Mikoyan-Gurevich MiG-25


The Mikoyan-Gurevich MiG-25 is a supersonic interceptor and reconnaissance aircraft that was among the fastest military aircraft to enter service. It was designed by the Soviet Union's Mikoyan-Gurevich bureau and is one of the few combat aircraft built primarily using stainless steel. It was the last plane designed by Mikhail Gurevich before his retirement.
The first prototype flew in 1964, and the aircraft entered service in 1970. It has an operational top speed of Mach 2.83 and features a powerful radar and four air-to-air missiles. When first seen in reconnaissance photography, the large wing suggested an enormous and highly maneuverable fighter, at a time when U.S. design theories were also evolving towards higher maneuverability due to combat performance in the Vietnam War. The appearance of the MiG-25 sparked serious concern in the West and prompted dramatic increases in performance for the McDonnell Douglas F-15 Eagle then under development in the late 1960s. The capabilities of the MiG-25 were better understood by the west in 1976 when Soviet pilot Viktor Belenko defected in a MiG-25 to the United States via Japan. It turned out that the aircraft's weight necessitated its large wings.
Production of the MiG-25 series ended in 1984 after completion of 1,186 aircraft. A symbol of the Cold War, the MiG-25 flew with Soviet allies and former Soviet republics, remaining in limited service in several export customers. It is one of the highest-flying military aircraft, one of the fastest serially produced interceptor aircraft, and the second-fastest serially produced aircraft after the SR-71 reconnaissance aircraft that was built in very small series compared to the MiG-25., the MiG-25 remains the fastest manned serially produced aircraft in operational use and the fastest plane that was offered for supersonic flights and edge-of-space flights to civilian customers.

Design and development

Background

During the Cold War, Soviet Air Defence Forces, PVO was given the task of strategic air defence of the USSR. In the decades after World War II, this meant not only dealing with accidental border violations, but more importantly defending the vast airspace of the USSR against US reconnaissance aircraft and strategic bombers carrying free-fall nuclear bombs. The performance of these types of aircraft was steadily improved. Overflights by the very high altitude American Lockheed U-2 in the late 1950s revealed a need for higher altitude interceptor aircraft than currently available.
The subsonic Boeing B-47 Stratojet and Boeing B-52 Stratofortress strategic bombers were followed by the Mach 2 Convair B-58 Hustler, with the Mach 3 North American B-70 Valkyrie on the drawing board at that time. A major upgrade in the PVO defence system was required, and, at the start of 1958, a requirement was issued for manned interceptors capable of reaching 3,000 km/h and heights of up to 27 km. Mikoyan and Sukhoi responded.
The Mikoyan-Gurevich OKB had been working on a series of interceptors during the second half of the 1950s: the I-1, I-3U, I-7U, I-75, Ye-150, Ye-150A, Ye-152, Ye-152A, Ye-152P, and Ye-152M. The Ye-150 was noteworthy because it was built specifically to test the Tumansky R-15 engine, two of which would later be used for the MiG-25. This led to Ye-152, alternatively known as Ye-166, which set several world records. The Ye-152M was intended to be the definite heavy interceptor design. But before it was finished, the PVO had selected the Tupolev Tu-128. As the work on the MiG-25 was well under way, the single-engine Ye-152M was abandoned.

