British Aerospace Harrier II

The British Aerospace Harrier II is a second-generation vertical/short takeoff and landing (V/STOL) jet aircraft used previously by the Royal Air Force (RAF) and, between 2006 and 2010, the Royal Navy (RN). The aircraft was the latest development of the Harrier family and was derived from the McDonnell Douglas AV-8B Harrier II. Initial deliveries of the Harrier II were designated in service as Harrier GR5; subsequently, upgraded airframes were redesignated accordingly as GR7 and GR9.

Under the Joint Force Harrier organisation, both the RAF and RN operated the Harrier II under the RAF's Air Command, including deployments on board the navy's Invincible-class aircraft carriers. The Harrier II participated in numerous conflicts, making significant contributions in combat theatres such as Kosovo, Iraq, and Afghanistan. The type's main function was as a platform for air interdiction and close air support missions; the Harrier II was also used for power projection and reconnaissance duties. The Harrier II served alongside the Sea Harrier in Joint Force Harrier.

In December 2010, budgetary pressures led to the early retirement of all Harrier IIs from service, at which point it was the last of the Harrier derivatives remaining in British service. In March 2011, the decision to retire the Harrier was controversial as there was no immediate fixed-wing replacement in its role or fixed-wing carrier-capable aircraft left in service at the time; in the long term, the Harrier II was replaced by the Lockheed Martin F-35B Lightning II.

The development of a much more powerful successor to the Harrier began in 1973 as a cooperative effort between McDonnell Douglas (MDD) in the US and Hawker Siddeley (in 1977, its aviation interests were nationalised to form part of British Aerospace) in the UK. First-generation Harriers were being introduced into the Royal Air Force and United States Marine Corps; operational experience had highlighted the demand for a more capable aircraft. The British government had only a minor requirement, for up to 60 Harriers at most and competing pressures on the defence budget left little room for frivolous expenditure such as the Advanced Harrier. A lack of government backing for developing the necessary engine for the new aircraft, the Pegasus 15, led Hawker to withdraw from this project in 1975.

Due to US interest, work proceeded on the development of a less ambitious successor, a Harrier fitted with a larger wing and making use of composite materials in its construction. Two prototypes were built from existing aircraft and flew in 1978. The US government was content to continue if a major foreign buyer was found and Britain had a plan to improve the Harrier with a new, larger metal wing. In 1980, the UK considered if the American program would meet their requirements – their opinion was that it required modification, thus the MDD wing design was altered to incorporate the British-designed leading-edge root extensions. In 1982, the UK opted to become fully involved in the joint US–UK programme. The US and UK agreement to proceed included a British contribution of US$280 million to cover development costs to meet their own requirements and to purchase at least 60 aircraft.

The UK agreement included the involvement of British Aerospace (BAe) as a major subcontractor, manufacturing sections such as the rear fuselage for all customers of the AV-8B. The Harrier II was an Anglicised version of the AV-8B, British Aerospace produced the aircraft as the prime contractor, with McDonnell Douglas serving as a sub-contractor; final assembly work was performed at Dunsfold, England. The first prototype flew in 1981, the first BAe-built development GR5 flew for the first time on 30 April 1985 and the aircraft entered service in July 1987. The GR5 had many differences from the USMC AV-8B Harriers, such as avionics fit, armaments and equipment; the wing of the GR5 featured a stainless steel leading edge, giving it different flex characteristics from the AV-8B. In December 1989, the first RAF squadron to be equipped with the Harrier II was declared operational.