Making The MiG-31 All Better

Despite problems with recently refurbished MiG-31 fighters Russia is moving forward with yet another round of fixes and improvements. In particular the D30F6 engines will be tweaked and upgraded to make them more powerful, efficient and reliable. This comes in the aftermath of two crashes (in early and late 2013) that involved these engines. In December 2013 Russia grounded all 122 of its MiG-31 fighters after one of them crashed because both of its engines failed.

See the full article at Strategy Page