Harrier Jump Jet

From Wikipedia, the free encyclopedia

This article is about the Harrier family of V/STOL aircraft. For other uses of "Harrier", see Harrier.
Harrier Jump Jet
A Harrier GR7A of the Royal Air Force
Type STOVL strike/fighter aircraft
Manufacturer Hawker Siddeley
McDonnell Douglas/British Aerospace
Boeing/BAE Systems
Primary users United States Marine Corps[1]
Royal Air Force
Fleet Air Arm
Spanish Navy
Developed from Hawker P.1127/Kestrel FGA.1
Variants Harrier
Sea Harrier
AV-8 Harrier II
BAE Harrier II

Harrier Jump Jet, often referred to as just "the Jump Jet", covers a series of a military VSTOL jet aircraft. It is capable of vertical/short takeoff and landing (V/STOL) via thrust vectoring and is the only truly successful design of this type from the many that arose in the 1960s.

There are four main versions of the Harrier Jump Jet.

Contents

[edit] Introduction to the Harrier Family

An AV-8B Harrier II+ of VMA-223 prepares for landing on the flight deck aboard the USS Nassau (LHA 4)
An AV-8B Harrier II+ of VMA-223 prepares for landing on the flight deck aboard the USS Nassau (LHA 4)

The Hawker Siddeley Harrier GR.1/GR.3 and the AV-8A Harrier are 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 Harrier was extensively redeveloped, leading to the Harrier GR7/GR9 and AV-8B Harrier II, that were built by BAE Systems and Boeing.

The BAE Systems Sea Harrier is a naval VTOL/STOVL jet fighter, reconnaissance and attack aircraft, a development of the Hawker Siddeley Harrier. The first version entered service with the Royal Navy Fleet Air Arm in April 1980 as the Sea Harrier FSR.1, and was informally known as the "Shar". The latest version is the Sea Harrier FA2. It was withdrawn from Royal Navy service in March 2006.

The Boeing/BAE Systems AV-8B Harrier II is a family of second-generation V/STOL jet multi-role aircraft of the late 20th century. Developed from the earlier Hawker Siddeley Harrier, it 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 (GR5, GR7, and GR9 series) is a second generation V/STOL aircraft used by the Royal Air Force (RAF) and, since 2006, the Royal Navy. It was developed from the earlier Hawker Siddeley Harrier and is very closely related to the US built AV-8B Harrier II. Both are primarily used for light attack or multi-role tasks, and are often operated from small aircraft carriers.

[edit] Development

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 a plane that could meet the current NATO specification for a "Light Tactical Support Fighter". There was no financial support for the development from the British Treasury, but aid was found through the Mutual Weapon Development Project (MWDP) of NATO.

The 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. 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 until cancelled 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.

[edit] Variants

the Hawker P.1127 predecessor of the Harrier
the Hawker P.1127 predecessor of the Harrier

[edit] Pre-Harrier protype and evaulation aircraft

Main article: Hawker P.1127
  • Hawker P.1127 (1960)
  • Hawker Siddeley Kestrel FGA.1 (1964)

[edit] RAF Harriers

Main article: Hawker Siddeley Harrier
  • Single-seater combat aircraft
    • Harrier GR.1 (1966)
    • Harrier GR.1/1A (1969)
    • Harrier GR.3/3A
  • Two-seater training aircraft
    • Harrier T.2/2A (1970)
    • Harrier T.4/4A
    • Harrier T.4N
    • Harrier T.8 (1994)
    • Harrier Mk.52 (two-seat company demonstrator)
    • Harrier T.Mk 60

[edit] AV-8 Harrier (US, Spain, Thailand)

Main article: Hawker Siddeley Harrier
  • AV-8A Harrier/Harrier Mk.50 (USMC version, 1970)
  • TAV-8A Harrier/Harrier Mk.54
  • AV-8C Harrier
  • AV-8S Matador/Harrier Mk.53 (for Spain, later Thailand)
  • AV-8S Matador/Harrier Mk.55 (second batch of AV-8S for Spain, later Thailand)
  • TAV-8S Matador/Harrier T.54 (for Spain, later Thailand)

[edit] British Aerospace Sea Harrier

Sea Harriers FA.2 on the deck of HMS Illustrious in the Persian Gulf
Sea Harriers FA.2 on the deck of HMS Illustrious in the Persian Gulf
US Marine Corp AV-8B Harrier
US Marine Corp AV-8B Harrier
Main article: BAE Sea Harrier
  • Sea Harrier FRS.1 (1979)
  • Sea Harrier FA2 (1988)
  • Sea Harrier FRS.51 (1983)

[edit] McDonnell Douglas-BAe/Boeing AV-8B Harrier II

Main article: AV-8 Harrier II
  • AV-8B Harrier II (1983)
  • EAV-8B Matador II (for Spain)
  • AV-8B Harrier II Night Attack (1987)
  • AV-8B Harrier II Plus (1992) (USMC, Spain, Italy)

[edit] BAe-McDonnell Douglas/BAE Systems Harrier II

Main article: BAE Harrier II
  • Harrier GR5/5A (1985)
  • Harrier GR7/7A (1992)
  • Harrier GR9/9A (2002)
  • Harrier T10
  • Harrier T12

[edit] Controls and handling

Sea Harrier FRS2 ZA195 vector thrust nozzle
Sea Harrier FRS2 ZA195 vector thrust nozzle

While the Harrier is one of the most flexible aircraft ever made, the level of understanding and skill needed to pilot it is considerable. The Harrier is capable of both forward flight (where it behaves in the manner of a typical fixed-wing aircraft above its stall speed), and VTOL and STOL maneuvers (where the traditional lift and control surfaces are useless). This requires skills and understanding more usually associated with helicopters. Most services demand great aptitude and extensive training for Harrier pilots, as well as experience of piloting both types of aircraft. Many recruit trainee pilots from the most experienced and skilled helicopter pilots in their organisations.

