While most downward-firing seats have been replaced, there is one aircraft that will soldier on with them perhaps until the middle of this century. The US Air Force's Boeing B-52 "Stratofortress" bomber, which first entered service in the 1950s, features downwards-firing seats for the navigator and radar navigator. This is not so much because of the aircraft's tail (the tailplanes are set low down and the B-52 is relatively slow) but because the two crew members sit on a lower deck, beneath the other crew.

อ่านต่อได้ที่ โรงเรียนบ้านลำพระ
สาระน่ารู้   รับประทานอาหาร