Walt has some skill as a pilot, but he’s no ace.
When acting as co-pilot he can grant +2 to checks made flying the vessel.
Walt was the escape-pod pilot when you fled the space station. He decided that following the man with a gun to his head was the smart course of action. When he later found his captors possessed abilities beyond normal humans, he decided that joining them might prove even more beneficial. Hell, he was one more infraction from being fired at the company anyway.