weight.
- Maximum acceleration (g-load) rating was just 2.2 g (21.6 m/s²) with full fuel tanks, with an absolute limit of 4.5 g (44.1 m/s²). One MiG-25 withstood an inadvertent 11.5 g (112.8 m/s²) pull during low-altitude dogfight training, but the resulting deformation damaged the airframe beyond repair.24
- Combat radius was 299 kilometres (186 mi), and maximum range on internal fuel (at subsonic speeds) was only 1,197 kilometres (744 mi) at low altitude (< 1000 meter).6
- The airspeed indicator was redlined at Mach 2.8, with typical intercept speeds near Mach 2.5 in order to extend the service life of the engines.22 A MiG-25 was tracked flying over Sinai at Mach 3.2 in the early 1970s, but the flight led to the destruction of its engines.23
- The majority of the on-board avionics were based on vacuum-tube technology, not solid-state electronics. Although they represented aging technology, vacuum tubes were more tolerant of temperature extremes, thereby removing the need for environmental controls in the avionics bays. The vacuum tubes were also easy to replace in remote northern airfields where sophisticated transistor parts might not have been readily available. With the use of vacuum tubes, the MiG-25P's original Smerch-A (Tornado, NATO reporting name "Foxfire") radar had enormous power – about 600 kilowatts. As with most Soviet aircraft, the MiG-25 was designed to be as rugged as possible. The use of vacuum tubes also makes the aircraft's systems resistant to an electromagnetic pulse, for example after a nuclear blast.25
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 ("Foxbat-E").6
Plans for a new aircraft to develop the Foxbat'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.6
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 and stayed until July 1972. They were operated by the Soviet 63rd Independent Air Detachment (Det 63) set up specially 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 17,000–23,000 m).6
On 6 November 1971, an Egyptian MiG-25 flying at Mach 2.5 was met by Israeli F-4Es and fired upon unsuccessfully.26 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 their later destruction.7 Unit Det 63 was sent back home in 1972, though reconnaissance Foxbats were sent back to Egypt in 19–20 October 1973 during the Yom Kippur War.26 Unit Det 154 remained there until late 1974.
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.27 In a similar engagement, on 29 July 1981, a Syrian MiG-25 was again downed by an Israeli F-15A,2829 after which a second MiG-25 launched its R-40 missiles at the F-15 and its wingman, but they missed.30 However, other sources say the missiles hit and downed one of the F-15s.29 On 31 August 1982, a third Syrian MiG-25 was damaged by an Israeli Hawk SAM and then destroyed by an F-15.31
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 missile fired by an Iraqi MiG-25.33 Iraqi MiG-25s made another kill against Iran in February 1983, when an Iraqi MiG-25PD shot down an Iranian C-130. On April 1984, an Iraqi MiG-25PD shot down an Iranian F-5E. On 21 March 1984, an Iraq