MiG-31 Foxhound, Mikoyan-Gurevich

MiG-31 Foxhound, fast long-range interceptor

The MiG-31 long-range interceptor was developed from the MiG-25. The two-seat MiG-31 fighter has more capable equipment, including the powerful 'Zaslon' phased array radar with a range of 200 km. It is claimed that an unit of MiG-31 can link their radars together, to establish a search pattern -- covering a width of 800-900 km with four aircraft, spaced at 200 km. The MiG-31 Foxhound was the most advanced interceptor fielded by the Soviet Union before its dissolution. About 500 MiG-31s were produced. It is not yet clear when the Russian Air Force will phase out the MiG-31, but according to their importance and with no clear successor in line, it is likely that it will continue serving for as long as 2015.

Type: MiG-31 Foxhound
Country: Soviet Union / Russia
Function: fighter
Year: 1983
Crew: 2 (pilot and weapons system officer)
Engines: 2 * 15500 kg Perm/Soloviev D-30F6 afterburning turbofans
Wing Span: 13.40 m
Length: 22.69 m
Height: 6.15 m
Wing Area: 61.60 m2
Wing loading: 666 kg/m²
Empty Weight: 21825 kg
Max.Weight: 46200 kg
Thrust/weight: 0.85
Speed: 3000 km/h at altitude, 1500 km/h at sea level
Rate of climb: 208 m/s
Ceiling: 20600 m
Range: 3200 km
Maximum g-load: +5 g
Armament: 1* 23 mm six-barrel Gatling gun. Fuselage recesses for four R-33 (AA-9 'Amos') or (for MiG-31M/BM only) six R-37 (AA-X-13 'Arrow') long-range air-to-air missiles.


The MiG-25 'Foxbat', despite Western panic about its tremendous speed, made substantial design sacrifices in capability for the sake of achieving high speed, altitude, and rate of climb. It lacked maneuverability at interception speeds, was difficult to fly at low altitudes, and its thirsty turbojet engines resulted in a very short combat range at supersonic speeds. The MiG-25's radar was also powerful enough to burn through the electronic countermeasures (ECM) of enemy aircraft. The radar's power system operated on vacuum tubes, which may seem odd to Western observers, but their use was very practical for the Soviets and served them well, including reduced susceptibility to damage from the electromagnetic pulses generated by nuclear explosions. Nonetheless, the Foxbat proved to be more useful in the reconnaissance role than as an interceptor, and by the mid-1970s a replacement was being developed.

Development of this replacement began with the Ye-155MP prototype which first flew on 16 September 1975. Although it bore a superficial resemblance to a stretched MiG-25 (with a longer fuselage for the radar operator cockpit), it was in many respects a totally new design. Soviet manufacturing limitations forced the MiG-25 to use nickel steel for 80% of its structure. The Ye-155MP doubled the use of titanium to 16% and tripled the aluminum content to 33% to reduce structural mass. The new structure was also stronger, enabling supersonic load ratings to rise to 5, compared to the Foxbat's 4.5. More importantly, supersonic speed was now possible at low-level altitudes. Fuel capacity was also increased, and new, more efficient lpw-bypass-ratio turbofan engines were fitted.

The most important development was the introduction of an advanced radar capable of both look-up and look-down engagement (locating targets above and below the aircraft), as well as multiple target tracking. This finally gave the Soviets an interceptor capable of engaging the most likely Western intruders at long range. It also reflected a policy shift from reliance on ground-controlled interception (GCI) to greater autonomy for flight crews.

The MiG-31 was surrounded by early speculation and misinformation concerning its design and capabilities. The West learned of the new interceptor from Lieutenant Viktor Belenko, a pilot who defected to Japan in 1976 with his MiG-25P. Belenko described an upcoming "Super Foxbat" with two seats and a capability to intercept cruise missiles. According to his testimony, the new interceptor was to have air intakes similar to the MiG-23, which the MiG-31 in reality does not have, at least not in production variants. While undergoing testing, a MiG-31 was spotted by a reconnaissance satellite at the Zhukovsky flight test center near the town of Ramenskoye. The images were interpreted as a fixed-wing interceptor version of a swing-wing fighter codenamed the "Ram-K". The latter was eventually revealed to be the Sukhoi Su-27, a wholly unrelated design.

Series production of the MiG-31 began in 1979, with operational models entering Soviet Anti-Air Defense (PVO) service in 1982. It was first photographed by a Norwegian pilot over the Barents Sea in 1985.

The MiG-31 was sought after for a variety of long-range missions. Following the collapse of the USSR, however, the budget for spares and maintenance collapsed, leaving many squadrons unable to maintain their complex aircraft. By 1996, only 20% of remaining aircraft were reportedly serviceable at any time; however, by early 2006, President Putin's economic policies permitted the return to service of around 75% of the Russian Air Force's (VVS') MiG-31s.

About 500 MiG-31s were produced, approximately 370 of which remain in Russian service, with another 30 or so in Kazakhstan. Some upgrade programs have found their way in the MiG-31 fleet, like the MiG-31BM multirole version with upgraded avionics, new multimode radar, hands-on-throttle-and-stick (HOTAS) controls, liquid-crystal (LCD) color multi-function displays (MFDs), ability to carry the Vympel R-77 (NATO codename: AA-12 'Adder') missile and various Russian air-to-ground missiles (AGMs) such as the Kh-31P (NATO: AS-17 'Krypton') anti-radiation missile (ARM), a new and more powerful computer, and digital datalinks. However, only a few Russian aircraft have been upgraded to the MiG-31BM standard, although others have been equipped with new radar and computer and the ability to carry the R-77 long-range missile as well.

