Born in Hobart, Tasmania, Brownell was working as a clerk with a firm of accountants when he enlisted in the Australian Imperial Force on the outbreak of the First World War.
After flight training in the United Kingdom, Brownell was commissioned as a second lieutenant and posted for operational service over the Western Front in September 1917.
Initially educated at Leslie House School, Brownell later attended Scotch College, Melbourne, where he was an active sportsman.
[3][4] Allotted to the 9th Battery, 3rd Field Artillery Brigade with the rank of gunner, Brownell embarked from Hobart aboard HMAT Geelong on 20 October, bound for Egypt.
Embarking with his unit from Alexandria, Brownell arrived in France for service on the Western Front on 29 March, following a six-day voyage.
Throughout the engagement, Brownell established and maintained communications between the battery and firing line, despite fatigue or personal risk to himself.
[2] On graduating from the course, Brownell was discharged from the Australian Imperial Force on 16 March and commissioned as a second lieutenant in the Royal Flying Corps the following day.
45 Squadron RFC flying Sopwith Camels, Brownell moved to France for operational service over the Western Front during September 1917.
[8] In his time flying over the Western Front, Brownell accumulated a total of five victories and achieved 'ace' status before his squadron was transferred to Italy in December.
[10] Later that month, Brownell and his observer, Lieutenant Henry Moody, shot down German ace Alwin Thurm over Asolo.
The dash, gallantry and offensive spirit displayed on all occasions by this officer are worthy of the highest praise.In April 1918, Brownell was granted compassionate leave to visit his seriously ill mother.
[1] On his return to Australia, Brownell was employed as a sub-accountant for a firm of merchants in Melbourne, and later with the Hobart City Council as a clerk.
45 Squadron officer, Captain Cedric Howell, who had been killed in an aeroplane crash while participating in the England to Australia air race.
[8] In a ceremony at St Andrew's Presbyterian Church, Hobart, on 26 August 1925, Brownell married Rhyllis Jean Birchall; the couple would later have two daughters.
[13] On the outbreak of the Second World War, more units were placed under Brownell's purview at RAAF Base Pearce and he was consequently promoted to temporary group captain in December 1939.
The Hudsons replaced the squadron's Avro Ansons, which were to be ferried back to the eastern coast of Australia to be used as training aircraft.
[1][20] Embarking aboard the SS Strathallan in mid-August, Brownell and his staff formed the RAAF station within two weeks of arrival at Sembawang.
[1] Following intelligence reports that a Japanese force was en route to raid Western Australia, the Australian Government ordered a build-up of the defences in the area.
The group assumed its role on 30 July, and had the initial jurisdiction of all Dutch territory in the area, along with British North Borneo and Sarawak.
It also held the three main responsibilities of local air defence and sea lane protection, support of adjacent formations and offensive operations against Japanese targets within range, and line-of-communication duties.
[26] Following his retirement from the Air Force, Brownell was made a partner of S. G. Brearley & Co., a stockbroking firm located in Perth.
Aged 79, Brownell died at Subiaco, Western Australia, on 12 April 1974 and was accorded a funeral with full Air Force honours.