Hill volunteered to join the RAF in 1941, and trained as a navigator. He joined No. 544 Squadron in March 1944, and flew 53 sorties in a de Havilland Mosquito with Frank Dodd, many involving long-range photo reconnaissance in the Arctic seas north and east of Scotland, and later over Germany and the Baltic Sea, and also flying diplomatic mail to Winston Churchill at conferences in Moscow, Athens and Yalta.
