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 Siddeley Harrier Harrier. At one point China came very close to becoming an operator of the first generation Harrier. Following an overture by the UK in the early 1970s, when relations with the West were warming, China became interested in the aircraft as it sought to modernise its armed forces; British Prime Minister James Callaghan noted significant hostility from the USSR over the sales bid. The deal was later cancelled by the UK as part of a diplomatic backlash after China invaded Vietnam in 1979. The Spanish Navy, Thai Navy, Royal Air Force, and U.S. Marine Corps have all retired their first-generation