相关题目
（ ） is a point on the airport designated as the official airport location.
（ ） is the area of airspace over land or water, extending upward from the surface, within which the ready identification, the location, and the control of aircraft are required in the interest of national security.
（ ） is a number expressing the relative effect for an aircraft on a pavement for a specified standard subgrade category.
（ ） 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.
