The Yak-B is a late Cold War era gatling gun of Soviet origin. It was developed for use on the Mi-24 attack helicopter as a far more capable machine gun than the UB-12.7 as used in the early models of the Mi-24. The Yak-B is a much heavier weapon than a heavy machine gun, but its 12.7mm caliber is much lighter than autocannon ammunition.

The Yak-B is a gas operated gatling type gun. It has four barrels, fed by a single belt and is solenoid fired. The gas operation results in a limited spin up time compared to externally powered gatling type weapons. In the Mi-24 attack helicopter it is mounted in the VSPU-24 chin mounted turret and slaved to the KPS-53AV sighting system.

The Yak-B fires the 12.7x108mm round that is commonly used in Soviet heavy machine guns. The rate of fire is 4.000 to 5.000 rpm. In the Mi-24 it is fed by a 1.470 round belt. The Yak-B proved effective against infantry in the open and soft skin vehicles. Against dug-in infantry and armored vehicles performance proved poor.

The Yak-B is was developed for in the VSPU-24 chin mounted turret of the Mi-24D attack helicopter. It was is also used on later models and export models of the Mi-24. The latest models of the Mi-24 feature for more powerful autocannon. These are the fixed GSh-30 and flexible GSh-23L. The Yak-B is also used in the GUV-8700 gun pod.