The wings are sharpened and swept back with square tips and negative slant. The aircraft’s fuselage is designed to provide lateral rectangular and diagonal cut air intakes and features a bubble canopy with a long pointed nose. Four underwing pylons are also fitted in the fuselage of the aircraft. The MiG-31’s airframe contains various materials including welded nickel steel (49%), titanium (16%), aluminium alloy (33%) and 2% of composites. The aircraft is specifically designed to track multiple targets simultaneously at high altitudes. The MiG-31 has a highly aerodynamic and streamlined body to enable flying at high speeds at low altitude. About 75% of these aircraft, however, re-entered service with the Russian Air Force in 2006 when strong economic growth returned. As a result, around 20% of the MiG-31 aircraft were removed from service. The economic slowdown in the USSR has made the maintenance of its complex MiG-31 aircraft difficult for many squadrons. Production of MiG-31 began in 1979 and the aircraft was fully operational with the Soviet Anti-Air Defence (PVO) by 1982. MiG-31 is equipped with efficient low-bypass-ratio turbofan engines, which allow an increase in combat range. In an effort to overcome the drawbacks of the MiG-25 Foxbat, the MiG-31 was developed to fly at low altitudes with required supersonic speeds. The installation of inefficient turbojet engines led to decrease in combat range at supersonic speeds and an increase in the speed gauge of the MiG-25 resulted in the destruction of the aircraft’s engine. The MiG-25 Foxbat was unable to fly at low altitudes. The order was cancelled in May 2009 due to pressure from Israel and lack of funds. The eight MiG-31 aircraft were ordered in a deal worth $400m signed in 2007. The deliveries of MiG-29M are ongoing, but those of MiG-31 were not effective till 2009 when the UAC confirmed its plans to deliver the eight MiG-31 aircraft to Syria as part of the $1bn contract. One contract was for MiG-29M and another for MiG-31. In 2007, Russia’s United Aircraft Corporation (UAC) signed two contracts worth $1bn with Syria. Russian MiG-31 aircraft contract to Syria Russia’s Defence Ministry announced its intention to invest in modernisation and life extension programme of MiG-31 Foxhound interceptors in July 2020.
Only some of the Russian MiG fleet have been upgraded to MiG-31BM standards under the upgrade programme. The remaining aircraft were upgraded to different variants under several upgrade programmes. More than 500 MiG-31 aircraft have been produced, out of which 370 were delivered to the Russian Air Force and 30 are in service with Kazakhstan Air Force.