Armstrong Whitworth Aircraft –The Jet Fighter Era

Armstrong Whitworth Aircraft – The Jet Fighter Era

This paper briefly describes the various jet fighter aircraft built by Sir W G Armstrong Whitworth Aircraft (AWA) Coventry, during what the author has entitled somewhat simplistically, “The Jet Fighter Era”. This period is rather elastic as it covers not only the original construction date of certain aircraft but also subsequent rebuilds and refurbishments, and very roughly encompasses the years 1949-1968. However, it should be noted that refurbishment and rebuilds, particularly of the Hawker Hunter, continued well after 1968 and are thus not covered in this paper.

Some of the aircraft featured in this discourse, such as the Meteor Night Fighter Series and Sea Hawk shipboard fighter were designed and manufactured at AWA Baginton and Bitteswell with complete autonomy. Other aircraft, including the Gloster Meteor & Javelin and Hawker Hunter were constructed to their respective design authority specifications.

The Gloster Meteor

Gloster Meteor NF.14 WS841 of 264 Squadron RAF at Blackbushe Airport, Hants, in 1955 – Photo – RuthAS / CC BY (https://creativecommons.org/licenses/by/3.0)

The Gloster Meteor, which saw very limited action at the end of the Second World War, mainly against the V1 Flying Bomb, was the first Allied jet-propelled aircraft. Although Frank Whittle, in the face of insuperable difficulties, had run the world’s first gas turbine turbojet at the British Thomson-Houston works at Rugby in April 1937, Britain had been very slow to exploit the potential of the turbojet powered aeroplane.

As has been noted in several other papers in this series, this was not the case with Germany, and by the end of the Second World War the enemy had numerous different types of jet aircraft under development and in production. These included the Arado Ar 234 Blitz Series, Gotha 229, Heinkel He 162 & He 280 and the Messerschmitt Me 262. Additionally, there was also the Lippisch / Messerschmitt designed Me 163 Rocket propelled interceptor fighter that saw limited action at the end of the war.

The Gloster Aircraft Company’s (GAC’s) pioneering work with jet powered aircraft had begun in February 1940 with a contract to design and build an aeroplane to specification E28/39. This resulted in Britain’s first jet propelled aeroplane, the experimental Gloster Whittle Pioneer. Headed by George Carter, the Gloster design team collaborated very closely with Frank Whittle and Power Jets Limited at Lutterworh to bring this aircraft to fruition. The very successful outcome for such a revolutionary aeroplane was a tribute to all those involved. In fact two E28/39 prototypes were built; W4041/G and W4046/G. The first prototype W4041/G had its maiden flight on 15thMay 1941 at Cranwell, with Gloster’s Chief Test Pilot, PEG (Gerry) Sayer at the controls. Much of the wartime development and test flying with this aircraft was done at Edgehill, in Warwickshire. W4041/G still exists and is exhibited in the Science Museum South Kensington; almost certainly the world’s oldest jet propelled aeroplane.

Gloster Aircraft’s next jet aeroplane, ultimately to become the Meteor, was a design to Air Ministry specification F9/40, for a single seat interceptor fighter. The first of the several F9/40 prototypes to fly was DG206/G. This flight took place on the 5th March 1943 at Cranwell, with Michael Daunt, Gloster’s Chief Test Pilot, at the controls. Daunt had succeeded Gerry Sayer as Chief Test Pilot after the unfortunate death of Sayer whilst flying a Hawker Typhoon on 21stOctober 1942. The development of the Meteor was quite protracted, involving several prototypes and it is well beyond the scope of this paper to discuss all the aircraft’s vicissitudes prior to the involvement of AWA in its manufacture after the end of the war.

AWA along with the Jaguar Car Company had been manufacturing Meteor units under sub-contract to the GAC from 1946. Eventually, in 1949, AWA was requested to build 45 complete Meteor Mk 4 aircraft for the RAF. This contract was completed in 1950. Further sub-contracts followed from GAC, including a requirement for 429 Mk 8 machines; an order completed in March 1953. The last Meteor Mk 8 off the Baginton assembly line, WK 935, was the aircraft selected by the company to be developed into the Prone Pilot Meteor. For a fuller description of this particular aeroplane please see the author’s, “The Armstrong Whitworth Prone Pilot Meteor”. By the early 1950s the Meteor was totally outclassed as an interceptor fighter, as the conflict in Korea demonstrated; the Russian Mig 15 being superior in practically all respects. However, the Meteor was very successful commercially for GAC; many aircraft being sold internationally to the world’s Air Forces.

