THE 456th FIGHTER INTERCEPTOR SQUADRON

THE PROTECTORS OF  S. A. C.

 

Click on Picture to enlarge

 

The Mig-25 The Worlds Fastest Production Aircraft

+ Larger Font | - Smaller Font

The MiG-25 Foxbat was designed as a high-speed pure interceptor to combat the developing XB-70 Valkyrie American bomber capable of Mach 3. Though the Valkyrie never materialized for US war planners, the MiG-25 was kept in production and became one of the fastest aircraft in the world.
 

 

Click on Picture to enlarge

Mikoyan Gurevich MiG-25 interceptor

The fastest fighter planes to ever enter service are the MiG-25 developed in the Soviet Union during the 1960s and the related MiG-31 that followed in the 1970s. The MiG-25 began as an experimental project called the Ye-155 and was built by the Mikoyan Gurevich design bureau with research assistance from the Central Aerodynamics and Hydrodynamics Institute (CASI or TsAGI). The goal of the effort was to build a high-speed interceptor capable of speeds near Mach 3 that could defend the Soviet Union from the threat posed by America's XB-70 Valkyrie bomber and A-12 reconnaissance/attack plane.

The ambitious project was one of the greatest challenges ever faced by the Soviet aerospace industry and required considerable research to address heating issues at such high speeds. One of the most significant hurdles overcome by the designers was the selection of structural materials capable of surviving the high temperatures near Mach 3. It was estimated that the earlier MiG-21 flying at Mach 2 would experience a peak temperature at its nose of about 225°F (107°C). The increase in air friction when flying an aircraft at Mach 3 generated a nose temperature nearly three times higher at 572°F (300°C). Aluminum, the conventional material most planes are made of, begins to fail and deform at a temperature of only 266°F (130°C) and would clearly not be suitable for the MiG-25.

Designers instead chose welded steel for most of the primary structure with special alloys of steel and titanium for the hottest areas like the nose and wing leading edges. All told, about 80% of the plane's structure was composed of tempered steel, 11% of aluminum, and 8% of titanium. The MiG-25 also required the development of advanced welding techniques to avoid cracking in the heat-resistant alloys. Over 75% of the airframe assembly required some form of welding while conventional riveting accounted for less than a quarter.

Click on Picture to enlarge
MiG-25 reconnaissance model with windows for several cameras located in the nose

The MiG-25 designers also faced considerable aerodynamic challenges in designing the external configuration of the aircraft. The most significant problem was selecting a configuration that provided adequate maneuverability and stability while maintaining high speed and high altitude performance. The best trade-off between these conflicting requirements was found by adopting large but very thin wings mounted high on the fuselage and passing over two large ducts containing the powerful jet engines.

The large wing appears relatively simple at first glance but its shape contains subtle variations in leading edge sweep, dihedral, and airfoil thickness to improve performance. Several options for the wingtip were also explored including a triangular-shaped winglet and an external fuel tank with a large under slung fin. The design ultimately selected featured a large wingtip tubular mass to prevent wing flutter during flight. Much of the wing's interior is dedicated to carrying fuel, and about 70% of the volume of the MiG-25 is taken up by fuel tanks to maximize range and endurance.

Click on Picture to enlarge

Two halves of a MiG-25 engine showing its massive diameter

Further sophisticated aerodynamic concepts were required for the air inlets. The MiG-25 makes use of variable geometry intakes with adjustable positions to improve engine performance at both low and high speeds. The inlets were placed sufficiently far apart to provide room for the narrow forward fuselage containing the cockpit and large search radar. Heating issues once again proved a dominant factor in designing the fuselage since complex cooling and insulation techniques were required for the avionics, engines, and cockpit. The canopy glass is said to be so hot at maximum speed that the pilot cannot touch it with his bare hand, yet the internal cooling systems maintain a comfortable temperature inside the cockpit.

Other systems fitted aboard the MiG-25 included the powerful Smertch-A radar with a detection range of 54 nm (100 km) and tracking range of 27 nm (50 km). Power was provided by two very large and powerful R-15B-300 afterburning turbojets based on a design that had previously been tested aboard a high speed cruise missile. Typical armament was four R-40 air-to-air missiles, including two R-40R semi-active radar tracking and two R-40T infrared-homing variants, carried on underwing pylons.

The MiG-25 began flight testing in 1964 and a special stripped-down, high-performance prototype called the Ye-266 soon broke all existing speed, altitude, and time to climb records. Ten of the records set by the Ye-266 and improved Ye-266M still stand today, including:

Although theoretically capable of even more impressive high-speed performance, production MiG-25 models suffered severe engine and control problems that limited their potential. Pilots were generally forbidden to fly any faster than Mach 2.35 to 2.5 and the aircraft's airspeed indicator was redlined at Mach 2.8. Pilots could fly up to Mach 2.83 for brief periods of a few minutes, but controllability was marginal and the engine would overheat if pushed any faster. The maximum speed ever observed for a MiG-25 was Mach 3.2 as recorded by an American radar during a flight over Israel in 1973. The Soviet pilot was conducting a reconnaissance mission over the nation when he was threatened by Israeli surface-to-air missiles. The pilot went to full afterburner and pushed the MiG-25 as fast as it would go to return to the safety of an Egyptian airfield. Though the MiG-25 survived the flight, its engines were completely destroyed and had to be replaced. This type of damage was inevitable beyond Mach 2.83 and proved to be the limiting factor on the plane's maximum speed.

Click on Picture to enlarge
Ye-266M record-setting test aircraft on display

Given the MiG-25's poor maneuverability, the type was quite limited in the missions it could perform. The MiG-25 was generally only used as a high-speed interceptor or reconnaissance aircraft, though attempts at bomber and air defense suppression models were also made. An improved model designed to redress some of these limitations came in the form of the MiG-31 conceived during the 1970s. The goal of this new aircraft was to build a long-range interceptor capable of defending against low-altitude targets like cruise missiles. The new interceptor would also complement the more general-purpose Su-27 fighter then under development.

Configuration studies for the MiG-31 had included several sophisticated concepts that later contributed to the design of the MiG 1-42. However, these advanced ideas were ultimately rejected in favor of an improved MiG-25 that could be developed more rapidly. It was also planned to use this new aircraft as an opportunity to improve upon the speed and range limitations of the earlier MiG-25. Although still limited to a maximum of Mach 2.83, the MiG-31 incorporated aerodynamic and structural enhancements to reach higher speeds at low altitudes. More fuel-efficient engines and an in-flight refueling probe were also added to significantly increase range and endurance.

Other notable enhancements over the MiG-25 included far more capable avionics and weapons systems. Perhaps most significant of these improvements was a new radar that doubled the detection range to 108 nm (200 km), increased the tracking range by nearly 2.5 times to 65 nm (120 km), and allowed tracking of up to ten targets at once while engaging up to four simultaneously. The MiG-31 also featured an automatic guidance network allowing up to four aircraft to share information via a datalink and a sensitive infrared search and track (IRST) system. Furthermore, the MiG-31 introduced significantly improved air-to-air weapons like the R-60 infrared homing and R-33 semi-active radar tracking missiles.

Click on Picture to enlarge

Mikoyan Gurevich MiG-31

The MiG-25 and MiG-31 family has proven quite successful for the interceptor and reconnaissance roles and saw considerable success on the export market. Production of the MiG-25 totaled 1,190 aircraft that have served with, among others, the Soviet Union, India, and several Middle Eastern countries like Iraq, Libya, and Syria. Small numbers remain in service throughout Asia. About 400 examples of the MiG-31 were delivered to the Soviet Union and many are still flown by Russia and perhaps Kazakhstan.

The MiG-25 and MiG-31 remain the world's fastest fighters to enter service, but a number of other designs came close to matching or even surpassing their capabilities. The US Air Force had planned to purchase a fighter model of the Lockheed A-12/SR-71 family called the F-12. Three YF-12 prototypes were built and one set a speed record of over Mach 3 in 1965, but the fighter model was cancelled. Another proposed Mach 3 interceptor was the North American F-108 Rapier intended to escort the B-70 Valkyrie bomber. The F-108 never got further than the mock-up stage, however, and was cancelled in 1959 along with production plans for the B-70 itself.

