The MT-LB AA is a Self Propelled Anti Aircraft vehicle based on the Soviet MT-LB multi-purpose tracked chassis. The MT-LB (Malotiagovoraya Bronirovannaya Lyukovaya, or "light armoured towing vehicle") entered Soviet service in the 1960s as an artillery tractor and APC; the AA variant mounts a dedicated anti-aircraft armament for short-range air defence. Weighing 12 tonnes, it is crewed by a driver, gunner, and commander with seating for eight passengers, and is fully amphibious at 6 km/h. The YaMZ 238 diesel produces 240 horsepower for a 20 hp/t power-to-weight ratio and a top speed of 62 km/h on land.
The primary armament is a 25mm DBTSU cannon in the gunner turret, with a commander turret mounting a 7.62mm PKT machine gun; both turrets offer high traverse rates (70 and 60 deg/s respectively) for engaging fast targets. The vehicle has an engine smoke system for defensive screening but no rangefinder or fire control system on the main sight.
This vehicle features a single addon: 57mm S-68 Swap. The 57mm S-68 Swap addon is free and replaces the stock 25mm DBTSU cannon with the high-caliber 57mm S-68, significantly augmenting both anti-air and anti-tank capabilities. This weapon system utilizes three specialized munitions: BR-281U APHE with 151 mm of maximum penetration, OR-281U HE featuring 0.235 kg of explosive mass, and the UOR-281U Proxy round, which is optimized for engaging infantry and aircraft. However, these benefits come with a substantial trade-off in survivability and sustainment; the 57mm turret offers significantly reduced protection with completely exposed sides and rear, and ammunition is strictly limited to 4 rounds per clip with a total capacity of only 12 clips.
