Details of his training are unrecorded. However, Groom was appointed a
flying officer on 30 January 1918 On 18 March, he was assigned to
No. 20 Squadron as a
Bristol F.2 Fighter pilot. On his first combat flight, his formation leader fired a
Very flare that landed in the rear cockpit of Groom's Bristol. While the observer burned his hands smothering the fire that threatened to set off munitions, Groom safely landed. Having survived friendly fire, Groom began to triumph over enemy fire on 8 May 1918, when he began a string of eight victories that would take him through to 30 July. Groom's final tally was three enemy planes set afire, four otherwise destroyed, and one driven down out of control; his observer/gunner for all these victories was
Ernest Hardcastle. Groom went on leave, was laid low by influenza, and did not return to combat in France. Instead, upon recovery, he was posted to
No. 111 Squadron in Egypt. ==Between the World Wars==