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.
Joint Force Harrier combined the Royal Navy's two Sea Harrier FA2 squadrons with the RAF's four Harrier GR7/7A squadrons under a single command structure within RAF Strike Command. This force was to be deployable from both "Invincible" class aircraft carriers, Royal Air Force stations and deployed air bases. The Royal Navy's contribution to the force was the Sea Harrier previously part of Naval Air Command. . In 2006, No. 3 Squadron RAF converted to the Eurofighter Typhoon. In the same year, the Sea Harrier was retired and 800 Naval Air Squadron re-equipped with former 3 Squadron Harrier GR7 and GR9 aircraft. At the