Originally Posted by
danib62
Yea that was my one fear. It didn't stop us on the flight down though or get flagged by the TSA ID scanning machine at IAD. Obviously we were better off having a valid passport in hand, but UPS was delayed a day and things definitely seemed dicey at one point...
I assume in the case where it works, the newer valid passport is entered into the reservation, likely already saved in the airlines profile, so no red flags are triggered.