- Yes
- No
Overview
The MiG-31 is an evolved variant of the MiG-25. It features a new composite construction, built-in cannon, countermeasures dispenser, more capable missiles, and the first Passive Electronically Scanned Array (PESA) radar on a production aircraft. 349 were produced and the type has been repeatedly modernized, with the MiG-31BM still in service with the Russian Air Force.
History
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Beginnings: the MiG-25
The story of the MiG-31 begins with the MiG-25 “Foxbat”. During the late 1950s, the US developed the A-12 and B-70 Valkyrie. These Mach 3 aircraft were designed to fly higher and faster than Soviet air defenses could counter, performing reconnaissance or delivering nuclear strikes. The latter was particularly worrisome, and in 1961 Mikoyan-Gurevich was tasked with developing the Ye-155, a Mach 3 interceptor capable of catching these threats, while also doubling as a reconnaissance aircraft. The MiG-25R reconnaissance aircraft would enter service in 1969, followed soon after by the MiG-25P interceptor. By this point, the B-70 Valkyrie had been canceled, making the MiG-25’s primary target the SR-71. Compared to the American aircraft it was designed to intercept, the MiG-25 was rather primitive.
To survive the extreme heating associated with its speed, the MiG-25 utilized an extremely heavy stainless steel construction. The MiG-25 was powered by a pair of enormously powerful R-15 engines, which had excessive fuel consumption, poor reliability and service life, and poor performance at low altitudes. The Foxbat initially mounted a Smerch radar, though later models featured the Saphir-25, a more powerful version of the MiG-23ML’s Saphir-23. Armament was missiles-only, being 4x R-40s or R-40Ds with later versions also capable of carrying R-60Ms. The MiG-25 was exported to a handful of countries, and is still in service with the Syrian Air Force.
Next Generation: the MiG-31
The MiG-31 began development in 1972, though it followed up on previous Ye-155 developments. Initially designated the Ye-155MP, then the MiG-25MP, the aircraft would be redesignated the MiG-31 by 1974 because despite being based on the Mig-25 and sharing a similar design and layout, it was a completely new aircraft with few shared components. Most early Ye-155MP designs were very similar to the MiG-25, though one interesting version featured variable sweep wings and looked essentially like a supersized MiG-23.
The MiG-31 was a complete reimagining of the MiG-25, intended to rectify the former’s many shortcomings. The airframe was largely similar, but it used double the amount of titanium alloys and triple the aluminium alloy, resulting in a lighter and stronger design. The R-15 engines were replaced with D-30s, which had much more consistent performance across altitudes and airspeeds, and were (and still are) renowned for their excellent reliability, low maintenance, and relatively high efficiency. The one drawback of the D-30s was their maximum operating speed of only Mach 2.83 compared to Mach 3.2 of the R-15. The MiG-25 had a crew of 1, meaning the pilot had to manage navigation, interception, and weaponry. On top of this, the MiG-25 could only operate where there were enough ground stations for navigation, meaning much of the northern and eastern frontiers of the Soviet Union were still defended by older MiG-23s and Su-15s. The MiG-31 added a navigator/WSO, lowering the workload of the pilot (interestingly, the WSO had duplicate flight controls until the M/BM), as well as an inertial guidance system to allow the aircraft to operate independently. The MiG-31 featured a built-in GSh-6-23 cannon, modernized SPO-15LM RWR (the MiG-25 had the outdated SPO-10), and quadruple APP-50 countermeasure dispensers, features missing on the MiG-25 that made it essentially helpless in a close-range fight. The wings were reinforced and included new leading strakes, which offered surprising maneuverability. While the MiG-31 could still carry R-40Ds and R-60Ms like the MiG-25, it also featured the new R-33 missile, which had over double the range of the R-40D, quadruple that of the original R-40.
Finally, there were the avionics. The original Smerch radar of the MiG-25 had no look-down shoot-down capability, and the Saphir-25 of the MiG-25PD had limited LD-SD in the form of MTI. The Zaslon PESA radar of the MiG-31 had exceptional LD-SD capabilities, allowing the aircraft to engage cruise missiles and low-flying aircraft such as the F-111 and B-1. It was capable of tracking and simultaneously engaging multiple targets and had over double the range of the Saphir-25. Additionally, the MiG-31 introduced the 8TP IRST, improving its capabilities in ECM environments. The MiG-31 also introduced advanced IFF and communication systems, allowing for effective coordination of multiple aircraft across hundreds of kilometers.
