You must be speaking about the GUN CREWS.

We in the slicks had to have superior crewmembers in the rear, our lives depended on them! Never disparage a slick crewman, they are the ones with the guts of a god. They hung out of the aircraft to clear us and at most they had a chicken plate, and they may have used that to sit on. Many times they were too busy clearing the aircraft to shoot, we didn't always have a long strip of safe ground to land on.
Huey