Aircraft › B-17FB-17FB-17FB-17FModification ofB-17FProduced3,386Changes3,405 built from May 1942: 2,300 by Boeing, 605 by Douglas and 500 by Vega; 19 went to the RAF as the Fortress II.Crew10Engines4Service193119321933193419351936193719381939194019411942194319441945United States · Western Europe≈ Sep 1942 – 25 Apr 1945