TSR2

by Damien Burke

  Warning bells

  The Treasury’s concerns with the way the project was going had been mounting steadily. Having examined the most recent draft of the OR, it had seen that there were numerous areas where performance had been upped, and this was bound to have an effect on costs. Rather than a maximum speed of Mach 0.95 at low level, for instance, the requirement now included supersonic speed at low level. High-level speed had risen from Mach 1.7 to Mach 2.0 or even higher. The 1,000nm combat radius was now to be entirely on internal fuel, not as an overload case, and this in particular raised eyebrows. Provision of active RCM now asked for double the weight and nearly treble the cubic capacity. Why did a tactical aircraft need such a huge combat radius? If low-level penetration was essential to survival, what was all this monkeying about at Mach 2 at high altitude for? Why did a low-level aircraft designed to sneak in under radar cover need active countermeasures? Almost a year after brochures had been received, it appeared the RAF was now asking for an aircraft of significantly higher capabilities. On that basis, if the requirements were now different, how could the selection of firms stand? These were all good questions, but after nearly a year of discussion and fighting to get the new project approved, the Treasury was not about to be allowed to derail things at this point.

  CHAPTER THREE

  Designing TSR2

  Months before the official announcement of the beginning of work on the new aircraft, English Electric and Vickers-Armstrongs had been hard at work trying to figure out how their differing designs could come together to form a viable aircraft, and how their two organizations could work together. This was a huge challenge, as each company operated in a different manner, with an entirely different culture both on the shop floor and in management. A common feeling at English Electric was that Vickers was home to arrogant Johnny-come-latelies muscling in on English Electric’s Canberra replacement and expecting everything to be done their way or not at all. Feelings at Vickers did not run so high, though the company did believe that its long history and recent experience on the Valiant and Scimitar put it in an unassailable position when it came to developing a modern strike aircraft, and that the upstarts at English Electric had some cheek to be trying to go it alone with just the Canberra and as-yetunproven P.1 under its belt. Emotions ran particularly hot at English Electric because, in the belief that time was short and a head start was necessary if the Ministries were to be kept happy, detail design work on Project 17 had already begun during 1958, and it now appeared that much of the hard work was going to be disregarded by Vickers.

  However, English Electric’s management, considered its weak point by the MoS, had experienced time and time again the painful, protracted and often fruitless process of translating technical offerings into actual contracts, and introducing Vickers into the mix breathed fresh air into its dealings with the bureaucracy. Vickers’s heavyweight management, particularly George Edwards, demonstrated that strong personalities and an illustrious company history went down fairly well with the bureaucrats, and two years down the line Ray Creasey, English Electric’s Director of Engineering, would admit to Jeffrey Quill, head of Vickers’s Military Aircraft Office, that Vickers ‘gave the project a new lease of life towards the end of 1958’.

  From the beginning both companies were handicapped by a lack of information received from the Air Ministry and MoA; OR.339 raised a lot of unanswered questions, and getting any response from either Ministry to requests for amplification of the detail of the requirements was a frustrating task. Similarly, reactions or comments were not forthcoming when the companies submitted their own reports on aspects such as predicted bombing accuracy, navigation systems, crew comfort and so on. Vickers in particular knew that the MoS had commissioned lots of reports on similar subjects from RAE and other organizations, but no bibliography of these reports had been made available, so Vickers had no idea whether it was duplicating efforts already under way or completed.

  Surprisingly, Vickers’s possible layouts for the OR.339 aircraft included an investigation in late 1958 into wingtip and under-wing engines, though neither the final Type 571 nor P.17 submissions had included such features. The primary attraction of this idea was that the wing would not need to be as stiff, and could thus be lighter, and more room would be freed within the fuselage for fuel. However, performance would generally be lower, and the result of losing an engine during take-off was a big concern. To improve the adverse-yaw situation with an engine out, the engines would need to be moved further inboard from the tips, introducing further performance penalties and interfering with the tailplane. It was clear that this layout was simply leading them towards a ‘pointy Canberra’, and thus it again led to a dead end. This sort of work did show that, despite supposedly beginning to co-operate with each other, Vickers and English Electric were still needlessly duplicating effort. In this instance, English Electric had looked at underwing engines and discarded the idea back in 1957. Much of its detailed work and reasoning behind discarding this layout was freely available in the P.17 brochure, yet was not referred to at all in Vickers’s work

