The MiG-25M is a modified interceptor powered by new R15BF2-300 engines, each developing 13,500 kgf. Development of the MiG-25M version was stipulated by the Council of Ministers resolution of 13 April, 1972. R15BF2-300 engines producing better thrust and boasting better ergonomics as compared to series-made R15B-300 were to enhance the interceptor's ceiling and speed, thus increasing the range and altitude of intercepts as well as flight
duration. The plane had been designed in the period of 1970-72. In 1973, based on Mikoyan's drafts and documents, the first
MiG-25P #1710 prototype (reg. #710) was made at the Gorky aircraft production plant. The plane boasted the Smerch-A2 radar and R15BF2-300 engines. Its flight testing was started in 1974 with the preliminary approval for series production being issued the next year.
The MiG-25P #710 underwent its official testing in 1976 but was never put into series production due to the need to concentrate the efforts on development of the re-worked MiG-25PD version.
The installation of engines R15BF2-300 in the modified versions of the MiG-25 recon variant was also provided for (they were designated E-155M too). This is a single-seat supersonic reconnaissance bomber, a follow-up version of the MiG-25RB with the R15BF2-300 engines, more sophisticated Peleng-2 navigation system and improved (up to 5,000 kg) bomb load capability. An experimental model of this aircraft (MiG-25RB # 703) entered the testing programme in February 1976. Testing of the new more powerful and fuel-efficient engines was also carried out on MiG-25 RB #401 and #601. In 1976, the testing of R15BF2-300 engines aboard the MiG-25RB were accomplished. A. Fedotov and P. Ostapenko in 1975 on the MiG-25RB #601, which in protocols of the FAI was known as E-266M with RD-F engines, put up three world records in speed-climbing to 25, 30 and 35 km altitude. In 1977, A. Fedotov on a R15BF2-300-equipped aircraft established three flight altitude records: 37,650 m (empty) and 37,080 m (with one- and two-tonne loads). For a number of reasons R15BF2-300 engines had never been installed on the production MiG-25RB. The preference was given to a double fighter - interceptor the MiG-25MP - to the prototype the MiG-31.
|Type||E-155M (MiG-25M, E-266M)|
|NATO code name||FoxBat|
|Dimensions & Weight|
|Overall height, m||6|
|Wing Span, m||14,1|
|Take-off weight, kg||36000 - 41000|
|Internal fuel, kg||14570|
|Engines||2 Turbojet R-15BF2-300|
|Thrust, kgf (kN)||in afterburner||13500 (132,5)|
|with drop tank 5300 l||2510|
|Max. speed at altitude, km/h (M=)||3200 (3)|
|Practical ceiling, m||24200|
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