Pinetree Line

2405 Aircraft Control & Warning Unit (Reserve) was located at Halifax, Nova Scotia and was formed on 1 May 1950. 2405 AC&WU was tasked to "train radar and communications personnel in all aspects of air control and warning procedures and to maintain and operate radar and communications facilities as directed the Group Commander Maritime Group". The unit converted to Auxiliary status on 1 November 1951. On 1 March 1952, 2405 AC&WU became the responsibility of Air Defence Command though they still worked closely with Maritime Group.

The unit reached Squadron status on 1 December 1953. Narrative reports on the Pinetree Line web site confirm that 2405 AC&W Squadron was active at RCAF Station Beaverbank, NS, during the years 1954 to 1961 inclusive. There is also evidence of deployment to RCAF Station Foymount in 1953, RCAF Station Mont Apica in 1957 and 1959, RCAF Station St. Margarets in 1958 and 1959, as well as RCAF Station Lac St. Denis in 1952.

On 31 August 1961, 2405 AC&W Squadron was disbanded as Auxiliary AC&W Squadrons were no longer required due to the SAGE system coming on line.