcycle engine came surprisingly close authentic sound two-cylinder Aeronca E 113 engine apparent slow pace C-3 added considerably realism flight combin ing its high static score gain first place Sportsman Division II Mario also flew Hawker Hurricane Division Art Johnson also made thousand mile trip Florida renowned Lockheed P-38 Lightning Art sealed joints points P-38 assembled give plane overall smooth exterior large model needed transported piece just barely fitting capacious station wagon popularity Arts plane best evidenced spectator contestant reaction flies Absolutely everyone watches complete flight special attention instant droppable fuel tanks deployed Apair OS Max 60 Schnuerle engines supply energy Tip Stalls Again February column de scribed method preventing tip stalls tapered wing greater percentage thick ness toward tip Dan Parsons writes agree what said have question recommended methods preven ting tip stall increase percentage wing thickness tip over root have seen suggested over years other modelers wonder idea came According studies airfoil lift curves section lift coefficient vs section angle attack Theory Wing Sections Abbott Doenhoff just opposite technique should employed percentage wing thickness tip should decreased over root reason being type airfoils com monly used modelers 12% airfoil stalls higher angle attack 15% Thus wing tapering 15% root 12% tip have built washout having warp wing following table illus trates NACA * Stall Angle Max Lift Cocif 24121516 2415 2421 4412 4415 23012 23015 23024 14 14 13 12 165 15 14 14 125 152 143 162 153 120 As will note max lift coefficient also higher 12% thickness years modelers have thought thicker airfoil lift Taint according curves least September 1979 107 THE chose Waco F-3 biplane flagship because represents Golden Era 1930s flying adventure Add easy snag-free building safe gentle flyingthe result thorough kit engineering careful prototype development features Platt Kits have satisfying building flying experience ahead Kit featuresTop-quality diecut machined balsa plywood Full size plans Separate instruction book isometrics Decals Injection-moulded vacuum-formed plastic cowl cowl blisters wheel pants required nylon fittings Formed wire langing gear & struts Span 60 Area 950 Sq 4 6 channel Engine good 40 60 2657 NE 188th Street Miami Florida 33180 Telephone 935-1436 KELLY PROPS Winningest Fiberglas Graphite Propellers U S Nationals 10-6 9 7 Nashville Slow Rat 8- 8 Gillopt 8 8 Regular 8-7 Regular 7 6 7 55 $650 $650 $500 $475 $475 $375 Graphite $500 614 5% Willoughby $375 Graphite $500 6 7/8 52 Anderson Ballard Latest Version Mk-3 $375 Graphite $500 7 4 FAI Combat Prop $375 TEAM RACE PROPS DRAZEK NOVA JOHN GRAY Fiber $375 Graphite $500 ODDY ONE BLADE PROP w/out counter balence Fiber $400 Graphite $500 DIESEL HEADS fit 15 engines $18 ORDER DIRECT 72 hour shipping cashiers checks money orders 10-day person al checks Money promptly refunded prop stock KELLY PRODUCTS INC P0 Box 38 Western Springs IL 60558 108 Model Aviation Reynolds number region full-size aircraft rm assuming holds true Reynolds number region cant imagine effects reversing have recently built wings taper 15% root 12% tip Martin Baker MB-S uses 2301523012 airfoil 34 ounce per sq ft wing loading consider moderate after some 75 flights have yet suffer unwanted snap roll Ive made some poor takeoffs routinely make high G turns tight square loops feel tapered % airfoil working Another sport plane Ijust finished also has tapered percent airfoil have difficult time getting snap roll command Since full-size planes use decreasing percentage toward tip increasing percent tip thickness would non-scale would look like h- constant percentage wings used scale kits look bad enough would interested comments right Dan about non-scale appear ance wing tips noticeably too thick searching through information airfoils find list stall patterns indicates tapered wing wash-out twist reduced percentage thickness tip will experience tip stalls first because smaller Reynolds number thinner airfoil loss aileron control nearthe stall tendency roll near stall Another stall patterns tapered wing increase 12% root 18% tip Bede 5 plane indicates excellent stall pattern good lift distribution no adverse drag cruise speed Planes have sharply tapered wings use large amounts washout avoid tip stalls high angies attack Douglas A-20 example 4i degrees wash-out com pensate low Reynolds number short chord wing tips tapered portion Cessna wings also use wash-out Overweight underpowered scale models flown near stalled condition need help increase thickness toward tips need great unsightly An alternative wash-out though used prototype certainly employed required original Bob Underwood used wash-out extremely narrow tips deHavilland Comet racer desired results plane neither overweight nor underpowered though wing loading Dans MB-S moderately high likely under powered therefore flies through maneuvers occasional bad take-offs evidence tip stalls RC Aerobatics/Van Putte continued page 33 Master flier Jim Edwards won 1968 Masters Tournament Indianapolis Indiana suggested operating rudder using two thin cables filed suggestion away almost year until judges Kirkland Memorial noted during judges training session rudder getting pretty py After pondering what about week remem bered Jims suggestion less half hour later conversion cable-driven rudder complete used two Sullivan 030 cables tubes Rocket City long servo arm two IM control horns cut down use inside holes new Sullivan cable packages come small threaded couplers sweat solder neatly cable clevis end cable locked threaded coupler ajam nut preclude movement install cable system simply put new horns side rudder drilled extra hole fuselage installed cables adjusted cable tension entire rudder system now very precise slop caused gear backiash servos seems negative reaction manufacturers new Beginner Simple Novice whatever call events limit aircraft system retracts fuel pumps tuned pipes Schnuerle ported engines attitude appears imply something being taken away having such events Just what logic results such conclusion escapes basic events intended draw new competitors pattern flying promote orderly transition highly competitive Novice class seems manufacturers would welcome events technique develop new sources income competitor encouraged continue competition pattern reasonable transition scheme will soon buying exotic products make other classes competitive mail often brings suggestions other fliers recent letter R Gregg Lovick Grapevine Texas warmed cockies Scottish heart mother born Scotland went follows use conductors punch little plier-like affairs punch round holes paper cut small circles out little scraps trim MonoKote accrue put red green dots gel cell Bob andDolly Wischer Ri 1 S221 Lap ham Peak Rd Delafleld WI 53018