The Westland Sea King HAR3 entered RAF service in 1978 and the 3A in 1996; both marks of aircraft are used in the Search and Rescue (SAR) role. The aircraft are operated from six locations around the UK, with each location supporting two aircraft. There is also a detachment of two HAR3s providing SAR cover in the Falkland Islands. The SAR squadrons provide 24-hour cover around the UK and the Falkland Islands throughout each year. Each squadron maintains a 15-minutes readiness state during daylight hours and a 45-minutes readiness state during the hours of darkness.
For the search aspect of its role, the Sea King is able to operate to precise navigational standards. For its rescue role, the aircraft is equipped with a hydraulically-operated main rescue hoist, an electrically-operated emergency rescue hoist and electrical connections suitable for powering medical equipment such as incubators. The SAR fleet of Sea Kings are fitted with a video/infrared detection pod, which is similar to the equipment used by police helicopters, to help search for casualties. All SAR crews are trained to operate using night-vision goggles over unfamiliar terrain. The standard SAR crew is made up of four members: two pilots, one of whom is the aircraft captain, a radar operator who acts as the winch operator at the rescue scene and a winchman, normally trained to paramedic standard, who will supply immediate first-aid and recovery services at the rescue site.