Volume 16 No 1 Feb 1965.pdf - Lakes Gliding Club

dead into sun, and the haze made VISibilityvery bad. There were no goodlandmarks, so I flew a compass coursefor a while. A large lake appeared wherethere was none marked on the map, andfrom this I concluded that the compasshad an error of about 90°. This wasquickly confirmed by the position ofthe autobahn. Returning to track, I madecontact with a K-6 and a Kranich, butsoon left these behind. By the timeNienburg had been rounded, the lift wasgetting weaker, and when it finally diedaway I was at Grossburgweddel, still50 km. from Brunswick. There was nodifficulty in finding a suitable field. Therewere plenty of soft plol.lghed fields, oneof which produced a very satisfactoryretardation on touch-down. Peopleappeared from all directions, and threecars had stopped on the road by thefield before the Dart had stopped rolling."In due course the trailer arrivedbehind Bill Kronfeld's Cortina G.T.After thanking the multitude of helpers,we took our leave and returned toBrunswick, where we learnt that four outof eleven aircraft had completed thetask.With cloud base around the 6,000-ft.mark and good lift everywhere, it becamea routine custom to fine pilots acrate of beer each time they overflewtwo hours' duration. The same impositionwas applied to pilots who indulgedin mild undershoots and to pilots whoclimbed into the cockpit from the starboardside - this, we were told, was anold German custom! Until then wehad wondered why it had been decided10 change the canopy hinge position tothe port side on the Dart. Needless tosay, there was never a shortage of beerat the several very enjoyable barbecuesarranged by the German students.At the conclusion of this extremelypleasant and instructive OSTIV-IDAFLlEGflight test course, the Dart prototypehad been flown by over 20 foreignpilots and had amassed a total of nearly40 hours' flying in two weeks. It comparedfavourably in performance withGerman )5-metre machines and wasundoubtedly more refined in cockpitcomfort and control systems. The keeninterest it aroused has created a veryfavourable continental climate of opiniontowards the products of Slingsby SailplanesLtd.There were many contributors to thesuccess of our expedition. Thanks aredue to Slingsby Sailplanes for the loanof the Dart prototype, to Pye Telecommunicationsfor the loan of the Bantamand Cambridge radios,. which proved,invaluable during comparison flying, andto Imperial College Union for its readyassistance. Finally. we would like tothank our friends in Brunswick for theirsplendid hospitality.K"RL DOETSH, BILL KRONFELD.DES LAMPARD, JOHN BRIDGEW"URTHE OARMSTAOT 0-36By GERHARD WAIBEL AND WOLF LEMKETranslated and abridged from "Aerokurier"HE D-36 was intended to achieveT the maximum possible cross-countryspeed in weak lift. This requirement wasdecisive for the design layout. Greatattention was therefore given to goodperformance in circling in thermals. Thehigh strength of the fibreglass-reinforcedplastic allowed an aspect ratio of 24 witha wing-section thickness of 13 %, whichhas proved to be the ootimum for maximumperformance in drcHng flight. Thisapproach brought the advantage that,if the optimum wing-loading was overstepped,the cross-country speed was·relatively little reduced.It is difficult to maintain laminar flowover a fuselage with a Reynolds Numberof I.5 x 10 7 , yet its drag has a decisiveinfluence, so the blown plexiglass canopywas divided in two and the forward portionattached rigidly to the fuselage. Aswind-tunnel measurements by F. X.W.ortmann at Stuttgart showed the pitotfitting at the front end of the fuselage