Air Navigation Facility

A facility used, available for use, or designed for use, in aid of air navigation, including--

(A) a landing area;

(B) a light;

(C) apparatus or equipment for distributing weather information, signaling, radio-directional finding, or radio or other electromagnetic communication; and

(D) another structure or mechanism for guiding or controlling flight in the air or the landing and takeoff of aircraft.

Source: U.S. Code.