Air Traffic Controller Law and Legal Definition
"Air traffic controller" or "controller" refers to “a civilian employee of the Department of Transportation or the Department of Defense who, in an air traffic control facility or flight service station facility--
(A) is actively engaged--
(i) in the separation and control of air traffic; or
(ii) in providing preflight, inflight, or airport advisory service to aircraft operators; or
(B) is the immediate supervisor of any employee described in subparagraph (A).” (5 USCS § 2109)