Originally Posted by
mattyj
If you set 1013 hPa on your altimeter and truck out on your planned track..and the environmental pressure drops (for example 1020 over NZ to 1000 over Australia)..what happens?
Not 350 down to 260 by any means but there is still an effect
Going back ... back ... back ... to basic theory ... 30' / hPa
So for a drop of 20 hPa, your height would drop by 600'.