Aerospaceweb

 

The Mig-25 "Foxbat"  &  Mig-31 "Foxhound

The Mig-25 Vs The SR-71

 

 

Mikoyan-Gurevich Mig-25

 

MiG-25
Type Interceptor/Spy Plane
Manufacturer Mikoyan-Gurevich OKB
Maiden flight 6 March 1964
Introduced 1970
Status Limited active service
Primary users Russian Air Force (70)
Algerian Air Force (11)
Syrian Air Force (11)
Armenian Air Force (1)
Number built 1,190
Variants Mikoyan MiG-31

The Mikoyan-Gurevich MiG-25 (Russian: МиГ-25) (NATO reporting name "Foxbat") is a very high-speed interceptor and reconnaissance/bomber aircraft designed by the Soviet Union's Mikoyan-Gurevich bureau. First flown as a prototype in 1964, it entered service in 1970. With a top speed of Mach 3.2, a powerful radar and four air-to-air missiles, the MiG-25 worried Western observers and prompted development of the F-15 Eagle.

The aircraft's true capabilities were not discovered until 1976 when Viktor Belenko, a Soviet MiG-25 pilot, defected to Japan. Subsequent analysis revealed a simple-yet-functional design with vacuum-tube electronics, two massive turbojet engines, and sparing use of advanced materials such as titanium. This allowed for a production run of 1,190 aircraft.[1] The MiG-25 flew with a number of Soviet allies and former Soviet republics and it remains in limited service in Russia and several other nations.

 

 

 

Mig-25 Development

 

Click on Picture to enlarge

MiG-25

The development of the MiG-25 began in the 1950s, paralleling American efforts to develop a Mach 3 bomber and interceptor aircraft, including the experimental XB-70 Valkyrie, the XF-103 Thunderwarrior, the Lockheed YF-12, and the XF-108 Rapier. With the first Mach 2 aircraft beginning to enter service, Mach 3 seemed like the next logical step. A variety of roles were considered, including cruise missile carriers, and even a small five to seven passenger supersonic transport, but the main impetus was a new high-altitude reconnaissance aircraft and heavy interceptor. If a Mach 3 bomber were to enter American service, it would have been nearly invulnerable to Soviet air defense.

The Mikoyan-Gurevich OKB accepted the assignment effective 10 March 1961. Although the XB-70 Valkyrie was cancelled before the new Soviet aircraft, which carried the bureau designation "Ye-155" (or "Е-155"), reached the prototype stage, it seemed that the Ye-155 would still be a useful addition to the PVO Strany air defense interceptor force for use against reconnaissance targets like the SR-71 Blackbird.

Because of the thermal stresses incurred in flight above Mach 2, the MiG-25 could not be constructed with traditional aluminium alloys. Lockheed had utilized titanium for their YF-12 and SR-71 series aircraft and North American used a honeycombed steel material for the XB-70. Both American companies struggled with the materials used to construct their respective aircraft. In the end, Mikoyan-Gurevich OKB constructed the MiG-25 largely from nickel alloy ("Inconel") steel. The steel components of the MiG-25 were formed by a combination of spot-welding, automatic machine welding and hand arc welding methods. Initially there was concern that the metal welds would crack when the aircraft experienced the normal jolting of a landing. This did not prove to be the case, and any cracks that developed in service were easily welded in the field. A small amount of titanium and aluminum alloys were also used in the construction of the MiG-25, in areas particularly susceptible to high aerodynamic drag.

Click on Picture to enlarge

Ye-155K3 Reconnaissance prototype (1964

The first prototype, which was a reconnaissance variant, designated "Ye-155-R1" by the bureau, made its first flight on 6 March 1964. The prototype interceptor, "Ye-155-P1", took to the air on 9 September 1964. Development, which represented a major step forward in Soviet aerodynamics, engineering and metallurgy, took several more years to complete. In the meantime, several prototypes, under the cover designation "Ye-266" (or "Е-266"), made a series of record-setting flights in 1965, 1966, and 1967. Series production of the two initial variants, designated MiG-25P ('Foxbat-A') (interceptor) and MiG-25R ('Foxbat-B') (reconnaissance), began in 1969. The MiG-25R entered Soviet Air Force (VVS) service almost immediately, but the service entry of the MiG-25P with the PVO was delayed until 1972. A non-combat trainer variant was also developed for each version, the MiG-25PU ('Foxbat-C') and MiG-25RU, respectively. The MiG-25R evolved several subsequent derivatives, including the MiG-25RB reconnaissance-bomber, the MiG-25RBS and MiG-25RBSh with side-looking airborne radar (SLAR), the MiG-25RBK and MiG-25RBF ELINT aircraft ('Foxbat-D'), and the MiG-25BM ('Foxbat-F') SEAD variant, carrying four Raduga Kh-58 (NATO reporting name AS-11 'Kilter') anti-radiation missiles.

The MiG-25 was capable of high performance, including a maximum speed of Mach 3.2 and a ceiling of 90,000 ft (27,000 m), although on Aug. 31, 1977, an E-266M, a specially modified Foxbat, flown by MiG OKB Chief Test Pilot Alexander Fedotov, set the recognized absolute altitude record for a jet aircraft under its own power, reaching 123,523.58 ft (37,650 m) at Podmoskovnoye, USSR in a brief zoom climb. The record is the only recognized absolute record not held by a pilot from the United States.[2] Although intended for intercepting or threatening high-altitude, high-speed aircraft the MiG-25's maneuverability, range, and close combat potential were extremely limited. Even its tremendous speed was problematic: although the available thrust was sufficient to reach Mach 3.2, a limit of Mach 2.8 had to be imposed to prevent supposed total destruction of the engines,[3] though whether this was inevitable is disputed.[4] Mach 2.5 and greater was difficult to reach without overspeeding the turbines.[5]

Despite these limitations, inaccurate intelligence analysis and several false assumptions caused a panic in the West, where it was initially believed that the MiG-25 was actually an agile air-combat fighter rather than a stand-off interceptor. In response, the United States launched an ambitious new program, which resulted in the McDonnell-Douglas F-15 Eagle.

 

The Design Description Of The Mig-25

 

Click on Picture to enlarge

A true understanding of the strengths and failings of the MiG-25 by the West came in 1976. On 6 September, a PVO pilot, Lt. Viktor Belenko, defected to the West, landing his MiG-25P at Hakodate Airport in Japan. It was carefully dismantled and analyzed by the Foreign Technology Division (now the National Air and Space Intelligence Center) of the United States Air Force, at the Wright-Patterson Air Force Base near Dayton, Ohio. After 67 days, the aircraft was returned to the Soviets in pieces. The analysis showed some surprising facts:

As the result of Belenko's defection and the compromise of the MiG-25P's radar and missile systems, beginning in 1978 the Soviets developed an advanced version, the MiG-25PD ('Foxbat-E'), with a new RP-25 Saphir look-down/shoot-down radar, infrared search and track (IRST) system, and more powerful engines. About 370 earlier MiG-25Ps were converted to this standard and redesignated MiG-25PDS.

About 1,186 MiG-25s were produced before production ended in 1984, and the type was exported to Algeria, Bulgaria (3 MiG-25R and 1 MiG-25RU until 1992), India (until 2006), Iraq, Libya, and Syria. Modest numbers remain in service.

 

 

Operational Service Of The Mig-25

 

Click on Picture to enlarge
Current operators of the MiG-25 in dark red and former operators in light red

Before entering operational service, four MiG-25Rs were temporarily in service with Egyptian Air Force in 1971 under the cover designation of "X-500". All four had EAF markings. They flew over Israel in pairs roughly 20 times. In 1973, an Egyptian MiG-25s was clocked at Mach 3.2 while it was being chased by Israeli F-4Es.[6] The Israeli Air Force found it impossible to intercept them, even though Israeli intelligence generally knew when the overflights were scheduled. The MiG-25Rs went back home in 1972, though reconnaissance Foxbats were sent back to Egypt in October 1973, after the Yom Kippur War, and remained there into 1974.[7] The Israeli Air Force did not have the capability to intercept MiG-25s until it received the F-15 Eagle.

The Israelis managed to set a trap and shoot down two Syrian MiG-25s in 1981 in two separate engagements. Some non-Western sources report that a MiG-25 downed an Israeli F-15 in the second of these two engagements. Another Syrian MiG-25 was shot down by an Israeli HAWK surface-to-air missile in 1982 according to Western sources.

The MiG-25 was in service with the Iraqi Air Force during the Iran-Iraq War, but its combat record is unclear.

