The end of the Second World War should have heralded the long promised "Peace in our Time", but all was not well with the wartime alliance that had stopped, and then defeated the advance of German National Socialism. Churchill had long suspected that Stalin had a hidden agenda, not coming as a liberator but as a dictator, and spreading the word of Communism throughout the eastern areas of Europe with an Iron Heel. Churchill made a speech in Fulton Missouri on 5th May 1946 in which he coined a phrase that would remain in common usage for over forty years, "The Iron Curtain". During June 1948 to May 1949 the Soviets blockaded Berlin in an attempt to get the Allies to leave, but this failed after a sustained airlift on an unprecedented scale, carrying supplies into the city. In 1949 NATO was formed and as a reaction Stalin convened a meeting and formed the Warsaw Pact. The Soviets only ratified their alliance with a full treaty in 1955, mainly as a knee-jerk reaction to the inclusion in NATO, against their wishes, of the Federal Republic of Germany. Meanwhile during 1950, almost on the other side of the world, Communist North Korea, with backing from China invaded and rapidly overwhelmed South Korea, dragging many nations into war under the United Nations banner for the first time. This was a mere five years since the end of the Second World War and all the hopes for a lasting peace appeared to be rapidly fading. After an all too brief period of reduced defence spending, money was once again having to be found to provide weapons for defence and if necessary offence. It was behind this sort of spending and investment that the Harrier found its wings.


At the end of the Second World War, 'The Big Three' nations (UK, USA, & USSR) busied themselves with the dismantling of the Nazi war machine's technological prowess. It was known that the Germans had developed several methods of waging war which where highly technologically advanced - the V1, and particularly the V2, being good cases in point. The Germans had also spent a lot of research on aerodynamics, and the research on the advantages of swept wings formed the basis for the basic shape of many a 1950`s fighter.

With the scientists and engineers "disappeared" both East and West, and given budgets and facilities to expand their research, a host of new ideas practical, impractical and some just down right dangerous came to the fore The most successful of these in the public gaze being the United states and Soviets Union's space race.

A vast amount of money was pumped into the expected battleground for the next conflict, West Germany. Stores, provisions, fuel and troops were all placed in garrisons within Germany to withstand any attack by the Soviet Warsaw Pact forces. Airfields were a prime commodity. Many were positioned close to the barbed wire and watch towers of the Iron Curtain, along the eastern Federal Republic border. Bases such as Gutersloh, Fassberg, Furstenfeldbruck and Celle used to provide airfield services were almost certain, with their position so close to the approaching troops, to be overrun, perhaps in a matter of hours. The decision was taken to give the air forces a breathing space within which to operate, and consequently a line of bases was built the length of the Federal Republic's western border, with the best known of these probably being the RAF "Clutch" stations of Bruggen, Laarbruch, and Wildenrath. All of these bases had one thing in common, however, and that was a long thin strip of concrete that was essential to utilise the capabilities of the aircraft that were in service. What was needed was a method of being able to deliver a decent payload, by preferably a high speed jet aircraft that would not be tied to traditional runways. The search was on to find a solution.

Vertical Take Off and Landing

The ability to take off and land vertically was almost science fiction to all but a few lateral thinkers. The Germans had attempted to perfect a vertical take off with the Bachem Ba349 "Natter" (in English 'Adder') in 1944. This was a rocket powered interceptor with the ability to rise vertically on a rocket motor, and after a period of time gliding, was recovered by parachute. As with many of Hitler's desperate late war "wonder weapons", once again this was too little too late to have any significant effect on the outcome of the Second World War.

Headway had been made with helicopter technology which also gave a vertical take off capability but with the engines of the day, the power to weight ratio was poor meaning only a small payload could be carried. It was not until the use of gas turbine engines in helicopters that improved power to weight ratios meant greater weights could be carried. Speeds for survivability remained a problem, however, that all but negated them from being considered.

Rolls-Royce Thrust Measuring Rig XJ314

British attempts to overcome the requirement for a shorter take off run centred on a converted Meteor which could deflect its thrust downwards to boost the aircraft into the air. The results were not that satisfactory and the idea was shelved. There was success however, when Rolls Royce utilising the "Flying Bedstead" and Shorts with the Shorts SC.1 demonstrated the principle of jet lift, and more importantly that control in the hover could be attained using a bleed air system from the engine to control roll and pitch. The Shorts SC.1 used the Rolls Royce RB108 dedicated light weight lift engine which led the world in its thrust class providing a power to weight ratio of 8.7:1, when the general thrust to weight ratio of a conventional engine was 4:1 to 5:1.

Shorts SC.1 XG900

In 1956 the Ryan Company, who built Lindbergh’s 'Spirit of St Louis', produced the X-13 'Vertijet' powered by a Rolls Royce Avon. This idea had an aircraft taking off and landing on a tilting platform built into a trailer. This suffered piloting problems during the transition from vertical to horizontal flight, and from a lack of 'overload capability' whereby wing lift assists the jet lift in raising a heavier load. It is quite feasible that the transitional problems encountered could have been overcome with the advances that have been seen in computer control of aircraft in the hover, the F-35 Joint Strike Fighter being the perfect case in point.

The Bell Company also entered the fray with the Bell X-14A powered by a pair of Armstrong Siddeley Viper 8 axial flow turbo jets. It utilised these engines, which were manoeuvrable and mounted one either side of the nose to provide vectored thrust. An air-bleed stabilisation system like the 'Bedstead and SC.1 was also fitted. This aircraft achieved transition from the hover and back again demonstrating this capability for the first time on 24th May 1958.

Several attempts to utilise buried fans were made, such as the Ryan XV-5A vertifan, however, technology at the time precluded the use of these fans as they imposed severe volumetric and weight penalties upon the airframe. They also contributed to a high level of drag which compromised any short take off capability. It is remarkable that with the passing of some fifty years, technology has finally caught up with imagination. The buried fan principle utilising power take off from the conventional turbine engine has been proved as viable by the F-35 Joint Strike Fighter.

At the same time as the XV-5, Lockheed were experimenting with the XV-4A "Hummingbird". Rather than the buried fan concept, Lockheed utilised the notion of buried jet augmenters - basically jet engines mounted in the fuselage that pointed down to give a column of powerful hot air to lift the aircraft. This technology was also demonstrated by the Dassault Balzac V which flew as a technology demonstrator for the Dassault Mirage III-V, which was the world’s first Mach 2 V/STOL aircraft. All of these designs suffered as the weight penalties for the downward jets removed capability in terms of manoeuvrability, fuel, and expendable ordnance. Experiments decreed that the most efficient approach was to deflect the thrust of the conventional propulsion engine down and add just enough lift engines to provide the required performance. This approach was utilised successfully by Yakolev with the YAK141"Freestyle" fighter, and would also feature in the engine proposal for the F-35 JSF.

Hawker project engineers studied Rolls Royce lift jet proposals, and it was for a time the preferred option of the MoD being 'the sensible way ahead', which basically meant other ideas would not receive funding!
This did not bank on Sir Sydney Camm, however. Camm was convinced that his colleagues at Derby had designed a system that was far too complex, and not compatible with the requirements of front line operations. He was adamant that he was not going to take this proposal to the Hawker Board, and that if (and it was a very big 'if' in the 1950’s) the company was to enter the world of V/STOL then his 'Young gentlemen of the project office' would have to come up with a far simpler solution.

Michel Henry Marie Joseph Wibault

The first USAF supersonic F-100 slammed on to the precious, vulnerable concrete at Bitburg on 12th March 1956. A week before an elderly Frenchman had climbed the steps of the French Air Ministry in Paris. He was Michel Wibault an aging aircraft designer, once famous for his all metal monoplane designs that were every bit as cutting edge as the F-100 for their time. The contents of his briefcase were exciting as contained within were designs for a new fighter with a novel design twist. He named it 'Le Gyroptere'. It was a small combat aircraft with a totally new vision of how to utilise the power plant to give a VTOL (Vertical Takeoff and Landing) Capability. Wibault realised that the major obstacle too many of the designs was their controllability while in the vertical hover, with the pilot laid on his back. Wibault proposed that the aircraft should take of vertically from a normal horizontal attitude, but the piece de resistance was the method of gaining flight.

The aircraft was designed to be lifted from the ground using four nozzles, which were powered fans, driven by a Bristol BE25 Orion turbojet. The moveable fan nozzles were evenly spaced around the centre of gravity of the aircraft giving it a level of inherent stability that had been sadly, and dangerously, lacking in other designs.


Wibault visited many groups and officials, including NATO’s AGARD Advisory Group for Aeronautical Research and Development), and the American funded MWDP (Mutual Weapons Development Program). Colonel Willis of the MWDP had the idea evaluated fully. The concept was never refuted, nor was the need for the survivability that it would bring dismissed. Its main problem was the engineering. The general consensus was it was a great idea, but they all thought the technical design was lacking.

Wibault required assistance and with the help of Col Bill Chapman, Wilbault was introduced to one of Britain’s foremost Aero Engine designers, Sir Stanley Hooker who had changed suits and on leaving Rolls Royce joined Bristol as Technical Director. Hooker looked over the proposals and gave it to Gordon Lewis, a Bristol engineer who within a week or two had redefined the concept, and circumvented some of Wibaults more clumsy features. Lewis made the Orion engine drive a front fan, via a reduction gear, made from the front two stages of an Olympus engine. The fan delivered air to two nozzles, one left and one right that could be vectored down to 90 degrees to vertical from horizontal, thus giving lift. This project was designated Bristol BE.48, and while a vast improvement, it was only a small step along the road.

BE.48 Orion Power unit

BE.48 Orion Power unit

Further study demonstrated that the Orion engine could be removed and replaced by the lighter Orpheus turbojet which supplied the same shaft horsepower and was cheaper. Furthermore the Orpheus matched ideally with the fan and it was found that by fitting a low pressure turbine into the Orpheus through the existing tubular high pressure shaft. This allowed the reduction gear of the BE.48 to be removed and created the BE.53 which gave a thrust of around 8000lbs, which was significantly better, and cosmetically more pleasing than Wibaults original design.

