clear

i. In air traffic control, it means permitted to take off or land, cleared to carry out other maneuvers, or cleared to proceed under specified conditions. The activity the pilot is cleared to perform is either suffixed to the word clear, as in “clear to take off,” or it is in response to the request by the pilot as when “Permission to take off?” is answered by an air traffic controller’s “Clear.”

ii. To rectify stoppage in an automatic weapon. Also to ensure its serviceability as in “clearing guns” (by firing a small burst into the air).

iii. Authorized to carry out any task as in “Clear to alter height” or “Clear to fly radial.”

iv. The area around the aircraft is clear for aircraft starting.

v. In reference to the sky, it is devoid of any clouds as in “clear sky.” The aircraft may also be in between layers but in VMC (visual meteorological conditions). Also means, “A portion of the sky is free or relatively free of clouds.”

vi. To check nearby airspace for safe airwork or maneuvering of aircraft.

vii. To clear an engine. To open the throttle of an idling reciprocating engine in flight to free it from carbon and/or an overrich mixture.

viii. To clear the air, meaning to gain a favorable air situation in a given sector.

ix. To authorize hardware as fit for use.

x. To fly over an obstacle without touching it (i.e., clear of obstacles).