[1] PCB was developed for the vectored thrust Bristol Siddeley BS100 engine for the Hawker Siddeley P.1154 and obtained the additional thrust by burning additional fuel in a turbofan's cold bypass air, instead of the combined cold and hot gas flows as in a conventional afterburning engine.

To reduce weight the airframe was to use lithium-based aluminium alloys, superplastic-formed diffusion-bonded titanium and carbon-fibre composites.

The P.1216 was extensively tested in model form during the 1980s, and a full-scale mock-up was viewed by British Prime Minister Margaret Thatcher during a visit to BAe's Kingston factory in December 1982.

In 1984 they assembled in a test rig at Shoeburyness a Harrier airframe created from the damaged remains of T.Mk.2 XW264 and GR.Mk.1 XV798 to assist in their investigations in the effects of PCB.

[3] It was identified that the design offered the possibility of vectoring in forward flight (VIFF) which would allow large longitudinal decelerations thus making it a superior air combat fighter.