BAC TSR-2

https://en.wikipedia.org/wiki/BAC_TSR-2

The British Aircraft Corporation TSR-2 (for "tactical strike and reconnaissance
2") was a cancelled Cold War strike and reconnaissance aircraft developed by the
British Aircraft Corporation (BAC) for the Royal Air Force (RAF) in the late
1950s and 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 nuclear or conventional weapons. Another
intended combat role was to provide high-altitude, high-speed stand-off,
side-looking radar and photographic imagery and signals intelligence, aerial
reconnaissance. Only one airframe flew and test flights and weight-rise during
design indicated that the aircraft would be unable to meet its original
stringent design specifications. The design specifications were reduced as the
result of flight testing.

The TSR-2 was the victim of ever-rising costs and inter-service squabbling over
Britain's future defence needs, which together led to the controversial decision
in 1965 to scrap the programme. It was decided to order an adapted version of
the General Dynamics F-111 instead, but that decision was later rescinded as
costs and development times increased. The replacements included the Blackburn
Buccaneer and McDonnell Douglas F-4 Phantom II, both of which had previously
been considered and rejected early in the TSR-2 procurement process. Eventually,
the smaller swing-wing Panavia Tornado was developed and adopted by a European
consortium to fulfil broadly similar requirements to the TSR-2.

GOR.339 (General Operational Requirement)

Aware of the changing operational environment, the Ministry of Supply started
work with English Electric in 1955, attempting to define a new light bomber to
replace the Canberra. These early studies eventually settled on an aircraft with
a 2,000 nmi (2,300 mi; 3,700 km) ferry range, Mach 1.5 speed "at altitude" and
600 nmi (690 mi; 1,100 km) low-level range. A crew of two was required, one
being the operator of the advanced navigational and attack equipment. The
bombload was to be four 1,000 lb (450 kg) bombs.

The requirements were eventually made official in November 1956 with General
Operational Requirement 339 (GOR.339), which was issued to various aircraft
manufacturers in March 1957. This requirement was exceptionally ambitious for
the technology of the day, requiring a supersonic all-weather aircraft that
could deliver nuclear weapons over a long range, operate at high level at Mach
2+ or low level at Mach 1.2, with STOL or possible VTOL performance. The latter
requirement was a side-effect of common battle plans from the 1950s, which
suggested that nuclear strikes in the opening stages of war would damage most
runways and airfields, meaning that aircraft would need to take off from "rough
fields" such as disused Second World War airfields, or even sufficiently flat
and open areas of land.

The TSR-2 was to be powered by two Bristol-Siddeley Olympus reheated turbojets,
advanced variants of those used in the Avro Vulcan. The Olympus would be further
developed and would power the supersonic Concorde. The design featured a small
shoulder-mounted delta wing with down-turned tips, an all-moving swept tailplane
and a large all-moving fin. Blown flaps were fitted 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. No ailerons were fitted, control in roll instead being implemented by
differential movement of the slab tailplanes. 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. The EE Chief Test Pilot, Wing Commander Roland Beamont,
favourably compared the TSR-2's supersonic flying characteristics to the
Canberra's own subsonic flight characteristics, stating that the Canberra was
more troublesome.

According to the Flight Envelope diagram, TSR2 was capable of sustained cruise
at Mach 2.05 at altitudes between 37,000 ft (11,000 m) and 51,000 ft (16,000 m)
and had a dash speed of Mach 2.35 (with a limiting leading edge temperature of
140° Celsius). Its theoretical maximum speed was Mach 3 in level flight at
45,000 ft (14,000 m).

The aircraft featured some extremely sophisticated avionics for navigation and
mission delivery, 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), side-looking radar for navigational fixing, only became commonplace on
military aircraft years later. These features allowed for an innovative
autopilot system which, in turn, enabled long distance terrain-following sorties
as crew workload and pilot input had been greatly reduced.

Role
Tactical strike/reconnaissance

National origin
United Kingdom

Manufacturer
British Aircraft Corporation

First flight
27 September 1964

Status
Project cancelled

Number built
3

Over a period of six months, a total of 24 test flights were conducted. Most of
the complex electronics were not fitted to the first aircraft, so these flights
were all concerned with the basic flying qualities of the aircraft which,
according to the test pilots involved, were outstanding. Speeds of Mach 1.12 and
sustained low-level flights down to 200 ft (above the Pennines) were achieved.
Undercarriage vibration problems continued, however, and only in the final few
flights, when XR219 was fitted with additional tie-struts on the already complex
landing gear, was there a significant reduction in them. The last test flight
took place on 31 March 1965.

Although the test flying programme was not completed and the TSR-2 was
undergoing typical design and systems modifications reflective of its
sophisticated configuration, "[T]here was no doubt that the airframe would be
capable of accomplishing the tasks set for it and that it represented a major
advance on any other type."

Costs continued to rise, which led to concerns at both company and government
upper management levels, and the aircraft was also falling short of many of the
requirements laid out in OR.343, such as takeoff distance and combat radius. As
a cost-saving measure, a reduced specification was agreed upon, notably
reductions in combat radius to 650 nmi (750 mi; 1,200 km), the top speed to Mach
1.75 and takeoff run up increased from 1,800 to 3,000 feet (550 to 915 m).

