Born in Malaya, his father was a judge and he was one of three brothers who would all serve as fighter pilots with the RAF. Educated in England, he then studied at McGill University in Canada, before joining the RAF in 1931, his first posting being to No 3 Squadron flying Bulldogs. In 1933 and 1935 he was awarded the 'Brooke-Popham Air Firing Trophy' and in 1935 he was a member of the 3 Squadron aerobatic team of five Bulldogs using smoke.In early 1937 he was tasked with reforming No 72 Squadron at Tangmere with Gloster Gladiators but when the squadron moved North to Church Fenton, he remained at Tangmere being appointed a flight commander in No 1 Squadron where he immediately set about forming a formation aerobatic team consisting of four Furies. From No 1 Squadron he moved to the CFS and having qualified as QFI, he returned to operational flying with No 151 Squadron. When he arrived the squadron was equipped with the Gloster Gauntlet but shortly after his arrival re-equipment began with Hurricanes. This also coincided with his promotion to Squadron Leader and appointment as CO.
His short operational career during WW2 resulted in him claiming five confirmed victories, with one more shared, three unconfirmed and one damaged. As OC of RAF Colerne, he commanded the first wing of jet fighters in the RAF.
During the war, most of the pre-war records had been broken, even if not recorded officially, and the RAF decided to recapture the World Speed record with its new generation of jet aircraft. They consequently set a new High Speed Flight with Group Captain Donaldson in command and on 7 September 1946, he established a new World Record of 615.78 mph in a Meteor.
After retirement, he became Air Correspondent for the Daily Telegraph until 1979.
World Record of 615.78 mph in a Meteor on 7 September 1946,flown by E.M.Donaldson