The design of the MiG-25 was directed entirely at achieving high speed and high altitude.
Originally developed to intercept the North American B-70 Valkyrie, a Mach 3 bomber, the Mikoyan-Gurevich MiG-25 (NATO reporting name: Foxbat) remains one of the fastest military aircraft ever to enter operational service. It was also the last aircraft designed by Mikhail Gurevich before his retirement.
It’s fascinating to note how the F-15—along with virtually all fighters of that era—was shaped by the MiG-25’s influence. The Foxbat’s appearances at Soviet airshows and May Day parade flypasts were striking, and the Soviets issued alarming performance claims that could not be independently confirmed. The F-15 Eagle was conceived specifically to counter these reported capabilities of the MiG-25. However, Western experts did not get the chance to examine a MiG-25 firsthand until a pilot defected and landed one in Japan, by which time the F-15 was already in production.
In truth, the MiG-25 was a highly specialized interceptor built for a very narrow mission set, whereas the F-15 was engineered as a powerful, all-weather, highly maneuverable tactical fighter designed to allow the US Air Force (USAF) to achieve and maintain air superiority over the battlefield.
Even so, despite being more advanced than the Foxbat, the F-15 was never able to match the MiG-25’s top speed. How come?
‘Simple, really: the MiG-25 HAD to be fast. It was meant to intercept one of the fastest aircraft ever conceived—what would eventually become the B-70 strategic bomber, capable of sustained Mach 3 flight,’ explains Jure Trnovec, an aviation expert, on Quora.
‘For that to happen, it had to be able to go just as fast, if not faster, and carry a large radar to guide its missiles. Since the Soviets hadn’t really mastered working with titanium at that time (not to mention it was eye-wateringly expensive), and aluminum was not quite heat-resistant enough for Mach 3 flight, it was made out of steel, which is quite heavy, but it compensated for that with engines of simply ridiculous size.
‘Even though those engines would be shot after flying at Mach 3, it didn’t matter to the Soviets, as long as they stopped the nuclear-armed bombers that were threatening their homeland.’
Trnovec concludes;
‘As it was so beautifully narrated by Peter Ustinov in what was perhaps one of the best documentaries in Discovery’s great Wings series (Remember the time when Discovery actually made content worth watching? Good times.) :
‘The design of the MiG-25 was directed entirely at achieving high speed and high altitude. It was not meant to be maneuverable. It was not meant to have good low-speed performance. It was simply meant to travel through the air as fast as Soviet ingenuity could make it go.’
Photo by Dmitriy Pichugin, Leonid Faerberg (transport-photo.com), Bukvoed, and Alan Wilson from Peterborough, Cambs, UK, via Wikipedia
