Number 11 was initially test-flown at Downsview by George Neal on 24 March 1947, bearing its constructor’s number as a registration. Registered as G-AKDN, it played a pivotal role in the UK’s decision to acquire the type. In its three years as a de Havilland test and demonstration aircraft, ’KDN was flown by numerous A&AEE pilots and four of DH’s top test pilots of the day: Pat Fillingham, John Cunningham, Geoffrey Pike and John Derry. It was also raced, winning the 1952 Goodyear Trophy and the 1953 King’s Cup. During the latter, in the hands of Pat Fillingham and his wife Sonja, ’KDN achieved an average speed of 142mph. George Neal once noted that it was “very light and the fastest Chipmunk I’ve ever flown.”
Having served its purposes for the company, in October 1950 Geoffrey de Havilland presented ’KDN to the London Aero Club. It subsequently passed into other private hands. In 2000 ’KDN was purchased by Phil Derry, nephew of John Derry. Derry was later approached by two Canadians, keen to return the aircraft to Canada. After assuring Derry they wanted nothing but to preserve the aeroplane and its heritage, a sale was agreed and the aircraft was shipped to Saskatoon in 2002. There it was restored to its original DHC company livery and reflown by George Neal on 17 May 2004, almost exactly 57 years after he first took to the air in it. Though now back in Canada, ’KDN continued to operate under its British registration, the only formal registration this aircraft has ever carried in its life.