  On 28 October 1958 officials from the MoS had visited Weybridge for a meeting about revising the requirement for take-off performance. Vickers’s original plan for a single-engine aircraft with miniaturized, or condensed, equipment had been changed at Ministry request in May 1958 to concentrate on the larger twin-engine aircraft, but retaining the equipment miniaturization; the ‘condensed twin’. With an apparent excess of fuel and engine power on this aircraft, this seemed a good opportunity to take advantage of the improved performance available, which Vickers had originally suggested could be taken as 30 per cent increase in range. However, with the tactical desirability of dispersing forces to protect them from a pre-emptive nuclear strike, and many hundreds of relatively short airfields scattered around the world, a reduction in takeoff distance was preferable. Additionally, the surfaces of many of these strips would only be adequate for an aircraft using suitable low-pressure tyres. Previous proposals to GOR.339 all had such high-pressure tyres that these airstrips would be unavailable to them. The ‘condensed twin’ could become a ‘STOL twin’ if given more wing area and lower tyre pressures, bringing its airfield LCN down to the numbers required by poorer-quality airstrips. The meeting ended with agreement to revise the specification. For the 1,000nm sortie the take-off distance would now be 1,300yd (1,190m); for the 500nm ‘Army sortie’ (300 miles (480km) at sea level economic cruise, then 200 miles (320km) to the target at Mach 0.9M, carrying a light load of two Bullpup missiles for a short take-off roll of no more than 650yd (595m)), it would be 600yd (550m); tyre pressure would be between 70 and 80psi, giving an LCN of less than 20. The Air Staff had been keen to get the aircraft’s maximum speed increased from Mach 1.7 to Mach 2 as well, and Vickers was keen to oblige, successfully getting this added to the OR. ‘Mach 2 from a cabbage patch’ was born.

  When personnel from the Air Ministry visited English Electric in November 1958 to discuss the P.17 in some detail, they found out just how much effort English Electric had been putting into the project. Some 200 people had been working on the studies since 1956, and windtunnel test results, a mock-up and a simulator were already in place. English Electric was unhappy with how little notice the RAE had taken of its work on gust response, and pointed out that its design was far superior to the Type 571 in this respect and many others; and English Electric was stunned to discover that Vickers had yet to carry out any serious windtunnel work on its design. In fact it soon became clear that English Electric’s detailed work on aerodynamics had put it way ahead on this score, though Vickers’s work on systems swung the balance back when it came to considering the aircraft as a complete weapons system. Another meeting with the Air Ministry on 26 November prompted revival of the idea of a joint RAF/RN type to OR.339, and further time and effort would be wasted on this nonstarter, in which the Admiralty was simply not interested.

  The Vickers-Armstrongs Type 571 with tip-mounted engines, October
1958. Damien Burke

  On 11 December 1958 Air Chief Marshal Sir Claude Pelly, Controller (Air), visited Weybridge for a presentation of OR.339 work carried out so far. Vickers let him know that agreement with English Electric had been reached in many areas (glossing over the many more where they were at loggerheads), and that the company was prepared to guarantee a timescale for the project, even though it knew at this point that it had insufficient manpower to cover the necessary design work, which would lead to English Electric’s burden being somewhat higher than it should have been, based on the work being split fifty-fifty.