The Meteor Night Fighters, NF 11, 12, 13 & 14

Armstrong Whitworth assumed sole design and manufacturing responsibility for all the Meteor Night Fighters Mk’s NF 11-14 inclusive. Initially the company was handed a contract to develop a two seat night fighter to Air Ministry Specification F24/48 based on the Meteor airframe. Some preliminary design studies had also been done by the GAC and the results of this were subsequently handed over to AWA.

The NF11 resulted directly from the Meteor T7 two-seat training aeroplane, an example of which (VW413) AWA had converted to night fighter standards in September 1949. On the 31st May 1950 the first true prototype of the NF11, WA 546, flew from Baginton with Chief Test Pilot Eric Franklin at the controls. An extensive flight-testing programme was undertaken, including spinning and under-wing fuel tank jettisoning trials. Although the basic airframe was that of a Meteor so much development had been undertaken it was ostensibly a new aeroplane. The first production NF11 was supplied to the RAF in October 1950 with deliveries continuing until May 1954, when the 338th and final machine left the Baginton assembly line. During production a peak output of 32 machines per month had been achieved. Apart from the RAF, the air forces of France, Belgium, and Demark had received the NF11.

The NF12 Meteor was basically a refined Mk11, with slight changes to the airframe including a fin with increased area, a modified bullet fairing at the fin / tail plane junction and a longer nose to house the latest APS 57 radar equipment. Additionally, more powerful Rolls – Royce Derwent 9 engines were installed. All this added up to a faster Meteor capable of reaching a maximum speed of 0.81 Mach. The first flight of the NF12, WS 590, was on 21st April 1953 again with Eric Franklin at the controls. Eventually 100 NF12s equipped 11 Squadrons of the Royal Air Force.

A tropicalized version of the NF11 resulted in the NF13 Meteor. Externally the aircraft was very similar to the NF11, although internally there were radio equipment changes and the provision within the cockpit of a cold air unit. Only 40 machines were built and most of these were supplied to two RAF Squadrons, Nos 39 and 219 attached to the Middle East Air Force. A small number were also supplied to the Egyptian Air Force.

The final nocturnal Meteor was the NF14, the prototype of which started life as a modified NF11. The most obvious changes to the aircraft were the extended nose and the new two – piece clear blown cockpit canopy. All the previous Meteor night fighters and trainer aircraft had been equipped with side hinging heavy framed canopies, providing minimal visibility, but the new canopy introduced the electrically operated, rearward sliding unit with vastly improved visibility. The prototype NF14, WM 261, first took to the air on 29th July 1953, with WH “Bill” Else at the controls. One hundred NF14s were built, the last machine leaving AWA on 26 May 1955. The NF 14 was to equip several RAF Squadrons, including No’s 25, 60 and 264.

From 1957 onwards some 24 NF11 Night Fighters were modified by AWA to TT20 Target Tug aircraft, the first conversion being to WD 767. These machines were able to stream a target sleeve up to 6,100 yards behind the aircraft.

Against any serious nocturnal intruders the Meteor Night Fighters would have been hard pressed to perform their duties adequately, and were virtually obsolescent from the time of their inception. They did, however, provide AWA with very welcome work throughout the 1950s and the exported NF11s in particular did their bit towards the balance of payments deficit!

The Hawker Sea Hawk

WV908 was built at Baginton, Coventry in 1954 by Armstrong-Whitworth – Photo Smudge 9000 from North Kent Coast, England / CC BY (https://creativecommons.org/licenses/by/2.0)

The Hawker Sea Hawk, together with the Hawker Hunter, were just two of many aeroplanes conceived on the drawing boards of the Hawker Aircraft Company at Kingston upon Thames, Surrey, under the aegis of the legendary Sydney (later Sir Sydney) Camm. After the outbreak of the Korean War, the Ministry of Supply allocated “Super Priority” status to both the Sea Hawk and the Hunter, requiring the urgent production of these aircraft for the Royal Navy and the Royal Air Force respectively. Thus in 1952 because of Hawkers heavy commitments with the Hunter, AWA was asked to assume total design and manufacturing responsibility for the Sea Hawk. AWA took on this task and considerably developed the machine’s basic design envelope, adding cockpit pressurisation, power controls, anti “g” systems and the ability to carry an extensive range of weapons.

