Among the Soviet aircraft that were now harassing German forces within the pocket and further to the west on the main front line was the formidable II-2 Shturmovik ground-attack aircraft that had originally been designed as a fighter. Powered by a 1770hp Mikulin AM-38F engine, it had a top speed of 404km/h (251 mph) at 1500m (4920ft) and a normal range of 765km (475 miles). The crew of the two-seater version were well protected by armour and the aircraft was armed with two fixed forward-firing 23mm (0.9in) VYa cannon in the wings, two 7.62mm (0.3in) ShKAS machine guns in the fuselage and a flexible 12.7mm (0.5in) UBT machine gun in the rear cockpit. It could carry up to 600kg (1323lb) of external ordnance. The two-seater Shturmovik with its combination of armour protection and powerful armament was a formidable Soviet Air Force ground attack aircraft, arguably one of the best aircraft employed for this role in World War II.