[caldrail]

It appears the sim gives a altitude reading of sea level and am wondering if anyone has considered a mod to get actual height from ground directly below them if thats possible. I know altimeter work on air pressure so it may be a cheat.

Altimeters give a reading based on air pressure and must be calibrated because the air pressure varies from day to day, and in some conditions changes even more rapidly. The reading for altitude above sea level is therefore a standard for which pilots adhere to, since the height of the ground below them should be known to them from charts or local knowledge. The variability of ground height would therefore make an altimeter based on that basis almost unuseable for traffic control or flight procedures, since one aircraft flying at 1000' is not flying at the 1000' of another, thus the risk of collision, both with other aircraft or the ground. There are uses for radio altimeters showing height above ground (ie - flight in bad weather) but all aircraft so equipped rely on the pressure altimeter and the sea level standard to maintain safe operation.