Updated: 6/18/2017; Authored By Staff Writer; Content ©www.MilitaryFactory.com
Breakdown of the Harrier Family Tree
The Harrier family line consists of four major versions composed of the Hawker Siddeley Harrier, the British Aerospace (BAe) Sea Harrier, the Boeing/BAe AV-8B Harrier II and the BAe Systems/Boeing Harrier II. Confusing at first, each model does differentiate from the other in some distinct way. The initial production model and beginning of the Harrier lineage was the Hawker Siddeley Harrier. The Sea Harrier (as the name implies) became the dedicated navalized version of the base Harrier and utilized for air-defense as a primary role and ground strike as secondary. The Sea Harrier also made use of the powerful Blue Fox radar and was a direct development of the land-based RAF Harrier GR.3. The Boeing/BAe AV-8B Harrier II became a "second generation" Harrier and is a highly-modified version of the original Harrier for use by the USMC while the BAe Harrier II is a British-modified strike version of the USMC Harrier II.
Hawker Aircraft Limited was absorbed by Hawker Siddeley Group in the late 1950s and became British Aerospace (BAe) in 1977.
This article covers the original first generation Hawker Siddeley Harrier. Other models are reviewed elsewhere on this site under their respective manufacturers.
Short Take-Off and Landings (also "STOL") were proving a pivotal part of the modern battlefield that changed substantially with the close of World War 2. The helicopter was debuted in the Korean War and solidified its role in the Vietnam conflict, in the latter becoming a dedicated weapons platform like never before. The ability for aircraft to go airborne in the shortest amount of time, using the shortest amount of runway distance, became an inherent advantage in responding to your enemy's initial round of attacks - particularly in the Cold War. The idea of an aircraft that could attain horizontal flight and translate this power to full-vertical performance was enticing to say the least and offered up warplanners options that were considered science fiction only decades before.
French engineer Michel Henry Marie Joseph Wibault developed a concept for V/STOL flight with his revision of the Brisol BE.25 Orion turboprop engine. The engine made use centrifugal compressors to drive thrust through two nozzles along the side of an aircraft's fuselage. Further revisions ultimately led him to propose the use of four such vectoring nozzles to achieve balance when in the vertical. Though a complex initiative, it proved a promising answer for sustained V/STOL flight so coveted by the military at the time. Wibault named his creation the "Ground Attack Gyroptere".
Wibault attached his engine design into a simplistic airframe featuring a single-seat cockpit, single vertical tail fin, swept back wings and a stout fuselage. Armament was envisioned as a pair of internal cannons backed by a retractable belly pod fitting 18 x unguided rockets. He proposed the idea to the French and American governments only to find rejection. In 1956, he approached NATO and the concept caught the imagination of American Colonel John Driscoll, who put Wibault in contact with people at Bristol Aero Engines Company.
Bristol engineers were concerned about the engines inherent complexity by driven by their curiosity in the concept. After some of their own revisions, they came away with the idea that a single reduction-geared axial-flow fan could take the place of the four compressors. Bristol had already been working on such a fan in their Olympus 21 series engine. The idea as to fit the Olympus with an Orion engine and the resulting solution would achieve the required action. The new Wibault design emerged under the Bristol company designation of BE.48. The Orion engine was then dropped in favor of a low-pressured Orpheus type. The Orpheus itself was high on fuel usage but proved a lighter and more promising arrangement in the long run. The Ground Attack Gryoptere of Wibualt's airframe design was reworked for the new engine. Despite some issues solved, the Wibualt design lacked a balancing solution through its two vectoring nozzles.
In 1957, the engine had evolved into the Bristol BE.53 and could produce up to 11,300lbf. With the powerplant in place, now all Bristol needed was an airframe to attach it to. Hunting eventually led Stanley Hooker of Bristol into contact with Sidney Camm of Hawker. Camm was intrigued in the prospect of the BE.53. The Hawker and Bristol teams now joined forces in a tentative development effort of the P.1127 "High Speed Helicopter". Hawker suggested an additional two nozzles be used in attempting to solve the aircraft balance conundrum. NATO, powered by the US Department of Defense, lent its financial backing to endorse 75% of engine production efforts while Bristol handled the remainder as a private venture. A new revised form of the engine emerged once again as the 11,300lb thrust powerplant dubbed the "Pegasus" in September of 1959. It was about this time that Hawker Aircraft Group became part of Hawker Siddeley Aviation while Bristol Aero Engines became Bristol Siddeley Engines (the former eventually becoming British Aerospace (BAe) and the latter ultimately becoming part of Rolls-Royce Aircraft Engines).
