Here's one of the little-known facts of air travel: you're not actually guaranteed a seat on that plane.
Up until Sunday, this would have come as a surprise to most travelers. Dr. David Dao's violent removal from a United (UAL) flight changed that ignorance. By now it's the rare flier who expects to enjoy his experience in the air. Cramped seats, dwindling overhead space and a feeling that the airline finds every possible way to dip into your wallet have all drained the experience of what joy it used to have. (It's bad enough that an increasingly credulous public believes pranks about coin-operated bathrooms and stacked seating.)
Yet the absolute, rock bottom the public feels entitled to is that the airline will get them from point A to point B.
That isn't necessarily the case. Thanks to the contract of carriage that each passenger agrees to with the purchase of their ticket most airlines can and will bump you off the flight for dozens of reasons including having bare feet, terrible body odor or being drunk as a skunk.
Or, just maybe, if the airline oversold the plane. Here, for example, is an excerpt from United Airline's (relatively standard) contract:
"If a flight is Oversold, no one may be denied boarding against his/her will until UA or other carrier personnel first ask for volunteers who will give up their reservations willingly in exchange for compensation as determined by UA. If there are not enough volunteers, other Passengers may be denied boarding involuntarily in accordance with UA's boarding priority:
"The priority of all other confirmed passengers may be determined based on a passenger's fare class, itinerary, status of frequent flyer program membership, and the time in which the passenger presents him/herself for check-in without advanced seat assignment."
Now, there are two things here that may surprise travelers. The first is that they can be involuntarily bumped from a flight. Despite the bribe-dangling bidding war each time an oversold flight needs to leave the ground, airlines don't actually have to offer any specific amount of money. They can just nominate a handful of people to stick around, ticket status notwithstanding.
The second surprise is that like just about everything else in the air, this is all about the money. When the contract says priority "may be determined based on a passenger's fare class," that's legal-speak for "the passengers who pay get to stay."
"I'm not sure how many people realize how many decisions are made based on the price that you pay," said Vinal Burbeck, the founder of Wanderlark Travel. "When people book these amazingly low fares, I don't think they realize that they're getting put into a hierarchy and that hierarchy will determine what their privileges are, where their seat is."