Career
Sidebottom joined the Royal Naval Air Service on 11 October 1917, and after completing his flying training was posted the Number. 3 (Naval) Squadron to fly the Sopwith Camel single-seat fighter. On 1 April 1918, the Royal Naval Air Service was merged with the Army"s Royal Flying Corps to form the Royal Air Force, and Sidebottom"s unit was renamed Number.
203 Squadron Royal Air Force. He then accumulated a series of victories between then and 29 October 1918, sharing in the destruction of two reconnaissance aircraft with Captain Leonard Henry Rochford and the mid-air burning of another with Captain Arthur Whealy.
Sidebottom"s final toll was the destruction of seven enemy aircraft, with five of those shared. Seven driven down out of control, including two shared.
His citation read:
Lieutenant William Sidebottom, 203rd Squadron. "This officer has carried out numerous offensive and low bombing patrols with courage, skill and judgment.
He has also proved himself a bold and resolute fighter in aerial combats, having nine enemy machines to his cartulary-register"
However, Sidebottom returned to Royal Air Force service on being granted a short service commission with the rank of flying officer on 24 October 1919.
On 8 December 1920 Sidebottom was serving in Number. 30 Squadron, part of the North Persia Force. His observer escaped unhurt.
Having no known grave he is commemorated on the Tehran Memorial, Gholhak Garden, Iran.