The US/NATO designated AT-8 'Songster' (Russian Federation and Associated States (CIS) industrial index number 9M112, named Kobra) entered development by the Tula KBP Design Bureau for Instrument Building in the mid-1970s and is a second-generation two-part 125 mm gun-launched weapon.

It is initially fired out of a 125 mm gun/missile launcher tube by a booster cartridge at 125 m/s to a point where the single-stage short burn solid fuel sustainer rocket motor of the missile cuts in to accelerate it to its maximum flight speed of 400 m/s.

All the gunner has to do is track the target with his optical sight and the system's fire-control computer determines the error in the position of the missile relative to the line of sight, converts the data into a course correction signal and transmits it to the weapon via a directional UHF radio command transmitter.

The overall system number is the 9K112 with other elements including the gunners IG42 range-finder/ sight which is located on the turret roof and the GTN-12 (9S461-1) radio command antenna.

The 'Songster' has a secondary capability in the ground-to-air role against low-flying battlefield helicopters. Standard combat load is four AT-8s. The complete radio command-guided missile system has the industrial index number 9K112-1 and was first fitted to the T-64B in 1980. The T-64 series MBT was never exported. The T-64 is now rapidly being phased out of service with Russia and the Ukraine.

Production complete. In service with the RFAS. Not offered for export.

• T-64B, T-64BV MBTs (125 mm gun/missile launcher -RFAS armies)

• T-80, T-80B, T-80BV, T-80U-1 MBTs (125 mm gun/ missile launcher- RFAS armies).