He enlisted into the army at Hampton Court in 1914 or 1915 and served on the Western Front until invalided out after suffering from trench foot. He volunteered to transfer to the Royal Flying Corps as a cadet, and was commissioned as a probationary temporary second lieutenant on 29 August 1917, being confirmed in his rank and appointed a flying officer on 8 February 1918. Gammon was assigned to No. 104 Squadron, part of the Independent Air Force, flying the Airco DH.9 light bomber, with Second Lieutenant Percival Appleby as his observer/gunner. He was appointed a temporary captain on 27 June 1918. Gammon and Appleby gained their first victory on 1 July 1918 destroying an Albatros D.V over Metz. A month later, on 1 August, they accounted for a Pfalz D.III at Boulay airfield. On 7 September Gammon was the commander of ten aircraft from No. 104 Squadron which, with eleven aircraft from No. 99 Squadron, mounted a daylight air raid on the Badische Anilin- und Soda-Fabrik chemical works at Mannheim. The British force, under the overall command of Major Lawrence Pattinson of No. 99 Squadron, were attacked by numbers of enemy aircraft on the outward flight, while over the target, and on their return. However, they successfully dropped over two tons of bombs on the target, and also shot down six enemy aircraft, two of which were credited to Gammon and Appleby. As a result of this raid Gammon and Appleby were awarded the Distinguished Flying Cross. Their citation read: Their fifth and final victory came two weeks later, on 15 September, destroying another Pfalz D.III over Verny. Gammon finally left the Royal Air Force after the end of the war, being transferred to unemployed list on 9 September 1919.
Gammon returned to service in the Royal Air Force Volunteer Reserve during World War II, being commissioned as a pilot officer "for the duration of hostilities", on 8 January 1940. He was promoted to the war substantive rank of flying officer, and then to flight lieutenant, in early 1941, and to squadron leader on 20 April 1943. Gammon remained in the RAF Reserveafter the war, until finally relinquishing his commission on 10 August 1954, being permitted to retain the rank of wing commander.
Personal life
Gammon, then living in Uxbridge, and married Kitty Isabella Mary Gough in 1921. She died in Worthing in 1986.
