With the outbreak of war, he joined the Royal Air Force, commissioned as Pilot Officer on 8 September 1939 and initially flying a Blenheim bomber.
He later served as a photo reconnaissance pilot in 208 Squadron RAF in the Western Desert, initially flying Westland Lysanders.
It was during these latter duties that he was awarded the Distinguished Flying Cross on 6 October 1942, for a hazardous reconnaissance flight in an unarmed Hurricane at extremely low level across the Italian front line.
[5] Glaister later drew on his RAF experiences when, in 1963, he produced Moonstrike, a drama about resistance agents in occupied Europe during the Second World War.
[6] Glaister's success ended with the 1991 series Trainer,[1] which was moved from prime time to a weeknight slot because of its perceived failure.