Now I get curious...
According to annex 4, an aeronautical chart shall show "geoid undulation" for thresholds...
I know the difference between the WGS84 geoid and local mean sea level is known as "geoid undulation", and that is relevant when flying using geometric VNAV, which is a requirement when flying LPV approaches. The threshold height in reference to the geoid can be seen in the FAS data block for LPV procedures.
The threshold elevation in reference to the geoid is then the geoid undulation for a threshold + the elevation for the threshold in relation to mean sea level.
But honestly, do anyone ever use this data when flying? Besides when programming the FMS (which I suspect is done by technicians before flight).
Last edited by jmmoric; 11th May 2021 at 10:35.