Dornier Do 31
The Dornier Do 31 was a German VTOL transport aircraft.
History
1959 began preparatory work first, and in February 1962 the aircraft manufacturer Dornier got the job, the Do 31 as a struggle zone transport the 25- ton class to transport 36 fully equipped troops to develop for the Air Force of the Federal Republic of Germany. The development program was limited in the first phase of the construction of two floating racks, two flyable prototypes and a IronBirds to test the systems. In the second phase, the Do- 31 should have been developed for mass production. At the end of the first phase of the program was not pursued further. It was discontinued prematurely from many experts view as the military requirements of NATO had changed. The whole do- 31 program cost just over DM 200 million, of which 40 % mainly attributable to UK firms for the development of the engines. The main and cruise engine Pegasus 5-2 was developed by Bristol - Siddeley (later Rolls- Royce ) was developed and used in the British Harrier VTOL aircraft.
The technically challenging development and testing program was provided by a strikingly small development and test team.
Were built three prototypes (SG, E -1, E -3); should fly but only the E-1 and E-3. The SG ( levitation chassis ) was only intended for testing on the ground. The prototype had E-1 (D - 9530 ) made its first flight on 10 February 1967. The second prototype, the E-3 (D - 9531 ) led on 14 July 1967 its (conventional) first flight and lifted on 22 September 1967 for the first vertical take off. On December 16, 1967, the first transition from vertical was performed for horizontal flight.
In 1969, the E-3 from Oberpfaffenhofen near Munich, was transferred to Paris for the Air Show, while five new world records were set for vertical takeoff aircraft; among other things for the hitherto highest speed of 514 km / h flown by pilot Drury W. Wood and co-pilot Dieter Thomas. On May 5, 1970 Thu, 31 flew for the last time in public at the International Aviation and Aerospace Exhibition in Hanover, although the project was stopped in October 1969.
After 154 test flights and a total of 39 flight hours, the E-3 was shut down and stood very long time before the main entrance to the museum island of the Deutsches Museum in Munich. After the completion of the flight Schleißheim In 1996 she was transported there, restored and can be visited there today.
The E- 1 was also shut down in 1970 after 101 test flights and a total of 59 flight hours, stored and transported from Oberpfaffenhofen to Friedrichshafen in April 2009. There, they will be issued in the new Dornier Museum since July 2009.
Vertical takeoff and level flight
The vertical take-off by means of eight Hubtriebwerken and the two march engines that are equipped with swiveling thrusters. In addition, a steering on the rear that can blow out upward and downward, available. In level flight, the two cruise engines are used.
To use the fuselage for transport purposes, the lift engines ( Rolls- Royce RB 162) are housed in the characteristic gondolas on the wing tips, four each on each side. These gondolas are removable in order to possibly assemble in their place additional container can.
Flight testing
The development and flight testing of the Do 31 was gradually carried out with four different test vehicles:
- A control experiment frame ( RVG ) for creating the specification for the flight controller and control kinematics. This tube grille frame with four Hubtriebwerken trials led by a column bound and in free hover.
- A large floating structure ( SG) for the testing of onboard systems, to study the control properties in hover and for developing appropriate methods for vertical take-off and vertical landing. Except for the hull, which was designed as a tube grid structure and no tail possessed, cockpit, wings, engines and Hubgondeln were already trained original. The fuselage was provided in the area of the wings with segments to test the effect of soil back exhaust steered beams with respect to heat and vibration.
- An experimental aircraft ( Thu, 31 E1) for conventional flight testing, ie runway start, runway landing and horizontal flights. This aircraft had no lift engines in the nacelles.
- An experimental aircraft ( Thu, 31 E3 ) for the vertical take-off testing.
In addition a airframe for structural tests at IABG in Ottobrunn, a system test bench (Iron Bird) in Immenstaad for on-board systems and soil erosion test rig for the investigation of the stability of natural and artificial soils were (landing and take-off places) built under the impingement of engine exhaust jet. In the erosion test rig was a on a low loader height adjustable mounted engine. Attempts were carried out on different floors, and airfields.
Since at least the two e- aircraft were equipped with ejection seats for the pilots, even penetration tests were carried out with a Martin -Baker ejection seat.
The entire flight program was completed without accident. This is remarkable, since it partly been serious accidents resulting in death in other international vertical take-off projects.
Milestones
- April 1964: First free flight of the RVG
- January 11, 1967: First free flight of the SG
- February 10, 1967: First flight of the conventional E1
- July 14, 1967: First flight of the E3
- February 28, 1968: First round of VTOL space E3 with complete takeoff and landing Transition
The program was technologically a great success and showed the full power of the revived after the war Dornier works. To a series it did not come, as the German Army changed the procurement planning and had taken the VTOL transport aircraft thoughts at parting. It was as late as 1970 a " tailing of " at NASA before the program was finally stopped. NASA and the astronaut Neil Armstrong rated the Do- 31 as "convincing positive." On 31 October 1969, the contract between Dornier and the Federal Office of Defense Technology and Procurement ran out.
Specifications
Trivia
When the Dornier Do 24 ATT was developed landing gear control cylinders were urgently needed - they were expensive and time- saving taken from the standing at the Deutsches Museum Thu, 31 E3. To fly at least these two parts of the Do 31 still in the truest sense of the word around the world.
In order to solve the mathematical problems of the very complex VSTOL designs, Dornier developed its own hybrid computers such as the Dornier DO- 960th