In the course of a very interesting and serious rumination about proposed air travel regulations ostensibly designed to allow the Center for Disease Control to react to epidemics — but which conveniently enact the surveillance regime on air travelers that this administration has been seeking for some time, Ed Hasbrouck throws out this great aside,
If you are ever denied transportation by an airline, ask them for a copy of their conditions of carriage, which they are required to have available at every check-in counter. Ask them to tell you under which specific clause of the conditions of carriage you are being denied transportation. Try to get them to put that in writing, preferably either on airline letterhead over the signature and legibly printed name of the station manager for the airline at that airport, or as part of a complete printout of your passenger name record , in which the reason you were denied transportation, citing the specific clause of the conditions of carriage, has been entered. (If you made your reservations from Canada, the European Union, or certain other countries, you are entitles to see what’s in your PNR. But not, unfortunately, if you made your reservations in the USA.) If the airline balks at giving you reasons, point out that your eligibility (or not) for a refund of your ticket is dependent on the reasons and the clause of the conditions of carriage under which you were denied transportation. So you need documentation of the reasons for their denial, in order to establish your refund claim. (If the airline refuses to transport you because you refuse to consent to being searched, you are entitled to a full and unconditional refund, even if your ticket would otherwise have been an entirely nonrefundable. Presenting yourself at the airport, and refusing to consent to search, is perhaps the most foolproof way to obtain a refund of an otherwise nonrefundable ticket.) The airline cannot refuse to transport you, except as provided by specific terms of their published conditions of carriage, without grave liability under the common carrier clause of the Airline Deregulation Act of 1978.
I’m sure it would be one @#%@$ of a hassle, but it’s an interesting idea nonetheless.