The Kh-31PD (Kh-31AD/Kh-31 Mod 2) medium-range supersonic anti-radiation missile is designed to destroy medium- and long-range SAM systems’ radars, air operations control radars and early warning radars and has a high supersonic speed through the use of a scramjet with a built-in booster. There has been talk of adapting it to make an “AWACS killer”, a long-range air-to-air missile. There are several variants; The Kh-31 (Russian: AS-17 ‘Krypton’) is a Soviet and 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. The Kh-31A is equipped with the ARGSN-31 jam-resistant active radar guidance system capable of discriminating the target from a dense homogenous group. The Kh-31PD uses a passive radar guidance system capable of operating in a broad band of frequencies.
In many respects the Kh-31 is a miniaturised version of the P-270 Moskit (SS-N-22 ‘Sunburn’) and was reportedly designed by the same man. The missile is conventionally shaped, with cruciform wings and control surfaces made from titanium. The Kh-31PD missile flies at a high speed of over Mach 3, at over 1,000 meters per second to strike enemy air defenses. On launch, a solid-fuel booster in the tail accelerates the missile to Mach 1.8 and the motor is discarded. It was necessary to design it to reach a technologically new level, arrange its production and upgrade it so that it can effectively cope with its objectives. The missiles employ mid-course radar guidance and terminal homing. This weapon can win duel battles with the Patriot system.
Kh-31P (Type 77P) is a passive seeker head for use as an anti-radiation missile. Stays at high altitude throughout its flight, allowing higher speeds and increasing range to 110 km (60 nmi; 70 mi). Kh-31PM is a modernized version of the Kh-31P with increased range and new multi-band L-130 seeker sensor. Kh-31PK installed non-contact fuse, maximum speed 900 m/s, range 120–160 km. Destined for Su-27SM, Su-30MK, Su-35. In serial production since 2009. Kh-31PD (“Kh-31 Mod 2”) – increase range through increasing the fuselage from 4.70 m (15 ft 5 in) to 5.3 m (17 ft 5 in) long. As of 2012, the Kh-31PD is serially produced. Kh-31AD is in series production since 2013.
The missile is equipped with a modern combined guidance system, including an inertial control system and a passive wide-range self-guidance radar head. The missile guidance system provides for the search and capture of a radio-emitting target in an autonomous mode or according to the target designation data of the carrier equipment when suspended under an aircraft, as well as target tracking and generation of signals for its guidance after launch.
Its seeker can operate in several homing modes, including automatic search and external control modes. If irradiated by an enemy radar, the missile can perform an evasive 10-g pull-up maneuver. Aircraft carrier’s radars like the Zhuk, Kopio and others are used for target detection. The missiles are transported and stored in sealed containers.