Production and Service
The MiG-31 was approved for production in June 1974, before any prototypes had even been completed. The first such prototype, minus avionics and armament and with refurbished MiG-25RB wings, was produced in mid 1975, taking its first flight in September of that year. The first full prototype took its first flight in May 1976, this aircraft being given the designation MIG-25MP. The first production aircraft followed in May 1977, with the aircraft finally receiving its final designation of MiG-31. Production aircraft had slightly smaller tail surfaces and larger flaps than the original prototypes, based on results from flight testing. This aircraft, along with the second production aircraft, were exclusively used for testing.
Acceptance trials commenced in May 1977. The aircraft itself proved reliable, though the engines required constant modifications. On one occasion, one of the engines exploded mid-flight, knocking out the hydraulic system in the process. Fortunately, the pilot was able to safely land the crippled aircraft. In particular, the Zaslon WCS was found to have exceptional performance, though it had some bugs initially. During firing trials in 1978, the MiG-31/R-33 combination had a 100% success rate against target drones, demonstrating the power of the aircraft’s multi-targeting.
Full-rate production began in early 1979, concurrent with service trials. Service trials once again showed the capabilities of the aircraft, though fatigue cracks were discovered after extended maneuvers of over 5g and the engines and fuel systems continued to be problematic. The aircraft was officially accepted into service in 1980, and over the next few years its powerplant issues were resolved and the aircraft proved highly reliable. 304 were produced, with first mass deliveries in 1982.
The MiG-31 sans suffix never fired a shot in anger. Being a powerful specialized interceptor never exported, it never got a chance. The aircraft served multiple regions, though primarily the Moscow, Far East, and Arctic air defense regions. In these areas, the MiG-31 primarily served to steer away SR-71s that wandered too close to Soviet airspace. This was particularly significant in the Arctic and Far East, where the existing fleet of Tu-128s, MiG-23Ps, and Su-15TMs hadn’t a dream of catching a Blackbird. By 1990, the MiG-31 had almost entirely replaced all other interceptors in service, a testament to the type’s performance. Interestingly, one MiG-31 regiment was assigned to the Fleet Air Arm, meaning the MiG-31 was technically also a naval aircraft (though it of course only operated from land-based airfields). Following the end of the Soviet Union, the majority of the MiG-31s were taken up by Russia, with the remaining being operated by Kazakhstan. Russia continues to operate the MiG-31BM, with the aircraft seeing its combat debut in 2022, while Kazakhstan decommissioned their MiG-31BS fleet in 2023, selling the aircraft to the US literally yesterday (April 29th 2024) as of writing this.
Later Upgrades and Modifications
The first modification of the MiG-31 was rather minor, not even receiving a new service designation. Thus was the Izdeliye 01DZ, which simply added a retractable in-flight refueling probe. 45 of this version were produced from 1989 before it was replaced by the first real major modification, the MiG-31B.
The next variant of the Foxhound was the MiG-31M, initially developed in 1983. The MiG-31M featured an entirely new Zaslon-M radar with a 50% longer range than the Zaslon and 24/6 targets tracked/engaged vs the Zaslon’s 10/4, as well as a new 42TP IRST. It replaced the 4x R-33 with 6x R-37, which were ARH variants of the R-33s with longer range and increased maneuverability even over the R-33S. The MiG-31M additionally had new wings with 4 hardpoints, each of which was compatible with a much wider variety of weapons, including R-73s, additional R-37s, R-77s, and R-27s. To accommodate the new avionics, as well as increased fuel load, the fuselage was modified. The first MiG-31M prototype was assembled in 1986. Five more would follow, but the collapse of the Soviet Union and the introduction of the more austere MiG-31B killed the project.
In 1985, it was discovered that Adolf Tolkachev, a high ranking Phazotron engineer, was a CIA spy who had already revealed to the West critical information about the avionics of the MiG-31 and R-33, among many other aircraft and weapon systems. This led to the hurried development of a new version of the MiG-31 without the compromised radar. The MiG-31B mounted a modified Zaslon-A WCS with modified radar and targeting computer, as well as improved communication and coordination systems. The Zaslon-A was capable of engaging 6 targets simultaneously compared to the standard Zaslon’s 4. The MiG-31B had a built-in datalink for the R-40TD-1s, negating the need for the APP-46TD. However, this might have been on earlier aircraft (perhaps introduced in the DZ?), unfortunately, information on the APP-46TD is extremely scarce. Finally, the MiG-31B introduced the improved R-33S, with a more powerful engine and seeker for longer range and larger, folding fins for dramatically increased maneuverability. It also featured the IFR of the Izdeliye 01DZ. This version entered service in 1990. Existing MiG-31s were upgraded to this standard (minus the IFR) and designated MiG-31BS. A downgraded export model, the MiG-31E, was offered to a number of nations including Syria, Egypt, China, and Finland, with no purchases.
