This movie is an adaptation of the play "Journey's End" by R.C. Sherriff, written just after World War I. The setting is transplanted from the trenches to an airfield, but most of the characters and some incidents are almost unchanged.
Many of the actors playing pilots in this film were in their early thirties, however in reality most of the Royal Flying Corps pilots were aged 18-25. Only the 21-year-old Peter Firth was the right age.
George Lucas was invited to a pre-release screening of this film during pre-production research for Star Wars (1977). He took particular note of uniform design and aerial battle visuals, some of which influenced the look of his sci-fi epic.
The scene with the balloon observer jumping out with a parachute is re-used footage from Le crépuscule des aigles (1966).
The "S.E. 5As" that the British pilots are flying are in reality modified Belgian "SV.4 Stampes" from the 1930s. Three airworthy and one static aircraft were used. The static was set on fire in a scene.