Pashin I-21
| Pashin I-21 | |
|---|---|
| Type: | Fighter plane |
| Design country: | |
| Manufacturer: | |
| First flight: |
July 11, 1940 |
| Commissioning: |
only prototype |
| Number of pieces: |
3 |
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Pashin I-21 ( Russian Пашинин И-21 ) is a Soviet fighter aircraft of the late 1930s. It was the ultimately unsuccessful attempt to replace the outdated Polikarpow I-16 .
The Paschinin I-21 was created in the course of the modernization program of the Soviet air force in 1938/1939, but did not reach series production . The abbreviation "I" stands for Istrebitel (Истребитель), the Russian word for fighter plane. The aircraft was developed in the OKB -21 of the aircraft factory in Gorky (now Nizhny Novgorod ). However, the designation I-21 does not come from the number in OKB-21, since the numbers of the Soviet fighter projects were assigned consecutively (I-1, I-2, I-3, etc.). Initially, the project also had the letter "P" for the designer Paschin ( IP-21 ).
development
The designer Mikhail Pashinin ( Russian Михаил Михайлович Пашинин ) designed the I-21 as a cantilevered low- wing aircraft made of wood with a slightly swept wing outer edge. The pilot's cabin was set relatively far back. The type was to have a V-engine M-107 with 1,210 kW and thus reach a speed of 680 km / h at an altitude of 7,000 m. However, due to the lack of availability, a weaker M-105P had to be used. During the construction, Paschinin attached importance to a clean aerodynamic design with a simple production method at the same time.
The I-21 represented a fundamental modernization of the outdated Polikarpow I-16 by installing the water-cooled aircraft engine M-105. Therefore 60–70% of the components of the I-16 could be used for the I-21. Paschinin used a symmetrical moment-free profile for the wing tips ( NACA-0012-0009 ; NACA-0012 on the wing root and NACA-0009 on the wing tip). With this profile, the wings could withstand speeds of up to 950 km / h during a dive (dive combat aircraft ). At the time of the development of this aircraft, the then new requirement was made to achieve high speed when diving and not to conduct aerial combat on spiral trajectories.
The first flight of the I-21 took place on July 11, 1940 with the test pilot P. U. Fokin. In the same month, flight tests began with test pilot Pjotr Stefanowski . On August 18, 1940, the aircraft was demonstrated at the air parade of the Soviet armed forces in Tushino and then handed over for state testing, which was completed in December 1940. The inadequate stability and very high landing speed were criticized. In the second prototype that was subsequently tested and completed in October 1940, the stability deficiencies could be remedied. In January 1941, a third prototype with a reduced wing span was built, which flew for the first time on April 5, 1941.
Ultimately, however, it was decided not to build the I-21 in series, as the relatively high landing speed of 165 km / h and the resulting long runways would at least have made it difficult to use it in front-line conditions. At the time of the German Reich's invasion of the Soviet Union , a pilot series of five aircraft was under construction, but was not completed due to the evacuation of the plant to the east of the country. Instead, the parallel designs Jak-1 and LaGG-1 / LaGG-3 had already gone into mass production.
Technical specifications
| Parameter | Data (2nd prototype) | Data (3rd prototype) |
|---|---|---|
| crew | 1 | |
| span | 11.00 m | 9.43 m |
| length | 9.00 m | 8.73 m |
| Wing area | 15.80 m² | ? |
| Empty mass | ? | ? |
| Takeoff mass | 2,670 kg | ? |
| drive | a liquid-cooled 12-cylinder V-engine Klimow M-105P | |
| power | 770 kW (approx. 1,050 PS) | |
| Top speed | 488 km / h near the ground 573 km / h at 5,000 m |
506 km / h near the ground 580 km / h at 4,750 m |
| Summit height | 10,600 m | ? |
| Range | ? (2 h flight time) | ? |
| Armament | a 23 mm BT-23 cannon in the propeller shaft and two 7.62 mm MG SchKAS above the engine |
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