Sukhoi Su-15

The Sukhoi Su-15 (NATO reporting name 'Flagon') was a twin-engined supersonic interceptor developed by the Soviet Union in the 1960s to replace the Sukhoi Su-11 and Sukhoi Su-9, which were becoming obsolete as NATO introduced newer and more capable strategic bombers. The Su-15 was a major part of the Soviet interceptor force until the early 1990s.

The aircraft is best known for having been involved in the downing of Korean Air Flight 007.

Development

Recognizing the limitations of the earlier Su-9 and Su-11 in intercepting the then-new Boeing B-52 Stratofortress, particular in terms of radar and aircraft performance, the Sukhoi OKB quickly began the development of a heavily revised and more capable aircraft. A variety of development aircraft evolved, including the T-49, which shared the fuselage of the Su-9 (including its single engine), but used cheek-mounted intakes to leave the nose clear for a large radome for the RP-22 Oryol-D ("Eagle") radar (NATO "Skip Spin"), and the T-5, essentially a heavily modified Su-11 with a widened rear fuselage containing two Tumansky R-11 engines.

Sukhoi Su-15 (1949)

The Sukhoi Su-15 (Aircraft P) was a prototype Soviet all-weather interceptor which never reached production. The name was later reused for an entirely different 1960s interceptor, see Sukhoi Su-15.

Development

The Su-15 was an early attempt at an all-weather jet-powered interceptor. Its development was ordered by the Soviet government in March 1947, with the approval of the Sukhoi Design Bureau’s preliminary midwing design featuring a pressurized cabin, radar, swept wings and tandem engines, similar to that already attempted by the Lavochkin La-200 and Mikoyan-Gurevich I-320. Per TsAGI, the sweep of the wings was selected to be 35 degrees. The first prototype was completed on 25 October 1948 — only four months after production had started. The Su-15 first flew on 11 January 1949 piloted by Sukhoi test pilot G. M. Shiyanov. In testing, Su-15 reached 1032 km/h (557 knots, 641 mph; Mach 0.888) at 4,550 metres (14,930 ft) and 985 km/h (532 knots, 612 mph; Mach 0.926) at 10,950 metres (35,930 ft), but experienced excess vibration at speeds in excess of Mach 0.87. During 39th flight on 3 June 1949, the aircraft developed severe vibration, forcing the test pilot S.N. Anokhin to eject. The exact cause of the accident was never determined. At the time of the accident, 90% of the flight test program had been completed, over the course of 42 flights with a total flight time of 20 hours, 15 minutes. The program was subsequently terminated, and the second prototype was not completed.