Hawker Siddeley SRAAM

Taildog/SRAAM
SRAAM mockup at Royal Air Force Museum Cosford
Type	Short-range air-to-air missile
Place of origin	United Kingdom
Service history
Used by	Experimental programme only
Production history
Manufacturer	Hawker Siddeley
Specifications
Weight	ca. 70 kg (150 lb)
Length	2.75 m (9 ft 0 in)
Diameter	165 mm (6.5 in)
Wingspan	ca. 320 mm (13 in)
Operational range	250 m – 2 km
Guidance system	Infra-red
Steering system	thrust vectoring
Launch platform	aircraft

The Short Range Air-to-Air Missile, or SRAAM, was an experimental British infrared homing ("heat seeking") air-to-air missile, developed between 1968 and 1980 by Hawker Siddeley Dynamics. It was designed to be very manoevrable for use at short range in a dogfight situation. SRAAM was unusual in that it was launched from a launch tube instead of being attached to a launch rail, allowing two to be carried on single mounting point.

Although initially intended to replace the AIM-9 Sidewinder, it was downgraded to a technology demonstrator program in 1974. Between 1974 and 1977, several SRAAM missiles were launched in tests. In 1980, the knowledge gained from the SRAAM project became the British contribution to the multinational ASRAAM missile project.

Early infrared homing missiles had two limitations that made them difficult to use in combat situations. The first was that the seeker was relatively insensitive and required large, hot sources to reliably track a target. In practice, this meant the engine of the enemy aircraft had to remain visible to the missile though the shot. The other was that the seeker had a limited field of view (FOV), meaning it could only see the target if it was in front of the missile. This meant it was possible for the target to escape by flying at right angles to the missile, maximizing its angular velocity relative to the seeker.

These limitations were made clear during the Vietnam War, when early missiles like the AIM-4 Falcon and AIM-9 Sidewinder had success rates on the order of 9 and 14%, respectively. Much of this was due to the fact that pilots had been trained to approach using radar or ground-controlled interception, which placed the enemy aircraft somewhere in front of them, but not necessarily flying in the same direction. In these situations, the seeker might see the target's engine and send the growling signal that indicated lock-on, but would fail to track when fired because the target would move out of the FOV in the time while the missile was flying off the mounting rail.