Originally Posted by
H Peacock
ie, with a sea level pressure of 1013.25 and a 'perfect' atmosphere, the QNE of a threshold 500ft above msl would be 500ft. If you were flying downwind in the circuit 1000ft above the threshold your altimeter would be reading 1500ft, but that is not the QNE.
What would be the difference between that and sitting on the ground at a 1500 ft elevation airfield with exactly the same altimeter reading ?
In other words, why would one be QNE and not the other ?