by Damien Burke
One big change to the GOR at this point was the addition of a much more varied selection of weapons for the aircraft to deliver. With budgets slashed, the RAF now had to put all of its eggs in this single basket, and ask for an aircraft capable of doing more than delivering a single Target Marker Bomb or a handful of dumb bombs. Subsidiary requirements were also generated to cover some of the additional systems that would be needed on board the aircraft; OR.3044 covered a navigation, bombing, reconnaissance and flight control system, for instance.
Reshaping the Aircraft Industry
While the MoD was smugly looking forward to a golden age of shiny pointy missiles and a world in which sideshows such as Korea or Suez did not happen, Aubrey Jones at the MoS realized that Sandys’ White Paper had effectively put the aviation industry on notice. With most aircraft projects cancelled, the manufacturers would be desperate to win work on the last major remaining project, GOR.339, and this put the MoS in a uniquely powerful position. It had a golden opportunity to use GOR.339 to reshape an aircraft industry it saw as bloated and inefficient. In this the MoS had a good point. The industry had grown into a mass of independent companies, often duplicating one another’s efforts and producing some equipment of frankly questionable utility. However, the increasingly heavy influence of an army of civil servants standing between the armed forces and their equipment suppliers was an example of bloating and inefficiency that dwarfed any in the aviation industry, and the chaotic and sloth-like manner in which aircraft requirements were drawn up and issued and contracts awarded was a good part of the reason behind fiascos such as that of the introduction into RAF service of the utterly useless Supermarine Swift fighter.
Within the Air Ministry, MoD and MoS, discussion on GOR.339 was batted back and forth. The NA.39’s case was continuing to be pressed by the Admiralty. This did nothing but harden attitudes within the RAF, which took steps to try to remove the NA.39 from the running in a dramatically permanent manner. The result was that, in April 1957, the MoD sent a letter to the CA at the MoS, suggesting that the NA.39 could be cancelled to save money, and the developed Scimitar put into production as a cheaper alternative for the RN’s strike requirement. The MoD also took advantage of the MoS’s known plans to reduce the aircraft industry’s size by pointing out that killing the NA.39 would make it possible to ‘eliminate both the Blackburn Aircraft Company and the de Havilland Engine Company’ earlier than would otherwise be possible. Of course, the far less capable Scimitar development would have been of no use at all to satisfy GOR.339, leaving the field clear for the RAF to get exactly what it wanted. The second step in this plan would be to demonstrate that RAF GOR.339s would be capable of covering all of the RN’s strike commitments and enable the removal of the entire RN carrier force. Luckily for the RN, and, as it transpired, the RAF too, this dastardly ploy failed, and in August 1957 the NA.39 project was allowed to continue. The RAF had won no friends in the process, and it was perhaps this episode that turned Admiral Mountbatten into such an implacable enemy of the GOR.339 project.
Meanwhile, the RAF was concerned that, despite its requirements being available in black and white, nothing had been officially communicated to the wider aircraft industry. Its original timetable had included the receipt of detailed design studies from industry by the end of August 1957, and the selection of a design to form a basis for a draft OR by the end of October. August came and went, and the industry had not even received the final GOR yet, let alone managed to respond to it in detail. The reason for this delay was entirely political. The MoS was still trying to decide which aircraft companies deserved to survive, and which groupings they would like to see. By September the MoS finally had some idea of what it wanted the future aircraft industry to look like, and so invited representatives of the major companies to a meeting at the Ministry on 16 September. The Minister himself, Aubrey Jones, was visiting the USA, and left it to his Permanent Secretary, Sir Cyril Musgrave, to preside over what turned out to be a momentous meeting. Attending were Mr (later Sir) Aubrey Burke of de Havilland; Lord Caldecote and Mr H.G. Nelson of English Electric; Captain E.D. Clarke of Saunders-Roe; Sir Roy Dobson and Sir Frank Spriggs of Hawker Siddeley; Sir George Edwards of Vickers-Armstrongs/ Supermarine; Sir Frederick Handley Page and Mr R.S. Stafford of Handley Page; Sir Matthew Slattery of Bristol Aircraft and Short Brothers; Mr E. Turner of Blackburn and General Aircraft; and Sir Reginald Verdon Smith and Mr Cyril F. Uwins of Bristol Aircraft.
