XP831 This aircraft is the first prototype of the Hawker P1127 - the XP831 - which proved the practicability of vertical takeoff and landing (VTOL), and led to the Harrier Jump Jet.

• 1946年，法国人韦伯提出一种新的设想：把喷气式飞机的发动机喷口转向下方，飞机就垂直起落，把喷口转向后方，飞机又可向前飞行。