Sukhoi Su-24

Su-24
Su-24M of the Russian Air Force, May 2009
Role	All-weather attack aircraft
Manufacturer	Sukhoi
Designer	Ye. S. Felsner from 1985 – L.A. Logvinov
First flight	T-6: 2 July 1967 T-6-2I: 17 January 1970
Introduction	1974
Status	In service
Primary users	Russian Air Force Ukrainian Air Force Kazakh Air Force Islamic Republic of Iran Air Force
Produced	1967–1993
Number built	Approximately 1,400
Unit cost	US$24–25 million in 1997

The Sukhoi Su-24 (NATO reporting name: Fencer) is a supersonic, all-weather attack aircraft developed in the Soviet Union. The aircraft has a variable-sweep wing, twin-engines and a side-by-side seating arrangement for its two crew. It was the first of the USSR's aircraft to carry an integrated digital navigation/attack system. It remains in service with the Russian Air Force, Ukrainian Air Force, and various air forces to which it was exported.

One of the conditions for accepting the Sukhoi Su-7B into service in 1961 was the requirement for Sukhoi to develop an all-weather variant capable of precision air strikes. Preliminary investigations with S-28 and S-32 aircraft revealed that the basic Su-7 design was too small to contain all the avionics required for the mission. OKB-794 (later known as Leninets) was tasked with developing an advanced nav/attack system, codenamed Puma, which would be at the core of the new aircraft. That same year, the United States proposal for their new all-weather strike fighter would be the TFX. The resulting F-111 would introduce a variable-geometry wing for greatly increased payload, range, and low-level penetration capabilities.

In 1962–1963, Sukhoi initially set out to build an aircraft without the complexity of moving wings like the F-111. It designed and built a mockup of S-6, a delta wing aircraft powered by two Tumansky R-21F-300 turbojet engines and with a crew of two in a tandem arrangement. The mockup was inspected but no further work was ordered due to lack of progress on the Puma hardware.

In 1964, Sukhoi started work on S-58M. The aircraft was supposed to represent a modification of the Sukhoi Su-15 interceptor (factory designation S-58). In the meantime, revised Soviet Air Force requirements called for a low-altitude strike aircraft with STOL capability. A key feature was the ability to cruise at supersonic speeds at low altitude for extended periods of time in order to traverse enemy air defenses. To achieve this, the design included two Tumansky R-27F-300 afterburning turbojets for cruise and four Kolesov RD-36-35 turbojets for STOL performance. Side-by-side seating for the crew was implemented since the large Orion radar antennas required a large frontal cross-section. To test the six-engine scheme, the first Su-15 prototype was converted into S-58VD flying laboratory which operated in 1966–1969.