相关题目
（ ） is the intersection of lines of reference, usually expressed in degrees /minutes /tenths of minutes of latitude and longitude, use to determine position or location.
（ ） is the speed of an aircraft relative to the surface of the earth.
（ ） is the direction in which the nose of the airplane points during flight.
（ ） is the vertical distance of a point or level, on or affixed to the surface of the earth, measured from Mean Sea Level.
（ ） is an altitude or flight level maintained during en-route level flight.
（ ） is the vertical distance of a level, a point or an object considered as a point, measured from Mean Sea Level.
（ ） is a control area or portion thereof established in the form of a corridor, the centerline of which is defined by radio navigational aids.
（ ） is navigable airspace between two points which is identifiable.
（ ） 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.
