Distinguished Flying Cross Inter-war career On 1 August 1919 the RAF introduced its own rank structure and Brown changed from lieutenant to flying officer. From 25 November he served aboard the aircraft carrier , and on 31 May 1920 was appointed an instructor at the School of Naval Co-operation and Aerial Navigation. On 5 January 1921 he was posted to No. 205 Squadron, and on 1 October to No. 3 Squadron, flying the Airco DH.9A from RAF Leuchars. On 6 September 1922, he was injured after making a forced landing in the Moray Firth, following an engine failure. On 1 April 1923 he was assigned to No. 420 Flight. Beginning in September 1923 he took the Signals Course at the Electrical and Wireless School at RAF Flowerdown, and in September 1924 was appointed a staff officer in the Signals Branch, at the Air Ministry. He was promoted to flight lieutenant on 1 January 1925. From 19 September 1927 he attended the RAF Staff College in Andover, Hampshire. On 29 January 1929 Brown was posted to No. 30 Squadron in Iraq, transferring to No. 84 Squadron at RAF Shaibah, Iraq, on 16 March to serve as a flight commander. On 28 August he was posted to the Headquarters of Iraq Command. On 1 February 1931 Brown was posted to No. 13 Squadron at RAF Netheravon to serve as a signals officer. On 12 December 1932 he became a staff officer in the Signals Branch. He was promoted to squadron leader on 1 October 1934, and from 1 December served as a signals officer, serving at No. 21 Group Headquarters, South Farnborough, on signals duties until 10 November 1935. On 5 October 1935 he was appointed commander of No. 26 (Army Co-operation) Squadron at RAF Catterick. On 30 August 1937 he was appointed station commander at RAF Catterick. On 1 January 1938 he was promoted to wing commander, and on 4 July was assigned to the Directorate of Staff Duties at the Air Ministry. Second World War Brown was promoted to acting group captain on 1 March 1940, and appointed Senior Air Staff Officer in No. 60 (Signals) Group, Fighter Command, which was responsible for the RAF's radar network. On 24 April he was transferred to the RAF's Technical Branch. On 1 September he was promoted to temporary group captain. In September 1941 he was made a Commander of the Order of