Thomson was seriously injured during flight training; the accident left him with lasting scars to his face. Nevertheless, he joined 46 Squadron during the summer of 1917, to fly a
Sopwith Pup. On 25 September 1917, he scored his first victory flying Pup no. B2196, destroying an enemy reconnaissance plane. The
Distinguished Service Order followed on 22 June. He also received the
Distinguished Flying Cross, gazetted 21 September 1918. ==Death==