The FT machine gun turret with more powerful 12,7mm BT heavy machine gun systeThe FT machine gun turret with more powerful 12,7mm BT heavy machine gun system was developed for the aircraft navigator. It was installed on all Pe-2 since 87 series. Aircraft equipped with heavy machine gun were firstly used in April 1942 at Kerch – Crimea peninsula. In large quantities they appeared during the combat in Voronezh area..