In 1915 18-year-old Alan Farmer, a country blacksmith, joins the Royal Flying Corps, and meets Charles Gaylion, an upper-class officer who transferred in. Mistaken for an seasoned pilot, Alan is taken up in a training plane he cannot land.

Alan's training advances well, but he has to learn both military and flying skills, while Charles has already completed his pilot's training. On a training flight, Alan's engine fails on take-off, and he crash-lands the plane in a field.

May 1915, and Alan arrives in St Marie, France. Some officers resent his lower class background. Alan and his friend Charles are reunited. On his first mission a German plane machine-guns them, and his observer, Bravington, is wounded.

The old CO, Captain Dornish, is shot down. He is replaced by Captain Triggers. Enroute to the unit, Triggers learns the horrible truth of Dornish's fate, from a wounded Infantry Officer.

Seeing the inadequacies of the planes, Triggers encourages the pilots and NCOs to put forward ideas for improvement.

Gaylion gets a taste of the horrors of life in the trenches when his plane is forced down and he must wait overnight for the arrival of a replacement propeller.

Charles devises a method of fitting a Lewis gun to their plane, and Alan makes it a reality, but in their first aerial combat they find the design still needs work, when they shoot out some struts in their own plane.

Alan helps Charles to capture a German plane and its crew. Entertaining the captured officers does not go to plan. The captured plane may be the perfect choice for a covert mission.

A new German monoplane is causing massive losses and the British military hierarchy do not believe their planes are being so outclassed. The reason for their success is found from an unlikely source.

On a reconnaissance mission with observer Conrad, Alan disregards Conrad's order to move closer to a German Eindecker, turns for home and avoids a confrontation. Conrad insists Alan be court-martialled for disobeying an order and cowardice.

After the court martial, Conrad continues to fly with Alan, ordering him to be more reckless. Conrad shoots down an Eindecker but is fatally wounded. Alan's incident report is complete, but Triggers rewrites it to leave out certain details.