427 Squadron started as a bomber squadron formed at Croft, England on 7 November 1942 and spent its wartime entirely in England as a part of No. 6 Group RCAF, RAF Bomber Command. 427 flew Vickers Wellington Mk IIIs and Mk Xs from its first operational mission on 14 December 1942, a minelaying sortie to the Frisian Islands, until May 1943 when it was relocated to Leeming, North Yorkshire. Re-equipped with Handley Page HalifaxMk V aircraft, the squadron flew intensely until early 1944 when it replaced its inventory with Halifax Mk III aircraft. This fleet saw the greatest number of missions and in slightly more than a year's time they were then replaced by Avro Lancaster bombers prior to the end of World War II. The Lancasters were used for prisoner of war repatriation until the end of May 1946. 427 was stood down on 1 June 1946. The squadron was reformed on 1 August 1952 at RCAF Station St. Hubert as 427 Fighter Squadron, flying Canadair Sabres, and was transferred to No. 3 Wing at Zweibrücken in March 1953. Selected as the first European RCAF squadron to receive the CF-104 Starfighter in the nuclear strike role, the squadron was stood down from its day-fighter role on 15 December 1962 and reformed as 427 Squadron two days later. On 1 February 1968, unification integrated 427 into the new Canadian Forces. The squadron was again disbanded on 1 July 1970. 427 came back into existence as 427 Tactical Helicopter Squadron at CFB Petawawa, where it remains today. The squadron has also taken an active role in humanitarian efforts such as the January 1998 ice storm in eastern Canada, where the squadron deployed eight aircraft to Ottawa and Kingston, and the November 1998 mission to help the victims of Hurricane Mitch. With only 24 hours' notice, four 427 Squadron Griffons deployed to La Ceiba, Honduras. Once in the country, Griffon crews airlifted medical teams into communities cut off by the hurricane. For the next six weeks, the squadron ferried supplies and aid workers to many isolated towns and villages. On 1 February 2006, command of 427 was transferred to Canadian Special Operations Forces Command, as it took on a full-time role of special operations aviation support. Shortly thereafter, it was renamed as, 427 Special Operations Aviation Squadron. Unlike the 160th SOAR and other units in CANSOFCOM—JTF 2, CSOR, and CJIRU—there are no specialized standards for any 427 SOAS members and entrance into 427 SOAS requires only "negotiations through Career Managers and losing units." The squadron has a dedicated concrete helipad, measuring, at Petawawa Heliport.
Battle honours in small capitals are for large operations and campaigns and those in lowercase are for more specific battles. 427 Squadron was awarded the following battle honours, which are carried on their standard:
