(b) A carrier shall not refuse to provide
transportation to a qualified individual with a
disability solely because the person’s
disability results in appearance or involuntary
behavior that may offend, annoy, or
inconvenience crewmembers or other
passengers.
Offend, annoy, or inconvenience does not include "endanger". Anyone who can't be confined to a seat during takeoff, landing, or periods of significant turbulence, is a hazard to themselves and others at those times and should not fly.