With careers lasting five or six decades, the American B-52 bomber and A-10 attack plane are frequently used examples of airplanes that defy aging. But keep in mind that, unlike the Mikoyan MiG-31, the Warthog and the Stratofortress never had to fly at nearly three times the speed of sound.
At a service altitude of roughly 82,000 feet, the aircraft could reach speeds of three times the speed of sound (24,994 meters). Despite those impressive numbers, Soviet pilots who flew the Foxbat reported it was a nightmare to fly. In particular, during takeoff and at low altitudes.
Concerns were heightened by the possibility of breaking the compressor blades in the Foxbat's two massive Tumansky R-15 turbojet engines by pushing the aircraft above the Mach three limit. One or both engines would very certainly self-destruct if such a catastrophic event occurred at Mach three 20 kilometers above the ground, causing the jet to disintegrate at a speed of more than 2,000 miles per hour (3,219 kph).
The Foxbat was practically useless if there was a circumstance where the Soviets needed the MiG-25 to shoot down a Blackbird. This was understood by the Soviet leadership fairly early in the MiG-25's operational history. The Soviet high command made the prudent decision to instruct Mikoyan-Gurevich to completely redesign the Foxbat because they were unwilling to write off the plane and cut their losses.
The outcome was a completely new aircraft with the NATO codename Foxhound. The MiG-31 and the long-since-defunct MiG-25 share a lot of similarities upon first glance. The two jet interceptors' massive engines require that the aircraft be as big as certain bombers from World War II in order to accommodate them.
As the skin of both planes is peeled away, the similarity disappears. The Foxbat's fuselage is much shorter than the Foxhound's. With full afterburners engaged, the modern Soloviev D-30F6 turbojet engines produced a barely credible thrust of 21,000 pounds (93 kN) and more than 34,000 pounds (152 kN).
Two of these could allow the MiG-31 to exceed Mach three for a longer amount of time than the MiG-25. Because to these advancements, the new Foxhound had a solid chance of shooting down nuclear ICBMs as well as Blackbird espionage planes with sufficiently sophisticated missiles.
The Foxhound's missiles represent some of the pinnacles of contemporary warfare. The R-33 long-range air-to-air missile, which was first developed to combat the SR-71, is the most famous of these. Up to four R-33 missiles can be fired at different aerial targets by the Foxhound's sophisticated phased scanning array radar.
Little information is known regarding the intricacies of the Foxhound's operational past, and the MiG-31 was never given the opportunity to shoot down a Blackbird espionage plane. As the Soviet Union fell, a lot of this data was probably destroyed. What is known is that between 1975 and 1999, more than 500 were created.