Harrier Jump Jet

The Harrier, informally referred to as the Jump Jet, is a family of military jet aircraft capable of vertical/short takeoff and landing (V/STOL) operations. Historically the Harrier was developed in Britain to operate from ad-hoc facilities such as car parks or forest clearings, avoiding the need for large air bases vulnerable to tactical nuclear weapons. Later the design was adapted for use from aircraft carriers. The Harrier is also distinct as being of modern era, yet subsonic, contrasting with most of the major Western post-World War II-era attack aircraft, which tend to be supersonic.

There are two generations of four main variants of the Harrier family:
 * Hawker Siddeley Harrier
 * British Aerospace Sea Harrier
 * Boeing/BAE Systems AV-8B Harrier II
 * BAE Systems/Boeing Harrier II

The Hawker Siddeley Harrier is the first generation-version and is also known as the AV-8A Harrier. The Sea Harrier is a naval strike/air defence fighter. The AV-8B and BAE Harrier II are the US and British variants respectively of the second generation Harrier aircraft.

Background
Following an approach by the Bristol Engine Company in 1957 that they were planning a directed thrust engine, Hawker Aircraft came up with a design for an aeroplane that could meet the NATO specification for a "Light Tactical Support Fighter". There was no financial support for the development from HM Treasury, but aid was found through the Mutual Weapon Development Project (MWDP) of NATO.

The Hawker P.1127 was ordered as a prototype and flew in 1960. NATO developed a specification (NBMR-3) for a VTOL aircraft, but one that was expected to have the performance of an aircraft like the F-4 Phantom II. Hawker drafted a supersonic version of the P.1127, the P.1150, and also the Hawker P.1154 which would meet NBMR-3. The latter was a winner of the NATO competition and development continued, initially for both services, until cancelled, by the new government on cost grounds, at the point of prototype construction in 1965.

Work on the P.1127 continued with 9 evaluation aircraft, the Hawker Siddeley Kestrel, ordered. These started flying in 1964 and were assessed by the "Tri-partite Evaluation Squadron" which consisted of British, US and German pilots. With the cancellation of the P.1154, the RAF ordered a modified P.1127/Kestrel as the Harrier GR.1 in 1966.

First-generation Harriers
The Hawker Siddeley Harrier GR.1/GR.3 and the AV-8A Harrier were the first generation of the Harrier series, the first operational close-support and reconnaissance attack aircraft with vertical/short takeoff and landing (V/STOL) capabilities. These were developed directly from the Hawker P.1127 prototype and the Kestrel evaluation aircraft.

The British Aerospace Sea Harrier is a naval V/STOL jet fighter, reconnaissance and attack aircraft, a development of the Hawker Siddeley Harrier. The first version entered service with the Royal Navy's Fleet Air Arm in April 1980 as the Sea Harrier FRS.1, and was informally known as the Shar. The upgraded Sea Harrier FA2 entered service in 1993. It was withdrawn from Royal Navy service in March 2006. The Sea Harrier FRS Mk.51 is in active service with the Indian Navy, which operates the jet from its aircraft carrier INS Viraat.

Second-generation Harriers
The Harrier was extensively redeveloped by McDonnell Douglas and British Aerospace (now parts of Boeing and BAE Systems respectively), leading to the Boeing/BAE Systems AV-8B Harrier II. This is a family of second-generation V/STOL jet multi-role aircraft, including the British Aerospace-built Harrier GR5/GR7/GR9, which entered service in the mid-1980s. The AV-8B is primarily used for light attack or multi-role tasks, typically operated from small aircraft carriers. Versions are used by several NATO countries, including Spain, Italy, and the United States. The BAE Systems/Boeing Harrier II is a modified version of the AV-8B Harrier II that was used by the Royal Air Force (RAF) and the Royal Navy until 2010.

Between 1969 and 2003, 824 Harrier variants were delivered. While manufacture of new Harriers concluded in 1997, the last remanufactured aircraft (Harrier II Plus configuration) was delivered in December 2003 which ended the Harrier production line.

Operation
The Harrier Jump Jet, capable of taking off vertically, can only do so at less than its maximum weight. In most cases the aircraft does a short take off where it gains forward speed and thus aerodynamic lift, saving fuel.

On aircraft carriers a ramp is frequently employed at the end of the carrier which allows the aircraft to accelerate along the carrier using less fuel for takeoff.

Landings are also typically performed very differently. Although a conventional landing is possible, the range of speeds that this can be done over is narrow (due to relatively vulnerable outrigger undercarriage). Operationally the aircraft therefore usually does a near vertical landing with some forward speed.

Replacement
, the F-35B STOVL variant of the F-35 Lightning II (formerly the Joint Strike Fighter) is intended to replace the AV-8B Harrier II in service with the US Marine Corps and the Italian Navy from 2014 onwards. , the RAF and Royal Navy are also scheduled to introduce the F-35B around 2020. In 2010, it was announced that the RAF and RN would retire their remaining Harriers by 2011, and in December 2010 the RAF's Harrier GR9s made their last operational flights. In June 2011, the MoD denied press reports that the aircraft are to be sold to the US Marine Corps for spares to support their AV-8B fleet, but options for disposal are still being considered. However, at the end of November 2011, Defence Minister Peter Luff announced the sale of the final 72 Harriers to the US Marine Corps. As many as possible of the 72 Harrier GR9s will be converted to match AV-8B Night Attack configuration to augment the total AV-8B end strength (this will allow the USMC to retire some high-flight-hour F/A-18D aircraft), while the remaining aircraft will be used as spare parts sources for the airworthy fleet.

Variants



 * Hawker P.1127
 * (1960)


 * Kestrel FGA.1
 * (1964)


 * Harrier GR.1/1A/3/3A
 * (from 1966)


 * Harrier T.2/2A/4/4A/8/52/60
 * (from 1970)


 * AV-8A/C/S Harrier Mk.50/53/55/Matador
 * TAV-8A/S Harrier Mk.54/Matador
 * Sea Harrier FRS.1/FRS.51/F(A).2
 * (from 1978)


 * AV-8B Harrier II/EAV-8B Matador II/AV-8B Harrier II Night Attack/AV-8B Harrier II Plus
 * (from 1983)


 * TAV-8B Harrier II/ETAV-8B Matador II/
 * Harrier GR.5/5A/7/7A/9/9A
 * (from 1985)


 * Harrier T.10/12

Operators



 * Indian Navy
 * Italian Navy
 * Spanish Navy
 * Royal Thai Navy (former)
 * Royal Air Force (former)
 * Royal Navy (former)
 * United States Marine Corps
 * Royal Thai Navy (former)
 * Royal Air Force (former)
 * Royal Navy (former)
 * United States Marine Corps
 * United States Marine Corps
 * United States Marine Corps

Specifications

 * Sources: Norden