The message of the meeting was blunt. There are too many of you, and there is too little work. The only significant military contract on the horizon was going to be GOR.339, possibly, and the contract for this aircraft would only be awarded to a group of firms, or perhaps a single firm taking leadership and co-ordinating two or three others. This was a particularly harsh blow to the Hawker Siddeley Group, which was already ahead of the pack in terms of consolidating and tidying up the industry. Furthermore, while the MoS would prefer the firms to come up with their own groupings, if it proved necessary it would nominate the groupings itself. Were this to be the case, the Ministry would choose them based on the ‘long-term structure of the industry’; its own vision being of three or four groups only, covering the entire industry. Regardless, any individual group would need to demonstrate four items to be acceptable: a diverse portfolio of work covering both civil and military projects; optimum design capacity including supersonic work; good productive capacity sufficient to cater for future needs; and, finally, considerable financial strength. It was clear that the Ministry wanted to be shot of the smaller companies altogether.
The meeting also covered future work beyond GOR.339, of which there was very little. There were various small civil projects, including the new British European Airways (BEA) airliner (this became the Trident), a possible supersonic transport (the first whispers of Concorde), and that was that. Beyond GOR.339 there could well be no military work at all, and the industry needed both to amalgamate and broaden its interests to survive in a world that could possibly consist only of civil contracts. Needless to say, this was shocking news to the assembled company directors, and pretty much to a man they pointed out that relying on civil projects only would doom the UK aircraft industry to recession. The USA simply could not be competed against in this sphere, being able to offer much larger production runs and thus lower prices, and with its own military production ramping down, its companies would be gearing up to make even greater inroads into the civil market.
The meeting was summed up by Sir Cyril, who said that they had to take a realistic view of the industry’s future prospects, and that ‘On this basis the decision had been taken that GOR.339 should be placed with a consortium of firms, or with a firm operating in association with several others.’ Furthermore, ‘an indication was required with each firm’s reply of the other firms it expected to associate with in the event of its being given a share of the contract’. The meeting ended with a procession of dismayed executives trooping out in near silence, resigned to the government’s vision of a radically restructured aviation industry. Sir Cyril turned to his Under Secretary (Air), Denis Haviland, and said: ‘We’ve won’.
CHAPTER TWO
Submissions to GOR.339
General Operational Requirement 339 was officially issued to the industry with a deadline of 31 January 1958 for receipt of proposals. (A complete copy of GOR.339 can be found in Appendix I.) While the firms worked on their submissions, the various possibilities of foreign aircraft to meet GOR.339 were also explored, types as diverse as the Convair B-58 Hustler and Republic F-105 Thunderchief being looked at, reduced to sets of numbers and discarded as one number or another failed to match up.
It might be assumed that, having issued the GOR to various firms and asked them to work on a submission to satisfy it, the OR staff would by now have been, at least, pretty clear about what they wanted. However, initial discussions with various firms had proved unsettling for them, most firms describing large and complex aircraft loaded down with various it
ems of equipment to try to satisfy every possible aspect of the GOR, which had itself been gradually amplified by discussions between the firms, the OR staff and the MoS. After publication of the first issue of GOR.339 it was suggested that good supersonic performance at medium altitude would be needed for fighter evasion, and a 600nm (690-mile; 1,100km) combat radius as a basic case was not aiming high enough when the Canberra could manage 1,000nm (1,150 miles; 1,850km). Consequently each firm was sent communications placing greater emphasis on high supersonic speeds at medium to high altitudes, and made the 1,000nm sortie a basic sortie rather than an overload case. With most of the firms already planning for lower performance, this left them struggling to meet the new requirements.