In 1960, the British Ministry of Aviation ordered two prototypes for evaluation as well as four developmental aircraft based on the P.1127 concept. A supersonic version was also beginning development by Hawker Siddeley under the designation of P.1154 for both the RAF and Royal Navy. An initial controlled flight was performed under the guidance of a tether line on October 20th, 1960 and included simple hovering exercises to test out the validity of the engine/airframe mating. Flight trials then came along beginning on March 13th, 1961 and put into action untethered hovering. Forward flight tests began on September 12, 1961 and ultimately culminated in a joint order by the Britain, the United States and Germany for nine evaluation P.1127s (now known as the "Kestrel") under the designation of Kestrel F(GA).Mk 1. The first Kestrel went airborne on March 7th, 1964.
The evaluation models were sent to an international test squadron made up of British, American and German pilots (known collectively as the Tripartite Evaluation Squadron) operating out of RAF West Raynham in 1965. This was accomplished based on each nation funding procurement of the P.1127 for testing. Six more development aircraft were ordered by Britain while the US took six of the original evaluation aircraft stateside for further testing in consideration for its use in the Marine Corps (one American test aircraft was later lost). Germany declined to purchase any Kestrels and essentially wrote off the Kestrel project altogether. The first pre-production Harrier achieved first flight on August 31st, 1966 at Dunsfold. Tropical climate testing was handled by a single pre-production Harrier shipped to Siciliy and operated from the helicopter carrier Andrea Doria.
Though the P.1154 program (essentially a larger supersonic form of the Kestrel) was scrapped in 1964 by the incoming Labor Party, the Kestrel program was pursued. Six preproduction P.1127 models were ordered in 1965 and carried the Harrier GR.Mk 1 designation by 1967. The supersonic solution was handled by the RAF in the purchase of the McDonnell Douglas F-4J Phantom II with Rolls-Royce Spey engines. Meanwhile, Pegasus engine development was also furthered at this time and produced a powerplant that featured transonic blades and increased airflow requiring larger intakes on the airframe of the Harrier. Blow-in doors (small controlled square openings fitted to the sides of the intakes) were increased from six to eight as a result. While development of the new Mk 103 engine was delayed for a time, an interim Mk 102 engine was used in the first production batch - essentially a "souped up" powerplant running higher than its rated value.
One-hundred thirty two were initially ordered for the RAF (including the two-seat R.2 trainer derivative). Twenty-seven GR.Mk 1s soon followed the preproduction series off the assembly line. The first RAF-sponsored GR.Mk 1 went airborne on December 28th, 1967 with first deliveries began on April 1st, 1969 to No 1 Squadron at RAF Wittering, service beginning in October of that year. Nos 3, 4 and 20 Squadrons based in Germany soon following. Production of GR.1s was handled at the Kingston Upon Thames.
With such a war implement at its disposal, Harriers would form a vital counter-attack force across Europe should the Soviet Union come calling. Instead of operating at forward bases where they could be eliminated while still on the ground through an expected "first round" of surprise air strikes by the Soviets, Harriers were instead kept under camouflaged positions away from these airfields and would be called upon to operate from rough airstrips within minutes. In this way alone, the West maintained a unique advantage in fielding this one-of-a-kind (and highly flexible) war tool. In contrast, the enemy would be fielding high-speed jet fighters and bombers, some prone to overshooting their targets at such high speeds while others taking some miles simply to turn a corner. The Harrier had them beat on both counts as a subsonic vertically-capable aircraft ready to deliver her potent munitions.
The Royal Navy later showed interest in the machine as a dedicated navalized variant and successfully landed and early-form Harrier on the deck of the HMS Ark Royal in February of 1963. The Harrier would later evolve into the Sea Harrier line which would be based on the GR.Mk 3 land-based form. Several major changes differentiated this product from its land-based origins and included a completely redesigned forward fuselage incorporating a radar system, applicable navalized avionics and a specialized form of the Rolls-Royce Pegasus Mk 104 series turbofan engine. These additions made the Sea Harrier more of a "true" fighter as opposed to a strike aircraft.
