For those wondering what "line maintenance" is:
Post# of 41413
Line Maintenance basically does the stuff that can be performed at the gate, between flights. I'm guessing that their name comes from the fact that they work on the flight line. It could also be called light maintenance. What I have seen done by Line Maintenance includes: tire changes, add fluids and gasses, change out parts, etc.
(I quoted that from this link: https://answers.yahoo.com/question/index?qid=...08AApHDrK)
Anyone want to verify this as definitely being true? (O&W, perhaps?)