by Damien Burke
Construction would be of light copper-based alloys, as they showed the most promise for the environmental conditions in which the aircraft would operate, combined with punishing low-level fatigue. Alternatives such as titanium alloys or stainless steel would be more expensive and would not offer many advantages, as their reduced structural efficiency would result in more material being used, and hence a heavier and larger airframe. Nonetheless, titanium would be used in the engine bays for load-carrying heat shields. The airframe itself would be constructed along conventional lines, with skin stringers and frames for the fuselage and multi-web-plus-post for the wing primary box. Fatigue from engine noise meant that the engines and, more importantly, the exhausts, would be located at the rear of the airframe. Fatigue from turbulent mixing in the boundary layer (effectively wind noise) meant that the equipment bay needed to be located as far forward as possible, just behind the cockpits, which also led to a useful saving in cabling requirements for all systems that had some cockpit presentation. This bay would have large full-size access doors on both sides of the fuselage, enabling equipment racks to be easily removed for rectification or upgrade.
The Type 571’s internal arrangement. BAE Systems via Brooklands Museum
A general-arrangement drawing of the naval version of the Vickers-Armstrongs Type 571. Damien Burke
Production would be undertaken at the South Marston (Supermarine) works, then in use for Scimitar production. Vickers considered its own manufacturing and drawing office capacity to be largely sufficient for a project of GOR.339’s expected size, but also pointed out that it subcontracted many of its airframe construction tasks to other companies anyway (e.g. Viscount wings to Saunders-Roe), and additional drawing office capacity could be gained from other companies too, if required. (A none-toosubtle suggestion that, while it was prepared to partner with English Electric, it would much prefer to go it alone.)
Naval version
An addendum to Vickers’s submission outlined a version of the smaller aircraft that could be used by the RN. Prepared at the request of the Deputy Director General of the Future Systems department of the MoS, it covered the modifications necessary to turn the single-engine GOR.339 aircraft for the RAF into a naval strike aircraft that remained compatible with the RN’s current carriers. To reduce approach speeds the wing was enlarged by 10 per cent, to fit within deck lift dimensions the nose and wingtips would fold, and an arrester hook and catapult attachment points were added.
HMS Eagle’s larger 199ft (60.65m) catapult was capable of launching an aircraft of up to 43,600lb (19,790kg) in weight with wind speed over the deck of 25kt (30mph; 48km/h). This permitted the naval Type 571 to operate at maximum weight, and, with a high/low sortie spent half at low level and half at altitude, entirely subsonic, the aircraft could carry a single nuclear store to a target up to 1,100nm (1,265miles; 2,035km) away and return to a deck landing at a weight of 27,000lb (12,250kg). The resulting approach speed and landing weight was not far off Scimitar figures. Throwing in a supersonic burst of up to Mach 2 at high altitude reduced the combat radius to 980nm (1125 miles; 1,800km). By sacrificing some fuel, and therefore range, heavier conventional loads could be carried, such as eight 1,000lb HE bombs, though range could be regained by in-flight refuelling after launch.
Naval fighter
The naval version’s high top speed and long range made it equally valuable as an interceptor. The weapons bay could hold a pair of atomic-headed air-to-air missiles, and a combat air patrol (CAP) at 130nm (150 miles; 240km) from the ship could last for nearly two hours from HMS Eagle’s shorter catapult, or over three and a half hours from the longer catapult. Both CAPs included allowance for a Mach 2 combat, dealing with targets varying from a Mach 1 low-level bogie to one approaching at Mach 2 and 70,000ft (21,340m).
A miniaturized brochure
The Vickers brochure was a hefty tome, split into several volumes and consisting of 272 pages. Only English Electric’s submission was larger, and only these two were of this sort of size and scope, though Blackburn’s B.103 brochure was also quite substantial. Vickers soon found out that English Electric’s P.17 brochure was, however, considerably more detailed and its work more advanced. If a quick decision was to be made as to which project to go for, the P.17 looked like it was going to win. Vickers, however, had been told during a visit to the RAE that the naval Type 571 it had proposed was of great interest, and believed it was this that was delaying a decision. However, the company did not want to scare the Air Staff off by implying that an RAF version would be penalized by any design for a naval version, and it had heard of the Air Staff’s doubts about the feasibility of its miniaturization policy. Consequently Vickers followed up its main submission with a smaller brochure, with an emphasis on easy-to-follow illustrations. This brochure, ‘a “miniaturized” brochure describing a “miniaturized” aircraft’, addressed the concerns that Vickers felt were important. First of all, it reiterated all the advantages of miniaturization of installed equipment, and the amount of work being done by itself and partners EMI and Elliott Brothers to design suitable equipment. Second, it emphasized in this second brochure that the aeroplane was designed to GOR.339 and ‘optimized entirely round the RAF requirement’. Any naval application was a mere bonus brought about by the low size and weight of the design. This smaller brochure was very successful at clearly explaining Vickers’s miniaturization concept.
