Why Q codes exist
They were designed to save words and cut language problems. A single code can carry a long sentence. A few of them, especially those about pressure settings and bearings, come up all the time in aviation.
Common codes
| Code | What it means |
|---|---|
| QNH | The altimeter setting that makes the altimeter read height above mean sea level at the aerodrome. |
| QFE | The altimeter setting that makes the altimeter read zero on the aerodrome, so it shows height above it. |
| QNE | The standard setting of 1013.2 hPa, used for flight levels. |
| QDM | Magnetic heading to steer to reach the station, in nil wind. |
| QDR | Magnetic bearing of the aircraft from the station. |
| QTE | True bearing of the aircraft from the station. |
Memory tricks
- QNH: “N” for “Nautical” height, the level above the sea.
- QFE: “F” for “Field”, the airfield itself.
- QDM: “M” for “Magnetic, Me to station”. QDR is the reverse, the bearing from the station.
Using them in a call
“Delhi Tower, VT-ABC, request QNH” asks for the sea-level pressure setting. The reply is “QNH one zero one two”. You read it back and set it on the altimeter.
Quick answers
Which Q codes are most common in the exam?
Pressure-setting codes such as QNH and QFE, and bearing codes such as QDM and QDR, are the usual ones to master first.
Is a Q code always a question?
No. It becomes a question when you add a question mark in writing or a questioning tone in speech.
Answer questions on this topic, or run a full radio call out loud.
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