17LE COPI j_NO. -W I C A S E F I L E COpy TECHNICAL MEMORANDUMS NATIONAL ADVISORY C0MLITTEE FOR AERONAUTICS No. 623 ELEVENTH RHN SOAPJTG-FLIGHT CONTEST, 1930 B:i Walter Georgii Zeitschrift fr Plugteciinik und. Lotor1uftschiffahrt Vol. 2J, No. 5, March 14, 1931 Verlag von B. Old.enbourg, M!nchen unci Berlin Tashint on Juno, 1931 NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS TECHNICAL MEMORANDUM NO. 623 ELEVENTH RH8N SOARING-FLIGHT CONTEST, 1930* By Walter C.eorgii In 1930 the general conditions considerably increased, the difficulty of a successful cnduct of the contest. The economic situation made it very hard for the various soaring-flight clubs to obtain the requisite funds for participation in the contest. It was also difficult for those in charge to collect sufficient money for the expenses of management. Despite the general eco- nomic depression and the bad. weatb.er (it being possible to fly on only ten of the sixteen contest days, while rain and. clouds prevailed on the remaining days) , the success of the contest was unquestionably great. Progress was manifest not only in the fact that, despite the much less favorable flight conditions, the performances of the previous year were coasiderably excelled, but also by the general improvement in the maximum performances. There were not only outstanding performances by the best pilots., but these met with more competition and were pushed to still greeter performances during the progress of the contest, espe- cially in the endurance flights. With distance flights of over 100 km '(62 miles), Kronfeld is still ahead, but more interest was aroused in this most difficult of all soraing-flight con- tests by the fine performances of a number of younger contes- tants. It is especially gratifying that systematic soaring flight was successfully accomplished this year by the youngest c on t e st ant. The conditions for the eleventh soaring-flight contest were essentially the same as for previous contests. The contestants were divided into three classes: primary, practice and perform- ance. The conditions for the primary class were generally of only a formal nature. Prizes were offered for soaring flights to be made between May 15 and August 17, 1930, at the home fields of- the primary gliding clubs. There were many of these local contests, -the most important ones being the Borkenberg contest in Westphalia, the West Group of the D.L.V. (Deutscher Luftfahrt Verband), the second Bavarian oraing-flight contest at Hesselberg south of nsbach and. the gliding and soaring- flight contest of the Wurttemberg Aero Club. At Hesselberg *"Bericht .ber den 11. Rhn_Sege1flug_Wettbewerb, h1 a pape read before the W.G.L I , November 14, 1930. From Zeitschrift fur Plug- technik und Mttorluftschiff.hrt, March 14, 1931, pp. 129-140. Verlag von R. Oldenbourg, Munchen und Berlin. 2 N.A.C.AO Technical Memorandum No. 623 soaring flights of long duration wore made. The local contests doubtless contribute much to'maintiningthe interest in soar- in flight and. thus constitute an imortant auxiliary of the Rhon contest. M 0 reover, the preliminary primary contest at the Vasserkuppe afforded the clubs ôonsiderable technical instruc- tion: aside from the practical training. The mere fact of the primary contest and the Performance contest being held contempo- raneously awoh.in the primary contestants the desire for soar- ing flight and afforded them the opportunity to obtain technical information regarding the conetructi on of high-performance gliders or soaring planes 0 The anibition of the primary'gliders to learn soaring flight through gliding flight should be encour- aged, 'in order to insure the continued development of unpowered flight • The main province of gliding flight should be to af- ford preliminary training for soaring flight. Gliding flight is an excellent means to awaken interest in flying and to inculcate the first conceptions of an airplane and of flight. It can, how- ever, satisfy only the beginner and lOSes its fascination for an advanced flier, unless followed by soaring flight. Just this necessary transition from gliding'to soaring flight is promoted by the preliminary Rhon gliding.contosts by giving the contes tants the incentive to soaring flight and awakening in them the desire to build soaring planes. Ii this gathering of all1the clubs and. individuals devoted. to unpowered. flIght, the Rhon contest is not only a sporting event, but an annual convention of the air-minded. German youth, from' which the unanimity of sportivo thought, technical activity and aeronautic information, so characteristic of the German soaring-flight movement, can develop. To this unanimity is largely due the unexampled. ascen- dancy of Germaii soaring flight. It'might be to the interest of German progress in soaring flight to consider from time to time this process of'developmnent and the p roblems arising from it, The proclamation of the practice and. performance contests in 1;general increased the minimum requirements for the Eleventh Rhon Soaring-Flight CRntest. An innovation for the practice contest was the closed-circuit flight, 'in which the aircraft must fly at ast 5 km (3.1 miles) from the asserkuppe and re- turn to the starting point without any intermediate landing. The chief results of the p ractice contest are given in Table I. Before l928'little attention was given to endurance flights in the Rh8n mountains. After the wind ascending the west slope of the WassorkuDpo had been utilized. 