TSR2
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English Electric P.1B XA847 in flight near Warton. Compared with the earlier P.1, the P.1B had gained the familiar circular intake with radar bullet centrebody, and is seen here flying ‘clean’ before the addition of the belly fuel tank. via Warton Heritage Group
By February 1957 the requirement was solidifying into a primarily low-altitude-penetration concept, though Bomber Command wanted to retain high-altitude capability. The Royal Aircraft Establishment (RAE) had been brought in to rough-out a baseline design that could be used to evaluate any submissions from industry. A number of studies had also been carried out of aircraft of interest, such as the Saunders-Roe F.177D (rocket fighter) and Fairey ER103 (the Fairey Delta 3 fighter), both submissions to OR.329 (an all-weather interceptor requirement), to see if they had any possibility of being used in the ground-attack role, and also of a Short Brothers design for a VTOL low-level strike aircraft.
English Electric also completed project report P/103, entitled ‘Possibilities for a multi-purpose Canberra Replacement – Aircraft Project P.17’. This summarized the impressive success of the Canberra, touched briefly on the fact that, despite its many versions, the interceptor version had never been fully developed, addressed the question of whether manned aircraft were still required in the ballistic-missile era and answered that with a firm ‘yes’. Missiles were inflexible, and just one part of a deterrent strategy. Being able to reconnoitre and strike accurately at enemy headquarters, missile bases, aerodromes, etc., was all part of the deterrent, and there seemed still to be a requirement for a manned aircraft ‘in the tradition of the Canberra’. Keeping development costs reasonable by using Canberra and P.1 experience, and producing an aircraft of maximum flexibility would be the key, ensuring foreign sales and a reduction in the cost to the RAF. The P.17 was then described. At this point the P.17 had obvious P.1/ Lightning inheritance, with a similar tailplane and fin and a delta mainplane that was effectively the Lightning mainplane with the area between the trailing edge of the wingtip and the fuselage filled in. The fuselage, however, bore no such similarities, being much longer, with side-by-side engines and quarter-cone intakes hidden under the wings. Unsurprisingly, given the aircraft’s P.1 ancestor, English Electric mentioned the possibilities that it would have as a fighter with long endurance (30min at Mach 1.6 instead of 5min for the P.1). In what would become a common theme, the company also pointed out that keeping a multi-role strike aircraft affordable would require the use of much off-the-shelf equipment, rather than specifying masses of exotic new kit, such as terrain clearance radar. The various strike, interdiction and reconnaissance missions could be carried out by differing equipment packs fitted in a large bomb bay; cameras, cannon, etc.
Interim submissions
In March 1957 the first draft of the GOR was also passed to de Havilland, Vickers, the Hawker-Siddeley Group and Blackburn, though Handel-Davies at the MoS was already concerned that the mix of low-level and high-altitude use, plus huge combat radius, was going to lead to a very large aircraft. Each firm duly submitted proposals to upgrade some of its existing aircraft to provide interim types to satisfy at least some aspects of the GOR. De Havilland offered a developed DH110 (Sea Vixen) and Vickers offered a developed N.113 (Scimitar). Hawker followed up with a proposal of its own based not upon an existing type, but upon one then in early development, the P.1121. The Admiralty had also raised the question of the RN’s upcoming new strike aircraft. When this submission arrived in April 1957 it turned out to be, to the RAF’s displeasure, Blackburn’s B.103 again, though this time Blackburn submitted a brochure containing not only the standard B.103 but also a slightly developed variation of it. English Electric’s P.18 was also briefly looked at, but not seriously considered. It is worth describing these four early submissions (plus English Electric’s P.18), even if they were only regarded as interim solutions to GOR.339, as they exposed attitudes that would have long-term consequences.
