 When Brinsmead was incapacitated in 1931, Johnston was acting Controller, until he took the office in 1933.He continued to be responsible for Aviation, after 1936 as controller-general and foundation chairman of the Civil Aviation Board, and after 1939 as Assistant Director General of the Department of Civil Aviation.In 1955, he retired from the Department of Civil Aviation, and took up a post with Qantas until his retirement in 1967.