The Su-24 remains a powerful long-range, low-level strike attack aircraft with real all-weather precision attack capability. With its variable geometry swing wing and side-by-side cockpit, the Su-24 is inevitably compared with the US General Dynamics F-111. The aircraft was never intended or used as a strategic bomber, however, a fact obscured by such comparisons. The Su-24 is more broadly equivalent to the Anglo-German-Italian Tornado.
The Fencer was designed to replace the Yak-28 in the all-weather low-lever tactical strike and attack roles. It was intended to carry free-fall TN-1000 and TN-1200 nuclear bombs, and a variety of conventional free-fall bombs, rockets and guided air-to-surface missiles to attack fixed and mobile targets with pinpoint accuracy. While optimized as a supersonic bomber the aircraft was also intended to have a secondary photographic reconnaissance role, and to replace the Brewer in the electronic warfare role.
The design of what became the Sukhoi Su-24 began in the early 1960s. Sukhoi, however, abandoned its initial design (an enlarged, twin-engined aircraft based loosely on the Su-7 configuration, but with a tandem cockpit) in favour of the compound Delta T6. This featured fuselage-mounted lift jets for enhanced STOL performance. The lift jets were heavy and bulky, however, and the T6 was redesigned six months later.
The resulting T-6-21G prototype had no lift jets (leaving increased space for fuel and weapons) but did feature a VG swing wing. This was added to improve take-off and landing performance. The aircraft made its maiden flight during May 1970 and was ordered into production as the Su-24 in late 1970.
The production Su-24 entered frontline service in 1973. The Su-24 was deployed with the Group of Soviet Forces in Germany in 1979, and in Poland. From 1984 the Su-24 saw active service in Afghanistan.
The original Su-24 underwent slight changes in configuration during production, and this led NATO's ASCC to assign three reporting names (Fencer-A through to -C). The aircraft was fast and stable at low level, and could carry an impressive warload (though only at the expense of range) but its avionics were backward and unreliable. The aircraft was thus never as capable as Western attack aircraft.
The improved Su-24M (Fencer-D) was a much better aircraft, and entered service in 1986. The Su-24M introduced upgraded avionics, with separate Orion-A forward-looking attack and Relief Terrain Following Radars. It also had a Kaira 24 laser and TV sighting system which gave PGM compatibility. The Fencer-D had a retractable refuelling probe above the nose, and could carry a buddy refuelling store on the center-line.
The Su-24MR (Fencer-E) is a dedicated tactical reconnaissance variant. It entered service in 1983. It lacks attack radar, cannon and attack avionics, in favor of panoramic cameras, side-looking airborne radar and infrared reconnaissance system. It also carries other podded sensors. Data from the sensors cold be relayed in real-time to ground stations. This reconnaissance aircraft can carry two R-60 (AA-8 Aphid) air-to-air missiles for self-defense. Production of the Su-24MR ceased in 1993. At least a hundred of these tactical reconnaissance aircraft were built.
The Su-25MP (Fencer-F) is a dedicated ELINT variant. It was developed alongside the Su-24MR. The Fencer-F entered service in 1983. This aircraft has additional intelligence-gathering sensors. Various SIGINT and ECM pods can be carried. It is armed with a cannon and has provision for up to four R-60 air-to-air missiles. Only 10 - 20 of these aircraft were built.
At least 670 Su-24s have definitely been built. The overall total is probably between 900 - 1 200. Fencer-Bs, -Cs, -Ds and -Es remain in wide-spread front line use in Russia, and various former Soviet states. Downgraded, non-nuclear capable export Su-24MKs have been delivered to Algeria, Iran, Iraq, Libya and Syria.
A proposed replacement for the ageing Su-24s is a new Su-34 long-range interdictor, which is a derivative of the Su-27 air superiority fighter. It has been accepted to service with the Russian air force, however due to funding restrictions only few of these new aircraft are operational.