A general-arrangement drawing of the Blackburn B.103A of April 1957. Damien Burke
Blackburn and General Aircraft B.103 / B.103A
Blackburn, for the second time in two years, submitted its polished and detailed B.103 brochure, putting forward the standard B.103 as before plus the B.103A, a developed version. The B.103 was destined to satisfy Naval Air Staff Target No. 39, abbreviated as NA.39, which was also the designation the aircraft was widely known by. The NA.39 was a carrier-borne naval strike aircraft primarily designed to deliver a nuclear weapon against a Soviet warship at sea or in inshore waters, or perhaps against a well-defined shore target. It had to be tough and it had to be capable of penetrating the formidable defences of a Soviet warship group. It was no wonder Blackburn thought it a good fit for the RAF’s requirement for a tactical bomber.
For the standard B.103 the normal takeoff weight would be 40,000lb (18,000kg), though an overload condition with two externally carried 300gal (1,365L) fuel tanks, full internal fuel and a Target Marker Bomb would bring it up to 45,000lb (20,000kg). The NA.39 had originally been intended to carry a pair of underwing missiles fitted with the Red Beard warhead, missiles named Green Cheese. Never let it be said that nuclear war is an entirely humourless business!
Leading Particulars: Blackburn B.103
Length
61.5ft (18.75m)
(51ft (15.5m) folded)
Height
16ft (4.87m)
(17ft (5.18m) with wings folded)
Wing span
42.5ft (12.95m)
(20ft (6.09m) folded)
Wing area
500sq ft (46.45sq m)
Wing aspect ratio
3.58
Tailplane span
14.2ft (4.33m)
Tailplane area
75sq ft (6.97sq m)
Tailplane aspect ratio
2.7
Engines
2 × 7,000lb (32,000kg)
s.t. Gyron Junior PS43
Max speed
640kt (740mph; 1,185km/h)
at sea level, Mach 0.98 at
30,000ft (9,000m)
Empty weight
22,290lb (10,115kg)
Max AUW
46,000lb (20,865kg)
Blackburn B.103 production components. The design was broken down into components small enough to be readily transportable by road between the company’s Brough and Dumbarton works or those of subcontractors. Most of the aircraft was to be of conventional construction, just the wings and tail surfaces being milled from solid alloy billets with integral stiffeners. BAE Systems
With a full load of fuel and the means to mark a target to bits, the NA.39’s combat radius would be 650 miles (1,050km) (or 725 miles (1,170km) if 400gal (1,820L) external tanks were fitted). The aircraft was basically subsonic, able to cruise at Mach 0.85 with bursts at Mach 0.94, and to just nudge past Mach 1.05 in a dive. Take-off performance on a normal runway rather than an aircraft carrier would be in the order of 1,650yd (1,500m) under standard atmospheric conditions, boundary layer control by blowing forming an essential part of the aircraft’s take-off and landing performance. It is noteworthy that this performance, apart from the inability to carry out a supersonic fighter evasion sprint or tool along at high altitude, waiting to be blown apart by a missile, pretty much met all of the needs of the first OR drawn up for a Canberra successor.
A crew of two operated the aircraft, which had a Blue Parrot search and ranging radar capable of picking up discrete targets such as ships at sea or large buildings on the shore and a Yellow Lemon Doppler navigation system. The accuracy of this system was not good enough on its own, and visual references and map reading would be an essential adjunct to the Doppler. Thus attacking a target at night or in poor weather would be a difficult, if not impossible, task. An internal bomb bay with a rotating door could accommodate the Target Marker Bomb or four 1,000lb HE bombs, with additional capacity under the wings for further bombs or rockets (though the latter would result in considerable reductions in range). The aircraft would be capable of a reconn
aissance role by carrying a battery of five F.95 cameras facing in various directions and having various focal lengths, or a single FX.100 night camera with 200 flash cartridges. Blackburn was predicting a Controller (Aircraft) (CA) release date of 1960 for the NA.39, and expected to be able to begin deliveries to the RAF in 1961. The cost per aircraft would be £0.5 million, and no additional research and development would be necessary as it was already well under way for the RN.