In 1997, the MiG-31M program was revitalized. Now called the MiG-31BM, the aircraft would additionally feature strike capability. The program ended in 1999 due to budget issues. Once again reborn in 2003, the MiG-31BM now featured an even-more improved avionics suite as well as the wings of the MiG-31M, though without strike capabilities or the modified airframe of the earlier upgrade programs. This version also introduced the R-37M, a Mach 6 missile with a 2-stage design that is the fastest and longest-range AAM in service anywhere. The MiG-31BM entered service in 2012, being entirely conversions of existing MiG-31Bs. MiG-31BS’s began retrofitting to MiG-31BM standard in 2014, being designated the MiG-31BSM.
The MiG-31 family also contains many unusual prototypes, including the MiG-31F strike/SEAD aircraft, MiG-31I satellite launch aircraft, a MiG-31 used as a testbed for the Buran shuttle, MiG-31 Izdeliye 08 anti-satellite aircraft, and MiG-31K ballistic missile launcher (this variant entered service in 2018).
Specifications
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Airframe
Length: 20.62m (22.67m including pitot)
Span: 13.46m
Height: 5.15m
Wing Area: 61.6m^2
Empty Mass: 21,820kg
Loaded mass: 37,100kg
MTOW: 46,200kg
Powerplant
2x D30F-6S
92.0kN dry (each)
154.0kN afterburning (each)
308.0kN maximum thrust
Max TWR: 1.44
Internal fuel: 18,500L
External fuel: 2x 2,500L
Systems
Zaslon WCS-
10 targets tracked
4 targets engaged
RP-31 Leningrad PESA radar-
±70 degree azimuth, search
±120 degrees azimuth, while tracking
-70/+60 degree elevation
Detection range, bomber-sized target: 200/80km in head-on/pursuit
Detection range, fighter-sized target: 130/60km in head-on/pursuit
8TP IRST-
±60 degree azimuth
-13/+6 degree elevation
6x6 degree ACM
Detection range, afterburning fighter-sized target: 40km, pursuit
Flight Performance
Max speed, sea level: 1,500km/h (Mach 1.21)
Max speed, 17km: 3,000km/h (Mach 2.83)
Max Mach with R-40TDs: Mach 2.35 (due to overheating concerns)
Max climb rate: 208m/s
Max g load: 5g (safety limit at combat weight)
Armament
Built-in
GSh-6-23
The GSh-6-23 is the fastest-firing cannon ever produced. It has a maximum theoretical fire rate of 12,000 RPM and a maximum recorded fire rate of 10,000 RPM, but is typically limited to 6-8,000 RPM in service to reduce overheating and jamming issues. It is chambered in 23x115mm and has the same muzzle velocity as the GSh-23L of around 700m/s.
6-barrel 23x115mm rotary cannon
260 rounds
Fire rate: 8,000 RPM
Muzzle velocity: 700m/s
Under-fuselage hardpoints x4
R-33
The R-33 is a very large, extremely long range SARH missile with a design similar to the AIM-54 Phoenix. It was designed specifically for the MiG-31 which is its only platform. It features initial inertial guidance with a datalink for mid-course upgrades. At approximately 2/3s of the radar’s maximum lock range, the seeker head comes within range and the missile can be given SARH terminal guidance. The seeker only comes online after the autopilot stabilizes the missile, which unfortunately gives the R-33 a very long minimum range of 2.5km.
SARH, IOG, CW, datalink, radar-fuze
446kg (at launch), 294kg (at burnout)
47kg warhead
Max speed: Mach 4.5
Max range: 120/40km in front/rear aspect
Min range: 2.5km
Max target overload: 4g
Under-wing hardpoints x2
1x or 2x R-60M
R-40TD-1
The R-40TD-1 is the ultimate infrared variant of the R-40 missile originally designed for the MiG-25. The R-40TD introduced a datalink, new all-aspect seeker, and more powerful motor that doubled the range over the previous R-40T. The TD-1 introduced a new fuze. It is the second-heaviest AAM ever produced, after the closely related radar-guided R-40RD-1. The MiG-31 is incompatible with the radar versions of the R-40.