Why the size of most of the aircraft designs under discussion came as a surprise is a mystery, but it prompted a meeting of the OR staff on 6 December to discuss exactly what it was they wanted the aircraft to do after all! The Assistant Chief of the Air Staff (OR) had made it clear that the aircraft was needed to deliver a tactical atomic bomb, with a secondary task of reconnaissance. Additionally, the various military chiefs of staff had recently approved a paper which accepted that the strategic deterrent was all-important and no additional systems should be developed if they were not required for ‘shield forces’, i.e. part of the NATO shield against Soviet invasion. Clearly GOR.339 had to be able to be considered as part of the shield, or it could not go ahead, and with plans to use it as a Canberra replacement world-wide there were doubts that they could get away with describing it as a shield component. Remarkably, amidst discussions on just about every aspect of the GOR, was the admission that ‘it would be an unwarranted penalty to demand a bulky undercarriage arrangement necessary to provide extremely low LCNs [load classification numbers]’ (i.e. operation from rough strips), and that it should be planned on the basis of using existing airfields, a complete about-face from what industry had already been asked for. Thus, as late as the middle of December 1957, the firms were receiving communications that were changing the requirements, and their deadline of 31 January 1958 was unchanged.
By the end of January 1958 the firms had submitted their responses. It was an eclectic mix. A few had clearly had many months of detailed work put into them, others were decidedly sketchy, and at least one was little more than a ‘back of a fag packet’ study from a firm clearly lacking any interest in playing the Ministry’s game.
A.V. Roe: Avro Type 739
Fresh from the disappointment of the cancellation of the Avro 730 to OR.330, Avro cannot have had much appetite to begin work on another bomber design, particularly with such a jack-of-all-trades requirement to satisfy. However, the company knuckled down and got on with it. It first addressed the needs for crew comfort by choosing a fairly small, highly loaded wing allied to sprung seating for the crew. A small wing would need lift assistance for landing and take-off, so blowing would be used across deflected leading and trailing edges. Variable sweep and direct-lift engines were considered, but both would have entailed considerable extra development effort and the 1964 deadline would not be met. Lift jets would also result in a much more expensive and difficult to maintain aircraft, conflicting with the dispersed tactical operations concept. Accordingly, neither idea made it into the brochure.
Avro proposed to address the inadequacies of the toss-bombing delivery method by using a winged stand-off bomb. Thus, instead of exposing the aircraft to missile attack during the pull-up to toss a ‘dumb’ Red Beard, and risking the bomb going off-target owing to wind shifts during its long toss, the weapon could be delivered from low level while the aircraft was still some distance from the target; up to 25 miles (40km) away, in fact. The winged bomb would weigh at least 50 per cent more than a standard Red Beard, but the increased distance from the delivery aircraft would make it possible to use a fusion rather than fission warhead (for a considerably bigger bang – megatons rather than kilotons). Much of the work going into the Blue Steel stand-off missile could be re-used, with a similar guidance system and the use of a rocket motor based on the principles used in the two-fifths-scale Blue Steel test shots. The method of carriage would be similar to that of Blue Steel on Avro Vulcans, with the weapons bay doors replaced by a fairing containing a recess into which the bomb would be mounted. With a stand-off bomb reducing the aircraft’s vulnerability, other means were also looked at to reduce the risk further. These included the use of radar-absorbing material (RAM), to be applied within aerial cavities, the crew cabin, the intakes and their half-cone centrebodies, and any portions of the exterior skin as necessary. The crew would even have RAM-coated blinds that could be pulled over the transparencies when flying at high altitude. Attack warning would be given by a system similar to the Blue Saga (ARI.18105) radar warning receiver (RWR).
Leading Particulars: Avro Type 739
Length
80.8ft (24.63m)
Height
19.4ft (5.91m)
Wing span
41.28ft (12.58m)
Wing area
568sq ft (52.77sq m)
Wing aspect ratio
3
Wing anhedral
5 degrees
Tailplane area
193sq ft (17.92sq m)
Tailplane aspect ratio
3
Fin area
192sq ft (17.84sq m)
Fin aspect ratio
0.86
Engines
2 × 14,600lb (6,630kg)
RB.142R
Max speed
Mach 2.2 at 36,000ft
(11,000m)
Empty weight
45,870lb (20,820kg)
Max AUW
97,130lb (44,090kg)
A general-arrangement drawing of the Avro Type 739 of January 1958. Damien Burke
When it came to conventional bomb carriage, Avro saw that it could fit three 1,000lb bombs side-by-side by widening the bay slightly from the dimensions required for Red Beard, but fitting four would require extending the bay’s length. Accordingly it went with a reduction from the GOR’s requirement for four, suggesting external carriage if extra bombs were really needed. Rocket packs would also fit within these dimensions, and would be extended by hydraulic jacks for firing. The weapons bay doors were conventional, being hinged to open at the edges, rather than rotating or sliding. External weapons carriage was provided in the form of six hardpoints on the wings for pylons, two of which would be plumbed for fuel. The wingtips could also carry rocket pods or missiles.
