For the case of planar interception, the so called relative heading error angle between the relative velocity vector and the LoS (Line of Sight) is chosen as the output to be controlled to zero.

Using the optimal control theory an optimal control law of agile turn is proposed enabling to eliminate velocity component in vertical director of initial sight under thrust vector control.

The paper gives an introduction of the principle and realization process of acquisition of projectile flight time from AA guns vector computing sight.