The B.103A was to be a de-navalized version more suited to RAF needs. Wing folding would be deleted, providing an unbroken wing with more room for internal fuel. An extension to the fuselage behind the cockpit would accommodate extra fuel, and the existing rear-fuselage tanks would be enlarged to balance things out (this extension was later incorporated into the standard NA.39). An improved Gyron Junior engine with 10 per cent more static thrust would be fitted. All of these changes gave the aircraft a 300gal (1,365L) increase in internal fuel, bringing take-off weight up to 48,000lb (20,000kg) and combat radius to 850 miles (1,370km), with the ability to carry all the weapons and reconnaissance kit that the standard B.103 could do, with the addition of a pair of F.96 cameras and eight 8in photo flashes. The all-important take-off run would unfortunately be extended by 50yd (46m) to 1,700yd (1,550m). The additional research and development (R&D) necessary for this version was expected to cost in the order of £5.5 million (including five development batch aircraft at £0.75 million each) and require an additional two years of design effort (to be run in parallel with existing B.103 work, hopefully putting deliveries no later than 1961/1962).
Needless to say, a minor variation to an aircraft the RAF had not wanted two years previously did not go down too well, of which more shortly.
De Havilland Aircraft Company Developed Sea Vixen
De Havilland’s existing Sea Vixen was entirely unsuitable, with a ridiculously inadequate 175-mile (280km) combat radius at low level and an expected short fatigue life in these conditions. It was, after all, designed to be a medium- to high-level interceptor, and had relatively low wing loading. However, de Havilland submitted a proposal for a development of the Sea Vixen, termed a ‘Tactical Bomber and Photographic Reconnaissance Aircraft’, suitable for both carrier- and land-based operations. Compared with the Sea Vixen this version would have a 6.75ft (2.05m) nose extension (making room for an additional 850gal (3860L) of fuel), a repositioned nose fold (so it could still fit within existing carrier deck lifts), permanent wingtip tanks (with slightly shorter wings so that the overall span remained identical), additional fuel tanks within the wing near the tips, and increased capacity for the existing outboard wing tanks. Measures to improve take-off and landing performance consisted of extra droop on the wing leading edge inboard of the existing wing fence, flap blowing, a larger elevator, a Spectre rocket for take-off assistance and a braking parachute for landing. To deal with the low-level role the structure would be beefed up, using different materials and thicknesses where appropriate (and entailing a complete redesign of the centre fuselage), the navigator/observer would be given a larger window to aid visual navigation, and sprung supports would be introduced for crew seats and instruments. The existing Rolls-Royce RA24 Avon engines could be replaced by the RB133, then under development for the Canberra PR.9, but equally could be left alone. Take-off weight would be 60,000lb (27,000kg) (compared with 40,000lb (18,000kg) for the standard Sea Vixen), with a combat radius of the full 1,000 miles (1,600km) required by GOR.339 if a pair of 250gal (1,140L) drop tanks were carried. Like the B.103, the aircraft would be subsonic at low level, cruising at Mach 0.85 with dashes at Mach 0.95. Above 14,000ft (4,250m), however, it could manage Mach 1.2. The take-off distance would be 1,050yd (960m) with rocket assistance or 1,400yd (1,280m) without, increasing to 1,700yd (1,550m) if the existing RA24 engines were retained. De Havilland expected a fatigue life of up to 1,000 operational hours, more than that of Blackburn’s B.103 or B.103A.
A general-arrangement drawing of the de Havilland DH110 Sea Vixen development of March 1957. Damien Burke
As with the B.103, the two-man crew would be retained, but navigation equipment was improved with Decca, a Ground Position Indicator (GPI, a basic moving map) and Doppler. Beyond Decca ground station range, accuracy would be as limited as that of the B.103. Limited fuselage space allowed only a shallow bomb bay, so a Target Marker Bomb would be only semi-recessed in the belly with around half of the weapon exposed to the airstream, introducing possible thermal issues at high speed and safety issues during take-off and landing (the Vickers-Supermarine Scimitar would be subject to a ban on carrier landing with a Red Beard under the wing because of similarly restricted ground clearance). The small bay could, however, fully accommodate a pair of 1,000lb HE bombs, and two more could be carried on the wing pylons (though with reduced full fuel load). Alternatives included up to ninety-six 2in rockets underwing or twenty-four OR.1099 rockets. In the reconnaissance role the aircraft was to be fitted with a permanent forward-facing F.95 camera in the nose (the airborne interception (AI) radar would not be fitted), with an optional fit of a pair of either F.95 oblique cameras, F.96 day cameras with 24in lenses or F.97 night cameras with 400 photo-flash cartridges.