During the Persian Gulf War, a US Navy F/A-18 piloted by Lt Cdr Speicher was shot down by an air-to-air missile on the first night of the war.[8][9] The kill was reportedly made with a R-40DT missile fired from a MiG-25PDS flown by Lt. Zuhair Dawood of the 84th squadron of the IrAF.[10]

Click on Picture to enlarge

Cameras of the MiG-25RB

In another incident, an Iraqi MiG-25PD, after eluding eight U.S. Air Force F-15s, fired three missiles at EF-111 Raven electronic warfare aircraft, forcing them to abort their mission. This may have led to the later loss of an F-15 to surface-to-air missiles, due to the lack of electronic jamming.[11]

In yet another incident, two MiG-25s approached a pair of F-15s, fired missiles (which were evaded by the F-15s), and then outran the American fighters. Two more F-15s joined the pursuit, and a total of ten air-to-air missiles were fired at the MiG-25s, though none reached them.[12] According to the same sources, at least one F-111 was also forced to abort its mission by a MiG-25 on the first 24 hours of hostilities, during an air raid over Tikrit.[13]

Two MiG-25s were shot down by USAF F-15Cs during the Gulf War. After the war, in 1992, a U.S. F-16 downed a MiG-25 that violated the no-fly zone in southern Iraq.

Click on Picture to enlarge
MiG-25R of Algerian Air Force

In May 1997 an Indian Air Force MiG-25RB was detected flying faster than Mach 3 at least 65,000 ft, over Pakistani territory. Reportedly this was a deliberate attempt by the Indian Air Force to demonstrate that the capabilities of the MiG-25 are unmatched by the Pakistani Air Force.[14]

On December 23, 2002, an Iraqi MiG-25 shot down a U.S. Air Force unmanned MQ-1 Predator drone, which was performing armed reconnaissance over Iraq. This was the first time in history that an aircraft and an unmanned drone had engaged in combat. Predators had been armed with AIM-92 Stinger air-to-air missiles, and were being used to "bait" Iraqi fighter planes, then run. In this incident, the Predator did not run, but instead fired one of the Stingers, which missed, while the MiG's missile did not.[15]

No Iraqi aircraft were used in the 2003 invasion, with most hidden or destroyed on the ground. In August 2003, several dozen Iraqi aircraft were discovered buried in the sand. That included two MiG-25s which were excavated and sent to WPAFB's Foreign Technology Division using a C-5B Galaxy. In December 2006, it was announced that one MiG-25 was being donated to the National Museum of the United States Air Force at Dayton, Ohio.[3]

 

Operators

 

Current Operators

Click on Picture to enlarge
Flag of Algeria Algeria

11 remain operational with the Algerian Air Force, including 5 MiG-25A, 3 MiG-25PD, and 3 MiG-25R models.

Flag of Armenia Armenia

1 is maintained operational.

Flag of Russia Russia

70 remain in service with the Russian Air Force. They are a mix of 30 MiG-25 fighters and 40 MiG-25RB Recon.

Flag of Syria Syria

11 remain in service, including 2 MiG-25R and a MiG-25U with the Syrian Air Force.

 

Former Operators

Flag of Bulgaria Bulgaria

Three MiG-25RBT (#731, #736 and #754) and one MiG-25RU (#51) were delivered in 1982. On April 12 1984 #736 crashed near Balchik. The pilot ejected successfully. They were operated by 26th RAB at Dobrich until their withdrawal. In May 1991, the surviving MiG-25s were returned to the USSR in exchange for five MiG-23MLD.

Flag of Azerbaijan Azerbaijan

As many as 20 operated in the past, recently retired from service.

Flag of India India

Retired from service in July 2006.

Flag of Iraq Iraq

7 flown over to Iran in 1991, the rest were destroyed in the Gulf War and Operation Southern Watch or buried during the 2003 invasion of Iraq. Some also may have been lost during the Iran-Iraq War.

Flag of Georgia (country) Georgia
Flag of Kazakhstan Kazakhstan
Flag of Libya Libya
Flag of the Soviet Union Soviet Union

The largest operator historically, Soviet aircraft were passed on to its successor states in 1991.

Flag of Turkmenistan Turkmenistan
Flag of Ukraine Ukraine

Withdrawn from service.

Flag of Yemen Yemen

 

 

Specifications Of The Mig-25 "Foxbat-A"

 

Click on Picture to enlarge

General characteristics

Performance

Armament

Avionics

Data from The Great Book of Fighters[16]

 

References

  1. Aerospaceweb.org | Aircraft Museum - MiG-25 'Foxbat'

  2. Steve Fossett Challenges | Virgin GlobalFlyer

  3. Mikoyan MiG-25 Foxbat http://aeroweb.lucia.it/~agretch/RAFAQ/MiG-25.html

  4. Gunston, Bill and Spick, Mike. Modern Air Combat: The Aircraft, Tactics and Weapons Employed in Aerial Combat Today. NY: Crescent Books, 1983, p. 132-133, Mikoyan/Gurevich MiG-25.

  5. Barron, John. MiG Pilot: The Final Escape of Lt. Belenko. Mcgraw-Hill, 1980. ISBN 0-380-53868-7

  6. Spick, Mike. The Great Book of Modern Warplanes. MBI, 2000. ISBN 0-7603-0893-4.

  7. MiG-25 Foxbat

  8. Schmitt, Eric. "Officer Says Iraqi Jet Downed Navy Plane During the Gulf War." The New York Times 15 Sept.1992.

  9. "Intelligence Community Assessment of the Lieutenant Commander Speicher Case". 27 March 2001. FOIA Electronic Reading Room. CIA. 10 Sept. 2006.[1]

  10. Sadik, A., Zampini, D. "Tretij Den' (i posledujuschie...)" ["The Third Day (and beyond...)"]. Aviacija i vremja [Aviation and Time] No. 6 (2005).

  11. Atkinson, Rick. Crusade: The Untold History of the Persian Gulf War. New York: Houghton Mifflin Company, 1993, pp 125-126. Quote: But as the Ravens began their second orbit in a counterclockwise turn toward the Syrian border (over Al-Qaim), a MiG-25 suddenly darted toward them at high speed. The Iraqi fired one air-to-air missile at the lead Raven and two at his wingman. The missiles flew wide, but the Ravens dived to escape and then, uncertain where the MiG was lurking, turned back to Saudi Arabia.

  12. Atkinson, pp 230-231.

  13. Atkinson, p 75.

  14. Steinemann, Peter. "Recce Incursion" Air Power International.[2]

  15. Krane, Jim. "Pilotless Warriors Soar To Success." CBS News 25 April 2003. & CBS Video of Shoot-Down

  16. Green, W. & Swanborough, G. The Great Book of Fighters. Osceola, WI: Motorbooks International Publishing, 2001. ISBN 0-7603-1194-3

Wikipedia

 

 

 

The Mig-25 "Foxbat"
Greg Goebel / Public Domain

The MiG-25 emerged from Cold War tensions. During the 1950s and early 1960s, the US built up a force of heavy bombers that could destroy the USSR with nuclear weapons, and so the Soviets put great effort into developing defensive systems, the Foxbat being high on the list, to defend their nation over its vast frontiers. The MiG-25 in turn would cause the Americans to fear that they were being outpaced by Soviet fighter design, leading to the development of a new generation of US fighters.

 

The Origins Of The Mig-25

 

Click on Picture to enlarge

Mig-25BM "Foxbat-F"

The MiG-25 ironically owed its origins to American aircraft development programs. In the late 1950s, the US fielded the General Dynamics B-58 Hustler Mach 2 bomber, and began development of the North American B-70 Valkyrie bomber, which was designed to penetrate Soviet airspace at high altitude and Mach 3 speeds. The USSR had nothing that could deal with such threats. Since homeland defense was a top Soviet priority, that meant that little expense was spared to develop an interceptor with long range, high performance, and advanced air-to-air missiles (AAMs) to deal with the B-58 and B-70.

In 1961, the Mikoyan OKB (experimental design bureau) was well along in design work for such a high-performance interceptor -- initially focusing on what amounted to scaled-up versions of the OKB's MiG-21 fighter, and flying prototypes of such aircraft with the designations of "I-75", "Ye-150", and "Ye-152" -- when the US reduced the B-70 effort to a purely experimental program. Intercontinental ballistic missiles (ICBMs) on one hand, and steadily improving defensive surface-to-air missiles (SAMs) on the other, had rendered the notion of a high-altitude manned bomber obsolete.