The USMC were sold on the capabilities of the Harrier and were in the market for a fixed-wing aircraft capable of supporting forward-operating troops. At the time, the USMC was close to purchasing the McDonnell Douglas F-4J Phantom II to fulfill its fixed-wing needs. The benefit of the Harrier lay in that it could operate close to the front lines without need to travel to a hot zone from a nearby airfield or off-shore navy craft. However, USMC interest developed for the Harrier in 1967 to which on-site observation began in 1968. Two USMC pilots were dispatched to England to test fly the new beast.
With just minor reservations, the USMC pilots were sold on the Harrier and the USN moved to procure 12 Harriers under the American designation of AV-8A for their fellow marines. The AV-8A was designated by Hawker as the Mk 50 and shipped off the dozen GR.Mk 1s stateside. Total USMC orders numbered 110 AV-8As in 102 attack models and 8 two-seat trainers known as TAV-8A (or Mk 54 in the Hawker inventory).
It has always proven wholly uncommon for the American government to make approvals for foreign born aircraft so some specific arrangements had to be made to allow the USMC to acquire their Harriers. McDonnell Douglas earned a 15-year contract to produce US-based Harriers and any future models based on the airframe. Despite this agreement, defense budget limitations forces all AV-8s to be constructed at the Hawker Siddeley plant in Kingston and delivered to McDonnell Douglas for reassembly. By purchasing the Harriers, the USMC passed on the purchase of the Phantom IIs.
These early American Harriers differed slightly with the addition of US Navy avionics, radios and a weight-on-wheel sensor. For self-defense, the USMC insisted on the outer underwing hardpoints were wired for the AIM-9 Sidewinder short-range air-to-air missile. The first dozen AV-8As were delivered with the Mk 102 Pegasus engines while the follow-up deliveries came with the Mk 103 engines (including the applicable trainers).
The first Marine AV-8As came to VMA-513 at Yuma in Arizona. They were followed into service by VMA-231 and VMA-542 at Cherry Point, North Carolina. Within a year, USMC Harriers dropped use of the complicated Ferranti FE541 nav-attack system - a system designed with the intention of all-out war over Europe, something the USMC was not going to be a part of anytime soon - replaced by US-developed systems instead. The Martin-Baker Mk 9A ejection seat was also replaced with the thinking being that the Stencel SEU-3/A was going to be standardized in the Grumman F-14 Tomcat and Northrop F/A-18 Hornet some time soon. While the use of the seat was never implemented in the Tomcat nor the Hornet, the Harrier was forced to carry on with the change to the Stencel seat.
Design of the Hawker Siddeley Harrier was decidedly British with attention to smooth contours and a layout culminating in a most unique and identifiable design. The nose was a slim affair, protruding from the forward fuselage just ahead and under the cockpit. The cockpit was situated between the large semi-circle intakes feeding the single engine with access via a rearward-sliding single-piece canopy. The pilot was afforded an excellent look-down vantage point, both forward and to the sides, from under a large clear canopy and forward windscreen (the latter with light framing). His view to the rear was completely obscured, however, due to the elevated spine running the length of the fuselage. The split intakes fed a family of Rolls-Royce powerplants with ever-increasing output throughout the Harrier's production line with the engine itself situated at the middle of the stout fuselage. The airbrake was a simple single-piece system hinged forward and extending downwards at an angle from the base of the empennage.
Wings were high-mounted swept-back assemblies fitted amidships with noticeable anhedral (downward slope) and tapered down to clipped wing tips. The rear quarter, or empennage, was a sleek assembly topped with a large curved vertical tail fin and downward sloping horizontal planes presenting even more anhedral than the main wings.
The Undercarriage - Why the Little Wheels?
The undercarriage was wholly unique to the Harrier and consisted of one two-wheeled main landing gear leg installed at the rearward portion of the fuselage underside with retraction completed in a forward manner. The nose wheel leg was fitted just under and aft of the cockpit floor, positioned between the twin intake openings, with and retraction also completing in a forward manner. The nose leg was decidedly longer than that of the main leg and promoted a distinctly "nose-up" appearance for the Harrier when at rest. The main landing gear leg was also complimented by a pair of smallish single-wheeled stems or strut assemblies held under each wing just near the wingtips. These systems retracted rearwards and were utilized to keep the Harrier from rocking or tipping to one side when landing. A perfect Harrier landing required that both of these struts hit the ground at the same time.
