Most interesting link if you haven't seen it before: British Production Costs American Production Costs I'm not that surprised by the building time for a Spitfire or Lancaster. What's most interesting though are the hours put in engineering. All too often we hear that "in the past they didn't do all that fancy math and just build a good plane". Well, over half a million hours on design alone halfway the war for the Spitfire. "When Rolls Royce brought over the Merlin blueprints, the American officer who's job was to bring it to Washington thought he would be able to fit it into a briefcase and carry it to Washington. The British escort just shook his head, and pointed towards a couple of crates. Two tons of paperwork"