The work at the Mikoyan OKB continued, however, as a countermeasure against American development of a high-speed high-altitude reconnaissance aircraft that could overfly the USSR, which emerged as the Lockheed "SR-71 Blackbird". The Soviets had been infuriated by reconnaissance overflights of Lockheed U-2 spyplanes in the late 1950s and were willing to go to substantial lengths to shoot down intruders -- though by the early 1960s, both sides were developing reconnaissance satellites that would eliminate most of the need for aerial overflights.

The Soviets also saw the new MiG interceptor as the basis for a high-speed reconnaissance aircraft of their own. In addition, there were design concepts for derivatives for the conventional strike and strategic nuclear attack roles; variants with variable geometry ("swing wings") for low-speed maneuverability, or lift-jets for short takeoff; a strategic cruise missile carrier; and even a 5-to-7 seat supersonic airliner; but these alternate ideas came to nothing.

Click on Picture to enlarge

 Development of the "Ye-155P" (where "P" stood for "perekhvatchik / interceptor") "Ye-155R" (where "R" stood for "razvedchik / reconnaissance") had been formally approved in February 1961, with prototype construction authorized a year later. System elements were flight-tested on a variety of platforms, including a MiG-21, a Tupolev Tu-16 bomber, and Tu-104 and Tu-110 airliners.

Two prototypes were built of the reconnaissance variant, with the two designated the "Ye-155R-1" and "Ye-155R-2". The Ye-155R-1 performed its maiden flight on 6 March 1964, with test pilot Alexander Fedotov at the controls. Two prototypes were also built of the interceptor variant and designated "Ye-155P-1" and "Ye-155P-2". The Ye-155P-1 performed its maiden flight on 9 September 1964, with test pilot Piotr Ostapenko at the controls.

All four of these initial prototypes were built in the MiG OKB's workshops. They were followed by four preproduction reconnaissance machines (including one ground-test aircraft), designated "Ye-155R-3" through "Ye-155R-6"; and nine preproduction interceptors, designated "Ye-155P-3" through "Ye-155P-11". The four reconnaissance machines were built at a factory in Gorkiy, now Nizhny Novgorod, while the nine interceptors were built in the MiG OKB workshops. At least two of the Ye-155Ps were lost in accidents.

The Ye-155R-1, Ye-155R-3, and Ye-155P-1 prototypes were used for a number of highly successful attempts to break world aircraft performance records in 1965, 1967, and 1973. They were given the cover designation of "Ye-266". The accomplishments of these machines included a 1967 1,000 kilometer close-circuit speed record of 2,920.67 KPH (1,814.87 MPH); and 1973 records for a climb to 30,000 meters (98,400 feet) of 4 minutes 3.86 seconds, plus an absolute altitude record of 36,240 meters (118,900 feet). Fedotov set the altitude record, executing a zoom climb until the engines flamed out, and then coasting up and over to the top of the arc. One suspects that the aircraft was flying with all the aerodynamic grace of a brick at that point. Once the machine fell back to lower altitude, he regained control and relit the engines.

Both the reconnaissance and interceptor variants of the Ye-155 entered production in 1969, as the "MiG-25R" and "MiG-25P" respectively. The MiG-25R entered service with the Soviet air force, the VVS, in 1969, and the MiG-25P formally entered first-line service with the Soviet national air defense force, the PVO, in 1972. All production MiG-25s would be built at the factory in Gorkiy.

 

The Mig-25 "Foxbat-A" Interceptor

 

Click on Picture to enlarge

This section of this document discusses the interceptor series in detail. Reconnaissance machines are discussed later.

Building a high-performance interceptor like the MiG-25P was a major challenge. Getting a big aircraft with large fuel capacity up to such speed implied advanced aerodynamics and engines, and keeping it at that speed implied the ability to tolerate high temperatures caused by to air friction. Finding and destroying a high-speed intruder dictated powerful radar, along with long-range AAMs with heavy hitting power.

The MiG-25P design that emerged had little obviously in common with the experimental scaled-up MiG-21 designs that had preceded it. The MiG-25P actually seemed to be more influenced by the pioneering US North American A-5 Vigilante shipboard strike and reconnaissance aircraft. Like the Vigilante, the MiG-25P had twin engines on each side of the fuselage, with wedge-style engine intakes featuring variable inlets using hinged ramps; thin, high-mounted swept wings; an all-moving tailplane; and a clamshell canopy between the inlets, with a nonexistent rearward view. The cockpit was pressurized, though pilots still generally wore full pressure suits for high-altitude operations. A KM-1 ejection seat was fitted initially, though this would be replaced after early production by the much better KM-1M.

Calling it a Vigilante copy would be both false and rude, however, since the MiG-25P was completely different in detail and distinctive in appearance, being more slab-sided and businesslike than the A-5. The MiG-25P also featured twin tailfins, each fitted with a rudder and canted outward 11 degrees, making it one of the first operational aircraft with such a feature. Twin tailfins had been considered for the Vigilante, but it had seemed like too much of an innovation at the time, even though the A-5's tall tailfin had to be hinged to get the aircraft into a carrier hangar deck. Ironically, a single tailfin had been considered early in the Ye-155 program. The twin tailfins would find their way back into American designs like the McDonnell Douglas F-15 Eagle. The MiG-25P also had twin fixed ventral fins, another item that became popular in Western aircraft.

The MiG-25P's wings had a 5 degree anhedral droop. They did not have a constant sweep, though the change in sweep was hard to notice, with a sweepback of 42.5 degrees inboard and 41 degrees outboard. Each wing featured a simple flap inboard and a two-section aileron outboard, plus two, distinctively Soviet, wing fences on top. Some sources claim early machines had "blown" flaps to reduce takeoff run. There was an airbrake on top of and below the rear fuselage.

The wings were "wet", containing substantial fuel tankage. The slab-sided appearance of the fuselage undoubtedly had something to do with the fact that 70% of the aircraft's internal volume was occupied by fuel tanks, giving the MiG-25 a total internal fuel capacity of 17,660 liters (4,666 US gallons). It had a single-point refueling system.

Despite the MiG-25's high operating temperature at combat flight speed, only 8% of the airframe was made of titanium. 80% was made of tempered steel, while most of the rest, 11%, was made of aircraft aluminum alloys. The design featured dual hydraulic systems for flight controls and landing gear; a high power electrical system to drive radar and other systems; plus extensive cooling and insulation to protect internal systems and the pilot. Developing temperature-resistant materials, such as paint, hydraulic fluids, canopy panels, and tire rubber, was a major design challenge.

The MiG-25 had typical Soviet heavy-duty landing gear in tricycle configuration, with twin-wheel steerable nose gear retracting forward into the nose, and large single-wheel main gear retracting forward into the fuselage. The nose gear was mounted just underneath the inlets, far enough back to reduce the risk of foreign-object ingestion. The landing gear had pneumatically-operated antilock brakes. The MiG-25 used two brake parachutes to reduce its landing roll, deploying either conical or cruciform parachutes. The brake chutes were stowed in a small tailcone above the engine exhausts, and were deployed automatically on touchdown. A single chute was used early on, but tended to drag on the ground and was replaced by the dual chutes in 1977.

The initial prototype Ye-155R-1 had a number of differences from production MiG-25s, including a wing with no anhedral, which led to yaw and roll instability; shorter tailfins; bigger ventral fins, which scraped the runway; and wingtip fuel tanks with winglets, which led to flight stability problems. The second prototype Ye-155R-2 had triangular wing endplates as a temporary fix for the lack of wing anhedral. The triangular endplates, which had a tacked-on appearance, were referred to by development engineers as "webbed feet".

Click on Picture to enlarge

 The webbed feet were featured in some of the preproduction interceptor machines, even though they had limited wing anhedral. The endplate fins were also fitted to some very early production MiG-25Ps, along with the shorter tailfins and longer ventral fins.

The initial production MiG-25P, which acquired the NATO codename of "Foxbat-A", was fitted with two big Tumanskiy (originally Mikulin) R-15B-300 afterburning turbojets with 100 kN (10,205 kgp / 22,500 lbf) afterburning thrust each. A water-methanol injection system was fitted for boost thrust. Engine fire-extinguishing systems were fitted, and there was a firewall between the engines to prevent the failure of one from crippling the other.

