The Wasp was a small shipboard gas turbine powered anti-submarine helicopter. Produced by Westland Helicopters, it came from the same P.531 development programme as the British Army Westland Scout. Its design was a response to the Royal Navy requirement for a helicopter small enough to land on the deck of a frigate and yet still carry a potent payload of two homing torpedoes. The increased range at which the submarine threat could be detected led to the need for “Manned Torpedo-Carrying Helicopter” (MATCH). Contemporary shipboard weapons did not have the necessary range so the helicopter effectively took the weapon to the adversary before being instructed on where and when drop it. Unlike the larger Wessex, the Wasp had no sonar capacity and so was limited to working in partnership with its parent ship, with other ships or other ASW units.
The first prototype Saro P.531 flew on 20 July 1958 with a pre-production order for two of what were originally called Sea Scouts being placed in September 1961. Following trials of a number of undercarriage designs, the first flight of the pre-production Wasp took place on 28 October 1962. Full production soon commenced, 98 in total being procured for the RN. The Wasp was successfully exported to Brazil, the Netherlands, Indonesia, Malaysia, New Zealand and South Africa. 133 aircraft were built in total.
The Wasp was essentially a Scout modified to be fit for Navy purpose. Differences included folding fuselage and rotors as well as its unique 4-wheeled caster style undercarriage that allowed the aircraft to be finely manoeuvred on small, pitching flightdecks. Although small, the Wasp was a versatile and effective aircraft for short range transport and casualty evacuation as well as its primary anti-submarine role. Its success is attested by the fact that its service career lasted until its withdrawal in 1988. Its most notable success was during the Falklands War when Wasps damaged the Argentinian submarine ARA Santa Fe and forced it the crew to abandon it and surrender to British forces. It was withdrawn from service when the last of the Type 12 Rothesay class frigates was decommissioned and was replaced by the Westland Lynx.