U.S. paratrooper braces himself in front of the door of a C-47, while learning proper jump procedures during training, mid-1940s. This photograph was obviously staged for the benefit of home front audiences. The standard procedure for exiting a C-47 in flight would have called for the trooper to stand in the doorway with both hands on the outside of the door. He is holding his static line in his left hand. After exiting from the plane, the static line would pull the cover off of his pack tray and deploy his parachute.
Book "Screaming Eagles: The 101St Airborne Division from D-day to Desert Storm" by Christopher J. Anderson