abort_takeoff: BAC TSR-2, British Govt.'s Blunder

The British Aircraft Corporation TSR-2 was an ill-fated Cold War strike aircraft developed by the British Aircraft Corporation (BAC) for the Royal Air Force (RAF) in the early 1960s. The TSR-2 was designed to penetrate a well-defended forward battle area at low altitudes and very high speeds, and then attack high-value targets in the rear with close-in bomb runs and precision drops. The TSR-2 included a number of advanced features that made it the highest performing aircraft in this role, yet the programme was controversially cancelled in favour of the General Dynamics F-111, a procurement that itself was later cancelled.

“	All modern aircraft have four dimensions: span, length, height and politics. TSR-2 simply got the first three right.	”
	— Sir Sydney Camm

The mission

The envisioned "standard mission" for the TSR-2 was to carry a 2,000 lb (900 kg) weapon internally for a combat radius of 1,000 nautical miles (nm) (1,850 km). Of that mission 100 nm (185 km) was to be flown at higher altitudes at Mach 1.7 and the 200 nm (370 km) into and out of the target area was to be flown as low as 200 feet (60 m) at Mach 0.95. The rest of the mission was to be flown at Mach 0.92. If the entire mission were to be flown at the low 200-ft altitude, the mission radius was reduced to 700 nm (1,300 km). Heavier weapons loads could be carried with further reductions in range.

Extensions to the TSR-2's range were planned to be made by fitting external tanks — one 450-Imperial gallon (2,000 L) tank under each wing or one 1,000 Imperial gallon (4,500 L) tank carried centrally below the fuselage. If no internal weapons were carried, a further 570 Imperial gallons (2,600 L) could be carried in a tank in the weapons bay.

Planned flight profiles - as of 3rd December 1963.

It was also planned to be able to equip the TSR-2 with a reconnaissance pack in the weapons bay which, coupled to the aircraft's capable sideways looking radar (SLR), would have turned the aircraft into a formidable "recon" asset not unlike the contemporary North American RA-5C of the United States Navy.

Design

TSR-2 prototype XR219 on its maiden flight

English Electric, manufacturer of the Canberra, and Vickers-Armstrongs had been judged to have made the best submissions for GOR.339. The two companies combined their ideas for the specification and put forward their joint design with a view to an aircraft flying by 1963. No order was forthcoming, and by the time the Ministry had made a decision the various companies had been amalgamated as the British Aircraft Corporation in 1960. EE had put forward a delta winged design and Vickers a swept wing on a long fuselage. The EE wing, born of their greater supersonic experience, was judged superior to Vickers, while the Vickers fuselage was preferred. In effect, the aircraft would be built 50/50: Vickers the front half, EE the rear.^[1]

The design was a large aircraft, to be powered by two Bristol-Siddeley Olympus afterburning turbojets, with a large shoulder-mounted slab-wing with down-turned tips, an all-moving swept tailplane and a large all-moving fin. The engines were a development of those used in the Avro Vulcan, and would later be developed further for Concorde.

The design featured blown flaps across the entire trailing edge of the wing to achieve the short takeoff and landing requirement, something that later designs would achieve with the technically more complex swing-wing approach. Roll control was by differential movement of the tailplanes, i.e., tailerons. The aircraft featured some extremely sophisticated avionics for navigation and mission delivery — far ahead of anything else available at the time — which would also prove to be one of the reasons for the spiralling costs of the project. Some features, such as forward looking radar (FLR) for terrain clearance, side-looking radar for mapping and the sophisticated autopilot, only became commonplace on military aircraft later.

The wing loading was high for its time, enabling the aircraft to fly at very high speed and low level with great stability without being constantly upset by thermals and other ground-related weather phenomena. This in turn made the innovative terrain clearance and autopilot system feasible.

There were considerable problems with realizing the design. Some contributing manufacturers were employed directly by the Ministry rather than through BAC, and the Ministry itself took on design tasks, with the usual long deliberations and meetings typical of civil servants.

Specifications

General characteristics

Crew: 2
Length: 89 ft ½ in (27.12 m)
Wingspan: 37 ft 1¾ in (11.27 m)
Height: 23 ft 9 in (7.24 m)
Wing area: 702.9 ft² (65.3 m²)
Empty weight: 54,750 lb (24,834 kg)
Loaded weight: 79,573 lb (36,169 kg)
Max takeoff weight: 102,200 lb (46,357 kg)
Powerplant: 2× Bristol-Siddeley Olympus BOl.22R (Mk. 320) turbojet
- Dry thrust: 19,610 lb (87.23 kN) each
- Thrust with afterburner: 30,610 lbf (136.7 kN) each

Performance

Maximum speed: Mach 2.15
Range: 1,150 (1,850 km)
Service ceiling: 54,000 ft (16,459 m)
Rate of climb: 50,000 ft/min^{[citation needed]} (16,000 m/min)
Thrust/weight: 0.77

Armament

Internal weapons bay, 20 ft (6 m) with (initially) 1 Red Beard 15kt nuclear weapon or as intended 2 x OR.1177 300kt nuclear weapons (cancelled) or 6 x 1,000 lb (450 kg) HE bombs. Final designed normal load in nuclear role of 4 x WE.177A nuclear weapons, two side-by-side in weapons bay, two on external underwing stores pylons.