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 400 aircraft like tankers and strategic transports: 180 were delivered between 1992 and 1997. The Japan Air Self-Defense Force 400T trainer shares the T1-A Type certificate. In 1993 Raytheon purchased the Hawker business jets from British Aerospace, renamed the Beechjet 400 as the Hawker 400 to include it in the line and the Hawker 400XP incorporated aerodynamic, mechanical and interior improvements from the Hawker 800XP. In October 2008, Hawker Beechcraft upgraded it as the Hawker 450XP including new, more fuel efficient Pratt & Whitney PW535Ds with 2,965 pounds of thrust each but it was canceled in June 2009 due to poor