Originally Posted by
ESpen36
Actually... you do need a passport to depart the USA by air. The airline has to swipe the passport to compare your name/identity against various government watch lists (for outstanding warrants, suspicious activity, unpaid bills or child support, etc). If you are okay to travel, your boarding passes will say "DOCS OK" and you can go.
First I've heard of anyone being denied the use of a US passport on-the-fly as opposed to a refusal to issue a passport. Does this really happen? Is the hapless individual then stuck with his nonrefundable ticket?