Letters to the Editor

New 14 Available now two styles AMA members AMA contest directors shown 111/2 pennyweight size college ring size Top spells out Academy Model Aeronautics membership status sides have name AMA number stone fire blue spinel Send AMA yours today rnrnrn NAME ADDRESS Check MEMBERSHIP J Eli STERLING SILVER $13500C POLARA PLUS $15000C COLD INFORMATIONC RING SIZENAME TO APPEAR first lest nick-neme AMANUMBER CHECK ENC _____________ M/C VISA SEND TO AMA RINGS 815 15th Street NW Washington DC 20005 70-12 Weeks Delivery --Each Ring Custom Made Xetters theditr loners will carefully considered general interest used Send Model Aviation 815 15th St NW Washington DC 20005 Biggin Biggen have never written magazine before feel must write correct error Model viat ion October 1981 page 20 superb model electric Spitfire rather spoiled new way spelling Biggin Hill Biggen Hill As Englishman living family great country yours feel must point out error No hard feelings hope produce really first-rate magazine caters model fliers As ex-member SMAE current member AMA hope readers realize lucky sent such publication am yet member club US cant spare greenbacks yet hope fully involved shortly am too busy spending money engines kits radio accessories etc leave nearly gear back England Sorry critical Biggin Hill possibly famous Fighter Command airfield England feel must point out error Incidentally during Battle Britain Biggin Hill base two Hurricane squadrons Nos 32 79 Three Spitfire squadrons based nearby Hornchurch Nos 504 65 74 However Biggln Hill Spitfire inter changeable airfield still use private club flying once year plays host Biggin Hill Air Show few air shows England WW II war birds may seen stars show B-i 7E flying memorial men Mighty 8th gave lives skies over Europe T A Wilson Santee CA Thanks correction interest ing tidbit history Its surprising suppose first bring spelling error attention anotherformerEnglishman other Geoff Styles AMA s Flying Sites specialist Solar Challenger Fantastic fine article about Dr Mac Creadys electric full-size aircraft certainly appropriate model plane builders no longer have doubt concerning argued merits full wing ribs versus half ribs right beautiful photo Solar Challenger cover ModelAviation plain day Thanks excellent presentation very remarbale sun-powered aircraft Dr Cyrus J Stow Conyers GA Dihedral Effect August 1981 issue Ron Van Putte RC Sport/Aerobatics column gave two explana tions dihedral effect intent correct misconception However correction flawed Forces resulting moments what L Right Wing w govern motion model Weight acts directiondown cannot cause side slip Fig 3 lift forces wing panel oriented perpendicular panel see accompanying sketch seen left wing panel has horizontal component lift component causes model move right resulting right side-slip right side-slip has effect increasing lift right wing panel decreasing left wing lift results leveling wings side-slip sideslip noticed vertical tail resulting force left swinging tail left thus diminishing side-slip Bill Bogart San Pedro CA Ron Van Putte comments Unlike aero nautical engineers apparently Mr Bogart other people have impression side-slip skidding motion horizontal plane Actually defined motion perpen dicular aircraft plane symmetry Con sequently aircraft banked component ofthegravityforce isperpen dicularto theplane ofsymmetry causing side slip Mr Bogart correct about vertical fin diminishing side-slip velocity using direc tional stability aircraft Supermarine 55 Floats noticed plan view Supermarine S5 page 42 October Model Aviation fuselage plane centered tween floats other float planes What purpose could have served Chuck McNeal Golden CO posed question Don Berliner wrote article about Schneider Trophy Races right float outward left counteract effect powerful engine torque Two additional things right float slightly larger left floats carried fuel way have noticed small important error drawing prop rotation actually counter clockwise clockwise shown SAFE FLYING IS NO ACCIDENT 8 Model Aviation Name AMA Number Displayed Shank