It is not yet clear when the Russian Air Force will phase out the MiG-31, but according to their importance in the VVS and with no clear successor in line, it is likely that it will continue serving for as long as 2015, depending on its upgrades and the growth of the Russian economy.

Airframe and engines

The wings and airframe of the MiG-31 are stronger than the MiG-25, permitting supersonic flight at low altitudes. Soloviev D-30F6 turbofans (also described as "bypass turbojets" due to the low bypass ratio) 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.

Given the MiG-31's role as a Mach 2+ interceptor and huge engines, its fuel consumption is higher when compared to other aircraft serving in different roles, such as the Su-27. As the result, the aircraft's fuel fraction has been increased to 0.40 -- 16350 kg of high-density T-6 jet fuel. The outer wing pylons are also plumbed for drop tanks, allowing an extra 5,000 liters (1,320 gallons) of external fuel. Late-production aircraft have aerial refuelling probes.

Despite the stronger airframe, the Foxhound is limited to a maximum of 5 'g' at supersonic speeds. It is not designed for close-combat or rapid turning.

Mikoyan MiG-31M "Foxhound-B"

Under development since 1984, the MiG-31M, a substantially improved MiG-31, will most likely not see service. Only six prototypes have been built, and none have been ordered, although it was originally scheduled to enter service in the mid-1990s.

The MiG-31M can carry six under-fuselage missiles in three columns. It can carry the R-37, a development of the R-33 (AA-9 'Amos'), and the R-77 (AA-12 'Adder'). A fully-retractable IRST and a new 1.4m-diameter Phazotron phased-array radar, which can simultaneously engage six targets, are used. The redesigned rear cockpit has three colour CRT MFDs. The MiG-31M also has a one-piece canopy and windscreen, a bulged, wider dorsal spine for more fuel, no gun, and uprated engines. Aerodynamic refinements include redesigned LERXes for better high AoA handling, larger curved fin root fillets, and smaller wing fences. It also has a larger brake parachute housing, a retractable IFR probe on the starboard side (as opposed to on the port side like on the standard MiG-31), rounder wingtips with front and rear dielectric panels, and the nose wheel landing gear is redesigned. Its maximum takeoff weight is raised to 52,000 kg (114,537 lb). One has been observed with large finned wingtip ESM pods. The MiG-31D is a version with the "Foxhound-A's" 1.1m-diameter radar. Converted MiG-31Ds are called MiG-31BS.

Text : Alex Stoll


The most capable Russian air defense interceptor aircraft, the FOXHOUND has a multiple-target engagement capability and was the first Soviet fighter to have a true look-down, shoot-down capability. The key to the MiG-31's effectiveness is the SBI-16 Zaslon fixed phased array antenna radar, codenamed 'Flash Dance' by NATO, which is said to be the world's most powerful fighter radar. The new Soloviev D-30F6 engine was specified for the MiG-31 in order to improve range, the key performance parameter for which an improvement over the MiG-25 was demanded. By 1987 over 150 Foxhounds were operationally deployed at several locations from the Arkhangelsk area in the northwestern USSR to the Soviet Far East. The Foxhound is dedicated to the homeland air defense mission. The Foxhound carries the long-range AA-9 air-to-air missiles, and can engage 4 different targets simultaneously with the M-9.

The wings of the aircraft are high-mounted and swept-back with square tips and a negative slant. There are four underwing pylons. There are two turbofan engines in the fuselage. There are rectangular and diagonal cut air intakes on sides of the fuselage. The exhausts extend beyond the tail plane. The fuselage is rectangular from the intakes to the exhausts and has a long, pointed nose. The aircraft has a bubble canopy. The tail fins are back-tapered with angular tips and canted outward. The flats are swept-back and tapered and mid- to low-mounted on the body.

In 1992 the Chinese reached agreement with the Russian Federation to buy 24 MiG-31 Foxhound long-range interceptors. The MiG-31s were expected to be assembled at a newly set-up factory in Shenyang, with production at a rate of four per month expected by 2000. The last aircraft was to be delivered by the year 2000. According to some reports the agreement included a license to build as many as 700 aircraft, and some projection envisioned that at least 200 would actually be deployed by the year 2010.

The first stage of tests of the upgraded MiG-31BM high-speed multifunctional long-range jet fighter were completed in mid-1999. The main difference between the MiG-31P (Foxhound, according to the NATO classification) and the new MiG-31BM multifunctional air strike system is that the latter is capable of destroying both air and ground targets. The designers and manufacturers of the MiG-31 hope that the new modification will result in international sales. The upgraded MiG-31BM is fitted with a powerful onboard computer system and a radar with a phased array which will allow the pilot to simultaneously activate the air-to-air and air-to-surface missile fire modes. When working with air targets, the MiG-31BM is capable of intercepting up to 24 targets simultaneously.

Countries of Origin CIS (formerly USSR)
Similar Aircraft
Crew Two
  • interceptor
  • air superiority
Length 21.50 m
Span 14.0 m
Height: 6.60 m
Wing span: 14.02 m
Wing area:61.41 sq m
Maximum speed: Mach 2.83
Weight: (empty)22,000 kg
Weight: (normal)36,720 kg
Powerplant: Two Tumanski R-15BD-300 afterburning turbojets rated at 49.78kN each
Maximum Range: 1,250 km
Service ceiling:20,700 m
Rate of climb:8 min 54 sec to 20,000 m
Ceiling24400 meter
Cruise range1620 nm
In-Flight RefuellingNo
Internal Fuel14200 kg
Drop Tanks2000L drop tank with 1600 kg of fuel for 91 nm range
SensorsLD/SD TWS radar, possible IRST, RWR
  • Cannon
  • R-33 AA-9 Amos
  • AA-11 Archer

  • Two R-40 missiles
  • Four R-60 missiles

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