Mikoyan-Gurevich MiG-25

Mikoyan-Gurevich MiG-25 — The Mikoyan-Gurevich MiG-25 (NATO reporting name: Foxbat) is a supersonic interceptor and reconnaissance aircraft that was among the fastest military aircraft to enter service. Designed by the Soviet Union’s Mikoyan-Gurevich bureau the first prototype flew in 1964 with entry into service in 1970. It has a top speed of Mach 2.83+ (as high as Mach 3.2, but at risk of significant damage to the engines), and features a powerful radar and four air-to-air missiles.

When first seen in reconnaissance photography, the large wing planform suggested an enormous and highly maneuverable fighter. This was during a period of 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 off serious concern in the west, and prompted dramatic increases in performance for the McDonnell Douglas F-15 Eagle in late 1960s. The capabilities of the MiG-25 were better understood in 1976 when Soviet pilot Viktor Belenko defected in a MiG-25 to the United States via Japan. The large wing turned out to be due to the aircraft’s very heavy weight.

Production of the MiG-25 series ended in 1984 after completion of 1,190 aircraft. A symbol of the Cold War, the MiG-25 flew with a number of Soviet allies and former Soviet republics, remaining in limited service in Russia and several other nations. It remains the fastest combat aircraft ever produced.

Development

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 “Å-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. It was widely believed that the MiG-25 was developed in response to the XB-70. However, A. Belyankov, head of the MiG design bureau, claimed that this was not in fact the case.

Because of the thermal stresses incurred in flight above Mach 2, the MiG-25 could not be constructed with traditional aluminum 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 decided the MiG-25 would largely be constructed of nickel alloy 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 alloy were used in the construction of the MiG-25.

The first prototype, which was actually the 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 “Å-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 3.0 and a ceiling of 90,000 ft (27,000 m), although a specially modified MiG-25 flew to an altitude of 123,524 ft (37,650 m) in 1977. Some believed that the MiG-25 was designed to intercept the SR-71 Blackbird and to deter, or at least threaten, other high-altitude, high-speed aircraft. However, its 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 total destruction of the engines. Even Mach 2.8 was difficult to reach without overspeeding the turbines.

Overall, the MiG-25 did not meet its design goals as an interceptor. Interception, to be successful, requires the interceptor to have 25% to 50% more speed and maneuverability than the intended target, plus reasonable endurance and range. The MiG-25 could not match the speed of the B-70 or SR-71, and once reaching their altitude, it could only maintain top speed for 10 minutes.These factors made a successful interception difficult.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.