R-37 (missile)

The Vympel R-37, with the NATO reporting name AA-13 Axehead, is a Russian very long-range air-to-air missile, also known as K-37, izdeliye 610 and, in its export form, RVV-BD. It was developed from the R-33 and is meant to shoot down tankers, AWACS and other command and surveillance aircraft while keeping the launching aircraft out of reach of any fighters that protect the target. Its semi-active seeker was replaced with a variant of the Agat 9B-1388 active seeker, and folding tail controls allow carriage on aircraft smaller than the MiG-31. Reported range depends on the variant and the flight profile: about 150 km for a direct shot, up to around 400 km for the R-37M on a cruise-glide profile, and up to 200 km for the export RVV-BD. The missile was designed in the early 1980s and first flown in 1989, the program appears to have been dropped around 1998 and restarted in late 2006, and the R-37M finished operational validation tests in 2018. It has been fired from MiG-31 and Su-35S aircraft in the war in Ukraine since 2022 and is operated by Russia and Algeria.