49 U.S.C. § 44902: Refusal to transport passengers and property

a passenger who does not consent to a search under section 44901(a) of this title establishing whether the passenger is carrying unlawfully a dangerous weapon, explosive, or other destructive substance; or property of a passenger who does not consent to a search of the property establishing whether the property unlawfully contains a dangerous weapon, explosive, or other destructive substance. Subject to regulations of the Administrator of the Transportation Security Administration, an air carrier, intrastate air carrier, or foreign air carrier may refuse to transport a passenger or property the carrier decides is, or might be, inimical to safety. An agreement to carry passengers or property in air transportation or intrastate air transportation by an air carrier, intrastate air carrier, or foreign air carrier is deemed to include an agreement that the passenger or property will not be carried if consent to search the passenger or property for a purpose referred to in this section is not given.