All-aspect IR, radar-slavable, datalink*, radar-fuze
*Under-fuselage APP-46TD pod required to utilize R-40D datalink, reducing R-33 carriage to 3
467kg (at launch), 359kg (at burnout)
35kg warhead
Max speed: Mach 4.5
Max range: 50/20km in front/rear aspect
Max target overload: 4g
Underwing hardpoints x2
2,500L fuel drop tank
The MiG-31 in game
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The MiG-31 would provide a powerful BVR aircraft similar to the F-14s. With high speed, excellent radar, and long-range missiles, it’d be a beast at long range. However, poor IR missiles and low maneuverability would make it rather ineffective in a dogfight. It’d be a great aircraft for the tech tree somewhere around 11.7/12.0.
Pros:
- Unrivaled speed and acceleration
- Great climb rate
- Maneuverable at high speeds and altitudes
- Exceptional radar, can hard-lock 4 targets and soft-lock 6 more
- Powerful IRST
- R-33s have exceptional range only surpassed by the AIM-54
- R-40TD-1 would be by far the longest range IR missile in the game
- R-40TD-1 has LOAL capabilities
- Fastest-firing gun of all time
- Redundant pilot controls for WSO
Cons:
- Low manueverability at low speeds and/or altitude
- R-33s still SARH, not ARH like the AIM-54
- R-33s have high minimum range
- R-33s and especially R-40TD-1s have low maneuverability
- R-40TD-1s require guidance pod for datalink
- R-40TD-1 lacks IRCCM, still easily beaten by flares
- R-60Ms outperformed by majority of IR missiles on other Rank VIII aircraft
- Limited ammunition for GSh-6-23, 260 rounds is <2s fire time
- Only 48 countermeasures, though they are large-calibre
- No air-to-ground ordinance whatsoever
Gallery
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Development
The MiG-25PD, predecessor of the MiG-31
Models of several early Ye-155MP designs, I think the swing-wing one in the front is really interesting-looking
The first MiG-31 (Ye-155MP at the time) prototype- 831 refers to the product code, 83/1
The first production MiG-31- the 011 refers to batch 1, aircraft 1
Systems
The heart of the MiG-31: the RP-31 PESA radar
The brain of the MiG-31: the Argon-15 computer
8TP IRST in the retracted and extended positions
Armament spread of the MiG-31
The GSh-6-23 with its 260-round drum magazine
GSh-6-23 on the MiG-31, undergoing maintenance. The aerodynamic fairing in front of the gun rotates out of the way when firing
The forward pair of R-33s are semi-recessed into the fuselage, while the rear pair are fully suspended
The MiG-31 can carry 4 R-60Ms on APU-60-2 pylons, or 2 on APU-60-1 pylons, though this rarely, if ever, happened- because why would you? Anyway, it allows for 2x R-60M as the stock loadout, pretty standard for Soviet vehicles
The R-40TD-1 missile. The hole on the side is one of the two engine exhaust ports. The cone on the rear covers the datalink antenna
The elusive APP-46TD, necessary on at least early Izdeliye 01s to connect to the R-40TD-1 datalink
MiG-31 with PTB-2500 underwing fuel tanks. These tanks were only used for ferrying, not combat, as they weren’t rated for supersonic speeds
The Izdeliye 01DZ introduced a retractable in-flight refueling probe on the port side of the aircraft just ahead of the cockpit. DZ stands for DoZaprahvka- refueling. This refueling probe would be standard for all new vehicles
Fore and rear cockpits- the control stick for the WSO is in the retracted position and extends when in use. This allowed the WSO to take over in case of emergency and allowed standard combat MiG-31s to be used for training
The MiG-31’s D30-F6S engines are enormous!
The MiG-31 has a rather high landing speed- to account for this, it has a trio of airbrakes and a pair of drag chutes
General photos
Menacing
Startup and takeoff at full throttle
The absolutely gorgeous livery of MiG-31 Izdeliye 01DZ 374 at the Paris Airshow 1991 and Farnborough Airshow 1992. This aircraft was the first Izdeliye 01DZ. A company-owned aircraft initially used for testing of the IFR system, it then became a demonstrator aircraft for airshows around the world
MiG-31 in service
MiG-31s of the Pacific Fleet’s 865th IAP- the only “naval” MiG-31s. The setting may look familiar- this part of the Kamchatka Peninsula is the inspiration for War Thunder’s Volcano Valley map
MiG-31 coming in for a landing
MiG-31Bs in formation
The upgraded avionics of the MiG-31B allowed cooperation with other non-MiG-31 aircraft, such as these Su-27s. The MiG-31 would use its powerful radar locate the intercept target and guide the more agile aircraft to it, acting as a mini-AWACS
MiG-31BS in Kazakh service
Sources
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“Mikoyang MiG-31, Interceptor”- Yefim Gordon
“Famous Russian Aircraft: Mikoyang MiG-31”- Yefim Gordon
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