14 CFR § 121.586 - Authority to refuse transportation.
(a) No certificate holder may refuse transportation to a passenger on the basis that, because the passenger may need the assistance of another person to move expeditiously to an exit in the event of an emergency, his transportation would or might be inimical to safety of flight unless -
(1) The certificate holder has established procedures (including reasonable notice requirements) for the carriage of passengers who may need the assistance of another person to move expeditiously to an exit in the event of an emergency; and
(2) At least one of the following conditions exist:
(i) The passenger fails to comply with the notice requirements in the certificate holder's procedures.
(ii) The passenger cannot be carried in accordance with the certificate holder's procedures.
(b) Each certificate holder shall provide the responsible Flight Standards office with a copy of each procedure it establishes in accordance with paragraph (a)(2) of this section.
(c) Whenever the Administrator finds that revisions in the procedures described in paragraph (a)(2) of this section are necessary in the interest of safety or in the public interest, the certificate holder, after notification by the Administrator, shall make those revisions in its procedures. Within 30 days after the certificate holder receives such notice, it may file a petition to reconsider the notice with the responsible Flight Standards office. The filing of a petition to reconsider stays the notice pending a decision by the Administrator. However, if the Administrator finds that there is an emergency that requires immediate action in the interest of safety in air commerce, he may, upon a statement of the reasons, require a change effective without stay.