Hawker Siddeley Harrier the AV-8C configuration; this programme involved the installation of ECM equipment and adding a new inertial navigation system to the aircraft's avionics. Substantial changes were the Lift Improvement Devices, to increase VTOL performance; at the same time several airframe components were restored or replaced to extend the life of the aircraft. Spain's Harriers, designated AV-8S or VA.1 Matador for the single-seater and TAV-8S or VAE.1 for the two-seater, were almost identical to USMC Harriers differing only in the radios fitted. The Royal Navy's Fleet Air Arm (FAA) operated a substantially modified variant of the Harrier, the British Aerospace Sea Harrier.
Hawker Siddeley P.1154 the single vectored thrust turbofan of the likes of the BS.100 and Pegasus which went on to great success in the Harrier. Wood described the overall situation as: "From start to finish the P.1154 programme was a story of delay, ministerial interference and indecision... the P.1150 would now be the ideal aircraft for the new generation through-deck cruisers" Hawker Siddeley P.1154 The Hawker Siddeley P.1154 was a planned supersonic vertical/short take-off and landing (V/STOL) fighter aircraft designed by Hawker Siddeley Aviation (HSA). Developed alongside the subsonic and smaller Hawker Siddeley P.1127/Kestrel, the P.1154 was derived from the P.1150. The P.1150