| Acronym |
Definition |
| QHI |
Qualified Helicopter Instructor. |
| Quadrantal Rule |
System of cruising altitudes used in UK uncontrolled airspace below FL250. |
| Q-code |
Code used when air-to-ground communication was via wireless telegraphy, enabling many routine phrases and questions to be reduced to three letters. Now largely redundant, except these:- |
| QDM |
Magnetic bearing to a direction-finding station. |
| QDR |
Magnetic bearing from the station. |
| QFE |
Atmospheric pressure at aerodrome elevation. With its sub-scale set to the aerodrome QFE an altimeter will indicate height above that airfield. |
| QFU |
Magnetic orientation of runway in use. |
| QNE |
Reading in feet on an altimeter set to 1013.2 millibars (standard pressure) when the aircraft is at aerodrome elevation. |
| QNH |
Altitude above mean sea level based on local station pressure. |
| QTE |
True line of position from a direction-finding station. |
| QUJ |
True bearing |