The Sukhoi Su-24 (NATO reporting name: Fencer) is a supersonic, all-weather tactical bomber developed in the Soviet Union. The aircraft has a variable-sweep wing, twin engines and a side-by-side seating arrangement for its crew of two. It was the first of the USSR's aircraft to carry an integrated digital navigation/attack system. The Su-24 started development in the early 1960s and entered full production in 1967. Production ceased in 1993. It remains in service with the Russian Aerospace Forces, Syrian Air Force, Ukrainian Air Force, Algerian Air Force and various other air forces to which it was exported. The Su-24 has a shoulder-mounted variable geometry wing outboard of a relatively small fixed wing glove, swept at 69°. The wing has four sweep settings: 16° for takeoff and landing, 35° and 45° for cruise at different altitudes, and 69° for minimum aspect ratio and wing area in low-level dashes. The variable geometry wing provides excellent STOL performance, allowing a landing speed of 230 kilometers per hour (140 mph), even lower than the Sukhoi Su-17 despite substantially greater takeoff weight. Its high wing loading provides a stable low-level ride and minimal gust response. The Su-24 has two Saturn/Lyulka AL-21F-3A afterburning turbojet engines with 109.8 kN (24,700 lbf) thrust each, fed with air from two rectangular side-mounted intakes with splitter plates/boundary-layer diverters. In early Su-24 ("Fencer A" according to NATO) aircraft these intakes had variable ramps, allowing a maximum speed of 2,320 kilometers per hour (1,440 mph), Mach 2.18, at altitude and a ceiling of 17,500 meters (57,400 ft). Because the Su-24 is used almost exclusively for low-level missions, the actuators for the variable intakes were removed to reduce weight and maintenance. This has no effect on low-level performance, but absolute maximum speed and altitude are cut to Mach 1.35 and 11,000 meters (36,000 ft). The earliest Su-24 had a box-like rear fuselage, which was soon changed in production to a rear exhaust shroud more closely shaped around the engines to reduce drag. The revised aircraft also gained three side-by-side antenna fairings in the nose, a repositioned braking chute, and a new ram-air inlet at the base of the tail fin. The revised aircraft were dubbed "Fencer-B" by NATO, but did not merit a new Soviet designation. For more details, including operational history and variants, click here.