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AGL (Above Ground Level)
A measurement of altitude expressed in feet above the terrain or ground directly below the aircraft. AGL is commonly used for traffic pattern altitudes and obstacle clearance.
Related Terms
- AileronA hinged flight control surface on the trailing edge of each wing that controls the aircraft's roll about its longitudinal axis. Moving the control yoke or stick left or right deflects the ailerons in opposite directions.
- AIRMET (Airmen's Meteorological Information)An in-flight weather advisory for conditions that may affect aircraft operations but are less severe than SIGMET criteria, such as moderate icing or turbulence, mountain obscuration, or widespread IFR. Modern briefings commonly present these as G-AIRMETs (graphical AIRMETs).
- AirspaceDefined areas of the atmosphere designated by the FAA with specific rules and requirements for aircraft operations. U.S. airspace is classified into Classes A, B, C, D, E, and G, each with different visibility, cloud clearance, and communication requirements.
- Airspeed IndicatorA flight instrument that displays the aircraft's speed through the air, typically in knots. It works by measuring the difference between pitot (ram air) pressure and static pressure. The indicator features colored arcs showing operating speed ranges.