Armament consisted of four big R40 (NATO codename AA-6 Acrid) AAMs, one of the largest AAMs ever built, on underwing pylons. Usually a mix of two R-40R semi-active radar homing (SARH) AAMs and two R-40T heat-seeking AAMs was carried. No gun armament was fitted.

Although the MiG-25P was directed to a target area under ground control, it still required a powerful radar to find and illuminate targets for the long-range R-40R AAMs, and so the MiG-25P was fitted with the RP-25 Smerch-A1 (Whirlwind-A1 / NATO Fox Fire) radar, derived from the RP-S radar used on the MiG-25P's predecessor, the oversized Tupolev Tu-128 "Fiddler" long-range interceptor. The Smerch-A1 had a detection range of 100 kilometers (62 miles) and a tracking range of 50 kilometers (31 miles). It was said to so powerful that it would fry rabbits sitting at the edge of the runway and had to be kept turned off until the aircraft was well clear of the ground, though this appears to be an exaggeration.

In any case, the Smerch-A1 was powerful enough to "burn through" jamming countermeasures. It was not very sophisticated, lacking the "look down" capability needed to find low-flying targets hiding in ground clutter; the Soviets hadn't developed an operational pulse-Doppler radar at that time to perform that trick. They conformed to their usual pragmatic design philosophy of running with what they had instead of waiting for something better, and continued to work on improvements. Later MiG-25P production featured modestly improved Smerch-A2 and then Smerch-A3 radars, which still lacked a look-down capability.

Other avionics included a Polyot 1L inertial navigation system (INS), working in conjunction with radio navigation aids; a Sirena S-3M radar warning system (RWR); HF and UHF radios; identification friend or foe (IFF) transponder system; low and high altitude radar altimeters; and a cockpit voice recorder. A MiG-25P would be directed to a target area automatically, with ground controllers using the aircraft's Vozdookh 1 and Lazur radio links. The links were integrated into the aircraft's Polyot 1L INS, making the MiG-25P effectively a "manned missile". This approach fit the Soviet inclination towards "ground controlled intercept (GCI)", and also eliminated the need for a back-seater to operate radar and navigation systems.

In service, MiG-25s flew in natural metal or overall gray markings, though a small number of them operating in East Germany were painted in rough green-tan camouflage colors. This was known in the West as an "Afghanistan scheme", since it was much like that applied to Soviet aircraft operating in the 1980s Afghanistan War, though the MiG-25 itself saw little or no action in that conflict.

The MiG-25 was pushing the limits, and in fact it wasn't until 1973 that the MiG-25P finally entered frontline service. There had been severe teething problems, particularly with the Tumanskiy turbojets, which initially had a rated operational lifetime of only 150 hours. The limited lifetime was partly because the engine had originally been designed for an expendable single-engine Mach 2+ reconnaissance drone, the Tupolev Tu-123 Yastreb (Hawk), which was only supposed to be flown once. The engine had been extensively redesigned for the MiG-25. The original engine had been designed to operate at constant thrust, which was not acceptable for a piloted aircraft and meant adding a throttling system and a variable nozzle, while changes were made in the compressor and combustor. However, it required still more work to bring it up to better standards of reliability. It would eventually be rated for up to 1,000 hours of operation -- not impressive but a great improvement.

In operational service, the MiG-25P did not come close to meeting its range specification and could not be flown at Mach 3+ for any length of time. Belenko said that the redline speed of his Foxbat-A was Mach 2.5, and that at speeds of Mach 2.8 or more the engines tended to run out of control and burn up. There were tales in the West that Foxbats that did fly at Mach 3+ for an extended period needed an engine swap when they came back down.

Assessment of Belenko's MiG-25P also suggested that the type was not very maneuverable, though as an interceptor designed to operate under ground control it really didn't need to be. There was sniping about the fact that the airframe's riveting wasn't countersunk, though as it turned out rivets were only used in areas where they wouldn't affect performance. The fact that the Smerch-A1 radar was also heavily based on vacuum-tube instead of solid-state technology also led to some criticisms. However, many microwave engineers insist even now that vacuum-tube technology is perfectly practical and cost-effective for high-power microwave applications, though it is clear that the Smerch-Aa lacked the "smarts" of the most sophisticated contemporary Western radars.

The MiG-25 also had some clear virtues from the outset. It was representative of Soviet design philosophy, being relatively cheap to build, rugged, reliable, easy to maintain, and straightforward to operate. Surprisingly, given that the MiG-25 was a big step up in performance for Soviet pilots, it had a very good accident record. The SR-71 was faster and capable of flying at higher altitudes -- the MiG-25 was really more in a league with the later US F-15 in terms of performance -- but the Blackbird was expensive, as well as demanding to maintain and fly.

Incidentally, after analysis of Belenko's Foxbat-A, it was dismantled and shipped back to the USSR. To no surprise, the Soviet government loudly demanded the return of the aircraft. The Japanese government was perfectly agreeable to do so, but for some mysterious reason one minor issue after another came up, each requiring discussion and clarification between the Russians and Japanese, that delayed return of the aircraft, until the analysis of the aircraft was complete. The analysis had been aided by the fact that Belenko made sure he had packed all the tech manuals he could get his hands on with him when he flew off to Japan. Belenko ended up with a career with the US Air Force as an expert on Soviet air power.

 

The Mig-25PD & Mig-25PDS "Foxbat-E" Interceptor

 

Click on Picture to enlarge

The MiG-25P still needed some work, and with Belenko's defection its radar and other systems had been badly compromised. As a result, in November 1976 the MiG OKB was ordered to develop an improved MiG-25P on a fast track basis. The new variant was designated "MiG-25PD", where the "D" stood for "dorabottanniy / upgraded". The MiG-25PD was introduced into service in 1979 and assigned the NATO codename of "Foxbat-E".

The most significant improvement in the MiG-25PD was the new RP-25M Saphir 25 radar, based on the Saphir-23 developed for the MiG-23 fighter. It was a great improvement over the Smerch-A, having slightly greater range and, more significantly, pulse-Doppler operation to provide a look-down / shoot-down capability. The aircraft's nose was slightly stretched to accommodate the new radar. The Saphir 25 was complemented in later MiG-25PD production by a TP-26Sh-1 "infrared search & track (IRST)" sensor mounted under the nose to provide passive target detection and tracking.

There had been upgrades in other avionics systems during MiG-25P production, and the MiG-25PD was fitted with the most up-to-date standard of radios, navigation systems, datalinks, and IFF. It also could carry improved R-40R and R-40T AAMs featuring more sophisticated seekers, these updated weapons being designated "R-40RD" and "R-40TD" respectively. In addition, the MiG-25PD could carry an alternate warload of two R-40s and four R-60 (NATO AA-8 Aphid) short-range heatseeking AAMs, with the Aphids replacing the outboard R-40s and carried on a dual stores rack.

Other improvements in the MiG-25PD included R15BD-300 engines, with no increase in thrust but modernized accessory gearboxes; and the ability to carry an oversized, spindle-shaped 5,300 liter (1,400 US gallon) belly tank, over half as long as the aircraft itself and one of the biggest external tanks ever fitted to any Soviet aircraft.

Older MiG-25Ps were updated to a similar specification and given the new designation of "MiG-25PDS", with the "DS" standing for "dorabottanniy v stroyou / field upgrade". They were also referred to by NATO using the Foxbat-E designation. 

   MIKOYAN MIG-25PD FOXBAT-E INTERCEPTOR:
   _____________________   _________________   _______________________
 
   spec                    metric              english
   _____________________   _________________   _______________________

   wingspan                14 meters           46 feet
   wing area               61.4 sq_meters      661 sq_feet   
   length                  23.82 meters        78 feet 2 inches
   height                  6.1 meters          20 feet
   normal TO weight        36,720 kilograms    80,952 pounds

   max speed at altitude   3,000 KPH           1,865 MPH / 1,620 KT
   service ceiling         20,700 meters       67,915 feet
   takeoff run             1,250 meters        4,100 feet
   range (subsonic)        1,730 kilometers    1,075 MI / 935 NMI
   range (supersonic)      1,250 kilometers    775 MI / 675 NMI
   _____________________   _________________   _______________________

In principle, a MiG-25 could intercept an SR-71 if everything was right, though the window of opportunity was narrow. However, it was apparently still wide enough to discourage the US from performing deep overflights of Soviet territory with the Blackbird. 

