Additional weapons include an electric gun turret in the telegraph room, chin turret (continued to become standard equipment on the B-17G version) and two machine guns 12.7 mm (0.50 inch) on the side. Alboreto is nothing shirt. The total number of ammunition to carry is over 11,000, making the YB-40 heavier than 4,500 kg (10,000 lb) compared to a loaded B-17F. Unfortunately, the heavily equipped YB-40 had the problem of not being able to keep up with the speed of empty bombers, and thus, with the introduction of the P-51 Mustang, the plan was stopped and finally ended in July 1943