Designing a new interceptor

Work on the new Soviet interceptor that became the MiG-25 started in mid-1959, a year before Soviet intelligence learned of the American Mach 3 A-12 reconnaissance aircraft. It is not clear if the design was influenced by the American A-5 Vigilante.
The design bureau studied several possible layouts for the new aircraft. One had the engines located side by side, as on the MiG-19. The second had a stepped arrangement with one engine amidships, with exhaust under the fuselage, and another in the aft fuselage. The third project had an engine arrangement similar to that of the English Electric Lightning, with two engines stacked vertically. Option two and three were both rejected because the size of the engines meant any of them would result in a very tall aircraft which would complicate maintenance.
The idea of placing the engines in underwing nacelles was also rejected because of the dangers of any thrust asymmetry during flight. Having decided on engine configuration, there was thought of giving the machine variable-sweep wings and a second crew member, a navigator. Variable geometry would improve maneuverability at subsonic speed, but at the cost of decreased fuel tank capacity. Because the reconnaissance aircraft would operate at high speed and high altitude, the idea was soon dropped. Another interesting but impractical idea was to improve the field performance using two RD36-35 lift-jets. Vertical takeoff and landing would allow for use of damaged runways during wartime and was studied on both sides of the Iron Curtain. The perennial problem with engines dedicated to vertical lift is they become mere dead weight in horizontal flight and also occupy space in the airframe needed for fuel. The MiG interceptor would need all the fuel it could get, so the idea was abandoned.
The first prototype was a reconnaissance variant, designated Ye-155-R1, that made its first flight on 6 March 1964. It had some characteristics that were unique to that prototype, and some of these were visually very evident: the wings had fixed wingtip tanks to which small winglets were attached for stability purposes, but when it was found that fuel sloshing around in the tanks caused vibrations, they were eliminated. The aircraft also had attachments for movable foreplanes, canards, to help with pitch control at high speed.
The first flight of the interceptor prototype, Ye-155-P1, took place on 9 September 1964. Development of the MiG-25, which represented a major step forward in Soviet aerodynamics, engineering and metallurgy, took several more years to complete.
On 9 July 1967, the new aircraft was first shown to the public at the Domodedovo air show, with four prototypes making a flypast.

Aviation records

The Mikoyan-Gurevich design bureau soon realized that the performance of the new aircraft gave it great potential to set new flight records. In addition to their normal duties, the prototypes Ye-155-P1, Ye-155-R1, Ye-155-R3 were made lighter by removing some unneeded equipment and were used for these attempts. Under Federation Aeronautique Internationale classification, the Ye-155 type belonged to class C1, which specifies jet-powered land planes with unlimited maximum take-off weight. Records set included:
In all, 29 records were claimed, of which seven were all-time world records for time to height, altitudes of 20,000 m and higher, and speed. Several records still stand.

Technical description

Because of the thermal stresses incurred in flight above Mach 2, the Mikoyan-Gurevich OKB had difficulties choosing what materials to use for the aircraft. They had to use E-2 heat-resistant Plexiglas for the canopy and high-strength stainless steel for the wings and fuselage. Using titanium rather than steel would have been ideal, but it was expensive and difficult to work with. The problem of cracks in welded titanium structures with thin walls could not be solved, so the heavier nickel steel was used instead. It cost far less than titanium and allowed for welding, along with heat-resistant seals. The MiG-25 was constructed from 80% nickel-steel alloy, 11% aluminium, and 9% titanium. The steel components were formed by a combination of spot welding, automatic machine welding, and hand arc welding methods.
Initially, the interceptor version was equipped with the TL-25 Smerch-A radar, a development of the system carried by the earlier Tu-128. While powerful and thus long-ranged and resistant to jamming, the system—due to the age of its design and its intended purpose —lacked look-down/shoot-down capability, which limited its effectiveness against low-flying targets. By the time the MiG-25 entered service in 1969, this was a serious shortcoming, as strategic bombing doctrine was shifting towards low-level penetration of enemy territory. After Belenko's defection to Japan exposed this flaw to the West, a government decree issued on 4 November 1976 called for urgent development of a more advanced radar. This resulted in the pulse-Doppler radar Sapphire-25 system fitted to the MiG-25PD variant.
As an interceptor, typical armament includes four supersonic UR great range R-40T air-to-air missiles with thermal homing head and R-40P with semi-active radar guidance system. A fuel tank can be suspended under the fuselage. The aircraft could carry unguided gravity bombs in a rudimentary strike capability. As the bombs would weigh no more and incur no more drag than its regular load of R-40 missiles, its performance was not impaired, leading to some impressive bombing feats; when released at an altitude of 20,000 m and a speed above Mach 2, a 500 kg bomb would have a glide range of several tens of kilometres.
The MiG-25 was theoretically capable of a maximum speed of Mach 3+ and a ceiling of. Its high speed was problematic: although sufficient thrust was available to reach Mach 3.2, a limit of Mach 2.83 had to be imposed as the engines tended to overspeed and overheat at higher air speeds, possibly damaging them beyond repair.
The design cruising speed is Mach 2.35 with partial afterburner in operation. The maximum speed of Mach 2.83 is allowed to maintain no more than 5 minutes due to the danger of overheating of the airframe and fuel in the tanks. When the airframe temperature reaches 290 C, the warning lamp lights up and the pilot must reduce airspeed. The use of a partial afterburner and a cruising flight altitude 19,000–21,000 m makes it possible to have a range only 230 km less than when flying Mach 0.9 at altitudes 9,000–10,000 m. The maximum altitude of flight without an afterburner in operation is 12,000 m. The poor fuel consumption in the subsonic regime, and hence range, is due to the engines having extremely low pressure ratio of just 4.75 at subsonic speeds. Specific Fuel Consumption of the engines is 1.12 in cruise and 2.45 with afterburners. For comparison purposes, this is 50% worse in cruise than the first generation of F-100 engines from the F-15 Eagle, but the SFC with afterburners is actually nearly equal despite the F-100 being a far newer engine design.

