Aeronautical Code signals
{{short description|Brevity codes used for aviation}}
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, 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.
| class="wikitable" summary="Most common Q codes used in aviation for altimeter settings, including meaning and sample use"
! Code !! Meaning !! Sample use | ||
| QFE | The pressure set on the subscale of the altimeter so that the instrument indicates its height above the reference elevation being used [e.g. aerodrome elevation][https://skybrary.aero/articles/altimeter-pressure-settings Altimeter Pressure Settings] | Runway in use 22 Left, QFE 990 hectopascals |
| QFF | Atmospheric pressure at a place, reduced to MSL using the actual temperature at the time of observation as the mean temperature. | |
| QNE | During conditions of exceptionally low atmospheric pressure it is not possible to set QFE or QNH on some aircraft altimeters. In these circumstances an aerodrome or runway QNE can be requested.
The QNE is the reading in feet on an altimeter with the sub-scale set to 1013.2 hPa when the aircraft is at aerodrome or touchdown | |
| QNH | The pressure set on the subscale of the altimeter so that the instrument indicates its height above sea level (the altimeter will read runway elevation when the aircraft is on the runway). | Request Leeds QNH |
| class="wikitable" summary="Most common Q codes used in aviation for radio navigation, including meaning and sample use"
|+ Radio Navigation ! Code !! Meaning !! Sample use | ||
| QDM | Magnetic bearing to a station | (callsign) request QDM (callsign)[http://www.caa.co.uk/docs/33/CAP%20413%20Radiotelephony%20Manual%2021%202%20complete.pdf CAP 413 Radiotelephony Manual 21 2 complete.pdf] {{webarchive |url=https://web.archive.org/web/20140508223114/http://www.caa.co.uk/docs/33/CAP%20413%20Radiotelephony%20Manual%2021%202%20complete.pdf |date=May 8, 2014 }}, p.12 |
| 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[http://acronyms.thefreedictionary.com/QFU QFU on The Free Dictionary] |
| QGE | Distance | (callsign) request QGE (callsign) |
| QGH | Controlled Descent through Clouds (Royal Air Force use) | |
| QTE | True bearing/track from a station | (callsign) request QTE (callsign) |
| QTF | Position in relation to a point of reference or in latitude and longitude | |
| QUJ | True bearing/track to a station | (callsign) request QUJ (callsign) |
| class="wikitable" summary="Most common Q codes used in aviation, including meaning and sample use"
|+ Radio Procedures ! Code !! Meaning !! Sample use | ||
| QGH | controller-interpreted DF let-down procedure, on UHF or VHF[http://acronyms.thefreedictionary.com/QGH QGH on The Free Dictionary] |