 

The Mig-25R "Foxbat-B/D" Reconnaissance & Mig-25BM SEAD Variants

 

Click on Picture to enlarge

Mig-25BM KH-58U

As mentioned, the Ye-155R-1 reconnaissance aircraft prototype flew first, and went into production in 1969 as the MiG-25R, which was given the NATO codename "Foxbat-B". It featured a modified nose with five ports for Zenit film cameras, one vertical and four oblique, and a dielectric panel along each side of the nose for electronic intelligence (ELINT) system antennas. The cameras were mounted on a pallet that could be dropped out of the nose. The MiG-25R featured a Peleng automatic navigation system, possibly the first Soviet inertial navigation system to go into operational flight service.

The MiG-25R had a slightly different wing configuration from the MiG-25P, with a shorter span and a straight, not slightly cranked, leading edge, with a sweep of 41.03 degrees. The tailfins of all but the first production examples were also longer than those of the interceptor variant, with fuel tankage incorporated into the fins, and the engine exhausts were slightly longer as well.

Even before operational introduction, four MiG-25Rs were sent to Egypt in 1971 under the cover designation of "X-500". They overflew Israel in pairs about 20 times and were never intercepted, even though Israeli intelligence generally knew when the overflights were scheduled. The MiG-25Rs went back home in 1972, though reconnaissance Foxbats were sent back to Egypt in October 1973, after the Yom Kippur War, and remained there into 1974.

It appears that the MiG-25R was only built in small numbers, since it was replaced on the production line by the "MiG-25RB" reconnaissance-bomber variant in 1970. It is a bit surprising that a bombing capability was added, since it would seem unlikely that dropping conventional bombs from very high altitude and very high speed would be particularly accurate. To provide the hoped-for precision, the Peleng navigation system was linked to radio navigation aids and a bombing computer. The MiG-25RB also carried a countermeasures jamming system.

The MiG-25RB could originally carry four FAB-500M-62T 500 kilogram (1,100 pound) bombs, carried by tandem double ejector bomb racks under the fuselage. The bombs were specially built to tolerate high temperatures. Late production MiG-25RBs could carry six FAB-500 bombs under the fuselage, using tandem triple ejector bomb racks, and also featured a stores pylon under each wing, with each pylon capable of carrying two FAB-500 bombs in tandem. This gave a total bombload of ten FAB-500s, or four FAB-500s plus the big centerline fuel tank.

The effectiveness of the MiG-25RB as a strike aircraft remains unclear. Some sources claim that the MiG-25RB could also carry a single nuclear munition instead of a conventional bomb load, which would have eliminated any concerns over accuracy. In any case, the standard camera nose was retained, though some improvements were made in equipment fit. The MiG-25RB went into service in 1970s and surviving MiG-25Rs were brought up to MiG-25RB standard.

The MiG-25RB led to several improved variants. In addition, although American reconnaissance aircraft such as the Lockheed U-2 and the SR-71 were designed to accommodate different classes of reconnaissance payloads by swapping out equipment pallets, the Soviets chose to field more or less dedicated MiG-25 reconnaissance variants for specialized reconnaissance roles:

 

Click on Picture to enlarge

Along with the interceptor and reconnaissance variants, the Soviets developed a "suppression of enemy air defenses (SEAD)" variant of the MiG-25. The idea had actually been around since before the first flight of any Foxbat prototype, embodied in a "Ye-155K" proposal, to eventually emerge as the "MiG-25BM" (NATO Foxbat-F).

The USSR did not like the "up close and personal" approach of American "Wild Weasel" defense suppression aircraft and decided to adopt a "standoff" approach. The Foxbat-F was equipped with a sophisticated Yaguar (Jaguar) "radar homing and warning system (RHAWS)", in a nose with 20 centimeter (8 inch) extension plug and dielectric panels for receiving antennas on the sides. The MiG-25BM carried a total of four Kh-58 (NATO AS-11 Kilter) antiradar missiles (ARMs) on its wing pylons. The Kh-58 had a range of more than 48 kilometers (30 miles), and was the first operational Soviet ARM that could be carried by a fighter-class aircraft.

 The MiG-25BM generally carried the big 5,300 liter (1,400 US gallon) centerline tank. Since the MiG-25BM was a single-seat aircraft while US Wild Weasel platforms were two-seaters, pilot workload was probably on the high side.

The initial prototype was rebuilt from a MiG-25RBV and performed its initial flight in 1976. Production of the MiG-25BM began in 1982 and continued into 1985, with about a hundred built. Most or all Foxbat-Fs featured black-painted noses as a "deception" scheme to make them look like interceptors in satellite surveillance images. 

 

The Mig-25PU & Mig-25RU "Foxbat-C" Trainer  /  Miscellaneous Variants

 

Click on Picture to enlarge

Since the MiG-25 was obviously something very different from anything Soviet pilots had flown before, a two-seat trainer seemed desireable early on. Two trainer variants were produced, including a "MiG-25PU" trainer for Foxbat interceptors and a "MiG-25RU" trainer for Foxbat reconnaissance variants.

Instead of fitting a tandem cockpit, MiG engineers simply lengthened the nose and put a second cockpit up front. This may have been done partly to get the trainer out the door as fast as possible, but it did have the benefit that the trainee's cockpit environment was almost identical to that which he would use in service. The instructor could initiate ejection for both himself and the flight trainee.

The two trainer variants were very similar externally, and in fact they used the same airframe, with the slightly cranked wing, short tailfins, and short exhausts of Foxbat interceptor variants. Both were given the NATO codename of "Foxbat-C". They differed in having optimized equipment fits for their respective training roles:

Click on Picture to enlarge

The MiG-25PU was the first trainer to be built, with initial rollout in 1968. The MiG-25PU was also flown on weather reconnaissance missions and apparently got a lot of use, possibly because it was regarded as an economical way to keep up flight hours.

A standard MiG-25PU was used in 1977 to set a number of women's aircraft speed and altitude records. It was given the cover designation of "Ye-133". The pilot was the remarkable Svetlana Savitskaya, who had won the women's world aerobatics crown; set a record free-fall parachute jump; and would go on two space missions to Soviet space stations, becoming the second woman in space and the first woman to perform a spacewalk.

There were a number of special modifications and minor variants of the MiG-25 series:

 

The "Foxbat" In Foreign Service

 

Click on Picture to enlarge

After the fall of the USSR in 1991, Foxbats ended up in the hands of many of the Soviet successor states, including Azerbaijan, Belorussia, Kazakhstan, and the Ukraine. The Foxbat was also exported to a number of foreign states, after Belenko's defection made security concerns less relevant. Export MiG-25 interceptors were typically MiG-25PDs fitted to a downgraded avionics standard, usually with the IRST but with the older Smerch radar. These export machines are referred to as "MiG-25PDs" here and are usually described as "Foxbat-Es" in the West, but that is a bit of a simplification.

In any case, export Foxbat users are listed below. Quantities of aircraft delivered tend to be uncertain, and the values given below should be regarded as approximate:

A total of 1,190 MiG-25s of all types was built from 1969 to 1984, with all except a handful of prototypes built by the factory in Gorkiy. Although the Foxbat is well past its prime, at last notice the Russian Air Force still seemed to be flying small numbers of them, particularly for reconnaissance. Some of the foreign users still seem to be flying them as well.

Greg Goebel / Public Domain

 

 

The Mig-31 "Foxhound"

Greg Goebel / Public Domain

Although the MiG-25 had been a considerable advance in combat aircraft design, it still left something to be desired, and advanced American aircraft were introduced in the 1970s that eroded its edge. As a result, the Soviets developed a substantially improved and more sophisticated derivative of the MiG-25, the "MiG-31", and fielded it in substantial numbers.

 

 

 

Origins Of The Mig-31

 

Click on Picture to enlarge

During the 1960s, the West increasingly focused on low-level strike tactics that stood to be highly effective in penetrating Soviet air defenses. In response, the Soviets invested a great deal of effort in building up those defenses. After considering a number of different options, in 1968 work was authorized on a follow-on to the MiG-25 interceptor series.

The improved machine was to provide a general increase in capability and effectiveness over the Foxbat. The Mikoyan OKB considered more radical designs to meet the requirement early on, including swing wing and delta wing configurations, but decided that it would be more effective to retain the basic arrangement of the MiG-25 and give it a thorough workover.

The OKB's investigation led to an order for full development and two prototypes, with the design effort conducted by a team under the Mikoyan OKB's Gleb Lozino-Lozinsky, and the prototypes built in the OKB workshops. The first "Ye-155MP" prototype performed its initial flight on 16 September 1975, with Fedotov at the controls, and the second followed in May 1976.

