ZRK-SD Kub 3M9
SA-6 Gainful

The SA-6 GAINFUL (2K12 KUB/KVADRAT) is a two stage, solid-fuel, low-altitude SAM. Although it is frequently reported that a naval version of the missile is the SA-N-3 GOBLET, this is evidently not the case. The 3M9 KUB self-propelled surface-to-air tactical low-altitude anti-aircraft missile system is intended for destruction of aircraft, missiles, cruise missiles and assault helicopters at low to medium altitudes.

The SA-6 low altitude surface to air missile uses radio command guidance immediately after launch, switching to semi-active radar homing in the terminal phase. In the event of jamming or radar shut down the SA-6 may be guided optically and acquire its target after launch. It has radio command guidance with semi-active radar terminal homing.

Design of the 2K12 is centered around the use of three rail-launched guided missiles utilizing an optical sight and continuous wave target illuminator. Each battery has its own STRAIGHT FLUSH (IS-91) fire control radar, four launchers on an armored carrier chassis, and four transport and support vehicles. Comparable systems include Hawk (US) and Rotale (FR).

The system is characterised by a very good mobility even in demanding cross-country conditions. The tracked platform assures that it can be relocated to any positions in defense of key installations. In its tracked form, the chassis makes use of six double-tired road wheels with the drive sprocket at the rear of the hull. The crew is entirely sealed in their armored vehicle while the traversing launcher - fitting the three missiles - sits atop the hull roof.

The high speed of its anti-aircraft missiles, achieving speeds up to Mach 2.8, permits it to destroy even highly manoeuvring air targets. The system can carry out combat activities in a totally independent manner - it can search, automatically track and recognise air targets, illuminate them and provide anti-aircraft missiles homing. The system can guide three missiles to one target at any given time. It can automatically track up to 6 air targets and control 2 missiles at the same time. Reloading of the missiles from transport vehicle to launcher takes about 10 minutes. A built-in TV camera with the range of 25 km range increases the resistance of the system against EW.

Design work on the 2K12 "Kub" system began in 1959 under at NIIP/Vympel (for the missile) and MMZ (for the tracked chassis). The system was developed by the Russian TOROPOV OKB-134 company and produced by Vympel MKB and NIIP. Development of the 3M9 antiaircraft missile for the Kub [Cube] system ended the career of Ivan Ivanovich Toporov, founder of the OKB-134 Special Engineering Office. The missile designed had not been experimentally verified, and it became necessary not only to build the missile but also to simultaneouly conduct basic research.

During the initial test launch in 1961, the 3M9 missiles disintegrated in the air. The associated aerodynamic, engine, and guidance problems compelled Toporov to ask the Ministry of Armaments to extend the deadline for submitting the 3M9 to governmental tests. Toporov was removed from his post of chief engineer at the end of August 1961, becoming department chairman at the Moscow Institute of Aviation, and replaced by Andrey Lyapinov as director of the team. This did not accelerate the work on the 3M9.

After successful completion of trials (delayed by various technical challenges), finally in 1966 the missile together with all the Kub equipment was certified as an operational weapon, and it turned out to be one of the most successful Russian antiaircraft missiles. The design entered serial production in 1968 which ran until 1985. The system was formally introduced into limited Soviet Army service in 1967 before seeing widespread use by 1970.

The 2K12 was modernized in 1973 to become the 2K12 Kub-M1. A further evolution of the system produced the improved 2K12 Kub-M3 of 1976. This was then followed by the 2K12 Kub-M4 in 1978 which was based on the 2K1 Kub-M3 and developed to work in conjunction with the newer 9K37 "Buk" anti-aircraft missile systems - which were inspired by the 2K12 family. The export version of the 2K12 became the 2K12E "Kvadrat" and these have since seen widespread use in Soviet/Russian-allied states and countries. In the Soviet inventory, the 2K12 Kub was superseded by the modern 9K37 "Buk" four-missile tracked system though both were eventually used as complements to one another for a complete integrated air defense network.

Operators of the 2K12 include Algeria, Armenia, Bulgaria, Bosnia and Herzegovina, Cameroon, Chad, Cuba, Czech Republic (formerly as Czechoslovakia), Egypt, Hungary, India, Iran, Libya, Myanmar, Mozambique, North Korea, Poland, Romania, Slovakia, Serbia, Syria and Vietnam. Wide-scale use of the series by Soviet/Russian forces is no more save for a few missile target imitator systems in circulation. Iraq and the former Yugoslavia are a few other former operators of the 2K12 series. Several localized and modified versions of the 2K12 have emerged in places like Poland and the Czech Republic. India has conducted flight tests of their new AKASH missile, which is based in large part on the SA-6.

The type has seen successful combat actions through the Yom Kippur War, the Chad Civil War, the Iran-Iraq War, the 1st Lebanon War, the 1991 Gulf War and the Yugoslav Wars of the 1990s. To date at least 500 launcher units have been processed with some 10,000 missiles delivered. The last SA-6B Gainful Mod 1 version with increased EW resistance was produced in 1992.

The SA-6 system is still an efficient weapon, although service is seriously limited by ageing electronics. The original system design and technology are very demanding in operation, maintenance and repair. Highly appreciated SAM system capabilities, namely vehicles mobility and missile performance, suffer from aging radar electronics and lack of superior command and control network interface. RETIA, a.s. has proposed an SA-6 upgrade that would include the SURN radar vehicle , missile launchers 2P25 and replace of 3M9 missiles including new loading vehicle. This upgrade would prolong system lifetime, increase combat efficiency and decrease operators load. The integrated logistic support is proposed to allow efficient use of upgraded system for the whole lifetime.