K-5 (missile)

The Kaliningrad K-5 (NATO reporting name AA-1 Alkali), also known as RS-1U or product ShM, was an early Soviet air-to-air missile.

History
The development of the K-5 began in 1951. The first test firings were in 1955. It was tested (but not operationally carried) by the Yakovlev Yak-25. The weapon entered service as the Grushin/Tomashevich (Грушин/Томашевич) RS-2U (also known as the R-5MS or K-5MS) in 1957. The initial version was matched to the RP-2U (Izumrud-2) radar used on the MiG-17PFU, MiG-19PM. An improved variant, K-5M or RS-2US in PVO service, entered production in 1959, matched to the RP-9/RP-9U (Sapfir) radar of the Sukhoi Su-9. The People's Republic of China developed a copy under the designation PL-1, for use by their J-6B fighters.

The difficulties associated with beam-riding guidance, particularly in a single-seat fighter aircraft, were substantial, making the 'Alkali' primarily a short-range anti-bomber missile. Around 1967 the K-5 was replaced by the K-55 (R-55 in service), which replaced the beam-riding seeker with the semi-active radar homing or infrared seekers of the K-13 (AA-2 'Atoll'). The weapon was 7.8 kg (17.2 lb) heavier than the K-5, but had a smaller 9.1 kg (20.1 lb) warhead. The K-55 remained in service through about 1977, probably being retired with the last of the Sukhoi Su-9 interceptors.

Specifications (RS-2US / K-5MS)

 * Length: 2500 mm (8 ft 2 in)
 * Wingspan: 654 mm (2 ft 2 in)
 * Diameter: 200 mm (7⅞ in)
 * Launch weight: 82.7 kg (183.3 lb)
 * Speed: 800 m/s (2,880 km/h, 1,790 mph)
 * Range: 2–6 km (1¼-3¾ mi)
 * Guidance: beam riding
 * Warhead: 13.0 kg (28.7 lb)

Operators

 * : Both the Soviet Air Force (VVS) and the Soviet Air Defence Forces (PVO) operated the K-5.
 * 🇨🇳: The People's Liberation Army Air Force operated licensed Chinese copy of Kaliningrad K-5 designated as PL-1 (PL: short for Pi Li or Pili, meaning thunderbolt).
 * : The Czechoslovakian Air Force operated RS-2U and RS-2US.
 * 🇵🇱: The Polish Air Force operated RS-2US on MiG-19PMs and MiG-21s, still in use as practice target.