BB-22IS (I-29) (Yakovlev)
The first option in the family of the OKB-115 multi-purpose aircraft was a single-seat fighter with very strong armament, including two ShVAK cannons placed under the fuselage and three Shkas stationary machine guns of 7.62 mm caliber located one on the engines and in the pilot's cabin. For shooting the collimator sight of the PAC was provided. For high-altitude flights, an oxygen device was provided.
The aircraft provided for machine guns that fired through the hollow shaft of the gearbox. The fact is that the prerequisites for this were in place, because at the end of 1937 they began to develop the first domestic motor-cannon with the M-103 engine and the cylinder of the ShVAK cannon located in the collapse of its blocks. But due to a number of reasons that occurred in the spring of 1938, work in this direction was stopped. Then a double pursuit fighter was proposed, differing from the “22” aircraft with a smaller wing span of 13.5 meters. The armament was planned from one cannon in the forward fuselage and the ShKAS machine gun to protect the rear hemisphere.
In accordance with the plans of 1939, the third prototype of the aircraft No. 22 was to be the single escort fighter BB-22IS (I-29). But because of the employment of the design bureau and the production of the more important I-26 (Yak-1) fighter, the design of the I-29 began in accordance with the decree of the Defense Committee No. 429 of September 25, 1940, and with the M-105 engines. The construction of the car was planned for 1941. At the time of issuance of the government document, the 23-mm PTB-23 by Ya. G. Taubin and MN Baburin was considered the most promising cannon.
On this machine, very little documentary information was preserved and, judging by the available photos, one of the prototypes of the S-22 was altered into the fighter, with the M-103 engines, one-wheel main landing gear and the PTB-23 prototypes. Apparently, the first flight of the I-29 took place in this form at the end of December 1940, while other information about flights on it in the archives has not yet been discovered. Most likely, it was a demonstration model of a fighter.
The construction of the BB-22IS (I-29) with M-105 engines started in accordance with the Resolution of the Defense Committee No. 429cc dated November 5, 1940, while the requirement of the USSR Defense Committee of October 2, 1940 to increase the flight range of twin-engine fighters was taken into account tracking up to 2,000 km at a speed corresponding to 0.8 of its maximum value. Apparently, this circumstance forced OKB-115 to change the aircraft’s fuel system, increasing the fuel supply, and the cargo bay was the only reserve for this, which delayed its construction.
The first flight of the I-29 took place in September 1941, and on October 29, OKB-115 was evacuated to Novosibirsk, which could not but affect the timing of the tests of the I-29 and its fate. Preliminary tests showed that the maximum speed of the fighter did not exceed 570 km / h at an altitude of 5000 meters, and on the ground - 470 km / h with a landing 140 km / h. The range is 1850 km at a mode of 0.8 from the maximum speed at an altitude of 5000 meters, which was less than that established by the government in October 1940. The fighter gained 5000 meters in 7.5 minutes and climbed 10,000 meters. Its armament included two ShVAK cannons with an ammunition of 300 rounds per barrel and three ShKAS (1500 rounds per machine gun). Work on the aircraft lasted over a year and stopped only in 1942, when the production of Pe-3bis fighters was adjusted.
A comparison of the I-29 with the twin-engine fighter Bf.110C-3 shows the advantage of its altitude-speed characteristics and especially the flight range over the German. But the landing speed of the fighter Yakovlev was noticeably higher, which required large airfields. At the same time, the I-29 was slightly inferior in small arms and guns. Suffice to say that the I-29 second salvo with a smaller number of barrels was 3.43 kg versus 2.86 kg for the Messerschmitt. Thus, the I-29 had all the chances to successfully counter not only Bf.110C-3, but single-engine Bf. 109F.
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