Boeing XP-9

The Boeing XP-9, company Model 96, was a single prototype fighter built to a United States Army request of 1928 for a monoplane pursuit aircraft, and it was the first monoplane fighter Boeing produced. Its main contribution was a semi-monocoque fuselage structure that later became standard and was carried into the P-12E biplane. The prototype first flew in November 1930, but the large wing set directly in front of the pilot blocked the view downward so badly that landing was hazardous, and an enlarged tail did not cure its instability. It was grounded after about fifteen hours of flying and the type was cancelled.