Kalinin K-7
| Kalinin K-7 | |
|---|---|
|
|
| Type: | Bomb plane |
| Design country: | |
| Manufacturer: |
Kalinin |
| First flight: |
August 11, 1933 |
| Commissioning: |
- |
| Number of pieces: |
1 |
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The Soviet Kalinin K-7 ( Russian Калинин К-7 ) was a giant aircraft that was to be used as a super-heavy bomber or wide-body airliner.
development
It consisted of an elliptical wing up to 2.33 meters thick with a span of 53 meters, in which up to 120 passengers should find space. The undercarriage comprised two large gondolas, each with two oversized wheels and in which, in the military version, two gunner positions were integrated. The passengers should reach the interior of the aircraft via stairs in the landing gear struts. At the end of the double tail girders with a triangular cross-section, there were also shooting positions and the horizontal tail unit. The two braced vertical stabilizers were placed on top of this and connected to one another with an additional strut (“Stabiliron”), which had a variable angle of attack. The basic structure of the aircraft consisted of welded steel tube with predominantly fabric covering. Only the wing center section, the landing gear nacelles and the crew positions or pilot cabins were clad with Koltschug aluminum .
Konstantin Kalinin began planning work in 1930. When the prototype was ready, the first attempts at taxiing were to begin on June 29, 1933, but after the engines had started, strong vibrations occurred in various parts, especially the tail girders. After numerous structural reinforcements had been made to the airframe , the taxiing tests could begin on August 9th.
Two days later the machine took off on its maiden flight on August 11, 1933. Further shortcomings emerged during flight testing. The catastrophe occurred on November 21 of the same year when one of the two tail girders broke in flight due to the vibrations already recognized during a measurement flight and the aircraft then turned from a height of 100 meters into orbit flight after a sudden turn and hit the ground. 14 crew members, including Kalinin's long-time test pilot Mikhail Snegirev, and one passenger, fell victim to the crash and subsequent fire . Five people on board survived. Construction on two more K-7s with tail girders with a square cross-section began shortly afterwards, but the machines were never completed and the whole project was finally abandoned in 1935.
Technical specifications
| Parameter | Data |
|---|---|
| Conception | Bomb and airliner |
| constructor | Constantine Kalinin |
| Construction year | 1933 |
| crew | 11 |
| Passengers | 120 |
| length | 28.00 m |
| span | 53.00 m |
| Wing area | 454.0 m² |
| Wing extension | 6.2 |
| Wing loading | 83.7 kg / m² |
| Empty mass | 24,400 kg |
| Takeoff mass | 38,000 kg |
| Engines | seven liquid-cooled 12-cylinder V-engines M-34F |
| power | 610 kW (830 PS) takeoff power each 552 kW (750 PS) rated power |
| Power load | 8.90 kg / kW (6.54 kg / PS) |
| Top speed | 234 km / h |
| Cruising speed | 180 km / h |
| Service ceiling | 4000 m |
| Armament | six 7.62 mm MG SchKAS |
| Bomb load | 9000 kg |
gallery
Kalinin K-7 in flight
Kalinin K-7 with crew before a test flight
See also
literature
- Peter Korrell: TB-3 . The story of a bomber. 1st edition. Transpress, Berlin 1987, ISBN 3-344-00116-7 , pp. 175-177 .
- Wilfried Copenhagen , Jochen K. Beeck: The large aircraft type book . 1st edition. Motorbuch, Stuttgart 2005, ISBN 3-613-02522-1 , p. 465 and 734/735 .
- Peter All-Fernandez (ed.): Aircraft from A to Z . Consolidated PBY – Koolhoven FK 55th volume 2 . Bernard & Graefe, Koblenz 1988, ISBN 3-7637-5905-0 , p. 413 .
Web links
- Model building page about this aircraft
- More pictures and videos (Russian) (accessed October 1, 2015)