Viktor Belenko mentioned the new machine during his debriefing by Western intelligence, describing a "Super Foxbat", with two seats, a strengthened fuselage for low-altitude flight, and a powerful look-down / shoot-down radar. Exaggerated details leaked in the Western press led to a best-selling technothriller novel, Craig Thomas's FIREFOX, involving a Soviet super-fighter with Mach 3 performance, vertical takeoff capability, and direct mind control over aircraft systems. The novel led in turn to one of the worst movies Clint Eastwood ever made.

Work on what would become a total of eight preproduction machines began at the factory in Gorky in 1977. In 1978, a US spy satellite observed one of the evaluation machines, flying at 6,000 meters (20,000 feet), intercepting a target drone emulating a cruise missile flying at 60 meters (200 feet) and 20 kilometers (12.5 miles) away. This was impressive, though since the Soviets were perfectly aware of the orbital schedules of American spy satellites, it suggests the whole thing was a staged "photo-opportunity".

Trials continued into 1980, leading to a formal authorization in 1981 of full production of what was originally to be designated the "MiG-25MP" but emerged as the "MiG-31". The type entered front-line PVO service in 1982, replacing the Tu-128 Fiddler. Aircrew were impressed by the MiG-31's sophistication, range, speed, and said it could climb "like a rocket". Like the MiG-25 before it, the MiG-31 was not very maneuverable, but there was really no need for it to be.

NATO assigned the MiG-31 the codename "Foxhound". The West finally got good pictures of the MiG-31 in 1985, when a Norwegian pilot intercepted one over the Barents Sea and took some shots of it. This was almost certainly a photo-opportunity, the Soviets having long used such intercepts as a means of unveiling new aircraft to the West, with the aircraft turning around for home the moment the photo session was over.

 

The Mig-31  /  Mig-31B & Mig-31BS

 

Click on Picture to enlarge

The general configuration of the MiG-31 is similar enough to that of the MiG-25 for the two be confused at a casual glance. They are both slab-sided aircraft with twin engines featuring ramp inlets, a high-mounted swept wing, twin tailfins, and ventral fins. However, any more than a casual glance shows the MiG-31 to be clearly different from the MiG-25.

The first visible difference is that the MiG-31 was built from the start as a two-seat aircraft. The Soviets had finally decided that a completely ground-controlled approach to air defense was outdated, and so the MiG-31 was designed to be able to hunt and fight more or less on its own, with a back-seater directing the pilot to targets using a much improved sensor suite and controlling the weapons systems. The USSR did not have a continuous ground-based air-defense barrier such as the US-Canadian DEW line, and the MiG-31 could be used to plug the gaps.

The two crew are placed in tandem under individual rear-hinged clamshell canopies, though the design team did consider a side-by-side arrangement as well. The crew sit on Zvezda K-36DM "zero-zero" (zero speed, zero altitude) ejection seats, which have built-in massage pads to keep the crew more comfortable on long patrol missions. The cockpits are painted using a dark turquoise color scheme, often used on Soviet-Russian aircraft, since it's judged by Soviet ergonomics experts as relaxing for aircrew. The rear cockpit features a simple set of flight controls and a retractable periscope, to allow the back-seater to get the aircraft home in an emergency, as well as to provide flight training without requiring a specialized trainer variant.

The MiG-31's wing is also noticeably different from the MiG-25's, with leading-edge root extensions with a sweep of 70 degrees and a thinner cross-section. Each wing features four-section leading-edge flaps; two-section trailing-edge slats; and outboard flaperons. The leading-edge flaps deploy automatically at low speeds, and are also used for combat maneuvering. The fuselage and engine inlets were designed to contribute to lift. The redesigned fuselage also features increased fuel capacity. Airbrakes are fitted under the engine inlets and forward of the main gear doors.

The landing gear is also new and distinctive. The two-wheel nosegear is moved forward relative to the MiG-25, retracting backward instead of forward as on the MiG-25, and the main gear features two wheels, arranged in tandem but offset. This prevents the rear wheel from following in the rut created by the front wheel as it rolls over snow or mud. The MiG-31 uses twin cruciform brake parachutes, stowed in a fairing between and above the engine exhausts.

The Foxhound's primary weapon is the big "R-33" (NATO "AA-9 Amos") SARH AAM, roughly in the same class and strongly resembling the US Hughes AIM-54 Phoenix long-range AAM used on the Grumman F-14 Tomcat. Some sources suggest that the R-33 is actually, to some lesser or greater degree, a copy of the Phoenix, with the design details obtained from samples of the Phoenix obtained from Iran after the Islamic Revolution in that country. The MiG-31 can carry four R-33s in recesses under the fuselage, in an arrangement along the lines of that used by the Tomcat to carry its Phoenix AAMs. An R-33 swings down on a hydraulically actuated trapeze for launch. All four missiles can be launched in salvo, with each seeking out a different target in parallel.

The Foxhound also has four underwing pylons, though apparently early machines only had two, which can be used to carry the R-40TM / AA-6 Acrid, R-60M / AA-8 Aphid, or new "R-77" ("AMRAAMski / NATO AA-12 Adder") missiles. Typical warload is four R-33s under the fuselage and two or four R-60s on the underwing pylons, or three R-33s under the fuselage, the fourth position being taken up by a controller pod for two underwing R-40s.

A 2,500 liter (660 US gallon) external tank can be mounted under each outboard pylon. The MiG-31 actually has gun armament, consisting of a GSh-6-23 six-barreled 30 millimeter Gatling-type cannon mounted in a fairing set well back on the belly of the aircraft, just behind the right main landing gear door. The cannon has a rate of fire from 6,000 to 8,000 rounds per minute, and the MiG-31 carries an ammunition store of 260 rounds.

The airframe features more titanium and aluminum alloy than the MiG-25. The MiG-31 is powered by two Aviadvigatel D-30-F6 bypass turbojets, with an impressive afterburning thrust of 152 kN (15,500 kgp / 34,175 lbf) each, as well as fuel economy unimaginable with the old RB-15 engines. The engine intakes, which were the focus of considerable design effort to ensure better efficiency, feature an upper moving inlet ramp and a lower moving inlet lip. There are auxiliary inlet doors on top of the intakes.

Avionics were significantly improved. The main sensor is the SBI-16 (S-800) "Zaslon" ("Shield" / NATO "Flash Dance") phased-array / electronically steered radar, the first such type of system to reach first-line service in a Soviet fighter, with 120 degrees coverage; excellent look-down / shoot-down capabilities; maximum detection range of 200 kilometers (125 miles); and maximum tracking range of 120 kilometers (75 miles). The radar can track ten targets and engage four of them at one time, with the targets prioritized by the interceptor's mission computer. A semi-retractable TP-8 IRST is also fitted as a passive sensor. Both are linked into an Argon-15 digital fire-control computer.

Click on Picture to enlarge

Although the MiG-31 is capable of autonomous operation, the Soviets did not abandon their ground-control network by any means, and the Foxhound can be directed semi-automatically by the AK-RLDN ground-based automatic guidance network, using the aircraft's APD-518 digital datalink and BAN-75 command link. The datalink can also be used to hook up the fighter to an Ilyushin A-50 "Mainstay" airborne warning and control system (AWACS) aircraft, as well as allow "wolfpacks" of four MiG-31s to cooperate under the control of a flight leader, covering a swath of airspace 900 kilometers (560 kilometers) wide. The flight leader can direct his three wingmates to specific targets.

The MiG-31 features other improved avionics, including updated radios; IFF; RWR; and particularly an NK-25 navigation system, featuring receivers for the Tropik medium-range radio navigation system, similar to the US LORAN, and the Marshrut long-range radio navigation system, similar to the US Omega. One of the motivations for such extensive navigation gear was to allow the Foxhound to patrol deep into Arctic airspace in search of Western cruise-missile carrier aircraft. Trial flights included such deep-arctic sorties, including one that overflew the North Pole.

