FVA (Flugwissenschaftliche Vereinigung Aachen) FVA-1 Schwatze Duvel/FVA-2 Blaue Maus/FVA-3 Ente
Варианты:
FVA (Flugwissenschaftliche Vereinigung Aachen) - FVA-1 Schwatze Duvel/FVA-2 Blaue Maus/FVA-3 Ente - 1920 - Германия
Страна: Германия
Год: 1920
Планер

Описание:
M.Simons The World's Vintage Sailplanes 1908-45
Flight, September 1921
SOARING FLIGHT IN GERMANY
Flight, November 1922
THE KLEMPERER "ENTE"
Фотографии

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.

Flight, September 1921

SOARING FLIGHT IN GERMANY
The Rhon Competition

The Machines

   The Aachen monoplanes on which Klemperer did his excellent work are well shown in our photographs, and are similar to the machine which did so well in last year's competition. Some refinements have been incorporated, notably as regards the placing of the pilot. This year's models retain the "trousered" undercarriage which characterized the previous machine and the curved skids appear to have worked well. The problem of skids of suitable shape is less simple than one would imagine, and on this subject we may have something to say later. For the present we must confine ourselves to congratulating the Rhon competitors on their achievement and expressing the hope that next year even better results may be obtained.

Flight, November 1922

THE KLEMPERER "ENTE"
An Interesting German Glider Incorporating Many Novel Features

