Entering service in 1981, the MiG-31 was the first fourth-generation combat aircraft to join the Soviet military and is considered the most capable in the Russian Air Force today in terms of air-to-air combat performance.

The Foxhound was the first combat aircraft in the world to use a phased array radar, the Zaslon, and other than the Foxbat it remains the fastest combat jet to enter service anywhere in the world.
The MiG-31 had an extremely long range and was the first aircraft of its kind in the world capable of sustained cruising at supersonic speeds. The aircraft’s maximum speed remains uncertain, with most sources indicating a speed of over Mach 2.8 and some estimating a speed of over Mach 3.

The Foxhound is expected to remain in service into 2040 and is quite possibly the most important combat jet in Russian service, due to the wide range of roles it can perform and to its growing versatility as new weapons have been integrated.