Pearson was commissioned a
second lieutenant in the
Royal Engineers on 31 July 1902. He transferred to the Royal Air Force on its formation. He reached the rank of
brigadier general in 1917, and became the RAF's first Director of Training on the service's formation in April 1918. Remaining in the RAF after the war, he was promoted to
air commodore on 30 June 1923. In the first half of the 1920s he held senior positions on
RAF Iraq Command, the British organisation responsible for maintaining control of Iraq. Towards the end of 1925 Hearson was appointed
Air Officer Commanding the Special Reserve and Auxiliary Air Force which later became the Air Defence Group and then
No. 1 (Air Defence) Group. Hearson retired from the RAF in 1927 but returned to service in the build up before the
Second World War to establish and command the UK's barrage balloon organisation. ==References==