The Mikoyan MiG-31 (Russian: Микоян МиГ-31; NATO reporting name: Foxhound) is a supersonic interceptor aircraft developed to replace the MiG-25 "Foxbat". The MiG-31 was designed by the Mikoyan design bureau based on the MiG-25.
Like the MiG-25, MiG-31 is a large twin-engine aircraft with side-mounted air intakes, a shoulder-mounted wing with an aspect ratio of 2.94, and twin vertical tailfins. Unlike the MiG-25, it has two seats, with the rear occupied by a dedicated weapon systems officer.
The wings and airframe of the MiG-31 are stronger than those of the MiG-25, permitting supersonic flight at low altitudes. Its D30-F6 jet engine, rated at 152 kN thrust, allow a maximum speed of Mach 1.23 at low altitude. High-altitude speed is temperature-redlined to Mach 2.83—the thrust-to-drag ratio is sufficient for speeds in excess of Mach 3, but such speeds pose unacceptable hazards to engine and airframe life in routine use.
MiG-31 is limited to only 5 g at supersonic speeds. At combat weight, its wing loading is marginal and its thrust to weight ratio is favorable. However, it is not designed for close combat or rapid turning.
The MiG-31 was the world's first operational fighter with a passive electronically scanned array radar (PESA), the Zaslon S-800. Its maximum range against fighter-sized targets is approximately 200 km (125 mi), and it can track up to 10 targets and simultaneously attack four of them with its Vympel R-33 missiles. It is claimed to have limited astern coverage, possibly due to drag chute housing above and between the engines. The radar is matched with an infrared search and tracking (IRST) system in a retractable undernose fairing.
Adopted in 1981
the range detection of air targets: 200 km (for the purpose of with the radar cross-section of 19 m² on a collision angles with probability 0.5)
target detection distance with radar cross-section of 3 m² in the rear within 35 km with a probability of 0.5 ()
number of detected targets: 24
the number of targets for attack: 8
the range of automatic tracking: 120 km
detection of thermal goals - 56 km
The basic differences between versions МиГ-31БМ:
The onboard radar complex MiG-31БМ is capable of simultaneously detecting 24 air targets, 8 of which can be simultaneously attacked by missiles R-33S. Achieved a possibility to intercept targets flying at a speed corresponding to M=6, improved other characteristics of the complex.
Modernized variants of the aircraft can be equipped with radar missiles Kh-31S, Kh-25MP or Kh-25МПУ (up to six units), anti-ship UR Kh-31A (up to six), class missiles air-to-surface Kh-29 and Kh-59 (up to three) or X-59M (up to two units), up to six corrected air bombs KAB-1500 or eight KAB-500 with television or laser-guided. Maximum mass of payload is to 9000 kg.
The MiG-31M-, MiG-31D-, and MiG-31BS-standard aircraft have an upgraded Zaslon-M radar, with larger antenna and greater detection range (said to be 400 km (250 mi) against AWACS-size targets) and the ability to attack multiple targets — air and ground — simultaneously. The Zaslon-M has a 1.4m diameter (larger) antenna, 50% to 100% better performance than Zaslon. In April 1994 it was used with an R-37 to hit a target at 300 km distance. It has a search range 400 km versus a 19/20 sq m RCS target and can track 24 targets at once, engaging six(282 km for 5m2).
The aircraft is a two-seater with the rear seat occupant controlling the radar. Although cockpit controls are duplicated across cockpits, it is normal for the aircraft to be flown only from the front seat. The pilot flies the aircraft by means of a centre stick and left hand throttles. The rear cockpit has only two small vision ports on the sides of the canopy. It is argued that the presence of the WSO (Weapon Systems Operator) in the rear cockpit improves aircraft effectiveness since the WSO is entirely dedicated to radar operations and weapons deployment. This decreases the workload of the pilot and increases efficiency. Both cockpits are fitted with zero/zero ejection seats which allow the crew to eject at any altitude and airspeed.
It has been claimed by Russian Federation Defence Ministry chief Colonel Yuri Balyko, that the upgrade will increase the combat effectiveness of the aircraft several times over.
The MiG-31's main armament is four R-33 air-to-air missiles (NATO codename AA-9 'Amos') carried under the belly. The R-33 is the Russian equivalent of the U.S. Navy's AIM-54 Phoenix.
Unlike the MiG-25, the MiG-31 has an internal cannon, a six-barrel, 23 mm GSh-6-23 with 800 rounds of ammunition, mounted above the starboard main landing gear bay. The GSh-6-23 has a claimed rate of fire of over 10,000 rounds per minute. However, after two Su-24 were lost because of premature shell detonation in 1983, plus some different problems with gun usage (system failures, etc.),