Avro thought terrain clearance was not a realistic prospect and the Type 739’s radar suite was to be biased entirely to navigation, coupled with an inertial navigation system (INS). Low-level terrain clearance would therefore be entirely visual, and a head-up display (HUD) for the pilot would be essential. A small radar-ranging dish would be mounted on the back of the main forward-looking radar (FLR), to be used for rocket attacks. The X-band SLR with a mere 5ft (1.5m) antenna would suffice for position fixes. It did not have sufficient resolution for reconnaissance purposes, so a higher-resolution 14.5ft Q-band SLR was suggested for use in a reconnaissance pack hung from the weapons bay. The pack would also contain four cameras (four 24in and two 6in lenses) and linescan, along with associated recording and transmitting equipment, but Avro provided few details.
While Avro ignored the Ministry’s request to consider naval applications, it did point out that the Type 739, with Mach 2-plus performance and a large fuel load, could make a suitable platform for fighter/interception duties, toting Red Top or Blue Jay Mk 4 missiles. Up to four missiles could be carried, two at the wingtips and two on fuselage-mounted pylons. This version would otherwise be externally identical to the bomber, with only internal changes such as the replacement of the bombing and navigational equipment with AI and missile support equipment. As with other submissions that would mention the possibilities of use as a fighter, this was aimed purely at the bomber destroyer role; it would have been no dogfighter.
The configuration of the airframe was fair
ly conventional, with engines buried in the upper mid-fuselage both for minimum drag and because this was just about the only place left to put them, the rest of the fuselage being taken up by crew compartment, radars, weapons bay and undercarriage. To keep the wings clear and crew visibility unobscured, the engine intakes were mounted high on the fuselage sides. Fixed half-cone centrebodies were optimized for transonic flight, and spill doors directed excess flow overboard as speed increased, rather than going to the expense and complexity of providing a variable-geometry centrebody. Access to the engines for replacement was provided by a break point in the rear fuselage; the entire rear fuselage would be removed and the engines slid out backwards. The fuselage used area ruling, one consequence of this being that the weapons bay ended up forward of the c.g. The resulting trim changes at weapons release were to be cancelled out by the flight control system. The fairly small mainplane was swept at 40 degrees and mid-mounted, the torsion box extending through the fuselage, between the engines and the weapons bay. A low-mounted tail plane was found to be the best position for stability. The all-moving tailplanes were differentially operated for roll control, backed up by small ailerons on the wing at low speeds. These would be locked in place when the aircraft was supersonic, avoiding the aileron reversal problems experienced on other high-speed aircraft. If the high wing loading proved insufficient to provide crew comfort in low-level turbulence, Avro suggested that an automatic gust-alleviation system could be used. This would deploy the wing flaps and alter tail plane angle as necessary to smooth out the ride. The leading- and trailing-edge flaps were both blown, and a notch in the wing delayed the vortex separation that would otherwise give rise to undesirable pitch-up. All conventional control surfaces were to be moved by duplicated hydraulic rams acting on a rod-lever system to give multiple operating points along the surface’s span, based on the units developed for the cancelled Avro 720 supersonic interceptor and 731 (a scale model of the 730 supersonic bomber) projects. The pilot would have a side stick, using mechanical signalling rather than direct mechanical control (i.e. rods and cables) to ‘talk’ to the control surfaces. Avro thought it likely that a ‘manoeuvre demand’ system would be needed, whereby the pilot’s inputs would not be directly passed to the control surfaces, but instead the automatic flight control system would apply the movements necessary to carry out the manoeuvre demanded by the pilot.
