Kh-31

Kh-31 (NATO reporting name: AS-17 'Krypton')
Kh-31A
Type	Medium-range air-to-surface missile
Place of origin	Soviet Union
Service history
In service	1988–present
Used by	Russia, China, India, Algeria
Production history
Manufacturer	Tactical Missiles Corporation (Zvezda-Strela before 2002)
Unit cost	$550 000 (2010)
Produced	1982
Specifications
Weight	Kh-31A :610 kg (1,340 lb) Kh-31P :600 kg (1,320 lb)
Length	Mod 1 : 4.700 m (15 ft 5.0 in) Mod 2 (AD/PD) : 5.3 m (17 ft 5 in)
Diameter	360 mm (14 in)
Warhead	HE shaped charge
Warhead weight	Kh-31A :94 kg (207 lb) Kh-31P :87 kg (192 lb)
Detonation mechanism	Impact
Engine	Solid fuel rocket in initial stage, ramjet for rest of trajectory
Wingspan	914 mm (36.0 in)
Propellant	kerosene
Operational range	Kh-31A: 25 km–103 km (13.5–55.6 nmi; Kh-31P: up to 110 km (60 nmi; 70 mi)
Speed	Kh-31A/P: 2,160–2,520 km/h (1,340–1,570 mph) MA-31: Mach 2.7 (low), Mach 3.5 (high)
Guidance system	Kh-31A: inertial guidance with active radar homing Kh-31P: inertial with passive radar
Launch platform	Both : Su-27SM, Su-30MKI, Su-34, Su-35, MiG-29M, HAL Tejas Mk1 and Mk2, MiG-29K Kh-31A only : Su-33 Also : Su-24M

The Kh-31 (Russian: Х-31; AS-17 'Krypton') is a Russian air-to-surface missile carried by aircraft such as the MiG-29 or Su-27. It is capable of Mach 3.5 and was 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.

The proliferation of surface-to-air missiles (SAMs) has made the Suppression of Enemy Air Defence a priority for any modern air force intending offensive action. Knocking out air search radars and fire control radars is an essential part of this mission. ARMs must have sufficient range that the launch platform is out of range of the SAMs, high speed to reduce the risk of being shot down and a seeker that can detect a range of radar types, but they do not need a particularly big warhead.

The Soviet Union's first ARM was developed by the Raduga OKB engineering group responsible for the Soviet Union's missiles for heavy bombers. The Kh-22P was developed from the 6-tonne Raduga Kh-22 (AS-4 'Kitchen') missile. Experience gained with this led in 1973 to the Kh-28 (AS-9 'Kyle') carried by tactical aircraft such as the Su-7B, Su-17 and Su-24. It had Mach 3 capability and a 120 km (60 nmi) range, greater than the contemporary AGM-78 Standard ARM. The Kh-28 was succeeded by the Kh-58 in 1978, which has similar speed and range but replaces the dual-fuel rocket motor with a much safer RDTT solid propellant.