МиГ-25 – где правда и где ложь?

The development of the MiG-25 began in the 1950s, paralleling American efforts to develop a Mach 3 bomber and interceptor aircraft, including the (ultimately abortive) 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 be 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 aircraft, which carried the bureau designation Ye-155, reached the prototype stage, it seemed that the Ye-155 would still be a useful addition to the PVO interceptor force 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 confirmed that this was not in fact the case.(???)
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The MiG-25 was capable of exceptional 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 in 1977 flew to an altitude of 123,524 ft (37,650 m) in 1977. Some believed that the MiG-25 was designed against the SR-71 Blackbird, made to deter, or at least threaten the 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. The limited maneuverability of the Mig-25 has often been overstated by Western observers, as under the same high performance parameters, the SR-71 has even more restrictive stress limitations.

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.

 

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Another case was related to the Soviet MiG-25 Foxbat airplane. The airplane was first seen in an air show in 1967 and it was said that the airplane was capable of a Mach number of about 3. Again there was some doubt of this performance in the minds of Western analysts since the airplane appeared to be fairly blunt and had a wing sweep angle of only 42 degrees. Estimates of the overall planform and profile shape for the airplane could be gotten from the airshow photographs. With these geometric estimates, an analytical study was undertaken to determine the
minimum drag level that would be required to meet the stated speed capability. Constraints that were to be respected included the following – maintain volume for known engine size; maintain volume requirements for internal ducts compatible with necessary thrust levels; maintain volume for landing gear stowage; maintain wing thickness compatible with wing structural requirements and with internal fuel stowage. Estimates were then made for various body cross-sectional shapes and for various wing airfoil section shapes. These various geometric shapes were submitted to the supersonic area-rule analysis technique for an analytical estimate of the minimum drag. Within these constraints an airframe shape was found that was compatible with the drag required for Mach number 3 flight.
A wind tunnel model for the analytically determined shape was designed and fabricated at NASA-Langley. Tests of the model were subsequently made in the Langley UPWT that verified the Mach number 3 capability. It should be noted that a MiG-25 airplane defected to Japan in 1976 and that a detailed examination of the airplane indicated that the analytical shape developed at NASA-Langley was essentially correct.