Fw 190 A-2 - first introduced in October 1941. 2 x 20 mm MG 151/20E cannon replaced 7.92 mm MG 17 (wing root-mounted).
Fw 190 A-3 - same as A-2, but with increased power BMW 801 D-2 engine.
Fw 190 A-4 - Introduced in July 1942, engine and basic armament are same as A-3
Fw190 A-5 - same basic armament as Fw 190A-4. D-2 engine was moved forward another 15 cm, moving the center of gravity forward to allow more weight to be carried aft. New radio gear, FuG 25a Erstling IFF (identification friend or foe)
BMW 327 (1937–1941) - a shortened version of the BMW 326 chassis. 1,965 built.