The Mikoyan Mig-31 Interceptor "Foxhound"

 
   _____________________   _________________   _______________________
 
   spec                    metric              english
   _____________________   _________________   _______________________

   wingspan                13.46 meters        44 feet 4 inches
   wing area               61.6 sq_meters      663 sq_feet   
   length                  22.69 meters        74 feet 6 inches
   height                  6.2 meters          20 feet 4 inches

   empty weight            21,825 kilograms    48,115 pounds
   normal weight           41,000 kilograms    90,388 pounds
   MTO weight              46,200 kilograms    101,851 pounds

   max speed at altitude   3,000 KPH           1,865 MPH / 1,620 KT
   service ceiling         20,600 meters       67,585 feet
   take-off run            1,200 meters        3,940 feet
   ferry range             3,300 kilometers    2,050 MI / 1,780 NMI
   operational radius      1,200 kilometers    745 MI / 648 NMI
   _____________________   _________________   _______________________

The MiG-31 proved to be highly satisfactory in operational service, and field commanders began to consider it for other missions, such as escort of long-range maritime patrol aircraft. This strained the range of the Foxhound, and so the MiG OKB designed a semi-retractable flight refueling probe that was fitted to the left side of the nose. This item was introduced into standard production.

In 1985, Soviet security arrested Adolf Tolkachev, head of the Phazotron radar design bureau, for selling secrets to the West. Tolkachev had compromised the radar systems of most of the USSR's first-line combat aircraft. The Soviets took a very dim view of traitors and Tolkachev was executed, but the damage had been done: the MiG-31's radar had been compromised, allowing it to be neutralized through countermeasures. The MiG OKB had already been working on improvements to the Foxhound, and came up with a new Foxhound variant, the "MiG-31B", which featured a new Zaslon radar with improved range and counter-countermeasures; as well as other updated avionics, including modernized digital processors; plus support for the improved R-33S AAM and fit of the inflight refueling probe as standard.

The MiG-31B entered production in 1990. The Gorkiy factory updated many early-production MiG-31s to the same standard, with these machines receiving the designation "MiG-31BS".

 

Miscellaneous Mig-31 Variants  /  Mig-31M & Mig-31 BM

 

A total of about 500 MiG-31s were built by the factory at Gorkiy up to the fall of the USSR. There were a number of minor and proposed Foxhound modifications and variants:

In the mid-1980s, the MiG OKB began work on an improved interceptor variant, the "MiG-31M", which was primarily designed as a carrier for the R-37 AAM, an improved follow-on to the R-33 with an astounding range of 300 kilometers (186 miles). Seven MiG-31M prototypes were built, with the first flying in late 1985.

An improved Zaslon-M radar was fitted, along with a new IRST with a laser rangefinder. A new "fat" spine was fitted to the aircraft to accommodate improved avionics and increase fuel storage. At least one prototype featured wingtip pods with vertical fins for electronic systems. Large LERXes were fitted to improve high angle of attack handling; the tailfins and ventral fins were reconfigured to a degree; and an improved inflight refueling probe was designed, to be fitted to the right side of the nose of the aircraft.

Click on Picture to enlarge

 Six R-39s could be carried under the fuselage in recesses, arranged as three rows of two missiles. All six could be launched in salvo and seek different targets. Four R-77 AAMs could also be carried on underwing pylons. The cannon was deleted.

The cockpit was redesigned, with the front seater getting a new single-piece windscreen, and the windows for the back-seater reduced to a small panel on either side to allow him to focus his attention on his displays. Back seat flight controls were deleted.

* The MiG-31M did not enter production since the Russian state lacked the money to buy many new aircraft, and so in 1997 the MiG organization began work on a multirole upgrade to existing MiG-31s, designated "MiG-31BM".

A MiG-31BM prototype was demonstrated publicly in 1999. It featured an updated Zaslon radar close to Zaslon-M standards; a satellite navigation receiver; and significantly upgraded cockpit arrangements, with the back-seater provided with three large flat-panel displays. It is unclear if the cockpit arrangements were inherited from the MiG-31M or, as would seem likely given technological advances since the 1980s, used more advanced systems. The MiG-31BM could carry six R-33S or R-37 AAMs, as well as underwing stores such as smaller AAMs, ARMs, or iron bombs.

The program moved along slowly, but by late 2006 the Russian Air Force (which absorbed the disbanded PVO after the fall of the USSR) was performing flight trials on two MiG-31BMs and had committed to an unspecified number of upgrades.

 

Mig-25 & Mig-31 Variant Summery

 

Interceptor And SEAD Variants

 

     Ye-155P               Prototypes.

     MiG-25P Foxbat-A      Initial production interceptor with Smerch radar.
     MiG-25PD Foxbat-E     Improved interceptor with Saphir radar.
     MiG-25PDS Foxbat-E    MiG-25Ps upgraded to MiG-25PD spec.

     MiG-25BM Foxbat-F     Dedicated SEAD variant.

Reconnaissance Variants

 

     Ye-155R               Prototypes.

     MiG-25R Foxbat-B      Initial photo-reconnaissance variant.
     MiG-25RB Foxbat-B     Improved MiG-25R with bombing capability.
     MiG-25RBV Foxbat-B    Updated MiG-25RB.
     MiG-25RBT Foxbat-B    Further updated MiG-25RB.

     MiG-25RBK Foxbat-D    Dedicated ELINT variant.
     MiG-25RBF Foxbat-D    Improved MiG-25RBK.

     MiG-25RBS Foxbat-D    Dedicated SLAR (imaging radar) variant.
     MiG-25RBSh Foxbat-D   Improved MiG-25RBS.

Trainers

 

     MiG-25PU Foxbat-C     Two-seat interceptor trainer.
     MiG-25RU Foxbat-C     Two-seat reconnaissance trainer.

Miscellaneous Varients

 

     Ye-266                Cover designation for record-setting prototypes
     Ye-133                Cover designation for record-setting MiG-25PU.
     X-500                 Cover designation for "Egyptian" MiG-25Rs.
     I-99                  Two test machines for D30F engines.

     MiG-25PDS             Prototype interceptor with improved ECM.
     MiG-25PDZ             MiG-25P fitted with refueling probe.
     MiG-25M (Ye-266M)     Two test machines for improved RB15 engines.
     MiG-25PU-SOTN         Trainer modified for Buran shuttle program.
     MiG-25MR              MiG-25RBs modified for weather reconnaissance.
     MiG-25RBVDZ           MiG-25RBV fitted with refueling probe.
     MiG-25RBShDZ          MiG-25RBSh fitted with refueling probe.
     MiG-25RBN             Prototype night reconnaissance machine.
     MiG-25RR              Eight MiG-25RBVs modified for fallout sampling.

MiG-31 Foxhound variants include: 


     MiG-31                Initial production version.
     MiG-31B               Later production version with updated radar.
     MiG-31BS              Initial production upgraded to MiG-31B spec.

     MiG-31LL              One early MiG-31 used for tests.
     MiG-31D               Two prototypes of an ASAT system.
     MiG-31A               Proposed smallsat launcher using MiG-31D.
     MiG-31F               Proposed multirole version.
     MiG-31E               Proposed export versions.

     MiG-31M               Next-generation Foxhound, 7 prototypes built.
     MiG-31BM              Upgraded MiG-31B with MiG-31M features.
   
 

Comments

 

I thought that writing up the MiG-25 and MiG-31 would be a straightforward exercise. I wasn't thinking. It turned out to be much more work than I expected: as with most Soviet-Russian aircraft, different sources on the MiG-25 tend to give frustratingly different stories, particularly in terms of variant descriptions and designations.

I remember from when I was a kid back in the 1960s how impressive the Foxbat seemed in the West. It is a bit surprising to look back from the 21st century and find that it has something of an outdated "boilerplate" appearance, and that the type has been, if not precisely forgotten, at least neglected. Information on it, particularly good information, tends to be hard to come by.

Sources include:

  • THE ENCYCLOPEDIA OF WORLD MILITARY AIRCRAFT, edited by David Donald & Jon Lake, Barnes & Noble, 2000

  • "Russia's 'Manned Patriot'" by Jon Lake, WORLD AIR POWER JOURNAL, Volume 13 / Summer 1993, 30:45.

  • "MiG-25 'Foxbat' And MiG-31 'Foxhound' Variant Briefing" by Jon Lake, WORLD AIR POWER JOURNAL, Volume 34 / Fall 1998, 98:123.

  • "Mikoyan's Long-Legged Hunting Dog" by Alan Dawes, AIR INTERNATIONAL, December 2002, 396:401.

Greg Goebel / Public Domain

 

 

USE YOUR BROWSER "BACK" BUTTON TO RETURN TO PERVIOUS PAGE

Last Updated

08/19/2009

 

Powered By

456FIS.ORG