BE.53 Orpheus power unit

BE.53 Orpheus power unit

In late 1956 Hooker began talking with the Ministry of Supply and with the Board of the Bristol Aeroplane Company. Both showed interest but with no written service requirement there was little the Ministry could do, although Hooker felt that should industry grasp the nettle and go ahead, this would be welcomed. Things now developed into that typical British farcical passion with committees all of which held very official meetings all of which seemed to have little or no objective. Hooker decided to take matters further and talk to aircraft designers. He began with Hawker Aircraft.

Hawkers, Camm, Hooper and Fozard

The famous company from Kingston-upon-Thames had had considerable success with previous aircraft and was revelling in the global success of its 'Hunter' Fighter, and spending large amounts of its own money developing a larger Mach 2 capable successor to the Hunter, known as the P.1121. The proposal, however, made to the Chief of the Air Staff was not well received when put to him by Hawker's senior technical director, Sir Sydney Camm. It is interesting to note that at the time that Camm was touting for business with the Chief of the Air Staff, the Defence Minister, Douglas Sandys, was writing his white paper that would throw defence policy, and aircraft production in the United Kingdom into turmoil for years to come. Published on 4 April 1957 the white paper is infamous for stating that the RAF would be 'unlikely to require' anymore manned fighters and or bombers. There was one exception, for a multi role reconnaissance bomber which like topsy grew and grew until Hawkers P.1121 design would never fit the requirement (this was to be met by the TSR.2).


Camm and the rest of the Hawker Board big guns, like Sir Frank Sprigg, and Sir Roy Dobson, were in no mans' land. They had the design for a next generation fighter/bomber, which should have been growing from metal stock in the workshops, and a customer that had little interest in it. It was at this moment that the brochure for the BS.53 landed on his desk. Camm had an intense care and respect for the Hawker brand and for the pilots that flew the product and this by nature made him dislike, distrust, and be somewhat generally suspicious of 'new' ideas. Writing a brief memo, he attached it to the brochure, and then sent it to Ralph Hooper. He then turned his attention to the mainstream problem of how to turn a single seat P.1121 into a twin engine, twin seat P.1129 to try to win the only military aircraft deal left on the table.

Ralph Hooper shared an office with John Fozard, who at the time was the former Project Engineer on the P.1121 and now suffering sleepless nights on the P.1129 project. On reviewing the brochure on the BE.53 neither was very impressed. The thrust from the rear of the engine was cancelled by rotating nozzles forward well past 100 degrees to blow forwards, reducing the power available to lift in the vertical. They were also not too impressed with the nozzles which were bent elbows with large fairing which did not work well in the Vertical take off environment. By March 1957 Hooper had drawn a three view project which was designated P.1127, but with the present engine configuration, Hooper himself knew it would not fly far, very fast, or carry very much. Had the P.1121 been rolling along it is conceivable that the P.1127 may well have disappeared never to be seen again. But Hawkers needed a long term project to keep the company alive, as day by day the prospects for both the P.1121 and P.1129 became bleaker.

In a moment of inspiration that took the design closer to Wibaults original four nozzle concept than he perhaps realised, Fozard hit on the idea of bifurcating, or splitting, the jet pipe as had been done on the Hawker Sea Hawk. The idea was simplicity itself, no more two nozzles and a jet pipe, just four nozzles that all rotate in unison. Fozard also knew that the nozzles could also be smaller and lighter if they contained vanes to turn the flow. Fozard drew the new engine with five vane nozzles which would give 'four poster' lift. The idea was put to Bristol, and was met by a wall of silence.

The suggestion was put more vociferously, and this time they explained they felt that it would be a good idea if the Low Pressure and High Pressure spools counter-rotated to reduce if not cancel out the gyroscopic effect of the engines torque. This time there was a reply, and the Bristol engineers said the bearings would not take the strain. By now Hawkers and Bristol were talking almost constantly, and after about six months the engine team came to the conclusion that the four poster nozzle design and the contra-rotating spools were possible. Bristol designed a new fan that contained mirror imaged blades to rotate in the opposite direction. As a result of this change the gyroscopic coupling of the engine fell to almost zero. The engine team also advanced the design of the inlet to provide common airflow too, so that the fan supercharged the core. Engine weight was reduced and the plenum chamber now provided compressed air to the front nozzles and to the HP Compressor with minimal frontal area and installation problems. This engine with its four nozzle design was designated BE.53/2. The engine thrust with this engine had risen to some 9000lbs but some juggling of the bypass ratios was to ensure that the amount of air passing from the front nozzles (which have a temperature in today’s aircraft of about 100 degrees C) was in symmetry with those of the `Hot` nozzles at the rear. The Bypass ratio to do this was settled at 1.35:1.

In early 1958 things were still far from certain for the P.1127 and its engine. The Bristol board decided that while the venture was still fraught with uncertainty, they would go ahead with the BE.53 design if the funding was available for 75% of the cost. NATO’s Mutual Weapons Development Program stepped in at this point and pledged the required assistance, with Bristol paying the outstanding 25% from its own coffers. As seems to be all too usual the costs escalated but neither Bristol, nor the MDWP (with their American taxpayers Dollars) wavered in their faith and determination to succeed in the project. The programme consisted of building six engines, two earmarked for bench testing and four for flight trials. The first BE53/2 ran at Patchway, Bristol, in September 1959 but not until the engine had undergone one more minor but significant change, which made it as synonymous with vertical take off as the name 'Harrier'. They christened it 'Pegasus'.

Pegasus 1

Pegasus 1 1959

Camm gradually allowed more engineers to work on the P.1127 project, although he still tended to show less enthusiasm for this project than any other. Hawkers funded research and development and engineering design out of their own pocket. By now a fundamental change had been affected to the engine to ensure control was maintained while in VTOL flight. To operate successfully in the hover the jet needed what are known as Reaction Control Vents (RCV’s), under the nose, tail and at the wing tips. These RCV’s provided the control inputs for the aircraft, as the conventional surfaces are inoperable due to there being little or no airflow over them. Hooper ran bleed air pipes from the engine through aluminium pipes to the RCV’s but found that to be effective they had to be of a size that would not fit into the wing! The answer was to run smaller stainless steel pipes at a higher pressure and temperature from the high pressure area of the engine. The system worked on a fixed and constant flow blowing down and allowing yaw control at the nose and tail by also blowing sideways.

Official interest was still not forthcoming and Hawker Siddeley, as they now were, took the brave decision to commit funds to the construction of two prototypes, and drawings arrived at Kinston that same month. The design was simple but very recognisable. A small aircraft with a bicycle undercarriage and out riggers to support the wings, a high shoulder mounted wing over the top of the engine, with design limits the same as the Hunter of 620Kts/Mach 1. It was not envisaged that the aircraft would attain that limit in level flight but the aircraft was being treated as a light attack aircraft rather than a technology demonstrator.

To meet the demand for more bleed air, Bristol came up with the BE.53.3/Pegasus2, which featured a re-matched two stage HP compressor. The engine first ran in February of 1960 and delivered 11,000lbs of thrust.

A new problem then reared its head which could have had serious repercussions. Wind tunnel testing and theoretical calculus had shown that the aircraft may be prone to being unstable. The problem appeared to be during the transition from jet borne to wing borne flight. There was a possibility that the aircraft would run into an uncontrollable divergence of pitch and the aircraft then tumble out of control nose over tail. While there was a chance that a skilled pilot may be able to catch the situation, it was no way to build an aircraft. Wind tunnel testing was urgently needed to investigate this potential problem but British Government facilities were not available. However,on the other side of the Atlantic a NASA scientist who was observing the development of the aircraft from afar became the saviour of the day. Dr John Stack allowed the use of NASA’s wind tunnels and authorised the building of a one-sixth scale model of the P.1127 complete with jet nozzles fed by fans driven by High Pressure air. Eventually the model was being flown by four pilots, each controlling one variable, and by February 1960 a transition from the hover to wing borne flight had been flown without incident, except for when the air hose broke free and blasted high pressure air at the model at about 300 psi. NASA also built a smaller metal model that they flew outside on the end of a long rotating arm, which was used to test Short Take Off and rolling landing techniques. They then allowed test pilots Bill Bedford and his colleague Hugh Mereweather to fly both the Bell X-14 and a flight simulator programmed with the handling characteristics of the 1127.

Perhaps it was all this positive assistance from the opposite side of the Atlantic, but at last the British Ministries were shamed into helping out. In June 1960, the Ministry of Supply finally became involved and repaid the Hawker board its costs and allocated serials for the two aircraft (XP831 and XP836). It was made abundantly clear, however, that the aircraft was not to be considered a light attack aircraft but a pure research aircraft and a contract was drawn up, followed by an Experimental Requirement. The end appeared to be in sight, but once again fate stuck her foot in the door. Apparently the Pegasus engine had not been designed to official requirements and was not covered by the required documentation! Nonetheless, by August the relevant paperwork had been created and the Pegasus 2 was cleared at 11000lbs for 15 hours of flight in the VTO mode or 20 hours of conventional flight.

P.1127 XP831

XP831 was completed with a set of temporary 'bell mouth' intakes to ensure a good smooth airflow. In spite of this the margin between the thrust provided, and the gross weight was very small and even the radio was removed, and replaced with a ground intercom link, in an attempt to save weight. The aircraft was wheeled out onto a metal mesh grid which was flush with the surrounding surface and then tethered by the outriggers and the nose gear to weights under the mesh surface. Initial engine runs and shakedown testing was completed, and with Bill Bedford at the controls - albeit with a broken leg in plaster! - the wheels of the P.1127 left the ground for the first time on the 21 October 1960.

Bedford and Mereweather (who took over as Chief Test Pilot in 1967) shared the initial flying of the 1127. Both remarked that it was clear that the real thing did not handle with the same hair raising qualities that the NASA simulator displayed. Mereweather described the learning of the controls to maintain an even keel as akin "to being a child trying to master learning to ride a bicycle in a corridor".