Into production

Full-scale production of the MiG-25R began in 1969 at the Gorkii aircraft factory. The MiG-25P followed in 1971, and 460 of this variant was built until production ended in 1982. The improved PD variant that replaced it was built from 1978 till 1984 with 104 aircraft completed. Subsequently the Gorkii factory switched over production to the new MiG-31.

Western intelligence and the MiG-25

Inaccurate intelligence analysis caused the West initially to believe the MiG-25 was an agile air-combat fighter rather than an interceptor. In response, the United States started a new program which resulted in the McDonnell Douglas F-15 Eagle. NATO obtained a better understanding of the MiG-25's capabilities on 6 September 1976, when a Soviet Air Defence Forces pilot, Lt. Viktor Belenko, defected, landing his MiG-25P at Hakodate Airport in Japan. The pilot overshot the runway on landing and damaged the front landing gear. Despite Soviet protests, the Japanese invited U.S. Air Force personnel to investigate the aircraft. On 25 September, it was moved by a C-5A transport to a base in central Japan, where it was carefully dismantled and analyzed. After 67 days, the aircraft was returned by ship to the Soviets, in pieces. The aircraft was reassembled and is now on display at the Sokol plant in Nizhny Novgorod.
The analysis, based on technical manuals and ground tests of its engines and avionics, revealed unusual technical information:
As the result of Belenko's defection and the compromise of the MiG-25P's radar and missile systems, beginning in 1976, the Soviets started to develop an advanced version, the MiG-25PD.
Plans for a new aircraft to develop the MiG-25's potential to go faster than the in-service limit of Mach 2.8 were designed as a flying prototype. Unofficially designated MiG-25M, it had new powerful engines R15BF2-300, improved radar, and missiles. This work never resulted in a machine for series production, as the coming MiG-31 showed more promise.

Operational history

Soviet Union

The unarmed 'B' version had greater impact than the interceptor when the USSR sent two MiG-25R and two MiG-25RB to Egypt in March 1971, which stayed until July 1972. They were operated by the Soviet 63rd Independent Air Detachment, which was established for this mission. Det 63 flew over Israeli-held territory in Sinai on reconnaissance missions roughly 20 times. The flights were in pairs at maximum speed and high altitude, between 17,000 and 23,000 m. On 6 November 1971, a Soviet MiG-25 operating out of Egypt flying at Mach 2.5 was met by Israeli F-4Es and fired upon unsuccessfully. A MiG-25 was tracked flying over Sinai at Mach 3.2 during this period. The MiG-25 engines went into overspeed, which led to them being scrapped. Det 63 was sent back home in 1972. Soviet-operated reconnaissance Foxbats returned to Egypt in 19–20 October 1973, during the Yom Kippur War. Det 154 remained in Egypt until late 1974.
During the 1970s, the Soviet air force conducted reconnaissance overflights across Iran using its MiG-25RBSh aircraft in response to joint US-Iran recon operations.
The Swedish Air Force observed Soviet Air Defence MiG-25s via radar regularly performing intercepts at 19,000 m and 2.9 km behind the Lockheed SR-71 Blackbird at 22,000 m over the Baltic Sea in the 1980s.

