Kalinin K-12

In accordance with the new military doctrine providing for the modernization of the air forces of the Red Army, by February 1931 the Air Force Research Institute developed tactical and technical requirements for a promising multi-purpose "military" aircraft. The design and construction of the machine under the VS-2 index was commissioned by the Kharkov pilot plant (HAZOSS), which was headed by Kalinin.

When solving such complex engineering tasks, KB employees showed themselves to be technically mature specialists. In April 1933, the first draft design ready future aircraft in three embodiments which had been developed by three different engine: M-22, M-49 and M-52. The last version of the aircraft according to the scheme was approaching the tailless. But because of the pronounced horizontal tail, which is located close to the fuselage, it was called the short-tailed.

After consideration by the Air Force Research Institute of VS-2/BC-2 project was not accepted due to a lack of full submission and increased (compared to the technical specification) of the aircraft load. IT was agreed with the Air Force headquarters only the scheme of the aircraft - the "flying wing." In its future Kalinin confidently believed and believed that "an aircraft without a tail has many advantages over a conventional aircraft. In military applications, it is especially valuable for its maneuverability and the ability to fire protection"

CDB believed that the aircraft of such a design was purely experimental, and therefore it is inexpedient to build a large tonnage aircraft (4-5 tons) at once. It is necessary to carry out testing in the wind tunnel, and in case of favorable results, to build a plane with a motor in 75-100 hp. for an experimental test.

In September 1933, HAZOSS presented the second draft design of the K-12 aircraft (VS-2). In the reports of the Air Force Research Institute, the following is recorded: "The design of the Kalinin airplane is a freely bearing twin-engine monoplane with a horizontal tail plane close to the wing and is a" flying wing "type.

Motors were located on the sides of the fuselage in the leading edge of the wing. The motor cokes are stretched across the entire wing and in the rear part they grasp the truss with two crutches, on top of which there are posts that serve as a fastener and the axis of rotation of the keels. The middle part of the engine cowling was used as a fairing for the retractable landing gear.

According to the tactical and technical requirements, the caliber of bombs is 8, 10, 15, 50, 82, 100 kg. Bombs of caliber 8,10 and 15 kg should be taken based on the total weight of 300 kg of bombs, and the bombs of caliber 50, 82 and 100 kg - for a total weight of 500 kg. Loading was made on the beams KD-1 or KD-2, which could be installed simultaneously. Thus, the meaning of the use of 8-kg bombs is eliminated, since they are taken as much as 10-kg bombs and within the same limits of bomb load. On the part of the chief engineer for armament of the Central Design Bureau, the assessment was positive.

It is clear from the comparison that the VS-2 M-22 significantly exceeded the R-5 and stood on par with the I-5. Considering that at the time of introduction of the M-22 aircraft into the series of aircraft, the I-5 fighter will already be replaced by a fighter I-14 or I-15, experts noted that even then the VS-2 will be in better proportion with I-14, than now R-5 with I-5. This spoke in favor of the aircraft VS-2, flight data of which in the project significantly increased against the specified tactical and technical requirements - thanks to the installation of the M-22 engines in place of the M-52.

Another conclusion, made in the report of October 29, 1933: "The design of the aircraft VS-2 is a mix of many little-studied innovations: for example, an anuran wing, wing ailerons, valves, side washers located above the wing ailerons, slats are extreme, automatic internal and controllable. Without experimental data on the work of these innovations individually, It is impossible to judge their work in the aggregate."

In the final document, signed by TsAGI Central Design Bureau chief S.N.Ilyushin, it says: "The outlined design of the aircraft VS-2 with engine M-22, presented by the designer Kalinin, is approved, except for the arrangement of tail surfaces and ailerons.As a result of the review of the project, I state that the" flying wing "scheme is the most expedient as providing the best overview and firing."

It was not until early 1936 that the experimental workshop started assembling the real aircraft. In July 1936 the K-12 was rolled out onto the airfield, and the pilot Borisov first lifted it into the sky. The flights under the factory testing program were also conducted by Borisov. The airplane painted for the fairy-tale "Firebird" was presented to the public at a parade in honor of the holiday of the Air Force of the USSR on August 18, 1937. At this time, the K-12 passed state tests at the Air Force Research Institute.

At the conclusion of the test report at the Air Force Research Institute, signed by Filin and Markov, the following is said: "The aircraft VS-2 2M-22 (K-12) is of unconditional interest, since with its construction for the first time the issue of creation of a" flying wing "in the armed version is solved.The VS-2 concept has tactical advantages in comparison with the normal scheme of a tail aircraft - for review, shooting, as well as a small takeoff and low landing speed. However, in the presented form, aircraft VS-2 has low flight performance and unmanned armament, can not be recognized as a modern combat aircraft, and is considered only as an experimental one."

"Firebird", demonstrated at the parade in Tushino, remained the only car built "K-12". Aircraft designer Konstantin Alekseevich Kalinin was purged in 1938. The leadership of the aviation industry decided to stop the serial construction of "military aircraft", already begun in the same 38th year. "Firebird" was dismantled.