The Sandys Defence white paper continued to draw a long shadow over the whole programme. It initially made starting the venture extremely difficult, it eliminated the possibility of normal attitudes to funding except on a research basis, and the very thought that there should be contact between the manufacturer and potential customers such as the Royal Air Force and the Royal Navy was tantamount to treason in certain circles. This was compounded by the total lack of interest by the Royal Air Force who believed that if they did receive any manned aircraft they had to be capable of exceeding Mach 2. Indeed during the period between 1958 and 1968 that misguided belief also meant that the Buccaneer was overlooked. had the RAF not been so short sighted in their misleading of a frankly gullible Defence Minister back in 1957 there is no doubt that the P.1127 would have been a different beast altogether, possibly with two engines, possibly with two crew, and would have certainly been developed into a highly capable ground attack platform. As it was the P.1127 was not so much an impressive achievement as a demonstrator of potential yet to be unwrapped.

Back at Kingston there had been a lot of discussion as to whether the P.1127 should have a helicopter style twist grip throttle, but ultimately the decision was made to go with a conventional throttle arrangement working in a ratchet box, which contained a hydraulic dashpot and spring. To go from lift to thrust the hydraulic valve was closed and the spring slowly rotated, over about 20 to 30 seconds, moving the nozzles from downward pointing VTO mode to rearward facing forward flight mode without the pilot moving his hand from the throttle. To go from thrust to lift the pilot moved the throttle to the rear and with the valve open the nozzles rotated immediately under the action of the spring on the control system. In 1961 several changes were made to the system, first the dashpot was removed, then the ratchet, and finally the pilot ended up with the control system that remains current today, twin levers - one the throttle,and the other a rapid and precise nozzle lever.

In the July of 1961 XP836 joined the programme. This aircraft made conventional take offs and brought the speed down close to the stall at about 90kts, the pilots cracking the art of vectoring the nozzles. On 12 September 1961 the two sets of tests coincided with each other, and both Bedford and Mereweather made accelerating and decelerating transitions. The Ministry were not impressed and a stern letter was sent rebuking them for carrying out the manoeuvres without the Ministry's permission. Bedford apologised, but explained he thought it better to go on and fly on the wings than try to stop the aircraft in the remaining area of the airfield! This was the first time that a transonic aircraft had accomplished transition to and from VTOL flight. The P.1127 demonstrated the ability to fly at any speed from around 20kts backwards to speeds close to that of the speed of sound. In fact although it was not a design objective the aircraft did go supersonic during December 1961 and a few days later accomplished a Mach number of 1.2 in a shallow dive.

The Ministry of Supply funded a further four aircraft and for the first time did not call them 'research' but 'development' aircraft. This gave the impression that there might be a military aircraft somewhere in the distant future coming from the programme. NATO staff had been busying themselves, as military staff tend to do, by writing up wish lists of future hardware, for short-sighted politicians to ignore. NBMR-3 was a requirement for a V/STOL close support strike fighter and NMBR- 4 a V/STOL transport aircraft. The P.1127 was not in the class that the requirement was set out to achieve, and was overlooked. In fact the whole project was now not expected to produce a serious military aircraft unless it had some training or indoctrination role. This view was peddled at the highest levels by the RAF who did not consider the single-engine P.1127 as worthy of their attention or consideration. NBMR-3, however, warranted full attention from the RAF but mainly because it was supersonic, impressive, expensive, and removed far enough from the taboo’s of the 1957 white paper to be looked at.

One of the early changes made to the Pegasus by BSEL was the deletion of the Glass Reinforced Plastic front nozzles and there replacement with steel items. This was brought about after the loss of a nozzle in flight which in turn caused the loss of an aircraft when control was lost at low speed on the approach to Yeovilton where an emergency landing was being attempted. Bill Bedford ejected safely.

Far more public was the failure of the nozzle motor control system during a display at the Paris Air Show of 1963, in front of around 11000 people. All four nozzles moved to the rear, quite slowly, but too fast to allow the aircraft to gain wing borne flight. The aircraft slumped to the ground hard enough for it to be a called a crash. The cause? a speck of dust in the air motor servo. The aircraft was eventually repaired.

The Kestrel

During 1961 the new Ministry of Aviation announced that it had been approached, and was in discussion with the Federal Republic of Germany with the view to negotiations for joint development of a V/STOL light weight strike fighter based on the P.1127. The United States watched closely as well as this was an area where patents were held by British companies that may compete directly with American companies. The German enquiry provoked a Washington reaction mostly fuelled by interest from the Army and the suggestion was made that the US, Germany and Britain should jointly fund a Tripartite Evaluation Squadron (TES) equipped with the P.1127 or similar type.

In early January 1962 Northrop, mindful of a possible order from the USAF or the US Army (who saw the aircraft as a possible way around restrictions on fixed wing equipment) threw their hat into the ring and announced a collaborative deal between themselves and Hawker whereby they would build the aircraft under licence in the event of an American order. Things seemingly moved in several directions at once from now on. The paper study of the ultimate P.1127 drafted in 1959 was dropped without ever seeing the public light of day. This was mostly due to the RAF’s polarised vision that the future had to be in the Mach 2 class and subsequently they placed all their interest, talents, and operational planning in the P.1154 concept, of which more later. This was in stark contrast to the interest being shown by Germany, Italy and the United States in the P.1127.

From the very beginning of flight testing 12000lbs of thrust was seen as inadequate for the task, but Bristol were on the ball and up to the task, and they developed the Pegasus 3 which ran for the first time as a bench test item in 1961, and first flew in 1962. The main modification was a new High Pressure spool with an eighth stage added at the rear of the compressor and a second stage added to the turbine. This gave the Pegasus 3 an initial rating of 13500lbs which was very quickly uprated to 14000lbs.All early flight development of the engine was carried out in the P.1127 itself or in a specifically modified Vickers Valiant (WP199). This aircraft was rebuilt to carry a Pegasus in a modified weapons bay which ensured the four nozzles were correctly distributed around the centre of gravity. With the Pegasus 3 the full flight envelope could be explored and data amassed for the future Kestrel project. In fact it was this engine that carried out the lion’s share of development work up to 1965, installed in the last remaining P.1127's, the others being Hors de Combat (out of action) after various incidents and accidents such as Yeovilton and Paris.

The leading edge of the intake received a lot of attention and was fitted with an inflatable rubber lip, designed to lie flat in the cruise but inflate in the jet borne VTOL mode. This was far from successful, as during the cruise phase they ripped and tore. They were subsequently removed from the aircraft but other refinements that were successful remained, such as improved out rigger stabilisation, new RCV fairing's, new engine inlets, larger anhedral tail planes and restyled low drag Kuchemann wing tips.

The ministry of Aviation issued FGA.236 on the 21 May 1962 which ordered nine Kestrel aircraft to equip the Tripartite Evaluation Squadron (TES). This required the aircraft to fly with some military load, and be able to operate under all weather conditions that were practicable for a basic VFR aircraft.

Bristol Siddeley once again turned to the Pegasus in the search for more thrust. The Pegasus 5 first ran 'on the bench' in June 1962, an occurrence that marked the beginning of the final, but most important phase, of thrust development. The new fan was no longer based on the Olympus, but was a completely new unit with three stages with no inlet guide vanes - a bold innovation for the time. Upstream of the High Pressure compressor, variable inlet guide vanes were added, the blades of which were manufactured from titanium. The revised combustion chamber was of the annular type with vaporising burners, and the first stage high pressure turbine was given air cooled blades. The design was for an engine producing 18000lbs thrust, but for use by the TES, and to save time and money the engine was derated to 15500lbs. It took to the air for the first time in February of 1964.


P.1127 XP984

Major changes to the appearance of the aircraft took place as the aircraft evolved in to the Kestrel. The most important was a new thicker swept plan form wing. The fuselage was extended, splicing in extra bays above the front and below the rear nozzles. The engine was given a sharper bifurcation to move the 'Hot' nozzles forward which gave a better relationship between centre of gravity, wing centre of pressure and the engine nozzles. Ventral strakes were added to improve airflow and increase pressure while in the hover. The main gear door was revised and stressed so that it could act like an air brake, and the wheels were fitted with low pressure tyres. Beneath the wings was the provision to bolt on a pair of stores pylons. The nose which had carried the long test instrumentation Pitot tube was replaced with a unit carrying an oblique camera. Unfortunately, citing cost and time constraints, the Ministry of Aviation did not specify auto stabilisation, despite the fact it had been demonstrated on the P.1127 to reduce pilot work load.

The first Kestrel FGA.1 flew on March 7th 1964, right on the heels of the last P.1127, which by now was a Kestrel in all but name, following all the modifications that it embodied. In December 1964 the Kestrel received a full release to service. This clearance was the first issued to any kind of jet lift or V/STOL aircraft, the nearest comparison being those aircraft employing rotary wings.

The TES formed at Dunsfold on 15th October 1964 under the stewardship of the Commanding Officer Wing Commander D.McL Scrimgeour. They received all nine Kestrels and the final production P.1127. After completing their initial training on type the TES moved lock, stock and rotating nozzles to RAF West Raynham in Norfolk. Pilots and ground crew from the RAF, USAF, US Navy, US Army, and Luftwaffe (but very surprisingly no US Marine Corps involvement) accomplished a great deal flying an aircraft that was actually equipped to fire guns or deliver anything but the most simple of practice bombs. It should, however, be remembered that this was not the Kestrel assigned role. The raison d`etre of the TES was to assess the merits and pitfalls of operating a jet aircraft in austere conditions, and to find the problems and their solutions to operating in such an area. To this end considerable emphasis was placed on operating off airfield in dispersed, basic locations, under canvas and camouflage, and exercising the logistical problems.

