The SA-6 GAINFUL is a two stage, solid-fuel, low-altitude SAM. It has radio command guidance with semi-active radar terminal homing. 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 system was developed by the Russian TOROPOV OKB-134 company and produced by Vympel MKB and NIIP. It first entered operational service in 1970. The system is characterised by a very good mobility even in demanding cross-country conditions, and by a high speed of its anti-aircraft missiles achieving up to M =2.8, which permits to destroy even highly manoeuvring air targets. Each battery has its own STRAIGHT FLUSH (IS-91) fire control radar, four launchers on an armoured carrier chassis, and four transport and support vehicles. 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. The last SA-6B Gainful Mod 1 version with increased EW resistance was produced till 1992.
