Originally Posted by
pinniped
YES, possession of a seat assignment is the best way to avoid IDB. You may think there's some sort of detailed algorithm driven by fare basis or whatnot, but when it comes right down to it it's musical chairs. For my two IDB's over the years, it was simply because I was the guy with no seat assignment. (Non-elite flying NW/DL, for what it's worth. VDB's were not sought - they simply bumped the people who didn't have seats.)
But no, seeing a completely full seatmap at booking time does not mean that the flight will need to IDB or even VDB.
In my years of flying UA and AA, it seems like those carriers at least make a modest attempt at VDB before they go to IDB.
Obviously if you fail to show by the CoC check-in time, you're simply a no-show...not a denied boarding. At that point, they will usually put you on a later flight ("flat tire rule") but owe you nothing.
DOT rules require the airlines to first ask for volunteers, though I know at least one airline has been fined for not following these procedures.
Originally Posted by
cbn42
Do airlines actually bump people who are already in their seats? In all my travels I have never seen or heard of this happening.
I was VDB'd one time when already in my seat. An agent came on the plane and announced that they were looking for a volunteer. I jumped up and was VDB'd because of it. I have never personally experienced seeing anyone IDB'd once on the plane.