  Combining the P.17A and Type 571

  With the official announcement on 1 January 1959 that Vickers and English Electric were to build the new bomber, no time was wasted. Personnel from Vickers visited English Electric at Warton on the same day to discuss the wing. Given the requirement for the aircraft to spend so much time at high speed at low level, English Electric had taken care to choose a planform and area that would keep fatigue of both airframe and crew to a minimum, while offering the best compromise between that and the short take-off and landing performance requirements. English Electric had therefore decided upon a low-aspect-ratio delta planform for the P.17’s wing by early 1957, after a great many theoretical studies and windtunnel tests. It had stuck with this after investigation of many different alternatives and, with its experience of the P.1 wing, firmly believed the choice had produced absolutely the only viable wing design. Vickers’s higher-aspect-ratio wing was optimized almost entirely towards the STOL requirement, and English Electric could barely believe that Vickers had paid so little attention to gust alleviation and crew comfort. Vickers considered its wing to give a small but worthwhile improvement in combat radius compared with the P.17 wing, based on aerodynamics alone, and much improved take-off performance. English Electric, naturally, believed the opposite. When English Electric reworked its calculations using Vickers’s assumptions and wing drawings, it reluctantly agreed that the Vickers wing did show slight superiority in combat radius. However, the P.17’s delta wing could carry so much more fuel, about 4,000lb (1,800kg) worth, that this would contribute to a further superiority of 20 per cent in combat radius, with which the Vickers wing could not compete. Vickers further believed that English Electric had underestimated the weight of its wing by a significant margin, but Vickers based this belief on analysis of B-58 Hustler wing construction data, and the B-58 was famously ‘built like a navy destroyer’, with high structural density. English Electric was curious to find out on what basis Vickers had calculated the P.17 wing weight. On finding out, and then discovering that Vickers did not believe the same technique applied to calculating the weight of its own wing, English Electric was somewhat unimpressed! Vickers did at least agree that transonic handling would be better with the delta wing. However, despite the P.17 wing’s obvious overall superiority, Vickers refused to shift on the subject, as it could not see that the delta was ever going to meet the STOL requirement.

  The new STOL requirement had come as an unwelcome addition to English Electric, as the company had thought STOL and VTOL a dead subject ever since Shorts had been unceremoniously shut out of the GOR.339 project. The P.17 simply could not meet the take-off distance requirements. By contrast, Vickers’s condensed twin could do so, even if it was forced to use English Electric’s wing. Neither company knew it at this stage, but the aircraft’s final configuration would effectively mate the P.17 wing with the Type 571 fuselage, though both wing and fuselage would end up looking rather different from those in the initial general-arrangement drawings.

  The Vickers-Armstrongs Type 571 (large) revised, with anhedral, December 1958. Damien Burke

  Members of the TSR2 design team take a break on part of the old racing-track banking at Weybridge. Brooklands Museum

  Item

  Type 571

  P-17a

  Forward-looking radar

  Rear view or rear viewing system for navigator OR.946 pilot instrumentation

  24in scanner based on APG-53, similar to AI.23

  Nil; contrail detection via air data computer

  Limited space; HUD for primary displays, and suggested use of ‘futuristic’ CRTs

  32in scanner based on Blue Parrot; more space provided

  TV camera in tail; large display in navigator’s compartment Conventional instrumentation space available

  Cockpit space

  Similar to that of Scimitar

  Wider and longer after poor reception of P.1 cockpit size

  Nose gear

  Low-pressure tyres, forward retracting

  High-pressure tyres, rearward retracting

  Side-looking radar location

  Lower sides of nose

  Top corners of fuselage

  Equipment bay

  90cu ft (2.55cu m); large access doors either side

  225cu ft (6.37cu m); access panel below fuselage

  Primary reconnaissance cameras

  Bomb-bay-mounted reconnaissance pack

  Permanent fit in dedicated bay

  Fuel system

  Integral tanks, fuel used as heat sink as heat sink

  Bag type preferred but would accept integral; fuel not used

  Bomb bay location

  c.g.

  9ft (2.74m) forward of c.g.