'to the best advantage dur- ing the p revious years, no further important results were to be expected., aside from the thrill of surpassing p revious perforth- ances and the practice flights of young aviators. The year 1928 brought a revival of endurance flying on the slopes 0±' the Was- serkuppe. In that• year endurance flying assumed greater impor- tance through the utilization of up-currents under clouds 'in N.AIC.AO Technical Memorandum No. 623 3 addition to the winds up the mountain slopes. This added a greater charn to endurance flights and was, of griat training value, beca.se the pilot had. to accustom hiiseif ic the difficult conditions of cloud flight. M 0 reover, the scientific value of endurance flights was greatly enhanced by' combination with cloud flying, because it often. afforded an opportunity to study the upward u:'rents in the vicinity of clouds T1')is year's endur- ance fligits afforded exceptionally valuable data in this re- spec Under th•se circumstances it. i especially gratifying that the interest, of the pilots in endurance flying has consid- erably increased duriig the last three Rlibn contests 0 In connec- tiofl'L with the results of the 1930 endurance flights, as given in Table I, it is interesting to note the unusual physical and psychical demands on a pil'ot participating at intervals in the contests, sometimes on two successive days, unprotected from the cold,, his every motion restricted in the small fuselage, usually pith an empty stomach, .for six to eight hours in contin- uous flight over the western slope of the Wasserkuppe, In 1929 only, two flights of. over five hours were made In 1930 there were twelve flights of over five hours, seven of which exceeded seven hours the ioiigest flight of all (8 hr 0 36 mm 0 ) being made by Van 1-lusen of,the Gottingen Academic Aero Club on the ' t Jupp Pitter1 This was anhou.r short of the Rhn endurance record of 9 hr. 36 mm. made by Hemmei inthe summer of 1930,' but surpassed the best record. of 'the 1929 Rhn contest 0 The considerable improve- ment in the .result,s of th practice contest over previous years did not consist, however, in the single peak performance, but in the larger number o,f excellent performances0 Starck, of the Darmstadt Academic. Aero Club, made three flights exàeeding five hours each over,the west slope of 'the Wasserkuppe, and won the hard-contested Swabian'prize for hic liib Patz, of the Aachen Scientific Aer.o Club ? who pilotoci. tht4 tRhe,nland,U had to yield the enduranôe record bya small margii to the Darmstadt, U al- though:he had two flight Of over 705 hours to his credit. In 1929 there' were', 'for the first time, eleven gliders soaring simultaneously over the west slope of the Wasserkuppe. In 1930. the number was increased to fourteen, or nearly half of all the gliders.par,tciating in the contest. Of the seventeen gliders taking the air on that day, only one met with an acci- dent. This formed' quite .a contrast with the previous year, when under similar conditions, five gliders, out of six which took off, fell •victims ' to' the' weather conditions. This comparison well illustrátes the progress which has been made in so.ring flight. , The expectation that endifl'ance flying would enable the at-" tainment of higier altitudes, has also been fulfilled. Cloud flying has made it possible to reach altitudes of several thous- and meters. Test flights with powered airplanes in the vicinity 4 N.i.C.A'. Technical Memorandum No. 623 of cumulus clouds have shown t.at the upward currents in and above the clouds sometimes reach altitudes of 4000 to 5000 in (13123 to 16404 ft.). In the 1930 contest the high altitudo of the p revious year, 2160 in (7087 ft.) by Kronfeld, was not reached 0 The weather conditions of the 1930 contest made the at-. tainment' of high altitudes very difficult ., the possibility of cloud flights being limited to the last day of the cntost 0 The brief duraionof the vertical cloud currents was skLIfully util- ized, howe7er, by several pi1ot. The highest aititu.cles were reached by Bodauon "Luftikus with 1640 m (5380 ft, Starck on "Darmstadt" with 790 in (2592 ft.) and Hemmer on "Schloss Main- berg° with 620 m (2034 ft 0 ).