Breguet 941
| Breguet 941 | |
|---|---|
|
|
| Type: | STOL - transport aircraft |
| Design country: | |
| Manufacturer: | |
| First flight: |
May 21, 1958 - Breguet 940 |
| Commissioning: |
1967 |
| Number of pieces: |
1 + 5 |
The Breguet 941 was a French passenger and transport aircraft manufactured by Breguet . The all-metal shoulder decker had a retractable nose wheel landing gear and was powered by four propeller turbines. It had STOL properties, but no pressurized cabin . The nose landing gear consisted of twin tires , while the main landing gear had two individual wheels on the right and left. It was designed for use on unpaved slopes.
development
The machine is based on the Breguet 940, which had the same technical concept. The development began in 1948, when Louis Breguet had fundamental investigations carried out on the possibilities of short take-off and landing. These studies led to the development of the blown grand piano (“l'aile soufflée”). This fundamental development provided for a slotted landing flap that extended over large areas of the wing and was blown on by slow-running propellers during landing. The flaps can be moved up to 97 °, so that a substantial part of the drive power can be used to generate a downward air flow.
First, a 1:75 scale model was created to check the basic design. The model confirmed expectations. Then a powered model on a scale of 1: 6 was produced, which was extensively tested and optimized in the wind tunnel in Villacoublay .
The technical design makes the aircraft very sensitive to failures or asymmetries of the landing flaps or the drive. In the take-off and landing phase, a corresponding incident would trigger an uncontrollable roll moment. In order to keep the risk as low as possible, the flaps were driven centrally by just one actuator. The engines do not work directly on the propellers, but rather on a shaft running through the entire wing, which in turn drives the individual propellers, so that the failure of two engines on one side during the approach remains controllable. The inner propellers work clockwise and the outer ones counter-clockwise.
Executed machines
The wind tunnel tests showed very good results and were supported by the French government with 210 million francs. Production of the prototype of the Breguet 940, equipped with four Turboméca Turmo IIs , began in 1957 and took off on its maiden flight on May 21, 1958. The machine caused a sensation with its demonstrations in Le Bourget in 1959 , in which it managed with take-off and landing distances of 50 m, also at McDonnell Douglas and on February 23, 1960 a series prototype of the Breguet 941 was ordered by the French government.
The machine should be able to transport 48 passengers or a corresponding cargo. It was equipped with 882 kW Turboméca Turmo III D engines and took off on June 1, 1961 for its maiden flight. Contacts with McDonnell led to a contract on June 6, 1962, in which McDonnell became a cooperation partner of the Breguet 941 and a possible successor.
The machine was repainted after a series of spectacular flight demonstrations - partly in downtown Paris - and went to the USA as a McDonnell 188 for flight demonstrations. The transfer began on June 6, 1964 and with intermediate stops in Prestwick - Keflavík - Kangerlussuaq Airport (Søndre Strømfjord Airport) and Goose Bay were reached the USA on June 9.
Demonstrations to US military officials began on June 12 at Andrews Air Force Base near Washington DC and from June 15 to July 6 at Eglin Air Force Base .
A 32-day test program was carried out at Wright-Patterson Air Force Base for further evaluation . During the last flight, the aircraft crashed from a height of about 10 m after grossly incorrect operation and was badly damaged. Due to the circumstances, a plot was suspected to keep the machine for a closer examination of the technology in the USA.
After eight months of repairs and further demonstrations, the machine returned to France on April 16, 1965. In November of the same year, a general overhaul was carried out and more powerful Turboméca Turmo III D 3 (1102 kW) was installed. A government order was placed for four improved machines, which were lengthened by 1.52 m and were given the designation Breguet 941 S. The first machine of this variant started on April 16, 1967.
The second machine of the 941 S was sent again to the USA after Eastern Air Lines and American Airlines expressed interest. The machine arrived in the United States on July 31, 1968. Eastern subjected the prototype to a three-month practical test, which from the technical side went without any problems. The FAA was also investigating. During an attempt on November 19, 1968, a wheel brake was applied so strongly on one side that the machine broke out and tilted, a propeller hit the ground and a blade broke off, penetrated the fuselage and injured a crew member. The repair took another four months.
Whereabouts
However, all these efforts did not lead to an economic success of the machine. Their performance data in slow flight were so outstanding that new airfields would have had to be created to use them. As long as these seats were not available and the 941 would have had to operate from normal airports, its complex technology would have been too expensive to procure and maintain.
The last remaining machine of this type was shut down in 1974 and is now on display in Le Bourget .
variants
- Breguet 940
- Experimental concept demonstrator, 1 piece
- Breguet 941
- Prototype, 1 piece
- Breguet 941S
- Extended version for the French Air Force , 4 pieces
Technical specifications
| Parameter | Data |
|---|---|
| crew | 2 |
| Passengers | 57 civilian passengers 40 soldiers including equipment 24 stretchers |
| length | 23.75 m |
| span | 23.40 m |
| height | 9.65 m |
| Wing area | 83.8 m² |
| Empty mass | 13,460 kg |
| Max. Takeoff mass | 26,500 kg |
| Cruising speed | 400 km / h |
| Top speed | 450 km / h |
| Service ceiling | 9,500 m |
| Range | 1,000 km |
| Engines | 4 × Turbomeca Turmo IIID3 turboprop engines with 1,119 kW each |
Web links
Individual evidence
- ↑ David Donald (Ed.): The Encyclopedia of World Aircraft . Aerospace Publishing, 1997, ISBN 1-85605-375-X .