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Aviation History
1955
1955 - 0242.PDF
242 FLIGHT Hunter mainplanes in production at a British factory. THE HUNTERS ARE HERE ... tools and materials. In many directions the outlook was bleakindeed. The vicissitudes of Hunter production were admirably outlinedlast April by Mr. E. H. Jefferson, general manager of Hawker Aircraft (Blackpool), Ltd., and a director of the parent company,in a paper before the Society of Automotive Engineers in New York. Mr. Jefferson made the point that from the date thatHawkers first knew that they were going to receive an order to the time when the first production Hunter was flying only twoyears and seven months had elapsed. Furthermore, as the Hunter was a new aircraft the company had to start from zero and builda completely new production set-up at a time when production of other types of aircraft had been allowed to run down, with lossof much skilled labour which sometimes seemed almost impossible to replace. An even more serious aspect was the find-ing of firms to make large jigs and tools in the numbers required —3,250 tool designs and about 40,000 jigs, tools and fixtures.The Government's "super-priority" scheme only partially pro- duced the required results, since priority had to be allocated toso many items that suppliers and sub-contractors were often unable to give any major preference. Additionally there was thecontinuing demand for exports. Eventually, toolmaking difficulties were overcome by a com-bination of two methods. The first took care of initial detail and sub-assembly work and involved a compromise—the develop-ment and use of "rough tools," prepared not by the virtually unobtainable toolmakers but by skilled fitters. Although capableof manufacturing several hundred parts these tools were intended as a temporary measure. Such methods obviously could not beemployed for major assembly jigs; here it was a matter of search- ing far and wide until someone with the capacity to accept orderscould be found. Eventually a large number of jigs were pro- cured from such Italian firms as Macchi, Breda and Fiat.Conforming to World War II practice, Hawkers had decided that the Hunter should be divided into major units which couldbe completed individually and would be available as fully equipped spares. Their size depended partly upon structuraldesign and partly upon Service requirements for transportation; but these units should not be confused with manufacturing sub-assemblies, into which the airframe was further sub-divided. The Hunter airframe is broken down into six fully interchange-able major components: front fuselage, which carries the cockpit, armament pack, nosewheel and cowling for radar-ranging sightand camera gun; centre fuselage, with integral wing roots, engine supports and air intake ducts; detachable rear fuselage withintegral fin base and removable jet pipe/tail cone unit; tail unit assembly; and mainplanes, complete with the main undercarriagelegs. For final assembly it was necessary only to connect the structural members and to plug the pipes and leads together. Mr. Jefferson has pointed out that one reason for this methodwas the difficulty inherent in building a complex aircraft in a number of factories some distance apart. During the early daysthe resources of the entire Hawker Siddeley Group were pooled for difficult items. Hawker Aircraft itself was far from beinghoused all under one roof. Production plans, therefore, called for the detail parts and main assemblies to be made in severalplaces, with Kingston-upon-Thames as headquarters. There were two other factories in the south of England and assemblieswere fed to the final-assembly plant and airfield about 30 miles from Kingston. Certain specialized components were sent 250miles from Hawker Aircraft (Blackpool), Ltd. When production for the R.A.F. was proceeding at a satis- factory rate a U.S.A. off-shore procurement order was placed for450 Hunters, to be delivered by June 1956 It was not, however, necessary (and was, in fact, impossible) for new factories to beerected to build off-shore Hunters alone, and the order is being met from the existing organization by continuing production atthe peak rate which had been planned to meet R.A.F. require- ments Thus, the off-shore order assured a longer run of peakproduction and promised a level of capacity not otherwise possible. As the aircraft are completed the M.o.S. and NATOrepresentatives will decide between themselves which shall go to the R.A.F. and which to other NATO countries. Over and above the off-shore orders