Q Code - Aviation

Aviation

Although the majority of the Q codes have slipped out of common use, several remain part of the standard ICAO radiotelephony phraseology in aviation.

Altimeter Settings

Code Meaning Sample use
QFE Atmospheric pressure at sea level, corrected for temperature and adjusted to a specified datum such as airfield elevation. When set on the altimeter it reads height. Runway in use 22 Left, QFE 990 millibars
QFF Barometric pressure at a place, reduced to MSL using the actual temperature at the time of observation as the mean temperature.
QNE Atmospheric pressure at sea level in the International Standard Atmosphere (ISA), equal to 1013.25 mbar or hPa and used as reference for measuring the pressure altitude. When Flight Levels are used as an indication of altitude, 1013.25hPa is used as mean sea level (QNH).
QNH Atmospheric pressure at mean sea level (may be either a local, measured pressure or a regional forecast pressure (RPS)). When set on the altimeter it reads altitude. Request Leeds QNH

Radio Navigation

Code Meaning Sample use
QDM Magnetic heading to a station (callsign) request QDM (callsign)
QDL Series of bearings taken at regular intervals
QDR Magnetic bearing from a station (callsign) request QDR (callsign)
QFU Magnetic bearing of the runway in use Runway 22 in use, QFU 220
QGE Distance
QTE True bearing from a station True bearing, True bearing, (callsign) request QTE (callsign)
QTF Position in relation to a point of reference or in latitude and longitude
QUJ True bearing to a station

Radio Procedures

Code Meaning Sample use
QGH controller-interpreted DF let-down procedure, on UHF or VHF

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