Quite possibly the most frustrating thing that can occur to a traveler – whether business or leisure - is being bumped from their flight. If it hasn’t happened to you, count yourself amongst the lucky. Most people have no idea what their rights are should they find themselves in this predicament. The good folks at iFly.com have addressed this situation and offer detailed advice on what to expect should you ever find yourself holding an airline ticket, but no airline seat.
There are several reasons for Airlines "bumping" travelers from their pre-booked flights:
One is that airlines overbook, taking into account that up to 15% of persons with prior reservation do not show up. When indeed everyone shows up, there aren't enough seats available and the call goes out for volunteers willing to give up their seats for a later flight by offering an incentive for the inconvenience this is causing. If there are no volunteers, the airline can request that a passenger will give up the seat for a later flight, which is called "involuntary bumping", as opposed to "voluntary bumping".
Another reason can be that inclement weather or mechanical problems has caused the carrier to cancel flights and its next-departing flights may not be able to accommodate many of the stranded passengers. After attempting to garner enough volunteers, the airline may also resort to "involuntary bumping" if they deem it necessary in case of special needs or circumstances of some of their passengers.