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SRAAM - Taildog

The Vietnam War experience warned about the need for short range air to air weapons to be developed. The SRAAM was the result of the American experience in Vietnam, and other theaters of operations, where a missile launch was only allowed after the positive visual identification of the target. This showed the need for better short-range air combat weapons as well as a missile capable of withstanding the great accelerations of aerial combat. The technology of the 70's already allowed to develop a missile much more capable than those in operation at the time.

Thus, Hawker Siddeley Dynamics, now MBDA, began a study of a short-range air-to-air missile for research and development. The project was called Taildog in the 1970's being the result of a research called QC.434 for use of thrust vector as the sole source of movement of the missile. The 1969 Blackburn P.146 naval light fighter design would be armed only with the Taildog missile and would be supported by the A.13 aircraft of the P.139 project. The two aircraft were canceled.

Length 2.724m
Diameter 165mm
Speed Mach 3
SRAAM was Hawker Siddeley's third generation air-to-air missile. Under development for the Ministry of Defence, this close combat weapon with thrust vector control could out-maneuver evading targets flying at sub-sonic and supersonic speeds. Visually aimed, SRAAM is guided by a passive infra-red homing system. Small, lightweight, easily fitted to any aircraft, the low-drag SRAAM launcher system contains all its essential services. Originally known as Taildog, the weapon introduced many of the concepts found on today's AIM-132 advanced short-range air-toair missile (ASRAAM). The Sidewinder AIM-9L was chosen to equip the British aircraft in the meantime. SRAAM was responsible for the cancellation of the American XAIM-95 AGILE project, which would also use TVC for high agility.

Hawker Siddeley Dynamics’s Taildog rocket first appeared in the late sixties as a counterweight to maneuverable fighters. It was a revolutionary design at the time that used a controlled thrust vector and could fly to a target with a large angle relative to the current direction of flight of the carrier. Taildog then reincarnated into a Short Range Air to Air Missile (SRAAM) rocket, but even at this early stage, the RAF was considering buying prefabricated Sidewinder or Matra rockets.

By February 1972, the Government decided, subject to a satisfactory outcome of negotiations, to place a contract with Hawker Siddeley Dynamics for project definition of a new missile known as S.R.A.A.M. 75. It was the Government's intention also to equip the Royal Navy with a new anti-ship guided weapon system for use with naval Lynx helicopters. Subject to satisfactory negotiations a contract for project definition will shortly be placed with the guided weapons division of British Aircraft Corporation. This missile is known as CL 834.

After the project definition phase, these two projects would be reviewed in the light of all the circumstances of the time, including the progress and latest estimated cost of the project, and the overall loading of the industry. A decision will then be taken whether or not to proceed to full development. Work in these initial stages of CL 834 and S.R.A.A.M. 75 will occupy important advanced technology resources in the British Aircraft Corporation and Hawker Siddeley Dynamics as well as in other British firms.

SRAAM was the first rocket in the world with a thrust vectoring and air launch using a container with low air resistance. The use of the container allowed to reduce the time of the missile launch at launch at high speeds of the carrier. By 1973, the SRAAM rocket acquired its own name - Mongoose, and somewhere along the line was promoted from SRAAM-75 to SRAAM-100.

IMI Summerfield produced the solid motor with control actuation by Sperry Gyroscope. It used a lightweight twin-tube launcher whose adaptor shoe housed the fire control system. The missile tube had nose doors, which opened during firing then closed immediately to reduce drag. Off boresight capability was 90 degrees.

The rocket had 3 compartments: 1st with infrared homing, safety-actuating mechanism, warhead and electronics, 2nd with engine, 3rd with thrust vectoring and aerodynamic control wheels. The missile is powered by a new single-stage rocket motor developed by the Summerfield Research Station of Imperial Metal Industries, which has carried out some 40 firings of the motor in its definitive form. About half of these tests have included operation of the jet tabs, or semaphores, which provide thrust-vector control (TVC) for maneuvering. By late 1973 SRS was near to freezing the motor design, having fired development motors more than 100 times in various forms. Both Summerfield and the Rocket Propulsion Establishment at Westcott had developed movable nozzles to fit missiles of Sraam size, but neither version was to be applied to that missile for the moment. The electrically operated semaphores used had the advantages of light weight and causing no thrust losses when not in operation, and can effect sufficient thrust-vector displacement (up to about 18°) to cater for demands for rapid angle changes by the missile.