Fly, Baby, Fly
To accomplish its vertical flight, the Harrier made use of four positional trust vector nozzles with two located ahead and under the wing leading edge (one to a side) and two fitted aft of the wing trailing edge (also one to a side). Total positional range of these nozzles is 0-degrees (pointing straight back for vertical flight) and up to 98-degrees (downward and slightly forward to achieve vertical flight). Control of these thrusters is accomplished via a selector component near the thrust lever in the cockpit and helps the operator to handle the Harrier in much the same way a helicopter makes use of its cyclic.
When launching vertically, the aircraft had to be facing into the wind to prevent any sideways slew with the wheels locked in place. The pilot would positions the thrust vector nozzles to 80-degrees with downward thrust achieved with full power from the throttle. Once airborne, the operator and onboard systems would skillfully work at keeping the aircraft under control until the desired altitude was reached. From about 50 feet to 100 feet of altitude, the pilot could then take his mount forwards to his destination by adjusting the angle of his vector thrust nozzles. Similarly, the Harrier could also achieve short "rolling" take-offs via positioning the vector nozzles at an angle less than 90-degrees to achieve both the forward and vertical required momentum at the same time.
When hovering, the Harrier would maintain its general position in the air across all planes with reactionary control accomplished through small "jets" located in the wings, nose and tail sections. These smaller jets were operated by the pilot through both his control column and rudder pedals as needed. In this way, the Harrier offered qualities that seemingly ranged between that of a true helicopter and true fighter. As a general rule of thumb, a lightly-loaded Harrier was afforded approximately five minutes of hover time to avoid overheating the engine. Conversely, a heavier-loaded Harrier was offered much less than this depending on the overall operating weight.
How High Can a Harrier Hover?
Experienced Harrier pilots list an effective hover ceiling of up to 5,000 feet, though they are quick to point out the such an action is limited. Available thrust naturally has to equal or best the weight of the aircraft. At incremental altitudes, an engine naturally loses a percentage of thrust the higher it climbs. Additionally, Harrier pilots have stated that the higher you are, the less fixed ground reference points you have. This means that there is no effective way to tell that you are indeed in a hover anymore for the aircraft could be moving forward, backward or to the side at this point without the pilot knowing. In short, only the calmest of days (i.e. no wind) would be able to provide a definitive hover ceiling for the Harrier. As this is unrealistic - and offers little to no combat value - it is safe to say that 5,000 feet is a fair value to assign the Harrier.
Standard armament for the Hawker Siddeley Harrier included a pair of 30mm ADEN cannons mounting in fairing pods under the fuselage at about amidships. Though foreign to American readers at first, one must keep in mind that it became something of standard practice at this time in history to feature an aircraft sans fixed armament. The cannons of the Harrier were allotted 120 rounds of ammunition apiece.
Four underwing pylons and one centerline hardpoint could field up to 5,300lbs of external ordnance, this coming in the form of air-to-surface rocket pods, conventional drop bombs and air-to-surface missiles. The Harrier was cleared for using the Matra brand of rocket pods fielding some 18 x SNEB 68mm high-explosive, high-velocity rockets as well as up to 4 x AIM-9 Sidewinder or 2 x AS-37 Martel air-to-air missiles (the latter in dealing with air-to-air threats). Rockets were always a favorite of the RAF so such use was quite standard on operational Harriers. The centerline hardpoint was cleared for up to 1,000lbs of bombs or a tactical reconnaissance pod as needed while the inboard stations could mount upwards of 1,500lbs while the outboard stations were limited at 750lbs.
Other external payload options included 2 x drop tanks for increased range.
The GR.Mk 1 was the initial Hawker Siddeley Harrier and a direct child of the Kestrel program. The GR.Mk 1A were nothing more than GR.MK1s retrofitted with the now-available (from 1971 onwards) Rolls-Royce Pegasus Mk 103 series turbofan engine. Several changes first introduced on USMC AV-8As were also brought into the GR.Mk 1A upgrade, helping to improve operations, reliability and maintenance tasks. The Harrier GR.1 achieved performance specifications that included a subsonic maximum speed of 735 miles per hour (Mach .97), a range of about 1,200 miles and a combat radius of 260 miles. A service ceiling of up to 49,200 feet was possible while a rate-of-climb nearing 50,000 feet per minute could be attained. Maximum take-off weight was listed at 25,350lbs.