It has been suggested that had Hawkers retained design authority for the Sea Hawk, it may have assisted them in the more expeditious development of the Hunter. This may or may not be correct, and hindsight is a marvellous thing, but Hawker Aircraft being a relatively small manufacturing enterprise did not have the capacity to deal with two new designs simultaneously, especially on a “Super Priority” basis. Their hands were pretty much full with the Hunter and its gestation period was prolonged.

The Sea Hawk was a single seat, shipboard fighter / fighter bomber fitted with a single Rolls- Royce Nene turbojet engine and all other necessary ancillary items for carrier operation, but initially on the F1 aircraft this did not extend to full power wing folding. The first 35 production F1 Sea Hawks were built at Kingston before production was transferred to Coventry. A number of these machines were used for development work and did not see active service. Coventry’s first production Sea Hawk, WF 162, made its maiden flight on 18th December 1952 with Eric Franklin at the controls.

The first F2 Sea Hawk, WF 240, introduced power controlled ailerons with spring feel to correct a problem with lateral control detected on earlier aircraft. This particular aircraft was retained by AWA for development purposes.

The Sea Hawk FB3 featured strengthened wings permitting it to undertake the fighter – bomber role. A few FB3s were converted to FB5s with the introduction of a more powerful Nene engine.

With strengthened outer wing panels, permitting the carriage of bombs and rocket projectiles, the FGA 4 became the definitive ground attack version of the Sea Hawk.

When the up-rated Rolls-Royce Nene 103 engine was installed in the FGA 4 it became the Sea Hawk FGA 6, the last version of a total of 400 aircraft plus spares ultimately to be supplied to the Royal Navy; the contract being completed on schedule in December 1955.

Apart from the machines mentioned above there also valuable follow-up orders from abroad, including 14 Sea Hawks from the Indian Navy; 22 machines plus spares for the Royal Netherlands Navy and 68 machines plus spares for the West German Air Arm.

A preserved Sea Hawk FGA 6 fighter can be seen at the Midland Air Museum, Coventry.

The Gloster Javelin

Gloster Javelin FAW.1 XA563 demonstrating at the Farnborough air show in 1955 – Photo – RuthAS / CC BY (https://creativecommons.org/licenses/by/3.0)

AWA became involved in building the Gloster GA5 Javelin a little after the Hawker Hunter. However, as the Hunter continued to be rebuilt and refurbished long after work on the Javelin ceased, it will be more convenient for the purposes of this narrative to discuss the Javelin first.

It was in the late 1940s that the Gloster Aircraft Company submitted a number of proposals for a two seat day and night fighter to Air Ministry Specifications F43 / 46 & F44 / 46. It is not known when GAC started to consider the delta wing configuration of what was to be their last aeroplane and the world’s first all-weather jet fighter.

The route by which the final specification for this aircraft was established is too labyrinthine for this short paper, but suffice to say it was finally issued in June 1948. Among the exacting requirements were a minimum flying time of two hours and a time not exceeding ten minutes from engine start-up to an altitude of 45,000 feet.

Although of unconventional appearance, the prototype was structurally fairly orthodox and made from predominantly light alloys. It was powered by two Armstrong-Siddeley Sapphire 2 turbojet engines, each of 9,000 lb thrust. The prototype was built primarily at Gloster’s Hucclecote factory, before being removed to the company’s Moreton Valence airfield, in July 1951, for completion and initial test work.

The prototype Javelin, WD 804, first flew from Moreton Valence on 26th November 1951, with WA “Bill” Waterton at the controls. A considerable amount of test flying was performed with this machine before a serious incident occurred on 29th June 1952. Waterton who was flying the machine at high speed, experienced a loss of both elevators due to serious flutter. Displaying great courage, Waterton elected to pilot the valuable prototype down, rather than eject, and despite some damage to the aircraft he stepped out unscathed. For his courage in saving the aeroplane and the vital flight recorder the Canadian born Bill Waterton was awarded the George Medal.

