Pilot and observer inside the cockpit of a two-man biplane, in France, during World War I. Holding up the regimental mascot of a pet dog and with big smiles on their faces, a pilot and an observer are pictured before setting out on a journey over enemy lines. Note the old-fashioned flying helmets and goggles that both men are wearing. The machine-gun fixed beside the rear cockpit has a swivel attachment on it, so that it can provide the plane with all-round firepower. During 'the war to end all wars', an aerial battle between two or more aeroplanes was called a 'dogfight '. At the start of the conflict, fighter planes had two seats, with the pilot sitting in the front cockpit and a gunner-cum-observer occupying the rear cockpit. As the war continued, however, single-pilot aircraft became more prevalent, since these planes were clearly more effective during a 'dogfight'. During a 'dogfight ', pilots used cloud cover as an aerial form of camouflage, and often swooped down on their prey from out of the sun. [Original reads: 'OFFICIAL PHOTOGRAPH TAKEN ON THE BRITISH WESTERN FRONT IN FRANCE. A cheery pilot and observer with their mascot pup ready for a flight over the German lines.']