DB Mathews OXYMORONS Webster defines oxymoron combination contradictory incongruous words Some classic examples military intelligence sanitary landfill new antiques pet converted rice Modeling also seems have created its share contradictory phrases amusing aspect phenomenon tendency verbalize write much consideration often catch myself saying writing phrases rather embarrassing stop think about As example glow ignition engines doesnt hold up well analytical process Dont glow plugs ignite fuel/air mixture too reality mean glow spark dont leads pet oxymoron repeated conversations between modelers modeling press t-bottomed Clark Y airfoils Weve duplicated some computergenerated drawings courtesy George Sauer graphically demonstrate airfoil truly flat-bottomed certainly Clark Y Notice leading edge entry point flat-bottom section almost parallel trailing edge whereas Clark Y leading edge raised above trailing edge Beyond semantics misconception has some real significance modeling am assuredly no expert airfoils nor anything else matter experts have clearly established some very significant aerodynamic differences between Clark Y flat-bottomed airfoils April 1993 column went considerable detail concerning welldocumented testing experts confirmed rapid changes lifting characteristics flat-bottomed sections pitch attitude angle attack velocity varied Please read comments numerous serious scientific articles various magazines have strong interest subject now suffice say considerations significant explain flat-bottomed-airfoil trainers tendencies bob up down flown windy conditions other hand raised entry Clark Y narrows movement center lift fore-and-aft producing stable model easily trimmed feature exactly Clark Y has remained favorite Scale Free Flight fliers least 60 years Scale Free Flight designs whether rubber-powered gas must remain stable widely varied forward speed angle climb attack environment non technical cut-and-try designers have learned raised-entry airfoil produces stable model power-on power-off seem superior flat-bottomed types matter undercambered types lesser extent Clark Y frequently used Sport Free Flight RC designs utilize same desirable stability characteristics full-scale aviation Clark Y variations has popular selection light aircraft years Aeroncas Piper Cubs other designs gain much desirable low-speed handling lift characteristics type airfoil Im aware true flatbottomed sections used full-scale aircraft Conversely some very successful RC trainers use true flat-bottomed airfoils midpoint leading edge parallel trailing edge Some designs frequently also use positive incidence leading edge up horizontal stabilizer Ever wonder simply attempt dampen models tendency balloon flying widely varied upwind downwind conditions contrary everything Ive ever read heard pointed thin leading edge entry some trainers should work really have never clearly understood 86 Model Aviation PLAT BOTTOMED CLARK Nhj Ias s ISrAJO P2512515 ISI I5 I20125i30140150I601P180OI9Slk9I LAut4sse I4 *tB 1uMi- IS a o 0 0 0 0 n40 IA5I2515 l71 IS 120125130140150 f60 l 18090195 IftI L&t0i42t 3 c&6i9-411647j4450 LaoiiZf9iJ,6Ajto*RS4O*MD toLo8E% ZIPPER ISWRJO lhSI2d15 17iIft Its I20I25130 I40 I5D160 170 180 Iso i5I/00I LA IS 31 M U1 13 3 1 IJ 0 i3I 7603 rk successful very obvious fairness Ive used true flat-bottomed airfoils several published designs now really wish can excuse fact claiming ignorance designed years ago appeal true flat bottom lies construction ease can lay down TE capstrips spars sheeting leading edge flat before adding ribs However also possible construct Clark Y same manner exception adhering front sheeting until ribs added leading edge place easier wait until panel off board before adhering bottom front sheeting Parenthetically newer versions manufacturers trainers anothers newer scale high-wing design use Clark Y type airfoils surely says something rate model has airfoil flat fore-and-aft certainly Clark Y Another Oxymoron Weve also illustrated two other airfoil types NACA 6406 Goldbergs Zipper subjected oxymoron tend refer airfoil undercamber high lift again doesnt stand up well critical reflection low airspeeds airfoils lift Clark Y symmetrical type back full-scale airplanes took off 60 mph flew 60 mph topped out 60 mph landed 60 mph stalled 60 mph such airfoils NACA 6406 worked admirably However faster aircraft developed sections became real liability standpoints drag poor lift critical stability Youll find such airfoil modern heavy high-performance airplane simply because likely would never get off ground did aircraft would dangerously unstable Goldberg section classic example superb Free flight airfoil designed provide lots lift very slow forward speed gliding mode higher speeds such contemporary