   MENTION has been made in our gliding notes from time to time of the tail-first machine or "Ente" (Duck) which Kerr Ingenieur Klemperer had produced for this years Rhon competitions. Unfortunately, the machine was finished late, and there had been no opportunity of making test flights with it when the competition opened. As the machine was of novel design, it is small wonder that a sufficiently thorough trial of it could not be made in time for it to take part in this year's Rhon meeting. Such flights as were made were purely in the nature of test flights, and revealed the fact that several alterations are still necessary before the machine can be considered tuned up. We believe that most of these were necessitated by wrong weight distribution. Before commencing a description of the machine, a drawing of which we reproduce by courtesy of Zeitschrift fur Flugtechnik und Motorluftschiffahrt, it may be of interest to quote some notes by Herr Klemperer in the same journal.
   "The problem of the 'Canard' type," Herr Klemperer writes, "cannot yet be said to have been solved. It is a question of building a 'Canard' type conforming to modern aerodynamical ideas, especially with regard to incorporating cantilever wings. Secondly, it was to be supposed that particularly for a glider, the front plane might under certain conditions be useful in acting as a 'wind vane.' [The word used by Herr Klemperer is Windfuhler.-ED., FLIGHT.] The tail-first machine offers favourable possibilities for carrying a passenger without this resulting in making the machine unsuitable for use as a single-seater. In this type the centre of gravity and centre of lift approximately coincide so that, as distinct from the tail-behind type, the e.g. and c.p. of the empty machine are close together. The crew can therefore be placed on the e.g. without the trim of the machine being altered. A further advantage is that the centre of gravity (and, therefore, the seats) does not fall inside the centre-section of the wing, but in front of it. The result is that the wing attachment is simplified, while 'straight-through' wing spars can be used. Finally, the 'Canard' type lends itself to experiments with Lachmann slotted wings, as it can be landed at a much greater angle of incidence than can the tail-behind type.
   "Thorough wind tunnel experiments carried out at Friedrichshafen and Gottingen have indicated the suitability of slotted wings on this type of machine, and the results of these tests will be published later. In the actual machine built, the slotted portion was confined to the ailerons, owing chiefly to the difficulty of providing a suitable arrangement for opening and closing the wing slots.
   "The tests on the machine carried out up to the present, ten in all, included a few short 'hops.' At first we had trouble with starting the machine. These were overcome by altering the skids, and after the end of the meeting the machine got off very easily. A wind of but 3 to 4 metres per second, and a very short run along the gentle slope running from the top of the 'Kuppe' towards the plantation near the camp was sufficient for getting off. The difficulties which were experienced with directional stability were considerably lessened when a rear rudder, connected up to the front swivelling plane, was fitted.
   "Although the 'Canard' type shows great longitudinal stability on tests of models, we found it very difficult on the elevator control. Even after the range of angles through which the front elevator could be moved had been increased, we found that longitudinal stability had not been attained. Evidently the large moment of inertia of this type of machine requires exceptionally large control surfaces. It is possible that difficulty may also be caused by the front plane, on taking off with the front at a considerable height above the ground, getting into a region of stronger wind which, at that low speed of the machine, may have considerable effect.
   "The slotted ailerons did not behave badly, even in cases of stalling, of which there were several during the tests As the machine, on account of its robust construction, suffered no serious damage during the tests, the experiments will be continued when the controls have been altered. The results will be published in due course."
   Regarding the machine itself, comparatively little information is available. The accompanying plan view gives a fair idea of the general arrangement. It will be seen that the main plane has a span of 39 ft. 5 ins., and a maximum chord of 5 ft. 11 ins. tapering to 4 ft. 2 1/2 ins. at the tip. The ailerons, which are of the slotted type, have a length of 9 ft. and an area of 13 sq. ft. each. The area of the main plane is 210 sq. ft. On the nose of the machine is placed the front elevator, which has an area of 42 sq. ft., the span being 17 ft. and the chord 2 ft. 9 ins. in the centre.
   An interesting feature of this front elevator is that it serves the double purpose of elevator and rudder. To this end it is mounted on a ball-and-socket joint, which allows it to pivot around a lateral axis and also to rock around a longitudinal axis. To reduce the force necessary to turn the plane around the latter axis, small ailerons are fitted near the tips. These ailerons are connected up with the controls which rock the plane in such a way that, when it is desired to tilt the plane to port, the starboard flap moves down and the port flap up. The controls in the cockpit are of normal type, so as not to present unduly great difficulties in mastering this unusual system.
Wolfgang Klemperer flying the Schwarze Teufel at the 1921 Rhoen competition on the Wasserkuppe, one of the few photographs taken of the machine in flight. The pilot sat on the front wing spar but on the Blaue Maus type the seat was set a little lower. The launch was made by rubber shock cord or ‘bungee’, a method invented by Klemperer. The bungee was a ‘V’ of strong rubber rope about 2.5 cm in diameter. A steel ring was tied to the apex and rope grips were provided at each end for the launching crew to hold as they ran down the slope. The ring fell clear as the sailplane flew over the crew's heads.
THE RHON SOARING COMPETITION: The Aachen Glider in Flight. This photograph gives a good idea of the nature of the country over which these gliding and soaring flights are being made.
THE RHON SOARING COMPETITION: Two views of the Aachen glider, which did so well in the turning competition. The attitude and indifference of the cattle indicate that the machine has no engine.
A Blaue Maus at the Ilford Hill meeting, organised by the Daily Mail newspaper in 1922. Three were built in Aachen to the Akaflieg design, one with an extended wingspan and improved performance. The prototype was wrecked by Klemperer himself when attempting a launch from a captive balloon in Switzerland. He was unable to pull out from the resulting spin before hitting the ground but still escaped injury.
MR. JEYES' AACHEN MONOPLANE: Inset, the machine in flight.
BRINGING HER BACK: Our photograph shows one way of bringing back a glider to the top of the hill after a flight. The wings are stacked on a German hay cart, the fuselage being trailed behind. The machine shown is the Aachen "Tail-first" monoplane on which Herr Klemperer crashed after getting into a spin when his glider was dropped from a kite balloon.
The FVA-1 Schwarze Teufel under construction in Aachen. The intricate workmanship and complex structure, with many lightening holes, is quite evident. The control column on its special universal pivot was in place but the rear fuselage and tail section had not yet been fitted.
Aachen
Schwarze Teufel
Aachen Monoplane 1921
THE KLEMPERER "DUCK": Plan view of the machine, with main dimensions, etc., shown.