  Engine installation

  Inserted/withdrawn horizontally via rear tunnel

  Inserted/withdrawn vertically via undercarriage bays

  Intakes

  Variable vertical ramp on inboard wall aft of fixed ramp; auxiliary intake doors; forward of wing leading edge

  Rectangular wedge style; aft of wing leading edge

  Tailplane

  All-moving

  Conventional

  Fin

  Large, all-moving

  Small, fixed. Too small, insufficient yaw stability, so ventral fins also required, folding away when on ground

  Braking

  Wheel brakes

  Wheel brakes, air brakes, braking parachute

  Thrust reversers

  No

  Possibly

  NOTE: Highlighted items would appear in the final TSR2

  English Electric personnel visited Weybridge on 7/8 January to discuss the fuselage. Both the Type 571 and P.17 fuselages would need to be widened or bulged to accommodate the low-pressure tyres and long-stroke oleos required by the rough-field capability, and the P.17 much more so. It was already quite wide where the undercarriage, wing, engines and bomb bay were all located in the same plane. On the plus side, the P.17’s long nose, once extended to make room for a longer nose leg, balanced the delta wing nicely, and the greater fuselage width meant that there was room further aft for fuel. Needless to say, the respective summaries of English Electric and Vickers showed differences of opinion, but the main differences were as shown in the box above.

  Each company had approached the fuselage design from a very different direction. Vickers was working towards a total ‘weapons system’ concept which, hand-inhand with its miniaturization philosophy, meant that it was providing limited space for equipment which it expected to be designed as part and parcel of the overall project, and thus fit into the spaces provided, and concentrated more on the type and provision of the various items of equipment, rather than where it would all actually go. Experience with the Scimitar had also showed that view over the nose on landing was an important design consideration, especially in concert with the recently introduced STOL requirement. (The Scimitar’s nose was redesigned after early carrier trials found that the view over the nose was hampering the pilot’s ability to carry out a safe approach.)

  In contrast, English Electric had been burdened by providing limited equipment space in its P.1 fighter project, which had led to access and maintainability problems (these dogged the P.1/Lightning throughout its service career), and the P.17’s fuselage was designed with more than ample room for various bits of equipment. Its nose was longer owing to the need to provide more
room for the radar, though this made the view on approach to landing noticeably worse. The space allocated for equipment was far too great in Vickers’s opinion, as much of it was going to be left practically empty. (English Electric would later investigate reducing the size of the fuselage by reducing the room set aside for hauling fresh air about, and finally agreed that if the customer was happy to pay for specialized equipment, it could provide restricted equipment space to match.) In return, English Electric criticized Vickers’s lack of provision for cable runs and electrical distribution panels, again feeling that detail work on the systems side was lacking. The English Electric equipment bay, size notwithstanding, was the better design for accessibility and weather protection for ground crew and contents. The side doors of the Vickers design meant that the equipment would be vulnerable to inclement weather, and lighting in the area would be visible from some distance; not ideal for dispersed operations.

  Placement of fuel within the fuselage was another bone of contention. English Electric recoiled from the idea of fuel in close proximity to the engine (Vickers had drawn a saddle tank above the engines) because of fire risks. English Electric also continued to shy away from too much work to satisfy the STOL requirement, on the basis that the aircraft would spend most of its life operating from normal airfields, never needing the STOL capability (history has certainly proved this point time and time again since then). English Electric had also designed a fin that gave limited yaw stability, which it proposed to improve initially by means of a pair of small ventral fins, enlarging these by 50 per cent when windtunnel tests found even these insufficient. Vickers, naturally, had different ideas when it came to the fin, and wanted an all-moving surface, which it generally considered superior to the conventional fin and rudder for supersonic aircraft owing to reduced vulnerability to aeroelastic effects and larger yaw control power. In combination with an auto-stiffening system (a system sensing side-slip and applying small fin movements to counteract it), such a fin could be smaller than would otherwise be the case, though there were concerns that failure of the auto-stiffener could result in loss of control, and of the aircraft. Additionally, the power controls would need to be beefed up considerably, and the manufacturer slated for that job, Elliotts, had already requested that control surfaces be kept as small as possible. Elliotts was out of luck on that score, and the all-moving fin was pencilled in as part of the design, despite resistance from English Electric.