Soviet designers, as the Second World War approached, gave a special priority to aircraft optimized to destroy tanks; the first workable version was the Il-2 Shturmovik from the Ilyushin design bureau. Even though antitank operations were definitely in the planners' minds, the initial aircraft, the name of which means "Storm Bird" in Russian, were also general-purpose close air support planes. Current designers still cite the it as an inspiration for armored CAS and antitank aircraft such as the Russian Su-25 and U.S. A-10.
Armament of the early models included some antitank capability, but was not truly optimized for the role. They had two ShKAS 7.62 millimeter machine guns and two ShVAK 20 millimeter autocannon; rails for eight 82 millimeter RS-82 rockets, which were new aircraft weeapons; and light bombs. There were two small bomb bays in each wing inboard of the landing gear, and there were external racks under the wings as well. Total external warload was 400 kilograms (880 pounds). Level speed was 470 KPH (300 MPH), and operating altitude was 2,000 meters (6,600 feet).  Various modifications were made to the engines and cockpit to improve low-altitude performance and give the pilot a very good forward view.
First modified aircraft
Two versions were developed in response to experience from the German invasion of the Soviet Union. In the initial Il-2M, the engine was upgraded to give adequate performance with upgraded 23mm high-velocity cannon, potent weapons against the light tank armor of the day. As was the prototype, this was a single-seater.
The next two-seat Il-2M3, in which the cockpit was lengthened to accommodate a gunner, who manually handled a single 12.7 millimeter UBT machine gun, on a flexible mount at the back of the cockpit and directed upward and backward. Armor was increased, partly to protect the gunner, who protected the low-level attack aircraft from diving fighters. Cannon were not the only weapon; it was among the first aircraft to use small antitank bomblets in large numbers. A 1943 variant went to even heavier cannon, but these were not successful, only having a small number of rounds and whose recoil interfered with engine and flight performance.
- Greg Goebel (November 1, 2008), The Il-2 Shturmovik