competition RC gliders fly section does provide much lift modern airfoils Such airfoils certainly provide high lift settings lift lot low airspeeds certainly high velocities So calling airfoils high lift really accurate undercambered likely much appropriate Lost Art researching piece dug out set airfoil sections drawn Paul Plecan 1943 Air Trails Annual Illustrated some airfoils popular use back seldom seen today simply because newer airfoils superior modeling use However does show Clark Y notes superior general model use just still 15 As custom years drawings include coordinates used enlarging sections involved stations measured front-to-back marked straight line measured factored points above below Once marked line drawn between points develop top bottom outlines took little skill hands of us used up large chunks time resulted woefully inaccurate sections advent copiers capable enlarging reducing drawings now computer-generated airfoil drawing programs seriously doubt anyone right mind would develop airfoil drawing using coordinates An art lostand good riddance Hopefully have found some amusement little diatribe about nonsense terms have some youve noticed modeling would share us Frankly want use oxymorons mentioned go right ahead hobby course English Comp No grade will givenexcept always should having fun uiie 1dI5 Convienent Top Cons Start Spring Disengagment Featuring Easy access motor No alignment required Extra Large Metal Clutch Smooth Fower Transmission High Efficiently Control system Front Servo Mounting Rotor Head Control Systems Simplifies Setup & Servo Linkages Reducing Flea Gyro mounted under center gravity improve tail control Fuel Tank Rear mount Ask fi #CNH $299~ Get. *Hitec Focus 4FM w/4 -300 A Hitec Frrjw 5 Hell Radin W/5-422 bearing servo Hitec Daul Rate Ball Tker 36 Hell Hlah Performace E ne C Integrated Fan Shroud moulded directly upper side frames eliminates shroud fitting adjusting standard parts mir g-in wire driven tan cisengages crash avoid damaging other components piece rotor tail grips tor solid control higher ievei curing flight fueling excellent aOsOrbtion & High strength during landings tuel standard parts Rigid Redesigned Rotor Rotor Head using stronger components Head increased rigidity Integrated Seesaw reduce parts imorovino durability Large Paddles Flebar ARF Fre
Edition: Model Aviation - 1997/03
Page Numbers: 86, 88
Edition: Model Aviation - 1997/03
Page Numbers: 86, 88
DB Mathews OXYMORONS Webster defines oxymoron combination contradictory incongruous words Some classic examples military intelligence sanitary landfill new antiques pet converted rice Modeling also seems have created its share contradictory phrases amusing aspect phenomenon tendency verbalize write much consideration often catch myself saying writing phrases rather embarrassing stop think about As example glow ignition engines doesnt hold up well analytical process Dont glow plugs ignite fuel/air mixture too reality mean glow spark dont leads pet oxymoron repeated conversations between modelers modeling press t-bottomed Clark Y airfoils Weve duplicated some computergenerated drawings courtesy George Sauer graphically demonstrate airfoil truly flat-bottomed certainly Clark Y Notice leading edge entry point flat-bottom section almost parallel trailing edge whereas Clark Y leading edge raised above trailing edge Beyond semantics misconception has some real significance modeling am assuredly no expert airfoils nor anything else matter experts have clearly established some very significant aerodynamic differences between Clark Y flat-bottomed airfoils April 1993 column went considerable detail concerning welldocumented testing experts confirmed rapid changes lifting characteristics flat-bottomed sections pitch attitude angle attack velocity varied Please read comments numerous serious scientific articles various magazines have strong interest subject now suffice say considerations significant explain flat-bottomed-airfoil trainers tendencies bob up down flown windy conditions other hand raised entry Clark Y narrows movement center lift fore-and-aft producing stable model easily trimmed feature exactly Clark Y has remained favorite Scale Free Flight fliers least 60 years Scale Free Flight designs whether rubber-powered gas must remain stable widely varied forward speed angle climb attack environment non technical cut-and-try designers have learned raised-entry airfoil produces stable model power-on power-off seem superior flat-bottomed types matter undercambered types lesser extent Clark Y frequently used Sport Free Flight RC designs utilize same desirable stability characteristics full-scale aviation Clark Y variations has popular selection light aircraft years Aeroncas Piper Cubs other designs gain