Attached to the
Royal Flying Corps from the 30th Training Reserve Battalion in November 1917, Fletcher was teamed with pilot
Samuel Frederick Henry Thompson in May 1918. Thompson already had scored three victories. The team of Sergeant Fletcher and Lieutenant Thompson was to become a deadly one; Fletcher scored all but one of his 26 victories flying in the rear seat of
Bristol F.2bs flown by Thompson. In turn, Thompson would become the leading ace of
22 Squadron with 30 victories. The new team got off to an immediate success; on 16 May 1918, they destroyed three German
Pfalz D.III fighters in ten minutes. Five days later, they destroyed another Pfalz and drove one down out of control, and Fletcher was an ace. Fletcher got two more wins in May, over German
Albatros D.Vs. June then became a succession of multiple victory days—two each on the 1st and 2nd, three on the 5th, and two more on the 23rd, to end the month with a count of 16 wins. There was a lapse in his tally until 8 August, when he shot down a
Fokker Dr.I. He then tripled on the 13th and doubled on the 27th. His final four victories came in September, including yet another double on the 5th. The final list of 26 victories with Thompson over German fighters was an impressive one. Three were shot down in flames; an
Albatros D.V, a
Pfalz D.III, and a
Fokker D.VII. Thirteen others were claimed destroyed; four Pfalz D.IIIs, five Albatros D.Vs, two Fokker Dr.Is, and two Fokker D.VIIs. All other victories were classified as "driven down out of control". Fletcher was commissioned as a temporary second lieutenant (observer officer) on 8 October 1918. He was awarded the
Distinguished Flying Medal, which was
gazetted on 2 November 1918. His citation read: P22398 Serjt. Ronald Malcolm Fletcher (attached from Training Res. Bn.). A most efficient and keen observer, in whom his pilots place implicit confidence. He has taken part in numerous combats with enemy aircraft, and invariably displays marked fearlessness and skill. He has personally accounted for seven enemy machines since 21 May. Fletcher finally left the RAF, being transferred to the unemployed list, on 28 February 1919. ==Post World War I==