E;lroy; is the hardened pilot of the spaceship LOST. He undoubtedly has an Alliance military background but does not talk about it much. Presumably he was booted out.

The job of pilot was offered to him literally on the fly. In fact, with the ship's Captain shot, the crew would never have escaped without him there to sit in the driver's seat.

Elroy's piloting skills are exemplary and he generally gets on with the rest of the crew because he keeps a cool head. Except with Jay...who he shot.