14 CFR § 259.7 - Response to consumer problems.
(a)Designated advocates for passengers' interests. Each covered carrier shall designate for its scheduled flights an employee who shall be responsible for monitoring the effects of flight delays, flight cancellations, and lengthy tarmac delays on passengers. This employee shall have input into decisions on which flights to cancel and which will be delayed the longest.
(b)Informing consumers how to complain. Each covered carrier shall make available the mailing address and e-mail or web address of the designated department in the airline with which to file a complaint about its scheduled service. This information shall be provided on the U.S. carrier's website (if any) and the foreign carrier's website (if marketed to U.S. consumers), on all e-ticket confirmations and, upon request, at each ticket counter and boarding gate staffed by the carrier or a contractor of the carrier.
(c)Response to complaints. Each covered carrier shall acknowledge in writing receipt of each complaint regarding its scheduled service to the complainant within 30 days of receiving it and shall send a substantive written response to each complainant within 60 days of receiving the complaint. A complaint is a specific written expression of dissatisfaction concerning a difficulty or problem which the person experienced when using or attempting to use an airline's services.
(d)Social networking sites. Each covered carrier that uses a social networking site (e.g. Facebook, Twitter) and that does not intend for that site to be a vehicle for receipt of written consumer complaints subject to this section shall clearly indicate on the carrier's primary page on that social networking site that it will not reply to consumer complaints on that site and shall direct consumers to the carrier's mailing address and e-mail or website location for filing written complaints.