Something of the order of 600 hours were flown during 938 missions during the formal TES Missions which ceased in November 1965. Further flying was carried out utilising the aircraft until April 1966 when six airframes were transferred to the United States, after being purchased for a nominal 'used goods' sum that had been written into the original agreement. Germany did not take up her option on its three allotted aircraft and these were in the batch en route to the USA. Of the remaining three, one had been lost in a crash, and the other two were transferred back from TES and RAF control to the Ministry of Aviation, who in turn allotted one to Hawker Siddeley at Brough for re-engining with the Pegasus 6, and the other to Bedford where it flew with the Blind Landing Experimental Unit, and was also used in research into jet lift automatic landing system.

XV-6A 418262

The aircraft delivered to the USA were designated XV-6A and were used and abused as research aircraft and general hacks. A lot of flight time was accomplished with the airframes but very little of useful substance came from it. The only notable advances being in use off-deck on a variety of ships and of using the vectoring effect of the nozzles during flight manoeuvres, called Vectoring in Forward Flight (VIFF). This skill of 'Viffing' would be seized upon by the media in the early 1980’s to explain why a small force of Harriers embarked on ships thousands of miles from our shores were capable of beating in air combat Mach 2 capable fighters of a South American nation, over and around a small cluster of stark, inhospitable, southern ocean islands.

The USAF did little to find a niche for the XV-6A or any derivative and in fact was actively dismissive of the concept in favour of protecting, in 1966, its world beating, go anywhere, do anything, at any time, F-111 which was, expected to sell around the world with Air Forces queuing around the block to get their hands on it.

P.1154 Supersonic VSTOL

At this point we must consider the implications of an aircraft that would never enter service.

As early as 1959 NATO staffs had realised that in the event of a worst case scenario conflict with the Soviet Union and its Warsaw Pact allies, 99% of the available NATO air power would be wiped off the map by tactical nuclear weapons delivery. To this end they wrote specifications to replace the FIAT G.91 with an aircraft with a V/STOL performance. Initially the requirement for speed closely resembled that attained by the P.1127 in the order of Mach 0.92. By 1960 this had somehow translated in to the almost magical figure of Mach 2.

A lot of time and money was expended on research into new methods of propulsion including the implementation of Plenum Chamber Burning, which burnt extra fuel between the fan and the cold nozzles to boost thrust. A modified Pegasus 5 was to have been capable of a plenum chamber peak (and horrific) temperature of 927 degrees C, with a boost to performance from 15500 to 20500 lbs of thrust.

In April 1962 the NATO Standing Group announced that the P.1154 was the best contender to fill the requirements it had laid out for performance, over the Dassault MirageIIIV. The group weakly stated, to placate the almost inevitable French outcry and indignation, the Mirage was 'of equal merit'. At this point the whole house of cards fell down around their ears, and people went their own way with the United States mantra of TFX (the F-111 in its earliest form) ringing in their ears. At the same time, however, the United States continued to fund research in to V/TOL at the astonishing rate of almost $1m a week, but totally remotely from any military application. Led by the United States, Air Forces around the world stuck steadfastly to their long runways using conventional take off aircraft, and consigned thoughts of airfield targeted missiles to the backs of their minds.

Unlike the United States, Britain did not suffer to any great degree from the 'not made here, not interested' mindset. Sandys was gone. His white paper was now five years old, and new faces, along with an Air Staff that realised it could make constructive comment and opinion heard without losing its job, were pushing the agenda in Whitehall. For two years the task had been to sit in committee and design an entry for a huge NATO competition. It was now realised that far from sitting on their hands, individual nation states had to stand up, put in their national requirements and more importantly put their hands in their pockets and fund the issue.


By March 1962 the Ministry of Defence had accepted the view that the P.1154 could in all probability replace the RAF’s Hunters and the Royal Navy's Fleet Air Arm Sea Vixen aircraft. Both services were told to draft Operational Requirements (ORs) and pretty damn quickly. The then Minister, Harold Watkinson, wanted to go down the collaboration path, but Air Minister Julian Amery could see that this was merely a merry go round for committees that would dither instead of grasping the burgeoning issues. Amery put his weight behind an all British project. While Camm and his team forged ahead with design studies the two services wrote separate ORs, the RAF OR.356 and the Navy OR.406, and predictably they were like chalk and cheese in their individual requirements. The Navy desired a high altitude fighter with a two-man crew, while the RAF wanted a single-seat low level ground attack fighter. Other Navy requirements, most of which were later demonstrated to be unnecessary by the Sea Harrier, were however, the critical nails in the coffin that dispatched the programme. They stipulated that the nose, tail, and wings must fold, catapult compatibility was essential, and a totally different continuous wave radar with a massive 300 inch dish aerial was required. This was the last time that Navy staff would make demands that would appear lethal for a project, or perhaps their heads had been turned by a proposal thrown into the ring by Rolls Royce, namely a McDonnell Douglas Phantom with Rolls Royce 'Spey' engines. Egged on by the Chief of the Defence Staff, Lord Louis Mountbatten, the Royal Navy formally withdrew from the P.1154 project in February 1964, opting instead to obtain 60 Rolls Royce powered F-4 Phantoms at a cost of £45 Million (in actual fact the Navy only received 24 aircraft at a cost of £113 Million pounds).

With the Navy out of the equation, the P.1154 started to make some real progress, and when the labour party won the 1964 General Election, the design project was nearing completion and the first flight prototype was taking shape at Kingston. Politicians then came into their own in a destructive way that only politicians from a seemingly different age could manage. The Labour Government decided that the aircraft building firms in Britain were an easy target. They announced that it was undesirable for home grown aircraft projects to be given any support, and that from now on aircraft would be purchased from the United States. In one sweeping act they all but destroyed the ability of the nation to produce aircraft and to be at the forefront of technological design. The TSR 2 was cancelled to make cost savings by buying another aircraft that would ultimately cost more to produce. In the smoke filled rooms of number 10 Downing Street the Prime Minister Harold Wilson was briefed on how to bring about the demise of the P.1154. He was advised to tell the tax payer that the aircraft would not be ready for service in time to serve as a Hunter replacement; he gave the impression that the Hunters were all but falling apart, and that the American F-4 Phantom with British engines would do as a quick replacement. Defence Minister Denis Healey was quoted as saying "the RAF will get its Hunter replacement four years earlier".

The P.1154 received its death sentence on the 2nd February 1965. The RAF finally received its F-4 Phantoms with Rolls Royce engines and anglicised avionics in 1969, at a greatly inflated unit cost than the final estimated unit cost of the 1154. And what of the Hunters that were on their last legs? They were still in service when the author joined the RAF in 1977, used to provide point defence for airfields in the UK, and soldiered on into the early 1980’s with the RAF Tactical Weapons Units, until replaced in both roles by another fine Hawker product, The Hawk. Hunters remained in service with the Royal Navy until the mid 1990’s, some twenty five years after the public were told they were not fit for purpose.

The Harrier

With the abrupt cancellation of the P.1154 in February 1965 the government did at least have the foresight to allow Hawker to continue to develop the P.1127 thereby not allowing the technology that had been gleaned to go to waste. Today some 45 years later aircraft utilising the same basic principles are still operating, in austere locations, in support of troops on the ground.

Hawker found themselves in a strange position. On the one hand they were faced with the still strong official line that any manned aircraft was a virtual non starter, this in spite of the fact that across the globe production lines were churning out MiGs, Mirages, Starfighters and Phantoms. On the other hand was the Air Staff, which instead of reaching out a steadying hand to the P.1127 was instead pouring scorn on this small, subsonic aircraft and considered it beneath them to even look at it with any degree of seriousness. Indeed, in the power palaces of London the official, blinkered view, remained as stubborn as it had been before - if it didn’t have swing wings, and couldn't do Mach 2 plus, please close the door as you leave. This posture was intensified when the Hawker Siddeley Group made the suggestion that the RAF might like to take a look at the Buccaneer. It would take another five years for Hawker Siddeley to discover, while acting as McDonnell Douglas’s engineering representative in the United Kingdom, that the much maligned Buccaneer carrying the same weapon load as the Phantom was not only quicker in terms of speed, but it actually burned fuel at half the rate to do it.

Shortly after announcing the cancellation of the P.1154, the Prime Minister Harold Wilson made a further announcement stating, "We believe there is an urgent need for an operational version of the P.1127. As soon as can be negotiated, a contract will be placed for a limited development program so that the RAF can have, by the time they need it, an aircraft which will be the first in its field, with vertical take-off for close support of our ground forces".

By this time Sir Sydney Camm was handing over the reins at the plant at Kingston, and it was during March 1966 that he passed away on his local golf course, drawing a parallel with R.J. Mitchell, the designer of the Spitfire who was also not destined to see his project reach full maturity. It was Ralph Hooper who had draughted the majority of the work on the early P.1127, but it was to be the Yorkshire-born John Fozard who would take on the mantle of becoming 'Mr Harrier'. Starting his career at Blackburn’s he had worked his way up at Kingston to being Chief Designer P.1154 and was now Chief Designer P.1127RAF. After February 1965 he described a meeting with personnel from the Ministry of Technology. They basically stated that they must, "stop work on the P.1154, but if you can take the nav/attack system out of it, and along with a new engine install it all into the P.1127, then we might just buy it for the RAF".

In this strange, round about way the P.1127RAF was born and two years later was renamed Harrier. This name was chosen originally for the P.1154, and had been used as far back as 1927 as the name borne by a Hawker biplane bomber, powered by an earlier Bristol engine, the Jupiter. The Ministry of Technology contract for six aircraft came through with almost frightening speed, arriving on the 19 February, a mere two weeks after the cancellation of the 1154, allocating them serials in the range XV276 – XV281.

Harrier GR.1 XV279

To the casual observer there may appear to be little difference between the P.1127, the Kestrel, and the P.1127RAF. That, however, would be a mistake as virtually every part of the aircraft was looked at, refined, improved and brought to the new aircraft in some slightly altered form. The wing was and received a dog tooth, was given an extended outer chord, and got a nice set of vortex generators on the wing surface at about 12% chord outwards. It was further stressed to carry four pylons rated at weights of up to 1200lb inboard and 650lb outboard. The undercarriage was redesigned and the main leg received particular attention. It acquired a modification known as the 'self shortening leg'. On touching the ground on landing the leg compresses almost seven inches without giving any resistance. This in turn ensured that the outriggers bore a substantial amount of the aircraft's weight.

