Kh-23 Grom

Kh-66/Kh-23 Grom (NATO reporting name: AS-7 'Kerry')
AS-7 'Kerry'
Type	Tactical air-to-surface missile
Place of origin	Soviet Union
Service history
In service	Kh-66 :20 June 1968[1] Kh-23 :1973[2] Kh-23M :1974[2]
Used by	FSU, Warsaw Pact, Iraq, India[3]
Production history
Designer	Yurii N. Korolyov[1]
Manufacturer	Zvezda-Strela
Specifications
Mass	A921 :287 kg (633 lb)[3]
Length	A921 :3.525 m (11 ft 7 in)[3]
Diameter	27.5 cm (10.8 in)[3]
Wingspan	78.5 cm (2 ft 6.9 in)[3]
Warhead weight	111 kg (245 lb)[3]
Engine	Solid fuel rocket[3]
Operational range	2–10 km (1.1–5.4 nmi)[3]
Maximum speed	2,160–2,700 km/h (1,340–1,680 mph)[3]
Guidance system	Kh-66 :Line-Of-Sight Beam riding Kh-23 :Radio command guidance Grom-B :TV guidance
Launch platform	Yak-38,MiG-21PFM, MiG-23, MiG-27, Su-17M3/20/22/22M3/M4,[3]

The Zvezda Kh-66 and Kh-23 Grom (Russian: Х-23 Гром 'Thunder'; NATO: AS-7 'Kerry') are a family of early Soviet tactical air-to-surface missiles with a range of 10 km. They were intended for use against small ground or naval targets. The Kh-66 was effectively a heavy-warhead, beam-riding version of the K-8 (AA-3 'Anab') air-to-air missile rushed into service in Vietnam in 1968. The Kh-23 was an improved Kh-66 with command-guidance, similar to the AGM-12 Bullpup.

Work on air-to-air missiles had started at the Kaliningrad Engineering Plant (then known as Plant #455, and later merged into Zvezda-Strela) in 1955.^[1] This had resulted in the Kaliningrad K-5 (AA-1 'Alkali') family of beam-guided missiles, including the K-51 (RS-2-US) carried by the Su-9 'Fishpot'. OKB-4 Molniya (later Vympel NPO) under Matus Bisnovat would go on to produce missiles such as the AA-6 Acrid.^[1] Meanwhile, in 1963 the RS-2-US was tested as an air-to-surface missile.^[1] It was concluded that the small warhead and inaccurate guidance made such an application "pointless".^[1]

However, in 1965 North Vietnam requested an air-to-surface missile from the Soviet government;^[1] the AGM-12 Bullpup had entered service with the US Air Force before the start of the Vietnam War. In April 1965 OKB-134 (later NPO Vympel) started work on this missile under the project name Kh-23, but they had problems developing a guidance system that would work with existing aircraft.^[3] As a result, Yurii N. Korolyov came up with his own proposals based on the earlier experiments with the RS-2-US. A design bureau to develop the RS-2-US for surface targets was set up under Korolyov by decree #100 of 12 March 1966 of the Ministry of the Aircraft Industry;^[1] this bureau would become the Zvezda OKB in 1976.^[4]

The resulting weapon used the body of a K-8 (AA-3 'Anab'), K-5 guidance and propulsion systems, but increased the warhead from 13 kg (29 lb) to 100 kg (220 lb).^[5] This had the big advantage of allowing the new weapon to be fitted to any aircraft capable of firing the K-5.^[3] Design began in 1966,^[4] so the project was known as Kh-66 or Izdeliye 66 ('Article 66'). The Kh-66 was a beam-riding weapon that was first tested on the MiG-21PFM,^[4] with the first launches of the missile in September 1966^[6].It entered production in 1968 for that aircraft. The Kh-66 was only an interim solution as it required the launch aircraft to dive towards the target to maintain lock on the target.It entered service on 20 June 1968^[1].The reason it was only carried on the MIG-21PFM was, since it was a beam-riding missile, it was paired with a radar, the RP-21M, which other aircraft did not have.

