Камов Ка-22 "Винтокрыл": Советский экспериментальный гироплан

Soviet experimental gyrodyne

The Kamov Ka 22 Vintokryl (rotor wing, or literally, (air)screw wing) (Cyrillic: Камов Ка 22 Винтокрыл) (NATO reporting name: Hoop) was a rotorcraft developed by Kamov for the Soviet Air Force. The experimental transport aircraft combined the capabilities of a helicopter for vertical take off and landing with those of a fixed wing aircraft for cruise. The Ka 22 carried a large payload, having a hold comparable in size to the Antonov An 12. Eight world records for altitude and speed were set by the Ka 22 in its class, none of which have since been broken.

In order to increase the effective range of a helicopter, Kamov designer Vladimir Barshevsky drew up a design for a helicopter with wings and an aeroplane propulsive system. In 1954 a proposal was agreed to produce three Ka 22s. The programme was delayed and on 28 March 1956 prototypes 2 and 3 were cancelled. The Ka 22 first lifted from the ground on 17 June 1959, and made its first untethered flight on 15 August 1959. Serious control difficulties were encountered, leading to orders being postponed until the problems were solved, and in July 1960 an order was received to manufacture three more Ka 22s.

The Ka 22 was in essence a fixed wing aircraft with rotors fitted above the wing tips. An engine was mounted on each wing tip, with drive to both a four bladed tractor propeller and a four bladed main rotor. The original prototype was powered by 5,900shp Kuznetsov TV 2VK engines, although these were later replaced by the 5,500shp Soloviev D 25VK. The fuselage contained three seat cockpit above the glazed nose and a main cargo area large enough to contain 80 seats or 16.5 tonnes of cargo. The entire nose could swing open to starboard for loading bulky items. In helicopter mode, the propeller drive was disconnected, and the flaps were lowered to 90 degrees. In fixed wing mode, the lifting rotors were free to windmill, and the aircraft was controlled by the ailerons and tail surfaces. The twin wheel landing gear was fixed.

During its short operational history, a total of eight world records were set by the Ka 22, piloted by D. K. Yefremov and V. V. Gromov. In the 1961 Soviet Aviation Day, this aircraft was on display, making its first public appearance. Subsequently, in order to improve stability and control, a complex differential autopilot was installed. This sensed attitude and angular accelerations, and fed into the control system. On 12 August 1964, while involved in Soviet Air Force testing, 01 03 was destroyed. The aircraft entered an uncontrolled turn to the right, and in efforts to correct the Ka 22 pitched into a steep dive. The order was given to abandon the aircraft, and three of the crew survived, but Col S. G. Brovtsev, who was flying, and technician A. F. Rogov, were killed.