M.Simons The World's Vintage Sailplanes 1908-45

THE SCHWARZE TEUFEL AND BLAUE MAUS

  One night in the late autumn of 1920 a goods train with at least one wagon load of illegal cargo left the ancient city of Aachen, close to the Dutch and Belgian frontier of Germany, headed for the equally old but smaller town of Fulda, north east of Frankfurt am Main. Parts of Germany were still occupied by the Allied armies of 1918. Transport of any sort of aircraft through the occupied zones into unoccupied Germany was forbidden. Aachen itself was in the Belgian zone, the British were based on Cologne, whilst the French and Americans held areas to the south. As the train steamed ponderously through the darkness it was subjected to inspection several times by the occupation troops. On board, carefully covered by tarpaulins, guarded and protected by a young student, was the FVA-1, a glider built by the Flugwissenschaftlichen Vereinigung Aachen, the student flying group of the Aachen Technical University. In case any of the troops should take too close an interest, the student carried a box of good cigars with which he hoped to buy them off. Fortunately he never needed to put this notion to the test. The train lumbered on, the tarpaulins undisturbed.
  The FVA had built their first flying machine during a frantic period of four months of day and night labor, following the announcement of the first Rhoen gliding contest to be held on the Wasserkuppe. Erich Meyer and Wolfgang Klemperer, the originators, wrote an announcement calling all those interested to the meeting and Oskar Ursinus published it with editorial support in his magazine, Flugsport. Ursinus volunteered to organise the contest and was its director. The contest began in July when the glider was only half completed. The design was by Klemperer himself and the student team was led by Paul Stock. Klemperer, born in Saxony, had been a lieutenant in the Austrian Flying Corps. He had recently taken up a post as assistant to the Professor of Mechanics at Aachen, Theodor von Karman, and in him found another enthusiast and staunch supporter. Von Karman and Klemperer were both convinced that the future of flight lay with the cantilever monoplane. The FVA-1 had a thick cantilever wing with three stiff wooden spars of 'I' cross-section. The central one alone was strong enough to carry five times the normal load but weighed only 7.5 kg for a span of 9.2 metres. The three spars were cross-braced one to another against torsion and light ribs with plywood webs formed the aerofoil section to the Junkers pattern, changing progressively toward the tips. The leading edge was covered with cardboard, the rear section with fabric, and the trailing edge was a length of stiff steel wire. The ailerons were hinged to a light auxiliary diagonal spar. Muslin was used for the covering. Its black color inspired the name, Schwarze Teufel (Black Devil), after a legendary wolf that was said to have manifested itself in Aachen during the time of Charlemagne. The complete wing weighed 24 kg for an area of 15 square metres.
  The front fuselage and the undercarriage were built directly onto the wing. The twin ash skids were carried on streamlined ‘spats’. The cockpit was located between the front and main spars, the seat on top of the front spar. The control column was supported in front of this spar, pivoted on a specially built universal joint, with wires running to the ailerons and the elevators. The streamlined form of the fuselage was provided by bamboo hoops and stringers. A normal rudder bar was fitted. The rear section of the fuselage with tail unit complete. was detachable for transport. The rudder was aluminium framed but fabric covered.
  After various adventures the glider reached the summit of the Wasserkuppe. The meeting was nearly over and was on the point of breaking up in a general state of gloom. Little had been achieved and one man had been killed. The Schwarze Teufel, however, restored confidence. It had been designed by experienced engineers who were up-to-date with all the latest research and well informed as to the general development of aircraft during the war years. Enough money and time had been put into it to render it truly airworthy.
  The Aachen team used, for the first time, a rubber rope or ’bungey' instead of relying on a running start or being towed off by hempen ropes, for launching. This was Klemperer’s idea. The method was a great success and remained for ten years afterward almost the only known way of getting a glider into the air. Klemperer made his first hop on 4th September and broke one of the skids on landing. This was soon righted and on his third flight he covered 1.83 kilometres and flew for two-and-a-half minutes, easily the best flight of the entire meeting.
  No-one was sure, at this time, if there would ever be another gliding contest. Probably the one good flight made by Klemperer was what turned the scales, bringing everyone, and more, back to the Wasserkuppe in 1921. The second meeting was attended by some great men. Von Karman, Prandtl, Handley Page, Anthony Fokker and others whose names were greatly respected in the world of aviation. Klemperer and the Aachen students arrived earlier this time, with a new glider, the FVA-2 Blaue Maus (Blue Mouse). The name had nothing to do with the aircraft’s color, which was white. It came from a famous warplane, one of the Rumpler two-seaters, which had been given that nickname by its pilots and crews. The FVA-2 was very similar to the Schwarze Teufel. The cockpit was moved forward a little so the pilot’s seat could be dropped lower in front of the spars, so that he would present less drag in flight by being more enclosed in the fuselage. Detailed improvements to the structure resulted in lower weight.
  During August the Schwarze Teufel was flown by students and by Klemperer himself, but did not exceed its best flight of the previous year. On one flight the undercarriage was badly broken and the Schwarze Teufel was retired from further use. Klemperer with the Blaue Maus quickly improved his previous record and even essayed a 360 degree turn, out over the slopes. On 30th August, he set off to glide down to Gersfeld, a long way off, it seemed, down in the valley. He tried to extend his flight by using the upward wind blowing over the slopes, and for a short time he did maintain height before heading off into the vale. He landed close to his target 4.6 km away after flying for 13 minutes 3 seconds. This has been described as the first true distance flight by a glider. As a world record, however, it lasted only one week.

  Technical data:
   FVA-1: Schwarze Teufel: Span, 9.30 m. Wing area, 15.0 sq m. Aspect ratio, 5.76. Empty weight. 61 kg. Flying weight, 136 kg. Wing loading, 9.07 kg/sq m.
   FVA-2 Blaue Maus: Span, 9.70 m. Wing area, 15.50 sq m. Aspect ratio 6.0. Empty weight, 53 kg. Flying weight, 128 kg. Wing loading 8.26 kg/sq m.