April 1943. Suddenly wedged in the front line the German mechanized brigade took the road of front-line value in control in the region of Ermoshino-Laptevka. It therefore cut out the Red Army base K140 from the main forces. A truck convoy with ammunition and provision for K140 base was sent from A35 base. The HQ of front commander had not received the report about the enemy position, that is why the convoy was assigned with only four T-34 tanks, as well as for the rear security.

The helicopter materializes in the region of the A35 base at the moment of convoy launch. It is necessary to provide cover for the convoy, so that at least 50% of the convoy trucks get to K140 base.