Bell Helicopter Co has won a contract to build two prototypes of its Model 301 tilt-rotor VTOL aircraft for a general research programme to be conducted jointly by NASA and the US Army. The Boeing Vertol Company's Model 222 was the losing design in a competitive evaluation.

Самолёты на фотографии: Aircrafts on the photo: Bell XV-15 / Model 301 - СШАUSA - 1977