R-37 (missile)

The Vympel R-37 (NATO reporting name: AA-X-13/AA-13 Arrow) is a Russian air-to-air missile with an extremely long range. It has also had the names K-37, Izdeliye 610 and R-VD (Raketa-Vysokaya Dalnost, "Very Long Range Missile"), and the NATO codename 'Andi'.

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.

Design
The R-37 was developed from the Vympel R-33. 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 nmi for a direct shot to 215 nmi 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).

History
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 nmi. However, the programme 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 programme to update the Foxhound with a new radar and ground attack capability.

Production
The R-37 is now in production to equip upgraded Russian MiG-31BM Foxhound interceptors, and export MiG-31BM aircraft for Syria. Despite the early intent to integrate the weapon on the Flanker, this has yet to be reported.

Similar weapons

 * AIM-54 Phoenix (retired) - 100 nmi-range missile once carried by the now decommissioned US Navy's F-14 Tomcat.
 * 9M317 surface-to-air missile of Buk missile system
 * Novator KC-172