"...nor shall private property be taken for public use without just compensation."
The FAA, unconstitutionaly, required the airlines, not to allow a passenger on their planes if that passenger was exerting their Second Amendment right, when boarding an aircraft.
This regulation is directly responsible for a group of thugs to commandeer an aircraft with knives and turn it into a bomb.
Since this regulation has "spooked" paying customers away from the airlines, the airlines must be compensated.
Remember, the regulation was enacted for "public safety."
Now, maybe the U.S. taxpayer will demand less regulations from their Congress when the cost of those regulations are properly borne by the taxpayer as additional taxes.