When WW1 broke out, the aeroplane was just 10 years old. Dan Snow looks at how it rapidly became a weapon of war. Dan discovers the origins of air-to-air combat – and the ingenious ways in which engineers solved the biggest challenge: how to fire a gun from a plane without shooting your own propeller off. He also takes to the sky to re-enact a WW1 dogfight (a term that was coined in WW1). Those first pilots had no manual or experience so they wrote the rules as they went along. Many of those early tactics on aerial combat still apply today – a century later.