The definitive GR.Mk 3 was fitted with improved nose sensors (including a Marconi laser ranger and marked-target seeker) in a new lengthened nose. Power was derived from a Rolls-Royce Pegasus Mk 103 series turbofan engine and in many ways made the GR.Mk 3 the pinnacle of the first generation Harriers. The GR.Mk 3 could now have its targets lazed by ground forces, other aircraft or its own onboard laser designator. Additionally, a Marxoni ARI.18223 Radar Warning Receiver (RWR) was installed in the vertical tail assembly - one along the leading edge and one on the trailing edge - to provide the pilot with tracking and incoming enemy missile warnings from the front and rear of his aircraft. All remaining GR.Mk 1 and GR.Mk 1A models were eventually brought up to GR.Mk 3 standard.
The British GR.1 and GR.3 models have since been retired.
The Harrier combat models were developed into two-seat trainers beginning with the T.Mk 2 and the upgraded T.Mk 2A for the RAF. The T.Mk 4 was developed from the GR.3 combat production variant. The T.Mk 4N was a two-seat trainer for use by the Royal Navy. These trainers have since been retired.
The US Marine Corps became a primary operator of the Harrier beginning with the AV-8A, taking delivery of 110 examples (including two-seat trainer TAV-8As as well). The Harrier certainly fit the bill in terms of what the US Marines were all about - combat anywhere and everywhere, whenever the situation warranted. The AV-8A was a single-seat ground attack multi-role derivative with dual reconnaissance and fighter capabilities in one sleek package.
To help improve the limited countermeasures suite of the original AV-8A, the ALR-45F/APR-43 radar warning receiver was added as was the ALE-39 countermeasures dispenser along the rear of the fuselage. Defensive capabilities could be further enhanced by the addition of an ALE-37 chaff-dispensing pod. The internal bomb camera was later dropped. The modified Harriers were redesignated as the AV-8C and first flown on May 5th, 1979. Other changes included revisions to the internal workings that improved the overall service life of the USMC Harrier family line by 1,000 hours.
The USMC TAV-8A trainers were added to the end of the AV-8A production order and included all the mentioned requested USMC changes. The initial TAV-8As made their way to Marine groups at Cherry Point, North Carolina.
After eleven years in the air, USMC AV-8As acrued an appalling accident record with the loss of some 55 aircraft in peacetime incidents. A review of practices was enacted and produced a list of low-cost solutions. Improved training and safety precautions led to a 50% reduction in such losses.
The AV-8B "Harrier II" brought along with it beyond-visual-range (BVR) capability as well as a multi-mode radar suite. The AV-8C were upgraded AV-8A models brought up to a new C-model standard. The TAV-8A became the primary two-seat Harrier trainer for the USMC and was powered by a Rolls-Royce Pegasus Mk 103 series turbofan engine of 21,500lbs. Early Marine Corps Harriers were retired as recently as 1997.
The Harrier existed as an export model under its "Matador" designation when it was sold to the Spanish Navy. At the time of the Harrier, relations between Spain and Britain had been soured over the debate centering in on Gibraltar. As such, the Spanish gained their Harriers through the United States as well as their Harrier training. Internal Hawker designations named the first batch of Matadors as Mk 54 with a second identical batch interestingly name Mk 55 - despite the similarities between the two orders.
The VA.1 Matador was the Spanish designation for the AV-8S which, in turn, was the export designation of the USMC AV-8A. This Matador was produced in two production batches under the company designations of Harrier Mk 53 (first batch) and Harrier Mk 54 (second batch) respectively. A two-seat trainer Matador also existed under the designation of VAE.1, a Spanish designation for the TAV-8S which, in turn, was the export designation of the same TAV-8A in service with the USMC.
Spanish Harriers were sold to Thailand in 1996 after being replaced by the upgraded Harrier II and Harrier II Plus models. Thai usage of Harriers has since been severely restricted due to lack of spare parts and additional funding. Intended use was to be in operations from a recently purchased (and formerly Spanish) aircraft carrier now designated as the Chakri Naruebet with the Thai Royal Navy.
