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A Typical Engagement.

Any potential target would normally first be detected by the ship's air search radar, the Type 965. This radar incorporated an Identification-Friend-or-Foe (IFF) interrogator; the lack of a correct response would result in the operator passing the range and bearing to the 992Q operator. This radar is the high precision target tracking and indicator which gives an accurate range and bearing to the ship's Action Data Automation (ADA) fire-control system. The (height finding) Type 278 radar is then brought onto the correct bearing in order to determine the target's height.

If the target is to be engaged, one or more missiles will be brought to a state of readiness in the ready-use magazine; once the electronics are warmed-up, power is continuously supplied to the missle through the support rails, and the 3-dimensional co-ordinates fed to the Type 901 fire control radar. Because this radar generated a very fine beam it would normally be given an area to search; on locating the target it would track it. The missile would be loaded onto the launcher, and the launcher traversed onto an appropriate bearing; while on the launcher the missile is supplied with electricity and cooling air through the Launcher Electic and Air Plug (LEAP). When the firing command is given the missile's gas generator starts up and the exhaust drives a turbo-alternator (which provides electric power) and a hydraulic pump. As soon as the missile's internal power is stabilised the launcher retracts the LEAP and the boost motors are fired. The four motors provide about 15 tons of thrust each, and accelerate the missile to between Mach 2 and 3 in three seconds! The boost motor nozzles are were angled sideways to make the missile roll during the boost phase; this was intended to counter any uneven thrust from them. After 3.3 seconds the boost motors burn out and the drop in acceleration triggers the release gear. The boost motors fall away and the sustainer motor fires, its efflux blows off the control surface clamp set which allows them to move. The guidance receiver and beacon radio switch on, and the former uses the roll stabilisation gyro to stop the missile's rotation; this normally takes about two seconds. The guidance receiver then gathers the missile into the centre of the beam, after this it switches on the time and range unit (TRU) which modulates the output of the beacon radio which enables the fire control system to accurately measure the missile's range. When this modulation is detected the type 901 radar switches from gathering to guidance mode, this typically happens at around 12 seconds after launching.

The missile then continues to ride up the beam to the target. When the missile is 1000 yards short of the target the 'arm' command is transmitted. This causes the Safety and Arming Unit (SAU) to make the final connection between the fuze and warhead. When the fuze detects a sufficiently 'hot' source (which could be the leading edge of an aircraft's wing), it detonates the warhead. This flicks a hoop of hardened steel rod out into a 70 foot diameter circle, which is quite capable of cutting through an aircraft's structure. In the case of a 'cold' target the warhead can be detonated by a command signal.

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Last updated: 23rd August 2012.