Sgt. Bowerman was born in Ealing.
He joined the RAFVR around May 1938.
At the outbreak of war in 1939, the FAA was short of pilots and after Oswald was called up he was posted to Donibristle and joined the Torpedo-Spotter-Reconnaissance Flight.
Oswald was later posted to 770 Squadron for deck-landing training on HMS Argus, in the western Mediterranean. He was offered a transfer to the FAA but declined and was posted to 3 BGS, Aldergrove as a staff pilot.

On 4th May 1940, Oswald was recalled to the FAA and joined 759 (T) Squadron at Eastleigh for a refresher deck-landing course. He was later posted to 804 Squadron at Hatston.
By mid-June the RAF was short of pilots and Bowerman was recalled and posted to 7 OTU, Hawarden.

After converting to Spitfires he was posted to 222 Squadron at Hornchurch in early July. Within two weeks Oswald was told to report to Uxbridge and became one of a group of nine Sergeants and one Officer. They were flown to Hullavington, and then picked up by Hurricanes which flew them to Abbotsinch, where they embarked on the carrier HMS Argus.
They were joined by four more officers and were told that their destination was Malta and they were now 418 Flight. The Argus sailed on 23rd July, called in at Gibraltar before going on to Malta on 31st July.

At dawn on 2nd August 1940, the Hurricanes flew off to Luqa. 418 Flight and the Malta Fighter Flight were amalgamated into 261 Squadron on 16th August 1940.
Oswald left Malta for Egypt on 7th April 1941. He ferried a Hurricane to Greece and then went to the Aircraft Delivery Unit at Takoradi.

In July 1942, Oswald was posted to 260 Squadron in the Western Desert and then moved to 601 Squadron in October.

Oswald Bowerman was killed on 24th October 1942 when he crashed after being seen to spin during a turn. Oswald, then aged 26, was a Warrant Officer.
He is remembered on the Alamein Memorial.