Project cancellation

By the 1960s, the United States military was developing the swing-wing F-111
project as a follow-on to the Republic F-105 Thunderchief, a fast low-level
fighter-bomber designed in the 1950s with an internal bay for a nuclear weapon.
There had been some interest in the TSR-2 from Australia for the Royal
Australian Air Force (RAAF), but in 1963, the RAAF chose to buy the F-111
instead, having been offered a better price and delivery schedule by the
American manufacturer. Nonetheless, the RAAF had to wait 10 years before the
F-111 was ready to enter service, by which time the anticipated programme cost
had tripled. The RAF was also asked to consider the F-111 as an alternative
cost-saving measure. In response to suggestions of cancellation, BAC employees
held a protest march, and the new Labour government, which had come to power in
1964, issued strong denials.

However, at two Cabinet meetings held on 1 April 1965, it was decided to cancel
the TSR-2 on the grounds of projected cost, and instead to obtain an option
agreement to acquire up to 110 F-111 aircraft with no immediate commitment to
buy. This decision was announced in the budget speech of 6 April 1965. The
maiden flight of the second development batch aircraft, XR220, was due on the
day of the announcement, but following an accident in conveying the airframe to
Boscombe Down, coupled with the announcement of the project cancellation, it
never happened. Ultimately, only the first prototype, XR219, ever took to the
air. A week later, the Chancellor defended the decision in a debate in the House
of Commons, saying that the F-111 would prove cheaper.

Aeronautical engineer Sir Sydney Camm (designer of the Hawker Hurricane) said of
the TSR-2: "All modern aircraft have four dimensions: span, length, height and
politics. TSR-2 simply got the first three right.

To provide a suitable alternative to the TSR-2, the RAF settled on a combination
of the F-4 Phantom II and the Blackburn Buccaneer, some of which were
transferred from the Royal Navy. These were the same aircraft that the RAF had
derided in order to get the TSR-2 go-ahead, but the Buccaneer proved capable and
remained in service until 1994. The RN and RAF versions of the Phantom II were
given the designation F-4K and F-4M respectively, and entered service as the
Phantom FG.1 (fighter/ground attack) and Phantom FGR.2 (fighter/ground
attack/reconnaissance), remaining in service (in the air-to-air role) until
1992.

The RAF's Phantoms were replaced in the strike/reconnaissance role by the
SEPECAT Jaguar in the mid-1970s. In the 1980s, both the Jaguar and Buccaneer
were eventually replaced in this role by the variable-geometry Panavia Tornado,
a much smaller design than either the F-111 or the TSR-2. Experience in the
design and development of the avionics, particularly the terrain-following
capabilities, were used on the later Tornado programme. In the late 1970s, as
the Tornado was nearing full production, an aviation businessman, Christopher de
Vere, initiated a highly speculative feasibility study into resurrecting and
updating the TSR-2 project. However, despite persistent lobbying of the UK
government of the time, his proposal was not taken seriously and came to
nothing.

Specifications

General characteristics
Crew: 2
Length: 89 ft (27.13 m)
Wingspan: 37.14 ft (11.32 m)
Height: 23.77 ft (7.25 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: 103,500 lb (46,980 kg)
Powerplant: 2 × Bristol Siddeley Olympus B.Ol.22R (Mk. 320) turbojet Dry thrust:
22,000 lb (97.87 kN) each
Thrust with afterburner: 30,610 lb (136.7 kN) each


Performance
Maximum speed: Mach 2.35 at 40,000 ft/12,000 m (Mach 1.1+ at sea level)
Range: 2,500 nmi (2,877 mi, 4,630 km)
Combat radius: 750 nmi (860 mi, 1,390 km) ; hi-lo-lo-hi
Ferry range: 2,500 nmi (2,877 mi, 4,630 km)
Service ceiling: 40,000 ft (final specification) (12,000 m)
Rate of climb: 15,000 ft/min (4,575 m/min)
Thrust/weight: 0.59

Armament
Total weapons load of 10,000 lb (4,500 kg); 6,000 lb (2,700 kg) internal and
4,000 lb (1,800 kg) external
Internal weapons bay, 20 ft (6 m) long, with (initially) 1 Red Beard 15 kt
nuclear weapon or as intended 2 × OR.1177 300 kt nuclear weapons or 6 × 1,000 lb
(450 kg) HE bombs. Final designed normal load in nuclear role of up to 4 ×
WE.177 nuclear weapons, two side-by-side or in tandem in weapons bay, two on
external underwing stores pylons, Or
4 × 37-inch (0.94 m) rocket pods or nuclear weaponry on inner pylons only.

Avionics

Autonetics Verdan autopilot modified by Elliot Automation
Ferranti (terrain-following radar and navigation/attack systems)
EMI (Side looking airborne radar)
Marconi (general avionics)
Cossor (IFF)
Plessey (Radio)




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