[2] After leaving Eton Birchenough developed an interest in flying and joined the Grahame-White training school on 7 February 1913.
[3] Over the following months he carried out his training under the instruction of Marcus Dyce Manton before being awarded his aviator's certificate on 13 June 1913 in a Grahame White Biplane.
[5] In 1914 he competed in a series of air races and won the Shell Motor Spirit Trophy for a special speed contest.
[6] On 6 June he flew a Maurice Farman aeroplane at the last Aerial Derby before the outbreak of war and two weeks later he competed in the London to Manchester handicap [7][8] On 3 August 1914 Birchenough flew a Maurice Farman aeroplane from Hendon to Leighton Buzzard to carry out a demonstration at a Flower Show but was forced to return after learning that the Government had imposed a ban on flights that day of more than three miles from an aerodrome due to fears of impending war.
[10] In August 1916 "The Aeroplane" reported that Birchenough was one of the steadiest and most skilful pilots in the country and that "since the outbreak of war he had passed a legion of machines through their tests" In 1917 he was elected a member of the Aeronautical Society of Great Britain.