It was powered by two Armstrong Siddeley Viper turbojet engines equipped with thrust deflectors sited at the aircraft's centre of gravity.

During the development of the P.1127, Hawker test pilots Bill Bedford and Hugh Merewether visited NASA Ames to fly the X-14 and acquaint themselves with jet V/STOL aircraft handling prior to the first flights of the prototype P.1127.

The X-14 project provided a great deal of data on VTOL (Vertical Take-Off and Landing) type aircraft and flight control systems.

[4][5] An onboard computer and digital fly-by-wire control system were also installed to enable emulation of landing characteristics of other VTOL aircraft.

[7][8][needs update] Data from Bell aircraft since 1935[9]General characteristics Performance Avionics Auto-stabilisation and computer-controlled engine controls.