Meanwhile, Korolyov took over work on the Kh-23 project intended for carriage on the Soviet Union's new MiG-23.^[3] The Kh-23 became a development of the Kh-66 design with an improved propellant and new Delta-R1M guidance system.^[3] The main practical difference was that it was a line-of-sight radio-command weapon similar to the Bullpup, allowing it to be fired in level flight (unlike the Kh-66). The first ten were tested in early 1968,^[3] but significant delays were caused by problems with unreliable guidance which was eventually traced to the smoke generator which interfered with the antenna.^[3] Once the receiver had been moved to a tail extension,^[3] the government tested the missile on the MiG-23 and MiG-23B between 20 March 1970 and 3 October 1973.^[1] and it entered service in 1973.^[2] A laser-guided version of the Kh-23, the Kh-25, became the basis for the AS-10 'Karen' family of missiles.^[1] Technology from these was 'backported' to the Kh-23 to create the Kh-23M in 1974.^[2]

The Kh-23 was later licensed for local production in both Romania and Yugoslavia.^[3] In 1977 a dummy Kh-23 was fired from a Ka-252TB helicopter,^[1] the prototype of the Kamov Ka-29TB 'Helix-B' assault transport.

The Kh-66 used the airframe of the Kaliningrad K-8 (AA-3 'Anab') air-to-air missile, with the nozzle split to make room for the antenna of the beam-riding guidance system of the Kaliningrad K-5 (AA-1 'Alkali').^[3] It has cruciform control fins on the nose, and four clipped-tip delta-wings at the rear with elevators for control.

The Kh-66 entered production for the MiG-21 in 1968, and the Kh-23 was certified for the MiG-23 'Flogger' in 1973.

• Kh-66 - the original beam-riding missile based on the K-8
• Kh-23 (Izdeliye 68)^[4] - First command-guidance version with improved propellant
• Kh-23M - improved Kh-23 with technology from the Kh-25 family^[2]
• Kh-23L - Western name for a laser-guided version that in fact was the baseline Kh-25 (AS-10 'Karen')^[4]
• A921 - Version made in Romania^[3]
• Grom (Grom 02) - Yugoslav version that appeared in the 1980s.^[7] This should not be confused with the Polish SAM
• Grom-B (Grom 2) - TV-guided version from Serbia's Vojno-Tehnički Institut in the mid-late 1990s; uses seeker based on that of the AGM-65B Maverick^[7]

•  North Korea^[8]

•  Afghanistan^[9]
•  Algeria^[9]
•  Angola^[9]
•  Azerbaijan^[9]
•  Belarus^[9]
•  Bulgaria^[3]
•  Cambodia^[9]
•  Congo^[9]
•  Cuba^[9]
•  Czechoslovakia − Passed on to successor states^[9]
•  Czech Republic^[9]
•  East Germany^[10] − Passed on to the unified German state^[9]
•  Egypt^[9]
•  Finland^[9]
•  Georgia^[9]
•  Germany^[9]
•  Hungary^[9]
•  India^[3]
•  Iraq^[3]
•  Kazakhstan^[9]
•  Libya^[11]
•  Nigeria^[9]
•  Poland^[3]
•  Romania − Locally produced as the A-921^[3][9]
•  Serbia −Grom^[3]
•  Slovakia^[9]
•  Soviet Union^[3] − passed on to successor states^[9]
•  Sudan^[9]
•  Syria^[12]
•  Ukraine^[9]
•  Vietnam^[9]
•  Yugoslavia − Passed on to successor states^[9]

• AGM-12 Bullpup
• AS-20 - French air-to-ground missile based on an early air-to-air missile

Wikimedia Commons has media related to Kh-23.

• Cooper, Tom (2018). MiG-23 Flogger in the Middle East, Mikoyan i Gurevich MiG-23 in Service in Algeria, Egypt, Iraq, Libya and Syria, 1973-2018. Warwick: Helion & Company Publishing. ISBN 978-1-912-390328.
• Gordon, Yefim (2004), Soviet/Russian Aircraft Weapons Since World War Two, Hinckley, England: Midland Publishing, ISBN 1-85780-188-1
• International Institute for Strategic Studies (2024). "Chapter Five: Asia". The Military Balance. 124 (1): 218–327. doi:10.1080/04597222.2024.2298593. ISSN 0459-7222. Retrieved 7 September 2024.