The engine inlet was looked at and the inlet angles redesigned to give surge free throttle handling within the norms for fast jet operations. The ejection seat, a Mk6HA in the Kestrel gave way to a second generation Martin Baker Mk9A gas-operated seat, with no face blind handle, only a seat pan actuator handle. This seat was the first to operationally incorporate a gas cartridge firing system, as opposed to the previous cable and sear activation system. Another new item on the aircraft escape system was the use of MDC (Miniature Detonation Cord) which is often seen as a jagged line above the pilots head on the canopy. On initiating ejection by pulling the yellow and black seat pan handle, the explosive cord detonates a fraction of a second before the seat begins to leave the aircraft. This system is preferred to canopy jettison as it is a far quicker method of removing the canopy when survivability is measured in fractions of seconds. Canopy jettison of the period was usually effected by raising the leading edge of the canopy frame into the airflow over the aircraft, allowing the airstream to remove it from the cockpit area. In the case of the Harrier its flight regime, ie in the hover with negligible airflow, covers areas that are not conclusive to this type of removal technique.

Development came in the engine department with the up-rating of the engine to Pegasus 6/Mk101 to 19000lbs - the original Harrier GR.1 engine - and not long after this the Pegasus 10/Mk102 at 20500 lbs, providing the Harrier GR.1A's powerplant.

This only left the avionic fit to be settled upon and investigations centred on a Ferranti FE.541 INAS (Inertial Nav/Attack System). This company was famous for its pioneering work on Gyro gun sights, and along with English Electric and Elliott Brothers, worked to produce a guidance system which could guide an aircraft without external aids. The heart of the system was the inertial platform which was mounted in the aircraft's nose and was bolted to the pressure bulkhead. This formed the main part of the IMS or Inertial Measuring System together with the present position computer in the avionics bay and the nav control box in the cockpit. All of this information was then fed to the largest avionic item in the cockpit, the Nav Display and Computer (NDC) which dominated the lower forward panel. The central display was of moving map design and was a projected topographic map, using a 35mm cassette, and covering an area some 800 miles north /south and some 900 miles east/west. Present position was displayed at the centre of the screen and the pilot could input destination and waypoints as offset positions. Other information was input from the Sperry compass and TACAN. Whilst airborne the pilot used not only the head down display of the NDC but mainly looked through the projected Heads Up Display (HUD) which provided him with navigation, heading, speed, and weapons release information. The Harrier HUD was one of the very first in production and was a creation of the small company called Spectro, who were quickly gobbled up by the opposition (Smiths Industries). To complete the package Ferranti also supplied the weapon aiming computer and a ballistic box into which plugs were fitted that input the ballistic characteristics of a particular type of weapon. The pilot then only had to check he had the correct plug for the type of weapon that was hung on the pylon, and then select that pylon before committing to the attack. The final pieces in the jigsaw were the radio navaids such as TACAN, UHF homing, and IFF. Also supplied were VHF, tactical VHF and UHF radio. An oblique post attack F95 70mm camera was mounted in the left-side of the nose, and a HUD recording camera was also included.

Internal armament was not specified, and the operational load is hung from seven pylons under the wings and fuselage. Either side of the centreline pylon the aircraft could be fitted with two aerodynamic strakes to assist the aircraft in the hover, or they could be replaced by a pair of gun pods, each housing a 30mm Aden Mk4 cannon with 130 rounds of ammunition.

Fuel totalled 630 gallons contained in five tanks in the fuselage and two in the wings. This could be supplemented by two jettisonable 100 gallon tanks, or two non jettisonable 330 gallon ferry tanks. Only the inboard pylons are plumbed for fuel. Air to Air Refuelling was accomplished using a 'bolt on' inclined probe, with the tip above and ahead of the pilot on the left side of the aircraft.

Go ahead to produce the Harrier GR.1 was received in late 1966, and the first contract for sixty aircraft was received in early 1967. A follow on contract for two prototype and eight production twin seat trainer aircraft was not far behind, and was given the designation Harrier T.2. The first was received into service by 233 OCU during August 1970, when ironically the vast majority of Harrier pilots had already converted to type. The Air Staff Target for this aircraft required a twin-seat aircraft for dual type conversion, to be used to speed proficiency on the Nav/Attack system. The Aircraft weighed in at some 1400lb heavier than the single seat GR.1. This weight was mainly taken up by the new cockpit area and by a change to the tail, which was raised 11 inches and moved 33.3 inches to the rear to maintain longitudinal stability. The aircraft during service underwent similar updates as the GR.1, receiving a new Mk 102 engine which produced a T.2A, and later a Mk103 engine and the LRMTS nose updates to produce the T.4.

Into Service

Harriers were delivered to the RAF at Dunsfold in January 1969 when the Harrier Conversion Unit (HCU) was formed. Pilot conversion to type was completed with little problem. The RAF celebrated its 51st birthday on 1st April 1969 when safe in the knowledge that they had become the first air force to be able to operate jet combat aircraft away from conventional airfields. On that day the HCU became 233 Operational Conversion Unit based at RAF Wittering in Cambridgeshire. Number 1(F) Sqn whose motto, "In Omnibus princeps" - 'in all things first', was quite apt, began converting to type at Wittering in July 1969. This was quickly followed by, in order of conversion, IV(AC) Sqn, 20 Sqn, and 3(F) Sqn, who collectively made up the Germany arm of the Harrier force, creating a complete Wing, being based at RAF Wildenrath on the German/Dutch border. It was ironic that this base was one of those constructed not twenty years before to negate the risk of being overrun on the first day of any East – West conflict. This, however, placed the aircraft in the very position that it was not expected to be, a long way from where they would be expected to operate, which was anticipated to be around sixty miles behind the Forward Edge of the Battlefield (FEBA), supporting 1 BR Corps, and our allies in Northern Army Group (NorthAG). Things improved with a replacement and relocation programme within RAF Germany in 1977. Phantoms replaced Lightning's with 19 and 92 Squadrons in the air defence role, their longer legs allowing them to be based further in the rear at Wildenrath. 20 Sqn disbanded and moved, literally, down the road to RAF Bruggen where they converted to the Jaguar. Their Harrier aircraft were distributed equally between 3(F) and IV(AC) Sqns, bringing them in line with the NATO standard establishment of 18 aircraft. With space now available, 3(F) and IV(AC) Sqns moved to their new home at RAF Gutersloh a mere 75 miles from East Germany and the furthest east of any allied air base. These two squadrons were, in actual fact, the only RAF Germany assets that could be expected to be relied upon to Survive To Operate (STO) in the event of a conflict, unless one subscribes to the unlikely scenario that the enemy would ignore trying to disrupt operations, and ultimately destroy our airfields.


Harrier GR.1 XV749 1(F) Sqn

Harrier GR.1 XV762 233 OCU

1(F) Sqn formed part of the Allied Command Europe Mobile Force or AMF and would have been forward deployed to advanced bases. Where exactly they would have been deployed would be speculation, but the squadron's long standing visits and exercises in Norway give a clue as to their likely employment. 233 OCU also had a war role, and they were earmarked to stop training and go forward in support of 3(F) and IV(AC) Sqns in the field in Germany.

Improvements to the type were forthcoming in an effort to improve the performance of the aircraft. The first major step involved the incorporation of the Pegasus 102 engine. This gave a boost in engine performance , taking the power from 19000lbs to 20500lbs. It also gave a change in designation to GR.1A.

The next improvement significantly changed the nose profile of the aircraft. The original twin 4kVA alternators were replaced with a single 12kVA example. The Lucas Mk2 Gas Turbine Starter (GTS) was also up-rated from 1.5 to 6kVA. These improvements in electrical power were essential to allow the use of the equipment that was going to be housed in the new nose profile, and the revised tail plane. The nose was changed to house a Ferranti Type 106 Laser Ranger and Marked Target Seeker (LRMTS). This unit was developed for the Harrier and in tandem with the unit fitted to the Jaguar which was virtually the same. The LRMTS comprised an active laser and receiver together with an electronics and data interface package which was tied into the aircraft's Nav/attack system. The laser can be used to illuminate targets ahead of the aircraft in a 20 degree cone. In this mode it returned continuous and accurate data on range-to-target, closing speed, and angles, with all of this information being displayed in the HUD. The target could also be designated by ground laser, and in this case the aircraft's laser was not used. The LRMTS searched for reflected laser radiation automatically and would lock-on to any found. It would then range the target and present the position, range, closure, and angle, in the HUD. The LRMTS was tested in a Ferranti Canberra in 1970 and was flown in various Harriers until fitted as initial equipment in XZ128 in 1976. Several other airframes had been retrofitted with the equipment, and all Harriers had had the equipment fitted by 1979. Interestingly it has no effect on performance and handling. The other major addition was in the tail area of the aircraft, and was accommodation for a Radar Warning Receiver. This comprised two passive aerials, one facing forward on the top of the tail fin leading edge, and one facing to the rear from the tail cone to the rear of the RCV’s. The system was designed and built by Marconi and received the designation ARI.18223 - a single seat version of the ARI.18228 fitted in the rear cockpit of the Phantom and Buccaneer. The pilot had a small threat warning display with an audible 'attention getter', which provided information regarding the illumination, such as type, signal strength, and direction. This, however, was only a method of advising the pilot that his time was up as, except for manoeuvring, the GR.3, and the GR.1/1A before it, had no defensive capability, with chaff and flare not being fitted. Indeed this would remain the case until after the Falklands conflict in 1982 where the aircraft and pilots faced radar laid 35mm cannon and Roland SAM systems with little more than a handful of basic chaff materials jammed between the pylons and the weapons, in the hope it would bloom and provide some protection.