Evaluating the proposals
On 31 January 1958 an Assessment Group began meetings to look at the submissions and begin preparing a report to help in putting together a more definitive draft Air Staff Target, OR.339. The new OR would basically be brewed from the good bits of each of the firms’ submissions. Normally this would have been a fairly rapid process, as the number of firms submitting to any particular requirement was always fairly low. Sometimes only a single firm would be interested, and usually no more than five or so. This was not so with GOR.339, with nine official responses and several other possibilities to look at. The RAE’s input was extremely important to this process, and it evaluated each proposal against its own thoughts as well as against the other proposals.
No firm had addressed in detail the more unusual aspects of the GOR, such as linescan and terrain-clearance radar, but the Assessment Group as a whole did not seem overly bothered by this, judging linescan to be of questionable use and terrain-clearance radar as being unlikely to be developed in time. The Air Staff representatives in the Group, however, still wanted terrain-clearance radar, and one suggestion was for a separate Air Staff Target to be issued covering such a system, which could then be added to a future development of the aircraft built to satisfy the GOR. Vickers’s miniaturization concept aroused a lot of interest, particularly as it could lead to an aircraft small enough to be priced competitively for export and also for use by the RN. However, the concept was greeted with equal amounts of scepticism. The Assessment Group found that Vickers’s brochure did not contain sufficient evidence to justify the claims, and the OR assessment was that the design itself was ‘extremely superficial’.
On the weapons side, Avro’s detailed description of ‘powered bombs’ to enable stand-off attack was of great interest. Keeping the delivery aircraft some distance from the target had attractions not just because it exposed the aircraft to fewer defences, but also because it would enable nuclear warheads of larger megaton yields to be used. Vickers had also mentioned the use of missiles to avoid the dangerous nuclear bomb delivery manoeuvre, but in nowhere near as much detail as Avro.
Gust response and the quality of ride at low level was difficult to judge for most of the submissions, as the necessary aerodynamic derivative calculations had only been included by Avro, English Electric and Vickers. On the basis of these and statistical work, the Avro design was not expected to be much better than a Meteor (the RAE’s baseline for gust-response comparison), the English Electric design was thought to be an improvement and the Vickers best of all. Structural strength and resistance to fati
gue were of such high importance that any firm that failed to produce realistic figures instantly had its entire submission teetering on the edge of dismissal. On that basis the de Havilland submission suffered badly, with structural weights that simply could not be tallied with the claims for fatigue strength. De Havilland was also felt by the RAE to have badly underestimated its take-off and landing distances, by up to 30 per cent.
The English Electric and Short proposal for a VTOL version of their aircraft, or a separate VTOL platform to be used in combination with the aircraft itself, were the subject of much discussion. The lifting platform was particularly attractive because it also separated the development tasks, and delays on the VTOL side would therefore not affect the strike aircraft. However, the platform’s configuration was of some concern. Its basically delta planform and deep wing were necessary to provide similar flight characteristics to the strike aircraft and room for the lift engines, but would result in the wing providing little lift itself, and there was inadequate room for sufficiently powerful control surfaces. Gaining enough intake flow for engine starting would also be problematic. The development of a system to enable the strike aircraft to home on the platform and then hook up, no matter what the weather and visibility were like, could take a long time; and it was considered that the strike aircraft would need some downward visibility for docking with the platform, perhaps through a floor window.
Unbeknown to Shorts, however, a chance meeting between Sir Charles Dunphie, chairman of Vickers, and one of English Electric’s directors had taken place after the GOR.339 brochure was submitted. The conversation had turned to GOR.339, and Dunphie had mentioned that cooperation between Vickers and English Electric would be a good fit. Vickers had the muscle and a proven track record of production, not only to military but also to commercial standards. English Electric had supersonic experience and a design team second to none. English Electric began quietly looking at the implications of joining up with Vickers; but it had signed up to a binding agreement with Shorts, so any co-operation with Vickers would need, somehow, to include Shorts as well. English Electric would soon work out a suitable agreement with Vickers and communicate the changes to the MoS, where the English Electric/Shorts/Vickers combination provoked a great deal of interest.
Bristol’s design came in for some stiff criticism from the RAE after an initially positive reception based on its expected excellent gust-response characteristics. On further examination the Group considered it to be likely to suffer badly in the areas of stability and control. The RAE had been working on a slender-delta configuration as the basis for the future supersonic transport, and the Type 204 seemed to be close to some of the less-than-ideal variations it had been playing with. On top of that, Bristol’s mistakes in its drag calculations soon condemned its proposal to the bin, even though the canard scheme ‘had many advantages’. The Fairey design, the only other canard design submitted, would need careful study, particularly in the areas of foreplane/intake interference and lateral stability; it could be that the aircraft would require twin fins. However, Fairey’s design was so handicapped by its crippling lack of realistic supersonic capability at low level that it received only the briefest of examinations.
