相关题目
（ ） is an area of land or water that is used or intended to be used for the landing and takeoff of aircraft, and includes its buildings and facilities, if any.
（ ） is an aerodrome specified in the flight plan to which a flight may proceed when it becomes inadvisable to land at the aerodrome of intended landing.
（ ） is a magnetic bearing extending from a VOR/VORTAC/TACAN navigation facility.
（ ） is a specified geographical location used to define an area navigation route or the flight path of an aircraft employing area navigation.
The contour on the map is the line joining （ ） at the same altitude.
（ ） is a radar system which uses reflected radio signals.
（ ） is the visibility at an aerodrome, as reported by an accredited observer.
（ ） is the visibility forward from the cockpit of an aircraft in flight.
（ ） is specified information provided to air traffic services units, relative to an intended flight or portion of a flight of an aircraft.
The flight plan as filed with an ATS unit by the pilot or his designated representative, without any subsequent changes is called （ ） .