Despite this incident, the Ministry of Supply decided to go ahead with quantity production of the GA5 Javelin on a “Super Priority” basis. A quarter-mile long assembly line was laid out at Hucclecote specifically for Javelin production. The first Javelins to be built by AWA were a batch of 38 F (AW) Mk 4 aircraft which were ultimately supplied to No. 141 Squadron, temporarily based at RAF Horsham St. Faith, Norwich. Deliveries commenced in January 1957.

One of the major concerns with the Javelin was its limited range and to improve the situation the F (AW) Mk.5 was introduced with increased fuel capacity in the wings. AWA ultimately constructed 44 of these machines.

AWA did not build the F (AW) Mk 6 Javelin but went on to construct the heavier and more powerful F (AW) Mk7 with Sapphire Sa7 engines. In addition to these modifications the Mk7 carried two 250 gallon ventrally mounted “bosom” tanks attached to the fuselage. The tanks could be jettisoned and AWA had quite a lucrative contract in refurbishing large quantities of them. The author can testify to this as he worked on the Javelin and Meteor drop tank  section at Baginton in about 1964. Some Javelins of this marque were also retrospectively fitted with in-flight refuelling probes, which were installed on the starboard side of the aeroplane at cockpit level. This twenty foot appendage projected beyond the aircraft and had all the appearance of a medieval knight’s jousting lance! AWA built 57 F (AW) Mk 7 aircraft. These were the last sub-types to be built by AWA, although the GAC went on to build the F (AW) Mk 8 and modify some existing aircraft up to Mk 9 standard.

In all AWA constructed 139 Gloster Javelins. A preserved Gloster F (AW) Mk 5 Javelin is exhibited at the Midland Air Museum, Coventry. Registered XA 699, this Coventry built machine completed only 789 flying hours before it was withdrawn from service.

The author of this paper was never very impressed by the Javelin and thought it an ungainly heavyweight aircraft, somewhat lacking in finesse. When the flight refuelling probe was added that completely sealed its fate for the author!

The Hawker Hunter

Privately-owned Hawker Hunter T.7 “Blue Diamond” (XL577, G-BXKF) of the Delta Jets fleet, at Kemble Airport Open Day, Gloucestershire, England, September 9th 2007. At speed during the air display. Blue Diamond was built in 1958 for the RAF, and sold to Delta Jets in 1996. She took 6 years to restore to flight. (Photographed by Adrian Pingstone and placed in the public domain)

If the Gloster Javelin was something of an ungainly heavyweight, the Hawker Hunter fighter was an aeroplane of a very different calibre. The author of this paper considers the Hunter the most aesthetically appealing of all the world’s warplanes, past and present – hardly a line could be improved upon. It is right up there with the Comet 4 airliner in the author’s view.

The Hunter was not only visually pleasing it was a very good aircraft too! With a total of 1,972 new Hunters constructed at Kingston, Blackpool (Squires Gate) and Coventry, not to mention 574 conversions, it was also commercially very successful. In addition to the Royal Air Force, it served with particular distinction in almost all the world’s major air forces, fulfilling the roles of interceptor fighter, fighter bomber and ground attack aircraft. The Hunter was also licence built in at least two countries; by Avions Fairey & SABCA in Belgium and Fokker Aviolanda in the Netherlands.

The gestation period of the Hunter was quite protracted, which was as much to do with the shortcomings of the Rolls – Royce Avon RA7 turbojet as the aircraft itself. Compressor surging under certain conditions seemed to afflict the early Avons, particularly when firing the 30 mm Aden cannon. This took some time to sort out and it is fortunate that another engine was available as an alternative. This engine was the Armstrong-Siddeley Sapphire and although having an axial compressor similar that of the Avon engine, it did not seem to manifest quite the same degree of compressor surging. The Sapphire also produced marginally more thrust for a lower specific fuel consumption than the early versions of the Avon and was slightly cheaper to manufacture.

Rather like the Javelin it is rather difficult now to pinpoint when and how the design of the Hunter was first conceived. Eventually out of many proposals came the Hawker P1067. This design culminated in a single seat, single turbojet powered transonic fighter, with moderately swept back wings and tail surfaces to meet Operational Requirement OR 228. Eventually three prototypes were ordered; the first two being Avon powered and the third by the Armstrong-Siddeley Sapphire. Work on the first prototype, WB 188, progressed steadily at Richmond Road, Kingston, and it was not until 27th June 1951 that the aircraft was transferred to Boscombe Down for Flight Testing.