Syria

On 13 February 1981, the Israeli Air Force sent two RF-4Es over Lebanon as decoys for Syrian MiG-25 interceptors. As the MiGs scrambled, the RF-4Es turned back delivering chaff and using ECM pods. Two IDF/AF F-15As were waiting for the MiGs and shot one of them down with AIM-7F missiles. The other MiG was able to escape. In a similar engagement, on 29 July 1981, a Syrian MiG-25 was again downed by an Israeli F-15A, after which a second MiG-25 launched its R-40 missiles at the F-15 and its wingman, but they missed.
The first reported activity of Syrian MiG-25 aircraft in the civil war was on 8 February 2014, when two Turkish Air Force F-16s were scrambled to intercept a Syrian MiG-25 which was approaching the Turkish border. On 27 March 2014, a MiG-25 was clearly filmed while flying at medium altitude over Hama Eastern countryside, possibly delivering the bomb seen hitting the ground in the same video.

Iraq

Iran–Iraq War

All confirmed air-to-air kills of the MiG-25 were made by Iraq.
The MiG-25 was in service with the Iraqi Air Force during the Iran–Iraq War. On 19 March 1982 an Iranian F-4E was badly damaged by a missile fired by an Iraqi MiG-25. Iraqi MiG-25s made another kill against Iran in February 1983, when an Iraqi MiG-25PD shot down an Iranian C-130. In April 1984, an Iraqi MiG-25PD shot down an Iranian F-5E. On 21 March 1984, an Iraqi MiG-25PD shot down an Iranian F-4E and on 5 June 1985 an Iraqi MiG-25PD shot down a second Iranian F-4E. On 23 February 1986, an Iraqi MiG-25PD shot down an Iranian EC-130E and on 10 June an RF-4E, later in October 1986, an Iraqi MiG-25PDS shot down a second RF-4E.
The most successful Iraqi MiG-25 pilot of the war was Colonel Mohommed Rayyan, who was credited with ten kills. Eight of these were while flying the MiG-25PD from 1981 to 1986. In 1986, after attaining the rank of Colonel, Rayyan was shot down and killed by Iranian F-14s. For the majority of the air combat Iraqi pilots used R-40 missiles.
On 3 May 1981, an Iraqi MiG-25PD shot down an Algerian Gulfstream III. On 2 October 1986, an Iraqi MiG-25PD shot down a Syrian MiG-21RF.
According to research by journalist Tom Cooper, at least ten MiG-25s may have been shot down by Iranian F-14s during the Iran-Iraq war. Only three MiG-25 losses were confirmed by Iraq.

Persian Gulf War

During the Persian Gulf War, a U.S. Navy F/A-18, piloted by Lt Cdr Scott Speicher, was shot down on the first night of the war by a missile fired by a MiG-25. The kill was reportedly made with a Bisnovat R-40TD missile fired from a MiG-25PDS flown by Lt. Zuhair Dawood of the 84th squadron of the IQAF,
Two IQAF MiG-25s were shot down by U.S. Air Force F-15s on 19 January. The MiGs attempted to hide from the F-15s by using chaff and electronic jammers in order to engage the F-15s undetected. However the F-15 pilots were able to reacquire the two Iraqi MiG-25s and shot both down with AIM-7 Sparrow missiles. In another incident, an Iraqi MiG-25PD, after eluding eight USAF F-15s at long range, fired three missiles at General Dynamics EF-111A Raven electronic warfare aircraft, forcing them to abort their mission and leave attacking aircraft without electronic jamming support.
In a different incident, two MiG-25s approached a pair of F-15s, fired missiles at long range which were evaded by the F-15s, and then outran the American fighters. Two more F-15s joined the pursuit, and a total of 10 air-to-air missiles were fired at the MiG-25s, though none reached them. 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.
On 30 January 1991, an IRAF MiG-25 damaged a USAF F-15C by a R-40 missile in the Samurra Air Battle. Iraq claims it was shot down and fell in Saudi Arabia.
After the war, on 27 December 1992, a U.S. F-16D downed an IQAF MiG-25 that violated the no-fly zone in southern Iraq with an AIM-120 AMRAAM missile. It was the first USAF F-16 air-to-air victory and the first AMRAAM kill.
On 23 December 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 aircraft, 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.
No Iraqi aircraft were deployed in the U.S. invasion of Iraq in 2003, with most Iraqi aircraft being hidden or destroyed on the ground. In August 2003, several dozen Iraqi aircraft were discovered buried in the sand.

