The Norden bombsight was a bombsight usedby the United States Army Air Forces during World War II, and the United StatesAir Force in the Korean and the Vietnam Wars to aid the crew of bomber aircraftin dropping bombs accurately. Its operation was a closely guarded secret ofWorld War II; however, Herman Lang, a German spy working at the factory, leakedthe design to the Abwehr in 1938.[1] The Carl Zeiss Lotfernrohr 7, or Lotfe 7,widely deployed by the Luftwaffe, was an advanced mechanical system quitesimilar to the original Norden bombsight.
在研究开发大型四发长距离战略轰炸机方面,无论是美国陆军航空队,还是英国皇家空军,都和欧洲大陆各国不同:二者都在大战爆发之前就各自开始了研究开发。虽然美国空军独立较晚,但是在参战之前的1941年6月,从原来的陆军航空兵(Army Air Corps)上升为了陆军航空队(Army Air Force,简称AAF),基本上可以说AAF是作为一个独立军种参加二战的。