Aeronautical Code signals
The Aeronautical Code signals are radio signal codes. They are part of a larger set of Q Codes allocated by the ITU-R. The QAA–QNZ code range includes phrases applicable primarily to the aeronautical service,[2] as defined by the International Civil Aviation Organisation.
First defined in ICAO publication "Doc 6100-COM/504/1" in 1948 and in "ICAO Procedures for Air Navigation Services, Abbreviations and Codes (PAN a S-ABC)" [Doc8400-4] (4th edition 1989), the majority of the Q codes have slipped out of common use; for example today reports such as QAU ("I am about to jettison fuel") and QAZ ("I am flying in a storm") would be voice or computerized transmissions. But several remain part of the standard ICAO radiotelephony phraseology in aviation.
Code | Meaning | Sample use |
---|---|---|
QFE | Atmospheric pressure at a specified datum such as airfield runway threshold. When set, the altimeter reads the height above the specified datum. | Runway in use 22 Left, QFE 990 millibars |
QFF | Atmospheric pressure at a place, reduced to MSL using the actual temperature at the time of observation as the mean temperature. | |
QNE | Indicated altitude at the landing runway threshold when 1013.25 hPa or 29.92 inHg (atmospheric pressure at sea level in the International Standard Atmosphere) is set as altimeter setting. | |
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 |
Code | Meaning | Sample use |
---|---|---|
QDM | Magnetic bearing to a station | (callsign) request QDM (callsign)[1] |
QDL | Series of bearings taken at regular intervals | |
QDR | Magnetic bearing from a station | (callsign) request QDR (callsign)[1] |
QFU | Magnetic bearing of the runway in use | Runway 22 in use, QFU 220[2] |
QGE | Distance | |
QGH | Controlled Descent through Clouds (Royal Air Force use) | |
QTE | True bearing/track from a station | (callsign) request QTE (callsign)[1] |
QTF | Position in relation to a point of reference or in latitude and longitude | |
QUJ | True bearing/track to a station |
Code | Meaning | Sample use |
---|---|---|
QGH | controller-interpreted DF let-down procedure, on UHF or VHF[3] |