With all these modifications also came another update to the engine and this saw the power rating raised from the GR.1A’s 20500lb Mk102 to a 21500lb Mk103. All these modifications gave rise to another designation change, from GR.1A to GR.3. In this guise the RAF operated the Harrier until its retirement and replacement by the GR.5/7 variant of the type.

Harrier GR.3 XV748 233 OCU

Harrier T.4 XZ145 233 OCU

Harrier GR.3 XZ974 1(F) Sqn

Harrier GR.3 XW924 3(F) Sqn

Harrier GR.3 ZD688 IV(AC) Sqn

Harrier T.4A XW175 Vectored thrust Aircraft Active Control (VAAC) Technology Demonstator

All at Sea - The Harrier afloat.

The idea that the Harrier could be successfully utilised as a ship-board asset had been tested on and off since the early days of the P.1127 when Bill Bedford demonstrated the capability on HMS Ark Royal in February 1963. The concept was repeated by the an ex-Tripartite Evaluation Sqn XV-6A in 1966 when they operated from the carriers USS Independence and USS Raleigh, while later that same year a Kestrel demonstrated that rotary wing and jet V/TOL were compatible on the same deck aboard HMS Bulwark. In 1969 a Harrier operated off the small rear deck of the command ship the USS La Salle, and another set the naval aviation world talking by operating from the rear deck of HMS Blake while the ship was rolling +/- 6 degrees with a 30-45 kt wind over the deck.

During 1970 1(F) Sqn flew service release trials from HMS Eagle clearing the way for operations from HMS Ark Royal should they be required. In 1972 a two-seater went aboard the Indian Naval Ship Vikrant and flew 22 sorties in two days in the tropical monsoon season.

The fact that V/TOL aircraft could operate in the naval environment was not in doubt and brought with it several advantages. Vertical Take Off gives rapid reaction times from engine start to take off, there is little requirement to alter course into wind except in the most severe conditions, smaller fuel burn (in a Harrier as little as 100lb of fuel to gain wing borne flight) and smaller spot clearances radii of 30 to 40 feet. Short Take Off allows mission load to be increased, wind over deck and take-off run can be traded, the 'runway' width need be no more than 38.5 feet, the landing is always vertical, and no arrester gear, barrier or catapult system is required.

Despite all this, the hierarchy in the Admiralty had a similar predilection with Mach 2 that the RAF had suffered from some years previously. While the low-level attack mission might have been coped with by the Harrier – although it was considered somewhat puny – the Navy wanted a fleet defence fighter with a radar and high speed. This meant that the Harrier would be totally and completely overlooked between 1965 and 1972 and it would be another three years on top of that before any decision was taken. The Admiralty were, however, not as bad in their decision making processes as their French counterparts who rejected out of had the Mach 1.6 capable Jaguar M, in favour for the Super Etendard which ironically was slower than the Harrier!

Sea Harrier FRS.1 899 NAS

Sea Harrier FRS.1 XZ454 800 NAS

Sea Harrier FRS.1 XZ457 800 NAS Operation CORPRATE

General acceptance of the possibility of a Royal Navy Harrier dated from 1971. However, during the period 1971 to 1975 the Sea Harrier remained a concept that was held to ransom. The Navy may not even have had the ships in the form of the 'Through Deck Cruisers' that were slated to enter service. The name stemmed from the fact that the term Aircraft Carrier caused a deathly hush in the halls of power. The RAF was a vociferous opponent of the 'See Through Carrier' from the viewpoint of its necessity from a strategic standpoint, and also from the position that it could have an adverse effect on the RAF’s portion of the Defence Budget. It was further stymied by lack of funding caused by a fuel crisis combined with a three day week. This in turn led the public to install to a new Labour Government who thought that the only thing that 'defence' meant was 'how can we cut this from the budget'. The only programme's that did receive any sort of funding was Rolls Royce to develop the Mk104 engine, basically a Mk103 with certain changes and improvements that incorporated a new Aluminium casing (in place of the magnesium/zirconium casing) to resist salt water derived corrosion, and an increased capacity gearbox. Ferranti was also given funding to explore 'Blue Fox'. The Blue Fox radar, which is widely acknowledged as one of the leading radars of its type in the world, was developed from Ferranti’s successful 'Seaspray' radar, carried by the Westland Lynx. The system is a frequency agile monopulse radar set with, good versatility in the ECM and ECCM environment in both the air/air and air/surface mode. Financial constraints dictated that the presentation of the radar's information could not be generated on the HUD but was placed in cockpit utilising a head down daylight viewing box with TV raster presentation.

By 1974 any forward motion in the programme was at best negligible, and by 1975 many in the industry were shrugging their shoulders in despair of anything ever coming of the programme. Then on 15th May 1975, in a sudden turn that was almost universally unexpected, Defence Minister Roy Mason announced an order for 24 Sea Harriers to operate off the new through deck ships, Invincible, Ark Royal and Illustrious. The news was announced over the BBC and was so unexpected that two of the main players, Chief Designer (Harrier) John Fozard, and Chief Test Pilot John Farley, were told by Dunsfold Tower as they were on approach in the company Dove!

It is quite possible that no other jet has had such a long and troubled gestation period. It is no surprise then that the order to proceed did not arrive until June, however by that time the majority of the design was well known and almost all the work that was required was put into building an all new front end. Almost nothing else in the aircraft was changed from the RAF Harrier. The aircraft would require more room in the cockpit for avionics to assist reducing the pilot workload and to accommodate a considerably modified Nav/attack system with more comprehensive displays. To this end the decision to raise the canopy and seat by 11 inches was taken, This gave considerable room to house the new avionics, and provided a better all round view for the pilot, indeed the pilot could see the out riggers gears whereas in the GR.3 they were hidden by the aircrafts air intakes. The canopy acrylic was also bulged slightly to give a better view downwards. The cockpit was also updated with a faster acting Martin Baker Mk 10a ejection seat which gave the occupant a fully deployed parachute a mere 1.5 seconds from seat initiation.

Work continued apace with the Blue Fox radar. Utilising experience gained from the attack radars developed for the Lightning, Buccaneer, and TSR.2, not to mention using research used to develop a prototype P.1154 radar, Ferranti soon had an I band air intercept and surface/search and strike radar that would eventually have a mean time between failure of 300 hours in a package that weighed in a trim 186lbs. The unit was first flown and tested in a modified Hawker Hunter T.8.M in January 1978.

Construction of the first aircraft was delayed by industrial unrest and other unconnected problems, but eventually the third machine XZ450, which had overtaken the others, made the first flight in primer on 20th August 1978. Two weeks later the Sea Harrier FRS.1 was performing 15 degree ski ramp take offs at the Farnborough International Air Show.


Sea Harrier FRS.1 XZ435 899 NAS

Sea Harrier FRS.1  XZ455 800 NAS


Sea Harrier FRS.1 801 NAS

XZ451 was handed over to the Royal Navy on the 18th June 1979 and the Intensive Flying Trials Unit, 700A Naval Air Squadron (NAS), commissioned at Yeovilton in September 1979. 700A NAS later morphed into 899 Harrier HQ Sqn with responsibility for pilot training and co-ordination of doctrines for the three ocean going NAS - 800, 801 and 802. During May 1978 a further order was placed for ten more aircraft. Further orders were forthcoming as attrition replacements and to bolster the Sea Harrier force's capabilities post the Falklands war. The Navy also received three airframes designated T.4N during 1983. These were essentially RAF T.4 aircraft but with updated avionics that were more akin to the service requirements of the FRS.1. These aircraft were then updated to allow training of FA.2 operations to T.8N standard with avionic changes and a new Mk106 engine.

Harrier T.8 ZD990 899 NAS

Sea Harrier Mid Life Update – the FA.2

Having gone through several small updates since first entering service, such as the capability to carry 190 Imp gallon under wing tanks in place of the old 100 Imp gallon tanks, and at the same time carry a twin AIM-9 Sidewinder launcher on the outboard pylons, which in addition to two 30mm Aden gun pods, came to be known as the 'Falklands Configuration'. The other significant upgrade saw the addition of the ability to carry the BAe Sea Eagle anti shipping Missile. The decision was taken to incorporate a mid life update (MLU) into the Harrier FRS.1 that would allow the carriage of an improved radar combined with a BVR missile system.

In 1983 the MoD awarded BAe a feasibility study contract. A further contract was awarded in 1985 for the project definition phase. The contract included the conversion of two FRS.1 airframes (XZ439 and ZA195) to trial installation or pre series aircraft. Early in 1994 the designation of the aircraft was changed to FA.2 in recognition of the equal importance of the fighter role with the conventional ground attack role. On 7 December 1988 the MoD awarded a contract to BAe valued at about £170m to upgrade the surviving fleet of FRS.1s to FA.2 standard. It did, however, take until 1991 for the first conversions to be started - a program which took about 12 months to complete on each airframe.

Sea Harrier FA.2 ZA175 899 NAS

Sea Harrier FA.2 ZD610 800 NAS

Sea Harrier FA.2 ZD610 801 NAS

The principal equipment change in the aircraft was the replacement of the Blue Fox radar with the GEC-Ferranti Blue Vixen pulse Doppler track-while-scan radar. This gave an all-weather, look down - shoot down capability, combined with the ability to engage multiple targets simultaneously. The larger antenna gave the aircraft a different enlarged nose profile. The second major change was the introduction of the Hughes – Raytheon AIM-120 AMRAAM, which provided a fire and forget beyond visual range (BVR) capability. The original concept was to carry four AIM-120s in the same way as the AIM-9 on the outboard twin launcher rails, and a brace of AIM-9s on new wing tips which incorporated the launch rails, but this was felt to be too ambitious. Simply satisfying the Navy’s request to carry our AIM-120s was difficult enough in itself. The use of the twin AIM-9 launcher positions for the AIM-120s was discounted due to the destabilising effect they had on longitudinal stability. It was proposed therefore that a single AIM-120 would be carried on each outboard pylon and a new position found for the remaining pair. One solution was to mount an AIM-120 under a drop tank but this idea was quickly rejected in favour of placing the missiles on pylons located where the gun packs/strakes would normally be mounted. These ventral carriers used the standard American LAU-106 rail, whereas the outboard pylons were replaced by Fraser Nash CRL’s (Common Launcher Rails) which could accommodate either the AIM-120 or the AIM-9.