India

The MiG-25 was kept a guarded secret in India, designated Garuda named after the large mythical bird of God Vishnu from Hindu scriptures. It was used extensively in the Kargil War and Operation Parakram, conducting aerial reconnaissance sorties over Pakistan.
In May 1997, an Indian Air Force Mikoyan MiG-25RB reconnaissance aircraft created a furor when the pilot flew faster than Mach 3 over Pakistani territory following a reconnaissance mission into Pakistan airspace. The MiG-25 broke the sound barrier while flying at an altitude of around 20,000 m, otherwise the mission would have remained covert, at least to the general public. The Pakistani Government contended that the breaking of the sound barrier was a deliberate attempt to make the point that the Pakistan Air Force had no aircraft in its inventory that could come close to the MiG-25's cruising altitude. India denied the incident but Pakistan's Foreign Minister, Gohar Ayub Khan, believed that the Foxbat photographed strategic installations near the capital, Islamabad.
Lack of spare parts and India's acquisition of unmanned aerial vehicles and satellite imagery eventually led to its retirement in 2006.
An aerial observation of the solar eclipse of October 24, 1995 over India was conducted by a MiG-25, which took images of the eclipse at an altitude of 25,000 m.

Libya

Libya was a major user of the MiG-25 as it imported 96 MiG-25PD interceptor, MiG-25PU trainer and MiG-25RBK reconnaissance aircraft in the late 1970s and early 1980s.
During the 1980s, Libya confronted the United States over some claims over the extension of its territorial waters. These incidents prompted a number of encounters between the opposing forces as it happened during the Gulf of Sidra incident with the Libyan MiG-25s taking part in them.
During the following years, the Libyan MiG-25 fleet was grounded, lacking maintenance. As MiG-25 air-frames were grounded for several years, NATO attacks spared them during the Libyan Civil War.
In 2014 and 2015, the Libyan forces under the New General National Congress controlled a number of former LARAF air-frames, that were retired and stored before the Libyan Civil War in 2011, among them a number of MiG-25s. Technicians started working on some of the air-frames to push them back to service in the fight against the opposing internationally recognized Libyan government forces.
On 6 May 2015, a New General National Congress MiG-25PU crashed near Zintan while attacking the civilian airport controlled by the opposing internationally recognized Libyan government, the pilot ejected and was captured by opposing forces which also claimed they downed the jet. The jet may have been on one of its first flights after re-entering service.

Variants

Prototypes

;Ye-155R
;Ye-155P
;Ye-266

Interceptors

;MiG-25P
;MiG-25PD
;MiG-25PDS
;MiG-25PDSL
;MiG-25PDZ
;MiG-25M
;Ye-266M
;Izdelye 99

Reconnaissance and strike versions

;MiG-25R
;MiG-25RB
;MiG-25RBV
;MiG-25RBT
;MiG-25RBN
;MiG-25RR
;MiG-25RBK
;MiG-25RBF
;MiG-25RBS
;MiG-25RBSh
;MiG-25BM "Foxbat-F": Single-seat defence-suppression aircraft, armed with Kh-58 or Kh-31 air-to-surface missiles.

Conversion trainers

;MiG-25PU
;MiG-25RU
;Ye-133

Operators