Hawker Siddeley Harrier AV-8As to the AV-8C configuration—the work focused mainly on extending useful service lives and improving VTOL performance. The AV-8C and the remaining AV-8A Harriers were retired by 1987. These were replaced by the Harrier II, designated as the AV-8B, which was introduced into service in 1985. The performance of the Harrier in USMC service led to calls for the United States Air Force to procure Harrier IIs in addition to the USMC's own plans, but these never resulted in Air Force orders. Since the late 1990s, the AV-8B has been slated to be replaced by the F-35B variant of the
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