A measurement, of the height of an aircraft, abbreviated FL; FL250

Official permission given by a controller for an aircraft to take an action

The direction in which a plane is pointing, expressed in degrees from north.

To keep an aircraft in a particular position on the ground or in the air while waiting for further clearance from ATC

A unit of speed (one nautical mile per hour)

A parking space for an airplane where passangers get on and off the plane

the intended route or direction to be followed, measured with respect to a geographic reference