Numbers 651 to 663 Squadrons of the RAF were air observation post units working closely with army units in artillery spotting and liaison. In 1944. the Canadian parliament voted for the creation of three additional AOP squadrons to support of the
First Canadian Army. These squadrons were approved on the RCAF list in the late summer of 1944:
No. 664 Squadron RCAF,
No. 665 Squadron RCAF, and No. 666 Squadron RCAF. The Canadian pilots were officers recruited from the
Royal Canadian Artillery. They were trained to fly at
No. 22 Elementary Flying Training School at Cambridge, and further trained for operational flying at No. 43 Operational Training Unit RAF, at
RAF Andover. The squadron was formed at RAF Andover, on 5 March 1945, the third air observation post squadron consisting of Canadian personnel to be formed at RAF Andover, The squadron operated under the overall command of
No. 70 Group,
RAF Fighter Command. Royal Canadian Artillery Major Dave Ely initially took command of each of the three squadrons, and was assisted by two RCAF Flight Lieutenants, D. Dougall (Acting Squadron Adjutant) and A.R. Woodhouse (Squadron Equipment officer). Major Ely was also assisted by nine AOP trained
Royal Artillery Officers, who began training the squadron's other ranks. In the last week of March 1945, 666 Squadron's aircraft – sixteen
Auster Mark V's – began to arrive, along with the squadron's ground transport. On 7 May 1945, ten qualified Canadian AOP pilots were posted to the squadron, and from their ranks, Captain A.B. Stewart was elevated to Squadron Captain. In April, 666 began a succession of moves. On 17 April, they moved to Alfriston Aerodrome; on 28 May, to
Gilze-Rijen, the
Netherlands; and on 6 June, the headquarters moved at
Hilversum, and the squadron's three subordinate Flights were dispersed to
Dordrecht,
Alkmaar, and
Ede. On 12 June, Major Ely was reassigned to
Canadian Far East Force (CFEF), and was replaced by Major A.B. Stewart as Officer Commanding. Through the summer of 1945, the squadron was tasked with 'air taxi' duties in support of
1st Canadian Infantry Division,
3rd Canadian Infantry Division, and #1 Canadian AGRA (
Army Groups Royal Artillery). On 25 June, 666 Squadron moved from Hilversum to
Apeldoorn, joining No. 664 Squadron and 665 Squadron in that location, then under the overall command of the First Canadian Army. When 665 Squadron was disbanded on 10 July 1945, many of its remaining personnel were transferred to 666 Squadron. Tasking thereafter included VIP, Courier, and Communications Flight duties in support of the
Canadian Army Occupation Force (CAOF). No. 666 Squadron RCAF in its turn was disbanded at Apeldoorn on 31 October 1945. The squadron had no motto or heraldic badge assigned to it. ==Squadron bases==