"The Royal Flying Corps on the Western Front, 1914-1918" Pilots and Observers of No. 22 Squadron handing over papers before going on patrol, in accordance with the notice "Empty your pockets before going on patrol". This precaution was taken to prevent information reaching the enemy in the event of a forced landing. In the background are some of the Bristol Fighters of the Squadron. Serny Aerodrome, 17 June 1918.