49 U.S.C. § 41704: Transporting property not to be transported in aircraft cabins

Under regulations or orders of the Secretary of Transportation, an air carrier shall transport as baggage the property of a passenger traveling in air transportation that may not be carried in an aircraft cabin because of a law or regulation of the United States. The carrier is liable to pay an amount not more than the amount declared to the carrier by that passenger for actual loss of, or damage to, the property caused by the carrier. The carrier may impose reasonable charges and conditions for its liability. not later than 12 hours after the arrival of a domestic flight; or not later than 15 hours after the arrival of an international flight; and the passenger has notified the air carrier or foreign air carrier of the lost or delayed checked baggage. the deadline relating to a domestic flight may not exceed 18 hours after the arrival of the domestic flight; and the deadline relating to an international flight may not exceed 30 hours after the arrival of the international flight.”