The Mk 104 engine of the FRS.1 was replaced by a 21750lb Mk106, which in turn was a navalised version of the Mk105 that was powering the RAF’s GR.5/7 fleet. The main structure of the fuselage was changed by elongating the area to the rear of the wing by some 13.75 inches (35cm). This modification provided improved longitudinal stability and also gave extra equipment space. Instead of simply placing a plug in the fuselage behind the engine, the aircraft was given a completely new rear fuselage, mainly to renew areas that were subject to Acoustic fatigue from the close proximity of the rear nozzles. The cockpit received attention as well, with the HUD being updated and two large multi-function displays now dominated the front panel, as well as updates to improve the HOTAS (Hands On Throttle And Stick) capability, and the autopilot. The original FRS.1 Radar Warning Receiver (RWR) was also replaced with the GEC-Marconi 'Sky Guardian'.

On 2nd April 1993 ZE695 was the first FA.2 airframe to be handed back to the Fleet Air Arm.

The 28th March 2006 saw the last official flight of the Sea Harrier FA.2 at a ceremony to mark the retirement of the type from service that day, the place of these airframes, some not ten years old, being taken by the Harrier GR.7/9 of Joint Force Harrier based at RAF Cottesmore and flown by naval personnel.

Harrier - The Next Generation

The Harrier GR.3 while acceptable at the time was not going to be a long-lifed aircraft by any stretch of the imagination, and would certainly not be in service as long as other types such as the Hawker Hunter and the A-4 Skyhawk. In 1972 Air Staff Target (AST) 396 outlined a proposal for a V/STOL aircraft to replace the Harrier and Jaguar. AST 403 refined this into an air superiority fighter capability, the V/STOL element being removed, this evolved into the Eurofighter Typhoon. AST 409 revived the requirement for a V/STOL aircraft to replace the Harrier GR.3, this became what we now know as the Harrier GR.5.

Hawker Siddeley had signed a 15-year deal with the American manufacturer McDonnell Douglas in 1969 who would build and market the Americanised version of the Harrier GR.1 (the AV-8A). This gave them the rights to build the AV-8A, but at the same time gave Hawker Siddeley the right to bid on up to 30% of the work, plus a nominal royalty, on US-built aircraft.

Harrier AV-8A 159252 VMAT-203 USMC

Harrier YAV-8 704 NASA

Working under this agreement, the two companies proposed the AV-16 a Harrier derivative with a 24500lb Pegasus 15 engine, and a supercritical wing which would give a boost to war load – radius figure for the aircraft. Engine development was going to be expensive and there was little common ground in terms of needs between the potential users, the Royal Air Force, Royal Navy, USMC and the US Navy which was eyeing V/STOL at that time. With this demonstration of little support, the two companies decided to follow their studies independently with relatively low cost developments, to be designated the GR5(K) and the AV-8B. With 20/20 hindsight this could be seen as a technical mistake on the part of the two manufacturers. Hawkers believed that they had established a world lead in V/STOL and with the possibility of a modest amount of government funding they felt confident they could maintain the lead, and should the competing American design not be funded, Hawkers may well have been able to repeat the AV-8A sales miracle again by selling the GR.5(K) to the US Marines, but that would have been a bonus.

The revisions proposed by both sides in relation to improve the GR.3/AV-8A were a larger super critical wing, a raised cockpit, and a stretched rear fuselage. The main difference between the designs was in the wing. Hawkers favoured the utilisation of an enlarged all metal construction wing incorporating all the aerodynamic data gathered over the proceeding years. This was the low risk approach and was not helped by the MoD view that any 'new' Harrier was to be a new build rather than an update with the associated removal of airframes from front line duty for a long period. The American approach was to utilise the new technology of carbon fibre to build a strong light structure using the new 'supercritical' aerofoil technologies being embraced by NASA and which looked very promising in the wind tunnel. The use of this wing was never suggested as a retrofit, simply because the loads imposed on the tail structure would have been unacceptable. McDonnell Douglas also suggested the extensive utilisation of carbon epoxy and glass reinforced plastics in the building of the front fuselage, cockpit and tailplane. As weight grew then jet borne performance decreased. In this respect Kingston recognised the St Louis design was superior and was something that their own factory could not match.

Harrier Fuselage and Wing Make-Up Design

It was something of a surprise to many people to find however, that Her Majesty's Government was not willing to fund development of the GR.5(K) and thereby maintain the country's only world leading aviation project. Others were also surprised at the generosity of McDonnell Douglas in raising the British company's share from 30% to 40% of the airframe manufacture of the AV-8B for the USMC and the GR.5 for the RAF, which would be assembled by BAe, and also included a 25% share of any final assembly work for delivery to third party purchases. Rolls Royce remained the prime engine contractor of the Pegasus but in the case of the USMC 25% of the work would fall to Pratt & Whitney.

McDonnell Douglas carried out the lion’s share of the flight test work, proving the surpercritical wing and demonstrating the use of Carbon fibre technology.

Engine work was carried out with the intended power unit being the Pegasus Mk 105 producing 21750 pounds of thrust. Four full-scale development aircraft were funded in fiscal year 79. Both the Pentagon and McDonnell Douglas came under political pressure to identify a foreign partner for the project. Both parties lobbied the RAF to make a commitment to purchase the new Harrier, and wanted an answer by 10 December 1979 so as to allow the aircraft to be included into the Fiscal year 81 budget. The RAF could only give a conditional "Maybe", requiring a substantial flight test programme with the one remaining AV-8B in 1980 to be able to make a firm decision. There was no purchase of AV-8Bs in FY 1981.

Harrier GR.5 ZD402 Pegasus 11-61 engine test aircraft

Harrier II+ AV-8B 165307 VMA-542 USMC

Harrier II+ TAV-8B 163186 VMAT-203 USMC

Kingston continued to support the AV-8B for the USMC but was adamant and continued to fight the case for the RAF to have the GR.5(K). This was based upon their position that they wanted to remain a world leader in the V/STOL field, and to protect UK jobs. The BAe board, however, had other ideas and is understood to have told the MoD during early 1981 that the company would not object to the RAF adopting the AV-8B.

In August 1981 the UK and US Governments signed a Memorandum of Understanding (MOU) which covered the procurement of sixty AV-8B airframes, from an estimated eventual total of one hundred, for the RAF. BAe received an updated responsibility for the work on the aircraft. Whereas they had been responsible for the centre and rear fuselage sections and their associated systems, the centre line pylon, and the reaction control system, they would now also be responsible for all horizontal and vertical tail surfaces, and would also complete final assembly of the RAF’s aircraft.

British procurement began with two development aircraft (ZD318 and ZD319). The first, ZD318, flew in the hands of Mike Snelling on the 30 April 1985 at Dunsfold. The procurement was to be for sixty aircraft the first 41 to GR.5 standard serialled ZD320-330, 345-355, 375-380 and 400-412. The remaining aircraft serialled ZD430–439 and 461-470 were to be built to GR.5A standard which incorporated wiring changes which allowed the aircraft to be retrofitted to GR.7 night attack standard at a later date. For recruiting purposes a plastic replica, ZD472, is used.

Harrier GR.5 ZD347 233 OCU

Harrier GR.5 ZD355 1(F) Sqn

Harrier GR.5 ZD355 1(F) Sqn

In 1988 an order was placed for a further 34 aircraft to be built as GR.7 aircraft from the outset. These were serialled ZG471-480, 500-512, 530-533, and 856-852. A contract to convert 58 GR.5/5A to GR.7 standard was announced on 2nd November 1992. From the 17th new build GR.7 aircraft a 100% Leading Edge Root Extension (LERX) was fitted, as opposed to the 65% unit on the GR.5/5A. This had a destabilising effect on the aircraft but this was offset by means of an angle of attack feedback to the Stability Augmentation and Attitude-Hold System. The new aircraft gave good capability increase over the GR.3 it replaced. In fact the aircraft could carry the same weapon load as the GR.3 twice the radius of action, or it could carry double the load the same radius of action.


Harrier GR.7 ZG471 3(F) Sqn

Harrier GR.7 ZD329 IV(AC) Sqn

Harrier GR.9 ZD410 IV(AC) Sqn


The attitude towards a trainer aircraft was the same as the USMC, namely that a training variant was required. In April 1988, however, the MoD stated that they would not purchase the TAV-8B simply on terms of cost. Instead the existing T.4 would be upgraded with new avionics (a reference to the GR.7’s night attack capability) and given the designation T.6. Then on 28th February 1990 the Minister of State for Defence procurement announced that the RAF was to receive 14 new Harrier training aircraft at a cost of £200m and they were to be built by BAe. These aircraft were given the designation T.10 and the design was to be based on the TAV-8B, but incorporating the FLIR system of the GR.7. Unlike the TAV-8B the T.10 was to be fully combat capable, although with the Angle Rate Bombing System (ARBS) removed. The MoD confirmed its requirement for 13 T.10s in 1992.

The first T.10 (ZH653) flew from BAe Warton on 7th April 1994, before being transferred to Dunsfold for flight testing. The thirteenth and last aircraft (ZH665) was delivered to RAF Laarbruch during October 1995. The vast majority of the airframes though were delivered to the Harrier OCU at Wittering, which had now been renumbered 20(R) Sqn.

The GR.7 did not stand still and a joint BAe – RAF programme to re-engine airframes to allow them more power for off-carrier deck and hot and high operations was begun. This modification boosted the GR.7’s engine power from the Mk105's 21500lbs to the Mk107's 23800lbs of thrust. This gave rise to a new designation of GR.7A.