An English Electric P.17A is winched on to a P.17D lifting platform. BAE Systems via Warton Heritage Group
On Hawker Siddeley Group advice the initial Hawker P.1129 submission went unconsidered. Similarly, the Vickers/ Wallis Swallow to GOR.339 received no real attention. Handley Page’s study was only of brief interest in terms of the gust-alleviation mechanism proposed. Blackburn’s NA.39 also received short shrift, being discarded within days owing to its inability to meet the supersonic requirement. Thus the nine formal submissions were very quickly boiled down to three of major interest: the Avro 739, the English Electric P.17A/D combination, and the Vickers Type 571. All of the firms’ estimates for a schedule were viewed as overly optimistic, one member of the Assessment Group suggesting that an in-service date of 1966 was more likely than 1964. Even that, as it would turn out, was optimistic.
The economics of GOR.339
The RAF’s own internal estimate of total development costs of £15 million now jumped massively to £35 million, a particularly unhappy state of affairs when compared with the much lower costs estimated for the NA.39 variant proposed by Blackburn. A detailed look at savings that could be made on various systems massaged the figures slightly, but the best that could be predicted was £33 million to £34 million for a large twin-engined type, or £32.5 million for a smaller single-engine aircraft. The MoS’s estimates were even higher, ranging from £33.5 million to £38.5 million, to include £16.5 million for airframe R&D, £3 million for engines, an additional £5 to £10 million depending on choice of engines and £9 million for weapon system equipment. The cost of the new bomber was already rocketing skywards.
English Electric’s submission, while heavy on detail of the P.17, was light on costs. In fact, English Electric had declined to include any predicted costs whatsoever, as it was not its policy to quote costs to anything except a solid specification, which GOR.339 was far from being. This was, in part, due to the cost rises experienced during P.1 development, which had basically doubled between 1955 and 1958. The MoS was outraged by this impertinence and kept returning to the subject time and time again, finally drawing a line in the sand and informing English Electric that its submission could not be considered unless something on costs was added to it. English Electric produced a report entitled The Economics of GOR.339, in which it continued its policy of quoting no firm costs whatsoever for its own equipment, while trying to teach the Ministry a few things about the economics involved not just in GOR.339, but in all military aircraft. The company pointed out that existing means of estimating cost were laughably crude; for example, quoting a fixed amount per pound of weight to give an overall estimate. When it came to a project involving not just a new airframe but also a new engine and lots of new electronic equipment, this sort of crude estimate would simply be misleading. Furthermore, some types, GOR.339 among them, would make attractive export prospects, and thus end up costing less. Attempts to reduce size to make the airframe cheaper could backfire by putting the aircraft into the same class as foreign competitors, thus losing exports and driving unit costs back up. Trying to share costs with the navy by aiming for a joint RAF/RN type was fraught with danger, as reductions in size and performance to fit the aircraft on current RN carriers would inevitably result in an aircraft less able to carry out its RAF role, and reduce its export attractiveness once again. The lifting platform, however, could give a cheap carrier capability.
Ray Creasey, the Director of Engineering at English Electric and the aerodynamic genius behind the Lightning and P.17 wings. Creasey guided the P.17 project from its beginnings, but was unwilling to produce cost estimates from thin air, to the displeasure of the MoS. BAE Systems
On the subject of reducing costs, English Electric pointed out that new equipment was very much more expensive per pound of weight than use of existing equipment; extreme methods of miniaturization as proposed by Vickers could well increase cost even though weight was saved. Statistical analysis of the costs of existing equipment gave them a mean price of £28 per pound, with £92 per pound for new equipment, along with R&D costs as high as several thousand pounds per pound. English Electric did not believe that GOR.339 justified the millions of pounds that would be necessary for R&D of all-new equipment. Only the use of existing kit could keep the equipment bill below £5 million, and it believed it would soar through the £10 million mark otherwise.
With the engines as the single most expensive item, English Electric was later instrumental in getting Bristol Siddeley Engines Ltd (BSEL) to produce a formal brochure on the Olympus 15R that included guarantees as to performance, weight and, most importantly, cost. This was all undone by the later switch to the Olympus 22R, at which point Bristol Siddeley was canny enough to avoid similar guarantees (the result of which would be poor cost control
on the engine project in its initial years, and spiralling costs, guarantees and fixed prices not being reintroduced until 1964).
Rethinking some of the more exotic bits of equipment such as linescan, terrain-clearance radar and a complex navigation system, was felt by English Electric to be worthwhile, as these would all result in high costs and, the company believed, would be of questionable value. This was a dangerous game for English Electric to play, flying in the face of the RAF’s own requirements and also going up against its chosen partner, Vickers, and its entire ethos of compact new-build equipment. The men at the Ministry already had doubts as to English Electric’s management ability, and this was unlikely to have helped reverse that situation. It also meant that the details in English Electric’s report showing how it could build the P.17 cheaper than anyone else, but only to an agreed specification, were given less credence than they should have been.