The missile would normally be mounted in a double launcher pack, with a beam between the two launch tubes containing all the fire-control equipment. The installation will be compatible with most existing and projected types of intercepter. On firing, the nose cone of the fully enclosed launch tube opens and the missile emerges, the six sprung fins on the rear body erecting themselves automatically. The fins are mounted on a freely spinning ring to stabilise the missile in flight.

There are no aerodynamic surfaces, lift being provided by the body tube. This, combined with the thrust-vector control system, allows the missile to be slewed rapidly for high-g manoeuvring without the danger of stalling the wings which are normally found on air-to-air missiles. Targets wide on the beam of the carrier aircraft and at short range can thus be attacked more effectively than is possible with present weapons. Sraam is visually aimed, has passive infra-red guidance, and the warhead is detonated by impact or proximity fuzes.

HSD was firmly wedded to TVC rather than aerodynamic surfaces for this type of missile and sees a major development potential for Sraam-type weapons. One possible application is in the short-range ground-to-air role, in much the same way as Sidewinder was adapted to become Chaparral. Sraam is tube-launched and requires very few external connections.

The missile was due to enter service with the Royal Air Force in 1976 and the initial production run is likely to be 1,500 units for the RAF and a further 6,500 for export. The initial testing ground passed in 1973.

Everything went relatively well until the UK government issued the 1974 White Paper on Defense, which brought a significant budget cut. The revolutionary SRAAM has been lowered to the level of just a technology demonstrator. Sraam (Short-range air-to-air missile) was reduced to a technology-demonstration vehicle as part of the British Government's plan to cut defense spending, it was announced in the House of Commons on 31 January 1974. The weapon was until then in the second stage of project definition and was expected to enter service in 1976.

It had been ground-launched several times at the Aberporth test range and the IMI solid-propellant motor, with its semaphore jet tabs for thrust-vector control, had been successfully fired a large number of times. Sraam would now be used to demonstrate techniques which might be applicable to other weapons, and a small number of airborne launches were to take place in 1976. About one-third of the Sraam labor force — 70 men — were transferred to other projects such as UK Sparrow (XJ521) and Undersea Guided Weapon.

The cut-back came at a time when both main competitors for Sraam in the export market, Matra's R.550 Magic and the US Naval Weapons Center's Agile, were forging ahead. Magic would enter service in 1975 with the French Air Force and was believed to have been ordered by three export customers, while fullscale Agile production was expected to be authorised in mid-1975 [didn't happen]. The British Ministry of Defence was previously sufficiently confident of Sraam's sales possibilities to have allocated 6,500 of the initial 8,000-unit planned production run for anticipated export.

The money saved by cutting back Sraam, less than £10 million, was paltry when compared with the estimated $235 million development cost of Agile, which is almost identical to the HSD weapon. Also, the Royal Air Force will now have to buy yet more foreign equipment — or wait until the 1980s for a short-range British weapon. RAF decided to concentrate funding in the program to create the English version of the AIM-7 rocket Sparrow. A small number of SRAAM flight tests were conducted from a Hunter aircraft in 1975. Toward the end of the development phase, Hawker Siddeley Dynamics requested further support from the government, but instead they were notified that RAF and RN would buy AIM-9L Super Sidewinder missiles from the USA.

In April 1977 the UK Government announced at the AIM-9L Sidewinder had been selected for the RAF instead of SRAAM. Asked if it was wise to commit the UK to a weapon nearing the end of its development potential rather than an allnew concept, the then defense secretary indicated that the potential availability in quantity of AIM-9Ls from the USA during a military emergency had been an important factor.

The US Navy's AIM-95 Agile vectored-thrust infra-red (IR) homing missile, in turn, was cancelled by Congress in 1975 because it was considered that the required level of missile performance could be met by advanced versions of Sidewinder. The Advanced Short Range Air to Air Missile (ASRAAM) project was actually a joint project of the US Air Force and the US Navy to search for a replacement for the Sidewinder missiles, it began in 1979.

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Page last modified: 28-04-2019 18:50:12 ZULU