Sukhoi Su-25

The Sukhoi Su-25 Grach is a single-seat, twin-engine jet aircraft developed in the Soviet Union by the Sukhoi Design Bureau. It was designed to provide close air support for the Soviet Ground Forces. The first prototype made its maiden flight on 22 February 1975. After testing, the aircraft went into series production in 1978 at Tbilisi in the Soviet Republic of Georgia.
Early variants included the Su-25UB two-seat trainer, the Su-25BM for target-towing, and the Su-25K for export customers. Some aircraft were being upgraded to Su-25SM standard in 2012. The Su-25T and the Su-25TM (also known as the Su-39) were further developments, not produced in significant numbers. The Su-25, and the Su-34, were the only armoured, fixed-wing aircraft in production in 2007. 
The type has seen combat in several conflicts during its more than 30 years in service. It was heavily involved in the Soviet war in Afghanistan, flying counter-insurgency missions against the Mujahideen. The Iraqi Air Force employed Su-25s against Iran during the 1980–88 Iran–Iraq War. Most were later destroyed or flown to Iran in the 1991 Persian Gulf War. Abkhazian separatists used Su-25s during the Abkhazian War from 1992 to 1993. The Macedonian Air Force used Su-25s against Albanian insurgents in the 2001 Macedonia conflict and, in 2008, Georgia and Russia both used Su-25s in the Russo-Georgian War. African states, including the Ivory Coast, Chad, and Sudan have used the Su-25 in local insurgencies and civil wars.
== Development ==
In early 1968, the Soviet Ministry of Defence decided to develop a specialised shturmovik armoured assault aircraft in order to provide close air support for the Soviet Ground Forces. The idea of creating a ground-support aircraft came about after analysing the experience of ground-attack (shturmovaya) aviation during the 1940s, 1950s, and 1960s. The Soviet fighter-bombers in service or under development at this time (Su-7, Su-17, MiG-21 and MiG-23) did not meet the requirements for close air support of the army. They lacked essential armour plating to protect the pilot and vital equipment from ground fire and missile hits, and their high flight speeds made it difficult for the pilot to maintain visual contact with a target. Having taken into account these problems, Pavel Sukhoi and a group of leading specialists in the Sukhoi Design Bureau started preliminary design work in a comparatively short period of time, with the assistance of leading institutes of the Ministry of the Aviation Industry and the Ministry of Defence.
In March 1969, a competition was announced by the Soviet Air Force that called for designs for a new battlefield close-support aircraft. Participants in the competition were the Sukhoi Design Bureau and the Design Bureaus of Yakovlev, Ilyushin and Mikoyan. Sukhoi finalised its "T-8" design in late 1968, and began in work on the first two prototypes (T8-1 and T8-2) in January 1972. The T8-1, the first airframe to be assembled, was completed on 9 May 1974. Another source says November 1974. However, it did not make its first flight until 22 February 1975, after a long series of test flights by Vladimir Ilyushin. The Su-25 surpassed its main competitor in the Soviet Air Force competition, the Ilyushin Il-102, and series production was announced by the Ministry of Defence.
During flight-testing phases of the T8-1 and T8-2 prototypes' development, the Sukhoi Design Bureau's management proposed that the series production of the Su-25 should start at Factory No. 31 in Tbilisi, Soviet Republic of Georgia, which at that time was the major manufacturing base for the MiG-21UM "Mongol-B" trainer. After negotiations and completion of all stages of the state trials, the Soviet Ministry of Aircraft Production authorised manufacture of the Su-25 at Tbilisi, allowing series production to start in 1978.
In the late 1980s and early 1990s, several Su-25 variants appeared, including modernised versions, and variants for specialised roles. The most significant designs were the Su-25UB dual-seat trainer, the Su-25BM target-towing variant, and the Su-25T for antitank missions. In addition, an Su-25KM prototype was developed by Georgia in co-operation with Israeli company Elbit Systems in 2001, but so far this variant has not achieved much commercial success. As of 2007, the Su-25 was the only armoured aircraft still in production.
== Design ==
The Su-25 has a conventional aerodynamic layout with a shoulder-mounted trapezoidal wing and a traditional tailplane and rudder. Several metals are used in the construction of the airframe: 60% aluminium, 19% steel, 13.5% titanium, 2% magnesium alloy and 5.5% other materials.
All versions of the Su-25 have a metal cantilever wing, of moderate sweep, high aspect ratio and is equipped with high-lift devices. The wing consists of two cantilever sections attached to a central torsion box, forming a single unit with the fuselage. The air brakes are housed in fairings at the tip of each wing. Each wing has five hardpoints for weapons carriage, with the attachment points mounted on load-bearing ribs and spars. Each wing also features a five-section leading edge slat, a two-section flap and an aileron.
The flaps are mounted by steel sliders and rollers, attached to brackets on the rear spar. The trapezoidal ailerons are near the wingtips. The fuselage of the Su-25 has an ellipsoidal section and is of semi-monocoque, stressed-skin construction, arranged as a longitudinal load-bearing framework of longerons, beams and stringers, with a transverse load-bearing assembly of frames. The one-piece horizontal tailplane is attached to the load-bearing frame at two mounting points.
Early versions of the Su-25 were equipped with two R95Sh non-afterburning turbojets, in compartments on either side of the rear fuselage. The engines, sub-assemblies and surrounding fuselage are cooled by air provided by the cold air intakes on top of the engine nacelles. A drainage system collects oil, hydraulic fluid residues and fuel from the engines after flight or after an unsuccessful start. The engine control systems allows independent operation of each engine. The latest versions (Su-25T and TM) are equipped with improved R-195 engines.
The cannon is in a compartment beneath the cockpit, mounted on a load-bearing beam attached to the cockpit floor and the forward fuselage support structure. The nose is fitted with distinctive twin pitot probes and hinges up for service access.
== Operators ==
Operators of the Su-25:
* Angola
* Armenia
* Azerbaijan
* Belarus
* Bulgaria
* Chad
* Democratic Republic of the Congo
* Czech Republic
* Equatorial Guinea
* Ethiopia
* Georgia
* Gambia
* Iran
* Iraq
* Ivory Coast
* Kazakhstan
* Macedonia
* Niger
* North Korea
* Peru
* Russia
* Slovakia
* Sudan
* Turkmenistan
* Ukraine
* United Islamic Republic
* Uzbekistan
Category:Warplanes