much desirable low-speed handling lift characteristics type airfoil Im aware true flatbottomed sections used full-scale aircraft Conversely some very successful RC trainers use true flat-bottomed airfoils midpoint leading edge parallel trailing edge Some designs frequently also use positive incidence leading edge up horizontal stabilizer Ever wonder simply attempt dampen models tendency balloon flying widely varied upwind downwind conditions contrary everything Ive ever read heard pointed thin leading edge entry some trainers should work really have never clearly understood 86 Model Aviation PLAT BOTTOMED CLARK Nhj Ias s ISrAJO P2512515 ISI I5 I20125i30140150I601P180OI9Slk9I LAut4sse I4 *tB 1uMi- IS a o 0 0 0 0 n40 IA5I2515 l71 IS 120125130140150 f60 l 18090195 IftI L&t0i42t 3 c&6i9-411647j4450 LaoiiZf9iJ,6Ajto*RS4O*MD toLo8E% ZIPPER ISWRJO lhSI2d15 17iIft Its I20I25130 I40 I5D160 170 180 Iso i5I/00I LA IS 31 M U1 13 3 1 IJ 0 i3I 7603 rk successful very obvious fairness Ive used true flat-bottomed airfoils several published designs now really wish can excuse fact claiming ignorance designed years ago appeal true flat bottom lies construction ease can lay down TE capstrips spars sheeting leading edge flat before adding ribs However also possible construct Clark Y same manner exception adhering front sheeting until ribs added leading edge place easier wait until panel off board before adhering bottom front sheeting Parenthetically newer versions manufacturers trainers anothers newer scale high-wing design use Clark Y type airfoils surely says something rate model has airfoil flat fore-and-aft certainly Clark Y Another Oxymoron Weve also illustrated two other airfoil types NACA 6406 Goldbergs Zipper subjected oxymoron tend refer airfoil undercamber high lift again doesnt stand up well critical reflection low airspeeds airfoils lift Clark Y symmetrical type back full-scale airplanes took off 60 mph flew 60 mph topped out 60 mph landed 60 mph stalled 60 mph such airfoils NACA 6406 worked admirably However faster aircraft developed sections became real liability standpoints drag poor lift critical stability Youll find such airfoil modern heavy high-performance airplane simply because likely would never get off ground did aircraft would dangerously unstable Goldberg section classic example superb Free flight airfoil designed provide lots lift very slow forward speed gliding mode higher speeds such contemporary competition RC gliders fly section does provide much lift modern airfoils Such airfoils certainly provide high lift settings lift lot low airspeeds certainly high velocities So calling airfoils high lift really accurate undercambered likely much appropriate Lost Art researching piece dug out set airfoil sections drawn Paul Plecan 1943 Air Trails Annual Illustrated some airfoils popular use back seldom seen today simply because newer airfoils superior modeling use However does show Clark Y notes superior general model use just still 15 As custom years drawings include coordinates used enlarging sections involved stations measured front-to-back marked straight line measured factored points above below Once marked line drawn between points develop top bottom outlines took little skill hands of us used up large chunks time resulted woefully inaccurate sections advent copiers capable enlarging reducing drawings now computer-generated airfoil drawing programs seriously doubt anyone right mind would develop airfoil drawing using coordinates An art lostand good riddance Hopefully have found some amusement little diatribe about nonsense terms have some youve noticed modeling would share us Frankly want use oxymorons mentioned go right ahead hobby course English Comp No grade will givenexcept always should having fun uiie 1dI5 Convienent Top Cons Start Spring Disengagment Featuring Easy access motor No alignment required Extra Large Metal Clutch Smooth Fower Transmission High Efficiently Control system Front Servo Mounting Rotor Head Control Systems Simplifies Setup & Servo Linkages Reducing Flea Gyro mounted under center gravity improve tail control Fuel Tank Rear mount Ask fi #CNH $299~ Get. *Hitec Focus 4FM w/4 -300 A Hitec Frrjw 5 Hell Radin W/5-422 bearing servo Hitec Daul Rate Ball Tker 36 Hell Hlah Performace E ne C Integrated Fan Shroud moulded directly upper side frames eliminates shroud fitting adjusting standard parts mir g-in wire driven tan cisengages crash avoid damaging other components piece rotor tail grips tor solid control higher ievei curing flight fueling excellent aOsOrbtion & High strength during landings tuel standard parts Rigid Redesigned Rotor Rotor Head using stronger components Head increased rigidity Integrated Seesaw reduce parts imorovino durability Large Paddles Flebar ARF Fre
