Interstate air transportation


means the carriage by aircraft of persons or property as a common carrier for compensation or hire, or the carriage of mail by aircraft in commerce:
  1. Between a place in a State or the District of Columbia and another place in another State or the District of Columbia;
  2. Between places in the same State through the airspace over any place outside that State; or
  3. Between places in the same possession of the United States;

Source: 14 CFR Federal Aviation Regulations §1