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
Harrier Jump Jet for use from aircraft carriers. There are two generations and four main variants of the Harrier family, developed by both UK and US manufacturers: The Hawker Siddeley Harrier is the first generation-version and is also known as the AV-8A Harrier; it was used by multiple air forces, including the Royal Air Force (RAF) and the United States Marine Corps (USMC). The Sea Harrier is a naval strike/air defence fighter derived from the Hawker Siddeley Harrier; it was operated by both the Royal Navy and the Indian Navy. During the 1980s, a second generation Harrier emerged; manufactured in the United States