K-12 (ВС-2) - experimental, tailless military aircraft - close-range bomber, reconnaissance and artillery spotter. Approaching the "flying wing" according to the scheme, the aircraft was of interest for creating a high-speed high-altitude rocket aircraft in the future.

The aircraft was designed in 1934, the first flight in the fall of 1936, flew P.M. Stefanovsky. Tests have shown low efficiency of vertical tail at low speeds, insufficient stability and controllability. The plane on Aviation Day, August 18, 1937, decorated in a bright red fairytale image of the "Firebird", was shown at the Tushino parade.

The impression of the car from the test specialists was as follows: "When creating this "tailless" aircraft, a number of problems were successfully resolved. ВС-12К in an incomplete form is dangerous. With the synchronous operation of the motors, the machine stably and reliably maintains all modes and is easily controlled in flight. The dimensions of the entire aircraft are too high. The fuselage is especially large, which also has poor aerodynamics. This negates all the advantages of the tailless scheme in obtaining high speeds. Production design is satisfactory. "

General conclusion: the VS-2 aircraft, even with the installation of modern engines and retractable landing gear, will not be better than the serial SB aircraft.

Decision: all work on the BC-2 aircraft should be immediately stopped as unpromising, and the released resources should be directed to the production of aircraft necessary for the Red Army Air Force and having a future.

In the fall of 1936, in connection with the outbreak of the war in Spain and the aggravation of the international situation, it was decided to stop all experimental work at plant No. 18 and urgently launch a new series of Ilyushin DB-3 long-range bomber . However, Kalinin, taking advantage of his position as chief designer, tried to continue work on his rejected aircraft and build a small series of VS-2. Because of this, the plan for the production of DB-3 was disrupted, and the engineering services of plant No. 18, which were subordinate to Kalinin, were disorganized. Based on the evidence collected and taking into account the severity of K.A. Kalinin was arrested, sentenced and shot in Voronezh on October 22, 1938.

Photo	Description
	Drawing K-12

Bomber First flight: 1936 Kalininн

In 1933, the HAZOSS design bureau received an assignment to design another combat vehicle - the K-13 bomber. The Soviet Air Force needed a long-range strike aircraft capable of carrying up to 1 ton of bomb load over a distance of up to 5,000 km at an altitude of 4,000 m at a speed of 350 km/h. The implementation of the project was entrusted to the design team under the leadership of P. V. Dybsky. In the same period, the Design Bureau of A. N. Tupolev - ANT-37 (DB-2) and S. V. Ilyushin-TsKB-26 (DB-3) worked on similar tasks.

For the new aircraft, a monoplane scheme with a mid-position cantilever wing was chosen. All-metal, trapezoidal in plan, the wing had two spars. The vertical plumage is two-keeled. Horizontal is missing. In fact, K-13 is a further development of the ideas embodied in K-12.

The aircraft had two liquid-cooled engines enclosed in NACA-type cowls. The landing gear was retracted into the same cowls after takeoff. The engines were powered from four tanks located in the wing.

Metal propellers with variable pitch in flight. To reduce the landing speed, the aircraft was equipped with Schrenk-type flaps with electric control. It was assumed that the crew of the aircraft would consist of three people - a pilot, a navigator-gunner and a rear gunner. Defensive armament: three ShKAS machine guns - two in front of the bomber and one in the aft gun turret.

According to calculations, the maximum speed of the K-13 was to be 407 km/h at an altitude of 4000 m. The landing speed was 90 km/h, which made it possible to use a relatively short runway, which is very important in a front-line situation.

In parallel with the combat version, a passenger one, the K-14, was also developed. Crew of two. The number of seats is 12. For short flights, it was planned to install additional seats. According to the calculations, the car had to develop up to 429 km / h, while the landing speed was only 84.5 km / h. In December 1934, the project was submitted to the Central Jury of the All-Union competition for a high-speed passenger aircraft.

The prototype K-13 was built in 1936 in Voronezh. At the very first tests, it showed that it was significantly inferior in its flight qualities to the DB-3 aircraft (partly due to less suitable engines), and it also turned out to be overweight. Interest in the car quickly faded.

• The history of designs of planes in USSR 1938-1950 /Vadim Shavrov/
• Aircraft of the country of the Soviets. 1917-1970 /Simakov B.L./