单选题 A unit established for the purpose of receiving reports concerning air traffic services and flight plans submitted before departure.

单选题 An office designated by a State for the exchange of NOTAM internationally.

单选题 A group of alphanumeric characters used to identify an aircraft in air-ground communication.

单选题 A group of letters， figures or a combination thereof which is either identical to， or the coded equivalent of， the aircraft call sign to be used in air - ground communications，and which is used to identify the aircraft in ground - ground air traffic services communications.

单选题 The flight plan as filed with an ATS unit by the pilot or his designated representative, without any subsequent changes.

单选题 A power-driven heavier-than-air aircraft, derivingitslift in flight chiefly from aerodynamic reactions on surfaceswhich remain fixed under given conditions of flight.

单选题 A publication issued by or with the authority of a State and containing aeronautical information of a lasting character essential to air navigation.

单选题 The pilot responsible for the operation and safety of the aircraft during flight time.