This programme was quickly followed by another BAe – RAF collaborative project to bring the GR.7/7A aircraft up to GR.9/9A standard. The possibility of a GR.9 derivative had been mooted as early as 1989 with new engine, and terrain referenced navigation system. There was even a plan to incorporate the AIM-120 AMRAAM into the equation which, following the early demise of the Navy’s FA.2 and its BVR missile capability would have added a capability to the aircraft that would have boosted its ability to operate autonomously from austere locations anywhere in the world.

Harrier GR.9 ZD328 1(F) Sqn


The final outcome for the GR.9/9A, while not providing a BVR missile capability does enhance the capability of the aircraft in areas that it has already shown itself to be more than capable. Similarly at a fairly early stage it was decided not to incorporate ASRAAM into the update, leaving the AIM-9 series as the weapon of choice for air-air encounters. Avionics updates include the High Order Language (Ada) Operational Flight Programme (OFP) software and a new Open System Mission Computer (OSMC). The smart weapons also necessitate the introduction of a new Inertial Navigation System/GPS (INGPS) flight software and will permit the aircraft to interact with the "Paveway III" LGB and "Paveway IV" PGM, with its GPS targeting ability. The aircraft is now also able to use the anti-armour "Brimstone" which will greatly improve the capability to engage heavily armoured vehicles, a capability that was poorly served in the past, and only improved by the purchase of AGM-65 Maverick missiles which are expected to remain in the inventory to provide weapon "flexibility". Indeed the only item that appears to have been missed from the upgrade to GR.9/9A was the inclusion of a suitable air to ground capability in the form of a cannon. The original cannon proposed never appeared through pod interface problems (it basically shook itself to pieces when fired and was totally inaccurate). What could have been procured was the 25mm GAU-12 gunpod as used by the USMC to round out the target engagement ability. The fitting of a Ground Proximity Warning System (GPWS) on the grounds of safety is also standard in the upgrade. The aircraft externally has little to distinguish it from other Harriers other than those aircraft that were fitted with the 65% LERX will be retrofitted with the larger 100% LERX as described earlier.

The T.10 will go through a similar update programme to the avionics and will in turn be designated T.12.

Harrier hover diagram

The Future

What does the future hold for the Harrier? It could be said that it was a bleak out look, with only the prospect of retirement and replacement looming in about ten years time.

F-35 Lightning II AA-1

True the Harrier will be replaced, presumably by the F-35 Joint Strike fighter. Called the Lightning II, mainly by the United States, this aircraft incorporates the many years of technological development that have been carried out since the P.1127 bounced none-too-steadily in the skies all those years ago. A vertical lift fan in the centre of the F-35’s fuselage will provide some 50% of the thrust, in concert with a horizontal to vertical rotating jet pipe, on which this aircraft will hover. A concept dismissed in the 1960s as too heavy, too inefficient, and creating too much drag has now become, with computer aided design and revolutionary new materials, the replacement for the Pegasus and its four rotating nozzles. The worries in the early days of the P.1127 about the stability of the aircraft, and the fact it might run away in pitch destroying the aircraft and killing its pilot, are now consigned to the history books, as the F-35 will hover using its fly by wire systems and sensors to prevent the pilot being 'dumb' and putting the aircraft in a part of the envelope he really doesn't want to go to. The intakes of the P.1127 were problematic in the early days, suffering from disrupted air entry and causing surges that could lead to the loss of the aircraft. The F-35’s intakes through clever design and shockwave management have, like the P.1127 and all other Harriers, no moving parts, but are able to cope with airflow's that will allow the aircraft to be propelled to speeds past Mach 1. It will be low observable, stealthy - the very holy grail that is recited as a mantra by impressionable people who cannot conceive the concept is, in many ways, already outdated by world events, in much the same way that 'it must exceed Mach 2' was rolled out all those years before, and nearly consigned the Harrier to the status of 'curiosity' before it could prove itself. Does it need to be stealthy? Or is there a cheaper, but perhaps less attractive, stealthless, alternative? Time will tell.

The Harrier will continue to perform to the best of its ability for at least the next ten years. The GR.9/9A programme reflecting only the beginning of a continuing programme to update the aircraft - although this may not readily re-designate the airframe to GR.11 - and enabling it to carry on for a period, if required, beyond the projected out of service date, should delays in the replacement F-35 programme be forthcoming.

Harrier Production History

Below we list the Harrier family and the 45 variants that have flown since 1960:




First Flight(s)



Experimental prototype V/STOL aircraft 

XP831 & XP836



Development batch

V/STOL development aircraft

XP972, XP976, XP980 & XP984




V/STOL ground attack aircraft for tripartite evaluation by UK, USA and West Germany; USA designation XV-6A.





Development batch V/STOL ground attack and reconnaissance aircraft 

XV276 - XV281




V/STOL ground attack and reconnaissance aircraft

XV738-762, 776-810 & XW630




V/STOL ground attack and reconnaissance aircraft (re-engined GR.1 and new build)

XW916-924 & XW763-770




V/STOL ground attack/reconnaissance aircraft with LRMTS (converted & re-engined GR.1/1A and new build)

XZ128-139, XZ963-973, XZ987-999 & ZD667-670

1976-77, 1980-82, 1986



Development batch of two seat V/STOL ground attack/reconnaissance trainer

XW174 & XW175




Two Seat V/STOL ground attack and reconnaissance trainer.

XW264-272 & XW925




Two Seat V/STOL ground attack and reconnaissance trainer (re-engined T.2 and new build)

XW926-927 & XW933-934




Two Seat V/STOL ground attack and reconnaissance trainer (converted & re-engined T.2/2A and new build)

XZ145-147 & XZ445, ZB600-603 & ZD990-993

1976, 1979, 1982-83 & 1987



Two Seat V/STOL 'fly by wire' technology demonstator with 'Vectored thrust Advanced Aircraft flight Control' (VAAC) system. Currrently operated by QinetiQ





 BAe two Seat V/STOL demonstrator & 'Skyhook' trials aircraft





USMC V/STOL ground attack and reconnaissance aircraft (initially designated AV-6B)

158384-395, 158694-711, 158948-977, 159230-259 & 159366-377




USMC AV-8A modified for extended life and improved capability

Retained original AV-8A serials




USMC two Seat V/STOL trainer 






V/STOL ground attack and reconnaissance aircraft for the Spanish Navy. Seven later sold to Thailand during 1996

159557-562 & 161174-178

1975-76 & 1980




Two Seat V/STOL trainer for the Spanish Navy. Both sold to Thailand during 1996




Sea Harrier

Fleet Air Arm development batch V/STOL interceptor, reconnaisance and strike aircraft 

XZ438 – 440



Sea Harrier FRS.1

V/STOL interceptor, reconnaisance and strike aircraft for the Fleet Air Arm 

XZ450-460 & XZ491-500, ZA174-177, ZA190-195, ZD578-582, ZD607-614 & ZE690-698

1978-83, 1985-88



Two Seat FRS.1 V/STOL trainer for the Fleet Air Arm




Sea Harrier FRS.51

V/STOL interceptor, reconnaisance and strike aircraft for the Indian Navy


1982-83, 1989-91



Two Seat FRS.1 V/STOL trainer for the Indian Navy


1983, 1990-91



Two Seat FRS.1 V/STOL trainer for the Indian Navy (converted ex-RAF T.4)




Sea Harrier FRS.2

Major mid life update development batch; to include Blue Vixen radar &  AMRAAM (conversions from Fleet Air Arm FRS.1)

ZA195 & XZ439



Sea Harrier FA.2

Major mid life update of Fleet Air Arm FRS.1 (included new build aircraft)  





Conversions of T.4/4N;  to Fleet Air Arm as V/STOL trainer 

ZB603-605 & ZD992-993




McDonnell Douglas conversion of AV-8A as prototype V/STOL ` ground attack aircraft for the USMC.

158394 & 158395



AV- 8B
Harrier II

Full Scale Development  V/STOL ground attack aircraft for the USMC. Joint McDonnell Douglas/BAe design and production




AV- 8B
Harrier II

V/STOL ground attack aircraft for the USMC. Joint McDonnell Douglas/BAe production

In range 162942-163852



Harrier II

AV-8B for Spanish Navy




Harrier II

Two Seat V/STOL trainer version of AV-8B for the USMC and Spanish Navy

In range 162747-164542 & Spanish 165036




AV-8B with FLIR & NVG.
Uprated engine from 15th airframe. One AV-8B converted as development aircraft (163853)




Harrier II+

Radar equipped AV-8B. Conversion and new build for USMC; new build for Italian Navy.
Converted aircraft allocated new serials (165305 onwards)

164548-571 and 165001-006.
Italian 164563-165019



Harrier II+

Two Seat V/STOL trainer version of AV-8B+ for Italian Navy




Harrier II+

AV-8B Harrier II+ for Spanish Navy (new build and EAV-8B rebuilds)




GR.5 Development

AV-8B based ground attack and reconnaisance aircraft for the RAF. Joint McDonnell Douglas/BAe design and production 

ZD318 & ZD319




AV-8B based ground attack and reconnaisance aircraft for the RAF. Joint McDonnell Douglas/BAe production

ZD320-330, ZD345-355, ZD375-380 & ZD400-412




Harrier GR.5 with provision for FLIR; all converted to GR.7 standard before entering service (new build and conversion)

ZD430-438 & ZD461-470




Harrier GR.5 development with FLIR & NVG for night/poor weather attack (new build and GR.5/5A conversions)

ZG471-480, ZG500-512, ZG530-533 & ZG856-862




Harrier GR.7 with uprated engine





Harrier GR.7 development with enhanced weapons capability and updated avionics (converted from GR.7)





Harrier GR.7 development with uprated engine of GR.7A and enhanced weapons capability & updated avionics of GR.9 (converted from GR.7/7A)





Two seat V/STOL training aircraft based on TAV-8B/GR.7 with full ground attack and reconnaisance capabilities  





T.12 with enhanced weapons capability and updated GR.9 avionics (converted from T.10)





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