Leading Particulars: Developed Sea Vixen
Length
59.5ft (18.14m)
Height
11.5ft (3.5m)
Wing span
50ft (15.24m)
(including tanks)
Wing area
611sq ft (56.76sq m)
Wing aspect ratio
4.1
Engines
2 × 13,880lb (6,300kg)
RB.133
Max speed
Mach 1.2 @ 25,000ft
(7,600m)
Empty weight
Not stated
Max AUW
62,080lb (28,180kg)
This photo of a Sea Vixen FAW.1 carrying a Red Beard ‘shape’ gives some idea of the challenges of carrying a bomb of this size on a relatively small strike aircraft. BAE Systems
Work on the existing Sea Vixen was well under way and aiming at CA release by the end of 1958. De Havilland had already started work on a mock-up of the developed version, and claimed it would be able to get it into service by 1960 at a cost of £0.5 million per aircraft, with R&D costs of around £5.5 million (including five development batch aircraft). This was a particularly attractive concept, as the RN could also operate the uprated version, though it would need to keep maximum weights down by launching aircraft with a restricted fuel load, flight-refuelling them once airborne. However de Havilland’s estimates were so optimistic that they raised eyebrows even among a normally sceptical RAF, something no doubt not helped by the RAF knowing of the protracted development period the Sea Vixen had already suffered, albeit due in part to the RAF’s own indecision when choosing between the Javelin and DH110 for their own interceptor needs.
English Electric P.18
English Electric’s P.18 was a minimal modification of its existing P.1B (and internally was described as ‘P.1 LABS version’), given extra fuel capacity (in tip tanks, roughly pencilled in on the only relevant drawing found to date) and carrying a single Target Marker Bomb semi-recessed in the ventral tank. Each tip tank held 100gal (450L) of fuel, extending the basic aircraft’s pitiful combat radius. To try and eke out the aircraft’s endurance, operation of the P.18 would be rather different from its fighter brethren, and take-off and climb would both be performed without the use of reheat and speed limited to Mach 0.9 with the tip tanks still attached. Once these were empty and jettisoned, speed could rise, but only to Mach 1.3. With the aircraft at an all-up weight (AUW) of 37,500lb (17,000kg) its take-off roll would be a whopping 2,000yd (18,290m). Assuming an entirely low-level and subsonic sortie at Mach 0.9, this would result in a combat radius of a mere 190nm (220 miles; 350km), so it was no wonder that English Electric wasted no further time on this idea. It was not seriously considered by the Air Staff either.
Vickers-Armstrongs Aircraft Developed Scimitar
The RAF must have felt under siege, with the third design submitted being a development of yet another naval type, the N.113 Scimitar. In terms of GOR.339 the standard Scimitar would have been pretty useless owing to a miserly 200nm (230-mile; 370km) combat radius when loaded up with full internal fuel, two 150gal (680L) and one 200gal (910L) wing drop tanks and a single Target Marker Bomb under the port wing.
Vickers, however, had been working on an improved version of the Scimitar for the RN even before the type entered service, and had put together a brochure entitled N.113 Developments, covering three major variations. The first was the Type 562, much like the existing Scimitar F.1 but with a new pointed nose radome containing an AI.23 search radar and huge 500gal (2,270L) slipper tanks under the outer wings. The second was the Type 564, similar to the 562 in most ways, but with Blue Parrot radar and Gyron Junior engines instead of RA.24s. The third was the Type 567, a two-seat version of the 564 with side-by-side seating (to keep the length the same and stay within carrier deck lift limits), with optional extra weapons pylons under the wings near the fuselage (thus retaining four pylons for stores use when the slipper tanks were fitted).
Leading Particulars: Vickers Type 565
Length
62.2ft (18.96m)
Height
15.75ft (4.8m)
Wing span
37.2ft (11.34m)
Wing area
485sq ft (45.06sq m)
Wing aspect ratio
2.84
Engines
2 × RA24 Avon