placed with HawkerSiddeley further contracts were awarded to Dutch and Belgian firms, so that eventually Hunters will be built by three com-panies in Holland—Fokker (who are to undertake the majority of manufacture in that country), Aviolanda and de Schelde—and bytwo in Belgium—S.A.B.C.A. and Avions Fairey. Many special machine tools for Hunter production, both onthe Continent and in Great Britain, had to be obtained from the U.S.A., and Mr. Jefferson has mentioned the fact that in anemergency the production jigs in the Hawker factories could quickly be dispersed to safe areas, for all main jigs are erectedon "rafts." Present orders are a measure of the Hunter s quality, and canbe summarized as follows: for R.A.F. Fighter Command, an undisclosed but "substantial," number; for NATO, 958, made upas follows—468 for the R.A.F. under off-shore contracts, 112 to be built under licence by Fokker in Holland and by S.A.B.C.A.and Avions Fairey in Belgium (also under off-shore contracts), 156 to be built in Holland by Fokker for the Dutch Government, 192to be built by S.A.B.C.A. and Ayions Fairey for the Belgian Govern- ment, and 30 for Denmark, to be built by Hawkers in Great Britain.Sweden, a non-NATO nation, has ordered 120 Hunters at a price of £12 million, so that, quite apart from the Ministry of Supplycontracts on behalf of the R.A.F., nearly 1,100 Hunters are on order from the various factories. These orders were followedlast September by an M.D.A.P. contract delivered by U.S.A.F.E. for £367 million worth of Sapphire-Hunters and Javelins forthe R.A.F., though the numbers of each type were not stated. During 1954 photographs of large-scale Hunter productionwere approved for publication, and on June 24th of that year the Ministry of Supply granted clearance for the Hunter to enterservice. The first squadron to be equipped (with F.ls) was, as we have said, No. 43—the "Fighting Cocks"—based at Leucharsand commanded by S/L. R. E. Lelong, D.F.C., a New Zealander and a Sabre veteran of Korea. Throughout 1954 there were rumours and reports (many ofthem half-truths, or completely unfounded) that the Hunter was beset by various troubles. Certain it was that application of theair brakes caused an unacceptable change in aircraft attitude, and during January the F.I prototype WB188 was to be seenwith experimental braking surfaces on each side of the tailpipe, whereas in the original scheme the brakes had been located onthe wings. After a lengthy period of experiment the now-familiar, externally applied "barn door" beneath the rear fuselage wasstandardized. An armament demonstration at Boscombe Down duringAugust 1954 bore witness to the staggering punch of the Hunter's four Aden guns, and it was then observed that a large stream-lined collector-box for links and shell cases was carried beneath the gun pack. In recent weeks it has been officially intimatedthat this fitment is being standardized. Engine-surging troubles, admitted to have been experienced under certain conditions atextreme altitudes when the guns are fired, are more pronounced on the F.I than on the F.2. Early this year a Hunter F.I appeared with pylon-mounted,finless, plastic under-wing fuel tanks of Bristol manufacture, and mention was authorized of the marks F.3, F.4 and F.5—the F.3a reheat version now abandoned, the F.4 with an Avon and con- siderably increased tankage, and the F.5 a Sapphire-powered equi-valent of the F.4. Although the modified Hunter XF833 demon- strated at 1954 S.B.A.C. Display had then been called the F.6, theairframe was, in fact, that of an F.I, adapted to take a more power- ful Avon. The foreign Press reports that the engine of the F.6will be the Avon RA.23. A full description of the Hunter has not yet been authorized,but it can be said diat the span, length, height and undercarriage track are, respectively, 33ft 8in, 45ft 3in, 10ft and 14ft 9in. Thegross wing area is 340 sq ft, sweepback at quarter chord 40 deg, thickness/chord ratio (constant) 8.5 per cent, aspect ratio 3.3 : 1,and tyre pressure 190 lb/sq in. The hydraulic system incorporates separate accumulators for the power-boost units and is fed by aDowry constant-volume two-stage pump. The system supplies power for undercarriage and flap operation, and for the flying con-trol boosters. There is an emergency pneumatic system for lowering the undercarriage and flaps. It has bfi«n officially announced that consideration is beinggiven to the adoption of an all-moving tail, as it is considered that this might be an advantage "in later development."
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