British Commonwealth Air Training Plan

Commemorating Canada’s greatest contribution to Second World War victory

In 2016, the Royal Canadian Air Force (RCAF) is commemorating Canada’s greatest contribution to the victory of Allied forces during the Second World War – the British Commonwealth Air Training Plan (BCATP) – which ran from 1939 to 1945.

2016 was selected to celebrate the five-year-long effort because the first Canadian squadrons that were established as a result of the Plan were formed in 1941 – 75 years ago.

These “400-series” squadrons continue to form the Royal Canadian Air Force of today; in essence, the RCAF as we know it came into existence 75 years ago as a direct result of the air training plan.

The 400-series squadrons were established because of a brief clause in the BCATP agreement known as “Article XV”: two vaguely worded but pivotal sentences in the history of the RCAF:

“The United Kingdom Government undertakes that pupils of Canada, Australia and New Zealand shall, after training is completed, be identified with their respective Dominions, either by the method of organizing Dominion units and formations or in some other way, such methods to be agreed upon with the respective Dominion Governments concerned. The United Kingdom Government will initiate inter-governmental discussions to this end.”

The agreement was signed on December 17, 1939, and training began in April 1940. Meanwhile, Canada and Great Britain entered negotiations to create at least 25 RCAF squadrons overseas, in addition to the three that had already been deployed. On January 7, 1941, representatives of the two nations signed a supplementary agreement governing the formation of the squadrons, which began coming into existence on March 1, 1941.

During the First World War, Canadians had flown as individual members of the British forces; a Canadian Air Force did not exist. This time, however, as a result of Article XV and the 1941 sub-agreement, Canadian aircrew overseas would fly in Canadian squadrons, under Canadian command.

The new squadrons were numbered from 400 to 4491. On March 1, 1941, the squadrons that were already overseas – 1, 110 and 112 – were renumbered as 401, 400 and 402 Squadrons, respectively. The first new squadron – 403 Squadron – was formed on March 1 and others soon began making their appearance.

Many of those squadrons, which began their service 75 years ago as a result of the BCATP, continue to fly – serving Canada and Canadians – to this day.


1 There are two exceptions to the 400 to 449 series of numbers that was allocated to the RCAF. Under the BCATP, the Royal Australian Air Force (RAAF) was allocated a series of numbers beginning with 450; 450 Squadron flew from 1941 to 1945. An administrative error resulted in Canada’s using 450 when a heavy transport helicopter squadron was authorized in 1968. Canada later received permission to use this number (the Australian 450 Squadron no longer exists) and the 450 RAAF Squadron Association and members of the Canadian 450 Squadron have formed a close bond.

103 Search and Rescue Squadron is the only non-400 operational flying squadron in the Royal Canadian Air Force. When it was redesignated from 103 Rescue Unit in 1997, it retained the 103 number.