The Mig-31 'Foxhound' was developed as the replacement of the Mig-25
'Foxbat',the prototype Ye-155MP took the first flight on 16 September 1975.As
the heaviest fighter/interceptor in the world,the Mig-31 is much heaver than
other similar aircrafts.At the same time,tow powerful D-30-F6 engines and a
stronger airframe gave it a top speed to Mach 2.8 at high-altitude and Mach 1.23
at low-altitude.
The Mig-31B were put out under the threaten of
the western countries in the 1980s,they can be regarded as the mixture of the
Mig-31BS which developed from the basic Mig-31 sans suffixe and the Mig-31DZ,the
IFR system testbed,however,a series of new avionics and WCS made it much more
efficient than any other version.