R-37 (missile)

R-37 AA-X-13 Arrow
R-37M at 2013 MAKS Airshow
Type	air-to-air missile
Place of origin	Russia
Specifications
Weight	600 kilograms (1,320 lb)
Length	4.20 metres (13 ft 9 in)
Diameter	38 centimetres (15 in)
Warhead	HE, fragmenting
Warhead weight	60 kg (135 lb)
Wingspan	0.7 m (2 ft 4 in)
Propellant	Solid rocket
Operational range	150-398 km
Speed	Mach 6
Guidance system	Inertial with mid-course update, semi-active and active radar homing

The Vympel R-37 (NATO reporting name: AA-X-13/AA-13 Arrow) is a Russian air-to-air missile with very long range. The missile and its variants also had the names K-37, izdeliye 610 and R-VD (Raketa-Vysokaya Dalnost, "Very Long Range Missile"), and the NATO codenames 'Arrow' and 'Andi'. It was developed from the R-33 (missile).

It was designed to shoot down AWACS and other C4ISTAR aircraft whilst keeping the launch platform out of range of any fighters that might be protecting the target.

The R-37 was developed from the R-33 (missile). For compatibility with aircraft that did not have the MiG-31's sophisticated radar, the semi-active seeker was replaced with a variant of the Agat 9B-1388 active seeker; mid-body strakes enhance lift and hence range, and folding tail controls allow semi-conformal carriage on planes that are not as big as the MiG-31. According to Defence Today the range depends on the flight profile, from 80 nautical miles (150 km) for a direct shot to 215 nautical miles (398 km) for a cruise glide profile. According to Jane's there are two variants, the R-37 and the R-37M; the latter has a jettisonable rocket booster that increases the range to "300-400km" (160–220 nm).

The R-37M designation has since been used for a modernized variant of the missile, also known as RVV-BD. This will be carried by the modernized MiG-31BM and Su-35S fighters. It is not known if the long range air-to-air missile for the PAK FA, designated the izdeliye 810, is a derivative of the R-37M.

The missile can attack targets ranging in altitude between 15–25,000 metres.

The missile was designed in the early 1980s and first flown in 1989. Testing of the R-37 continued through the 1990s; in 1994 a trial round scored a kill at a range of 162 nautical miles (300 km). However, the program appears to have been dropped around 1998 on grounds of cost.

Work on the missile appears to have restarted in late 2006, as part of the MiG-31BM program to update the Foxhound with a new radar and ground attack capability.