The Harrier has two control elements that a fixed-wing aircraft does not usually have. These are the thrust vector and reaction control system. The thrust vector refers to the slant of the four engine nozzles and can be set between zero degrees (horizontal, pointing directly back) and 98 degrees (pointing down and slightly forwards). The 90 degree place is generally used for VTOL maneuvering. Thrust vector is adjusted by a control next to the thrust lever. The reaction control is achieved by manipulating the control stick and is similar in action to the cyclic control of a helicopter. While irrelevant during forward flight mode, these controls are essential during VTOL and STOL, and are used together during these maneuvers. Wind direction and the point of reference of the aircraft to this is also crucial during VTOL maneuvers (in this sense operation is limited compared with a helicopter, which can take off and land in side winds). The Harrier's landing gear configuration also complicates normal landing; it is necessary to ensure that the wing-mounted stabiliser struts contact the runway simultaneously; bounce or tilt to one side can result if this is not achieved.

The procedure for VTO involves parking the aircraft facing into the wind. The aircraft is brought to a halt, throttle to idle, wheels locked. The thrust vector is set to 90 degrees and the throttle brought up to maximum. The aircraft leaves the ground rapidly. The throttle is trimmed until a hover state is achieved at the desired altitude. During the ascent and hover, the reaction control system is continuously adjusted to maintain position over the patch of ground, much as it is with a helicopter. The aircraft has to face into the wind when taking off in this way. A side wind causes the aircraft to pitch away from the lee side. This would alter the thrust vector away from vertical and cause the aircraft to slew sideways. This is hard to control and dangerous. In severe cases the aircraft can settle with power while moving to the side. While taking off in windy conditions is always more difficult when within ground effect, it is easier to maintain heading away from the ground effect as the tailplane tends to stabilise the heading into the wind. At hover, the thrust vector is slowly returned to horizontal while the altitude and angle of attack is maintained in a specified range. At or shortly after normal take off speed, the thrust vector is set to horizontal and thrust is usually trimmed back to control acceleration.

Operators of the Harrier (all variants)
Operators of the Harrier (all variants)

The STO procedure involves proceeding with normal take off and then applying a thrust vector (less than 90 degrees) at a runway speed below normal take off speed. For lower take off speeds, the thrust vector applied is greater. The vector and thrust is then trimmed until take off speed. Several procedures have been described for different runway lengths.

In forward flight, the Harrier is at an advantage compared with fixed wing aircraft in that in the event of stalling, recovery is possible by quickly adjusting the thrust vector and throttle. For STOL and VTOL landing, it is necessary to drop below the normal stall speed and apply this method (against all the instincts of the trained fixed wing pilot). The thrust vector control allows for the engine nozzles to be adjusted to a maximum stop of 98 degrees. This facilitates backward motion as needed but is not normally applied during VTOL as the heading into the wind tends to require some forward thrust via attitude control to maintain a fixed hovering position.

The technique of VIFFing ("Vectoring In Forward Flight"), i.e. rotating the vectored thrust nozzles into a forward-facing position during normal flight, was developed as a dog-fighting tactic for both (a) higher turns rates than would normally be possible for an aircraft with such a short wing-span and (b) sudden braking. The latter causes a chasing aircraft to overshoot and present itself as a target for e.g. air-to-air missiles.

Because VIFFing reduces forward thrust, acceleration and manoeuvers in the vertical plane are hampered by thrust vectoring, where thrust-to-weight is more necessary than low wing loading.

[edit] Popular culture

Main article: Harrier Jump Jet in popular culture

The Harrier's unique characteristics have led to it being featured in a number of films and video games.


[edit] References

  1. ^ "[Harrier Production http://www.harrier.org.uk/history/history_production.htm]." [www.harrier.org.uk Harrier.org.uk].
  1. ^  House of Commons Hansard, Written Answers, January 5 2004 [1]
  2. ^  RAF Cottesmore Station Harrier Specifications [2]

Cowan, Ed Charles W. (1972). Flypast 2. Profile Publications Ltd, Berkshire, Windsor, England. ISBN 0-85383-191-2. 

[edit] External links

[edit] Related content

Wikimedia Commons has media related to:

Related development

Comparable aircraft

Designation sequence

Related lists

See also

v • d • e
Harrier Jump Jet family and related aircraft

Predecessors: Hawker P.1127 · Hawker Kestrel · Hawker Siddeley P.1154

First Generation: Hawker Siddeley Harrier · BAE Sea Harrier

Second Generation: McDD/Boeing AV-8B Harrier II · McDD-BAE Harrier II

v • d • e
Lists relating to aviation

Timeline of aviation
Aircraft · Aircraft manufacturers · Aircraft engines · Aircraft engine manufacturers · Airports · Airlines
Air forces · Aircraft weapons · Missiles · Unmanned aerial vehicles (UAVs) · Experimental aircraft
Notable military accidents and incidents · Notable airline accidents and incidents · Famous aviation-related deaths
Flight airspeed record · Flight distance record · Flight altitude record · Flight endurance record · Most produced aircraft

Retrieved from "http://en.wikipedia.org../../../h/a/r/Harrier_Jump_Jet_0bea.html"