The AgustaWestland AW101 is a medium-lift helicopter used in both military and civil applications. First flown in 1987, it was developed by a joint venture between Westland Helicopters in the United Kingdom and Agusta in Italy in response to national requirements for a modern naval utility helicopter. Several operators, including the armed forces of Britain, Denmark, and Portugal, use the name Merlin for their AW101 aircraft. It is manufactured at factories in Yeovil, England and Vergiate, Italy, licensed assembly work has also taken place in Japan and the United States.
Prior to 2007, the aircraft had been marketed under the designation EH101. The original designation was, in fact, EHI 01, from the name given to the Anglo-Italian joint venture - European Helicopter Industries - but a transcription error changed this to EH101 and the designation stuck.
The AW101 entered into service in 1999 and has since replaced several older helicopter types, such as the Sikorsky Sea King, performing roles such as medium-sized transport, anti-submarine warfare, and ship-based utility operations. The Royal Canadian Air Force (RCAF) operates a variant of the AW101, designated CH-149 Cormorant, in the air-sea rescue role.
Civil operators also use AW101s in roles such as passenger and VIP transportation. The type has been deployed to active combat theatres, such as in support of coalition forces during the Iraq War and the War in Afghanistan.