【B-17F轟炸機】一代空中霸王 二戰飛行堡壘 號稱轟炸機界的天花板，總投放640000噸炸彈，世界第一款全金屬外殼

B-17空中堡壘轟炸機（B-17 flying fortress）是美國波音在1930年代為美國陸軍航空軍所發展的的四引擎重型轟炸機。當時參與競爭此200架新型轟炸機合約的還有道格拉斯和格倫·L·馬丁兩家公司。在三家競爭者之中，波音設計的機型不但性能突出且更加的符合美國陸軍航空軍之期望。然而，由於B-17的原型機在一次試飛時墜毀，波音最終並沒有得到該筆合約。不過由於陸軍航空軍對波音的B-17設計印象深刻，因此仍舊訂購了13架B-17型轟炸機作為後續評估使用，也自此揭開B-17轟炸機輝煌的戰爭歲月。自1938年第一架B-17出廠，B-17轟炸機在二戰前後歷經多次改良，以適應快速變化的空中戰場與局勢。
The B-17 flying fortress is a four-engine heavy bomber developed by Boeing in the 1930s for the US Army Air Force. At the time, Douglas and Glenn L. Martin also participated in the competition for this 200 new bomber contract. Among the three competitors, the Boeing-designed models not only have outstanding performance, but also meet the expectations of the US Army Air Force. However, because the B-17 prototype crashed during a test flight, Boeing did not get the contract in the end. However, because the Army Air Force was very impressed with Boeing's B-17 design, it still ordered 13 B-17 bombers for follow-up evaluation, and since then unveiled the glorious war years of the B-17 bombers. Since the first B-17 was shipped from the factory in 1938, the B-17 bomber has undergone many improvements before and after World War II to adapt to the rapidly changing aerial battlefield and situation.