The first flight of the Avon powered P1067 prototype took place on 20th July 1951 with Neville Duke at the controls. It was uneventful flight lasting 47 minutes, during which time the aircraft was taken up to an altitude of 32,000 feet. Duke expressed his delight with the new machine and declared that it handled beautifully, although it was noted that some of the “stick” (control column) forces were high. As has been related, the Hunter took quite a time to settle down into a viable production proposition. A large amount of test flying was needed to solve a whole host of problems. Many modifications were to ensue. The first production Hunter aircraft was the F1 with the Avon engine, a version not built by AWA.

AWA’s first contribution to the Hunter production programme was the F2. Coventry built 45 of these machines with the Sapphire 101 engine, the first being WN 888, probably delivered in November or December 1953. Two RAF Squadrons, Nos 257 and 263, were equipped with them. Due to its Sapphire engine, the F2 Hunter was definitely superior to the Avon engined FI, which was so afflicted by compressor surging that the guns could hardly be fired at any altitude! A very serious deficiency in a fighter!

In order to improve the rate of climb the F3 Hunter incorporated the Avon RA 7R with reheat. This modification did result in some improvement in climb rate but the aeroplane still fell short of Operational Requirement 228 in this respect. The F3 did not go into production.

Quad ADEN cannon unit sitting under the wing of a Hawker Hunter

Although the Hunter F4 was built in quantity by the Kingston and Blackpool factories, AWA did not produce this variant. The F4 Hunter introduced a pair of streamlined excrescences below the front fuselage and situated just aft of the Aden gun pack. These were spent ammunition link collector tanks. Previously, Aden cannon cartridge cases and links had just been allowed to fall into the slipstream and this had resulted in damage to the fuselage and secondary items such as drop tanks, etc. The introduction of link collector tanks and lengthened cartridge case chutes cured the problem. Because the collector tanks superficially resembled the ample breasts of a certain celebrity starlet of the 1950s, they were sometimes called “Sabrinas”.

Although Coventry did not produce the F4, they went on to manufacture 105 F5s. The F5 retained the Sapphire engine and the first production machine flew on 19th October 1954.

With the introduction of the F6 with the Avon Mk 203 or Mk 207 engine, the Hunter was becoming an extremely capable aeroplane with most of its faults eliminated, although there was always a lack of endurance from which all Hunters suffered. Of course additional operational requirements meant that the aircraft had to be constantly adapted to accept heavier loads, resulting from ever more external stores, drop tanks and weaponry. AWA built 128 machines of this marque, the last being delivered on 29th March1957. This brought the total of new-build Hunters constructed at Coventry / Bitteswell to 278 machines. A preserved Coventry built Hawker Hunter F6A may be seen at the Midland Air Museum, Coventry.

The Hunter was a very robust aeroplane which probably explains its longevity. This is ably demonstrated by the fact that Hawker Siddeley Aviation (HSA) purchased a number of ex – Belgian and ex-Dutch licence built F Mk 6 machines (Avions Fairey / SABCA and Fokker – Aviolanda respectively) for reworking to FGA Mk 59,T66 &T67 standards for various Middle Eastern Air Forces. Some additional Hunters were ex-RAF machines. All these reworked aircraft were destined for the Air Forces of Iraq, Saudi Arabia, Jordan and Lebanon. There was an increasing urgency to supply these machines as a Middle Eastern war was looming. The author recalls working on some of these machines probably in 1966 at HSA Bitteswell.

The author also remembers at this time one slightly amusing / bemusing incident whilst working as “apprentice inspector” on the Hunter wing assembly line at the Old Site, Bitteswell. Fortunately, the author’s mentor believed in delegating responsibility to those that could handle it, and so the Stage-Inspection of a line of Hunter wings became the responsibility of the writer.

One day sometime in 1966 the author was requested to internally inspect a pair of Hunter wings prior to the final fitting of the closure plates to seal the fuel tank cells. The inspection procedure entailed a check for internal cleanliness, freedom from foreign bodies and any damage, correct fitting of the fuel tank rubber membranes, correct fitting and functioning of any float switches, etc, etc.

