I'm trying to find a reliable formula to convert a QNH to the QFE for an aerodrome for which I know the elevation
Set the QNH initially and then wind the altimeter down by the amount of the threshold elevation. Your QFE will be displayed on the subscale and your altimeter will be reading height above threshold. Or to do it in your head:-
30 feet per Millibar has worked well for the past 50 years
I second that.
Originally Posted by
The Ancient Geek
Getting back to reality, I see no need for QFE. It just causes problems when someone forgets to set QNH in the cruise, all altitudes are referenced to QNH, flight levels to 1013. When landing a simple bit of mental arithmetic gives you the height above the runway for the circuit etc. Runway is 220 ft AGL, circuit is 800 ft so fly the circuit at 1020 ft QNH - simple.
Have landed on plenty of decks about 30' ASL. Certainly never landed on a runway 220' AGL.
