Kh-31: Mikoyan MiG-29, Sukhoi Su-27, Sea skimming, Kilometre, Nautical mile, Mile, Anti-radiation missile, YJ-91, Moskit, AGM-88 HARM

The Kh-31 (Russian: ?-31; AS-17 'Krypton') is a Russian air-to-surface missile carried by aircraft such as the MiG-29 Fulcrum or Su-27 Flanker. It is a sea skimming cruise missile with a range of 110 kilometres (60 nmi; 70 mi) or more and capable of Mach 3.5, the first supersonic anti-ship missile that could be launched by tactical aircraft. There are several variants, it is best known as an anti-radiation missile (ARM) but there are also anti-shipping and target drone versions. There has been talk of adapting it to make an "AWACS killer", a long-range air-to-air missile.