Russian Air Force has taken delivery of 24 modernised MiG-31BM 'Foxhound' interceptors.
12-13 MiG-31 airframes will be upgraded each year and more than 130 aircraft are expected in the inventory.
United Aircraft Corporation is modernising 110 interceptors by 2019.
The service life of the modernised aircraft will be 40-45 years, and could be extended to 50. Russia's MiG-31 aircraft have been operational for 20-30 years. janes