(6) "Aircraft engine" means an engine used, or intended to be used, for propulsion of aircraft and includes all parts, appurtenances, and accessories thereof other than propellers.
(7) "Airman" means any individual who engages, as the person in command or as pilot, mechanic, or member of the crew, in the navigation of aircraft while under way; and (except to the extent the Administrator may otherwise provide with respect to individuals employed outside the United States) any individual who is directly in charge of the inspection, maintenance, overhauling, or repair of aircraft, aircraft engines, propellers, or appliances; and any individual who serves in the capacity of aircraft dispatcher or air-traffic control-tower operator.
(8) "Air navigation facility" means any facility used in, available for use in, or designed for use in, aid of air navigation, including landing areas, lights, any apparatus or equipment for disseminating weather information, for signaling, for radio-directional finding, or for radio or other electrical communication, and any other structure or mechanism having a similar purpose for guiding or controlling flight in the air or the landing and take-off of aircraft.
(9) "Airport" means a landing area used regularly by aircraft for receiving or discharging passengers or cargo.
(10) "Air transportation" means interstate, overseas, or foreign air transportation or the transportation of mail by aircraft.
(11) "Appliances" means instruments, equipment, apparatus, parts, appurtenances, or accessories, of whatever description, which are used, or are capable of being or intended to be used, in the navigation, operation, or control of aircraft in flight (including parachutes and including communication equipment and any other mechanism or mechanisms installed in or attached to aircraft during flight), and which are not a part or parts of aircraft, aircraft engines, or propellers.
(12) "Board" means the Civil Aeronautics Board.
(13) "Citizen of the United States" means (a) an individual who is a citizen of the United States or of one of its possessions, or (b) a partnership of which each member is such an individual, or (c) a corporation or association created or organized under the laws of the United States or of any State, Territory, or possession of the United States, of which the president and two-thirds or more of the board of directors and other managing officers thereof are such individuals and in which at least 75 per centum of the voting interest is owned or controlled by persons who are citizens of the United States or of one of its possessions.
(14) "Civil aircraft" means any aircraft other than a public aircraft.
(15) "Civil aircraft of the United States" means any aircraft registered as provided in this Act.
(16) "Conditional sale" means (a) any contract for the sale of an aircraft, aircraft engine, propeller, appliance, or spare part under which possession is delivered to the buyer and the property is to vest in the buyer at a subsequent time, upon the payment of part or all of the price, or upon the performance of any other condition or the happening of any contingency; or (b) any contract for the bailment or leasing of an aircraft, aircraft engine, propeller, appliance, or spare part, by which the bailee or lessee contracts to pay as compensation