"Star Wars" literature also holds that TIE fighter pilots are considered an elite group within the Imperial Navy, relying on their quick reflexes and fearlessness to survive multiple tours of duty. Training involves hundreds of flight hours learning to coordinate as a team and intense psychological conditioning to put the accomplishment of their mission above other considerations. As such most TIE fighter pilots have a life expectancy of less than a year. TIE fighter pilots wear self-contained flight suits with life-support systems connected to reinforced vacuum-sealed flight helmets. These helmets feature ship-linked communications and displays.