The fitter who had offered the wings for inspection was known to the author and indeed they both had worked together previously, very harmoniously. The author never did subsequently determine whether it was “a put up job”, a test, a genuine oversight or whatever, but a massive open-ended wrench, perhaps two foot long and out of all proportion to aircraft work, was found in one of the tanks by the author and retrieved. The fitter looked very sheepish indeed, as did his companions. The author thinks it was in all probability a “put up job” but still cannot be absolutely sure. One thing is certain, if the tank had been “boxed up” with that massive object inside, untold damage would have been done when the aircraft first banked and there certainly would have been a massive audible “clunk”! If it had been missed by the author it may have been detected at a later stage, perhaps when the wing was being attached to the fuselage – who knows?

All of this was taking place just prior the “Six Days War” that commenced in June 1967. There were frequent collections of aircraft from Bitteswell during this period. Clearly there was a mood of tension in the air. When the Six Days War actually broke out virtually all of the Jordanian Hunters, so carefully refurbished by Hawker Siddeley Aviation, were destroyed on the ground in pre-emptive air strikes by the Israeli Air Force. However, the Iraqi Air Force Hunters fared much better and managed to give a good account of themselves against the Israeli opposition in the much contested air fighting of the Six Days War. Not more than six Iraqi Hunters were lost, nearly all to ground fire.

In the Yom Kippur War of October 1973 Iraqi Hunters accounted for at least twelve Israeli fighters, some of them probably Super Mysteres and A – 4 Skyhawks, with little loss to themselves. Iraqi Hunter pilots’ very wisely tended to avoid the Israeli Phantoms.

The period covered by this particular paper spans very roughly twenty years, during which time AWA built five distinctly different types of jet fighter aircraft for the Royal Air Force, the Royal Navy and the air forces and navies of many foreign countries. By the author’s calculations this amounted to a total of 1,973 new build aircraft, excluding conversions, rebuilds and refurbishments. This period was a very lucrative one for AWA but it did tend to mask inadequacies in the company’s overall strategy, ie, its inability to break into the civil aeroplane market; the commercial failure of the Apollo airliner and Argosy transport being cases in point. When the Ministerial axe finally fell in the form of the Sandy’s 1957 Defence White Paper, AWA, Gloster Aircraft and several other companies were ill-equipped to weather the storm.

This discourse completes a series of six papers on the history of Armstrong Whitworth Aircraft and its successors; covering a period of approximately fifty years from 1935 through to the closure of Bitteswell in 1985. During this time many different types of aircraft were built, modified and refurbished and for the most part they served their country of origin well, particularly in times of national emergency. In many respects AWA’s history is a microcosm of the British Aircraft Industry as a whole; of brilliant ideas, golden periods and years of complacency and decline not helped by idiotic political and governmental decisions of the very worst kind. Nevertheless, AWA’s history has survived to be told and retold.

Privately-owned ex-RAF Hawker Hunter T7A (RAF code WV318, civil registration G-FFOX) flies with privately-owned ex-RAF Gloster Meteor NF11 (RAF code WM167, civil registration G-LOSM) at Kemble Air Show, Kemble Airport, Gloucestershire, England. The Hunter is in the colours of the former RAF Black Arrows aerobatics team and was delivered to the RAF in 1955. The Meteor was built by Armstrong Whitworth in 1952 at their Baginton (Coventry) factory. It entered RAF service in 1952 and left RAF service in 1975. (Photographed by Adrian Pingstone and placed in the public domain)

VIVA AWA!

Copyright © J F Willock October 2020

References;

  • Armstrong Whitworth Aircraft, the Archive Photographs Series, Compiled by Ray Williams, Chalford Publishing, 1998
  • Jet Pioneers, Gloster and the Birth of the Jet Age, Tim Kershaw, Sutton Publishing, 2004
  • The Gloster Meteor, Edward Shacklady, Macdonald Aircraft Monographs, 1962
  • The Armstrong Whitworth Prone Pilot Meteor, JF Willock, WIAS Publication
  • Hawker Hunter, Biography of a Thoroughbred, Francis K Mason, Patrick Stephens, 1981
  • The Rise and Fall of Coventry’s Airframe Industry, JF Willock, WIAS Publication