Other VTOL Attempts Outside of Britain
The Yakovlev Yak-38 "Forger" was the Soviet attempt at a VTOL fighter aircraft and the only real world competitor. The system achieved first flight in 1971 and became operational in 1976 with operations conducted under the flag of the Soviet Navy. However, the Yak-38 did not fare as well as her British counterpart and was limited to only a small production total of some 230 or so examples. Yak-38 development encompassed just four major variants along with a slew of underdeveloped and proposed projects based on the original Yak-38 concept. The Forger remains the Soviet Union's/Russia's one and only attempt at a VTOL combat platform.
America's Rockwell International firm attempted to produce their own VTOL fighter for the United States Navy in the 1970s. The system was designated as the XFV-12 and appeared in only two prototypes from 1977 onwards. The project was ultimately cancelled in 1981 when the design consistently failed to produce enough vertical thrust despite more powerful engines being fitted before project's end.
In Action: the Falklands
The Harrier first earned her stripes in the Falklands War against the dictatorship of Argentina which, for whatever reason, had invaded the seemingly useless Falkland Island chain located off the south eastern Argentine coast. The British Task Force was formally arranged and made the 8,000 mile journey (long ways) across the Atlantic Ocean. Though initially made up of just 20 Sea Harriers, these groups would ultimately composed of both the land-based Harrier GR.3s and ship-based Sea Harrier FRS.1s with operation conducted by both RAF and Fleet Air Arm (FAA) personnel. Sea Harriers were launched from the HMS Hermes and the HMS Invincible with their American-made AIM-9 Sidewinder short-range air-to-air missiles to help combat and deter Argentine aircraft which also included the ultra-speedy Israei-made Daggers (based on the French Dassault 5) and the French Mirage III series. By-the-numbers, British aircraft were wholly outnumbered but technology and superior training gave UK pilots the edge over their Argentine counterparts.
The Royal Air Force GR.3s were also launched from HMS Hermes but were instead charged with close-support strikes near friendly forces against Argentine ground units (and applicable installations) and ultimately made their way to operations from land bases. Only four RAF GR.3 systems were lost in the conflict while six Sea Harriers were downed - though none, it should be noted, were lost through air-to-air combat but instead through accident, friendly fire and enemy ground-based fire. In all, Harriers (land and sea-based)accounted for some 1,850 total sorties in the conflict, racking up 32 enemy aircraft destroyed with 23 of these in air-to-air combat - a great ratio for any warbird. The Falklands War lasted from April 22nd through June 12th, 1982 in a resounding defeat for the Argentine dictatorship.
Some Harriers went on to see service in foreign countries that included Belize and Norway (Bardufoss), all operating under the flag of the Royal Air Force. The Belize action was brought about as Belize was once known as British Honduras. In 1948, the nation became independent and was threatened by military action from nearby Guatemala. As a show of force, British Harriers were stationed in Belize for 18 years to quell the tensions, becoming the first overseas deployment (and longest) of the new machine. The hotspot became a normal stop for all Harrier pilots in their tours and the high temperatures of Belize surely put the Harrier through her paces, allowing for live-fire exercises and constant training of her various systems. In 1993, these Harriers were ultimately returned to the UK after the situation normalized. Overseas deployments also eventually included Sardinia.
In all, the United Kingdom operated Harriers through their No. 1, 3, 4, 20, 233, 1417 and 1435 Squadrons. With the fall of the Berlin Wall and ensuing collapse of the Soviet Union, British Harriers in Germany were withdrawn from the region in 1999. The USMC operated the AV-8A, AV-8C and TAV-8As in their VMA-231, VMA-513, VMA-542 and VMA-203 squadrons. AV-8S and TAV-8S Matadors served with the No. 008 Escuadrilla of the Spanish Navy. The Royal Thai Navy has operated AV-8Ss and TAV-8Ss as part of their Squadron 1 Wing 3 formations.
Some 718 Hawker Siddeley Harriers are reported to have been produced with production running from 1967 into the 1970's.
Service Year: 1969
Type: VTOL Strike / Reconnaissance / Trainer Aircraft
National Origin: United Kingdom
Manufacturer(s): Hawker Siddeley - UK
Production Total: 718