Experimental bomber K-12 Firebird

(K-12, “Firebird”) – an experimental tailless bomber with two M-22 engines, approaching the “flying wing” according to the scheme, on which K. A. Kalinin worked hard, looking for ways to an ultra-high-speed high-altitude missile aircraft – the flying wing. Crew – three people, weapons – front and rear shielded turrets and a bomb compartment in the fuselage for 500 kg of bombs. The wing of the K-12 aircraft is of the P-II profile, trapezoidal in plan, without sweep, with a significant narrowing to the ends on which the vertical tail was installed in the form of “washers”.

On August 18, 1937, an unusual plane flew over the Tushino sky, attracting the close attention of all the guests of the parade and provoking exclamations of admiration from the audience. The plane had no tail and looked like the mythical Firebird. It was the K-12 of the talented designer Konstantin Alekseevich Kalinin. However, the history of this aircraft began much earlier. In the early 30s, the most massive R-5 multipurpose aircraft designed by N.N. Polikarpov did not meet the requirements for it anymore and by February 1931 the command of the Air Force Research Institute had developed requirements for a new aircraft, called “military”.

On July 4, 1932, the creation of this aircraft was entrusted to the staff of the Kharkiv Aviation Plant of Experimental and Serial Aircraft Engineering (KhAZOSS), under the leadership of the director and chief designer K.A. Kalinin. In April 1933, experts of the Air Force Research Institute were provided with preliminary designs for the future aircraft, and in three versions. One is of the traditional scheme, the second is a two-frame frame aircraft, and the third is the scheme of a flying wing. The last option seemed the most interesting. Kalinin convinced the head of the Air Force Research Institute V.K. Lavrov to stop precisely on the last diagram. In his opinion, such an aircraft would have greater maneuverability and greater security due to the reduction of the dead zones of fire, the work began by blowing models in the KhAI wind tunnel and taking into account the data obtained in September 1933, a second preliminary design was submitted.

The project also provided for a civilian modification of the aircraft for 11 passengers with baggage. To finally verify the theoretical calculations, a manned plywood glider was built – a copy on a 1: 2 scale. Pilot P.O.Borisov made more than one hundred successful flights on it. Such a technique has been widely used today. In 1935, Kalinin Design Bureau was transferred to a new place – in Voronezh. As a result, the construction of an experimental aircraft was delayed for almost a year. In July 1936, the K-12 was rolled out onto the airfield. The pilot test pilot Borisov piloted the first flight.

46 test flights were carried out, and in early October 1936, he was transferred to the airfield of the Air Force Research Institute near Moscow, where state tests had already begun. The control of the aircraft, in view of its unusual design, turned out to be unusual for many pilots, which ultimately played a bad role in the fate of the aircraft. At the end of 1937, Kalinin was provided with one of the aircraft factories to further refine the aircraft. Within two months, the machine was equipped with more powerful M – 25 engines with variable-pitch propellers, a retractable electric chassis and slightly modified armaments. In this form, the K-12 aircraft was already recommended for mass production.

After short but intense tests in the spring of 1938, the K-12 bomber was approved by the state commission and an act was signed on the deployment of serial production of the aircraft. On April 1, 1938, Kalinin was arrested on false charges. Shortly after his arrest, unable to bear the hardships, he died in a Voronezh prison.

For some time, the K-12 was built in a small series of a dozen aircraft, but soon the order of the people’s commissar of the defense industry stopped all work, the aircraft was disassembled and sent to a warehouse, where they were destroyed during the bombing during World War II. The further theme of the development of tailless aircraft in the USSR was never received.

Specifications

  • Crew 3
  • Length, meters 10.3
  • Wingspan, meters 20.9
  • Height, meters no data
  • Wing Area, m2 72.7
  • Empty weight, kg 3210
  • Normal take-off weight, kg 4200
  • Powerplant 2xPDM-22
  • Horsepower 2×480
  • Cruising speed, km / h 189
  • Maximum speed km / h 228
  • Practical range, km 110
  • Practical ceiling, m 7170
  • Armament, machine guns, mm 2×7.62
  • Bomb load, kg 500
Graduated from Embry-Riddle Aviation University with a master's degree in aviation science. He began his career as an aviation researcher in local periodicals. Has a pilot license. Now are the author and developer of the Plane Worlds.