Originally Posted by
Discorde
A simpler procedure would be to set local QNH for the whole flight, resetting only if the QNH changes. Rarely does barometric pressure change rapidly, so even if the subscale was not reset at all during the flight the resulting altimeter error would be unlikely to exceed 100 feet or so. Is this significant for VFR flight?
I think that's what the CAA want you to do but because of some diehard civil pilots plus the RAF who insist on using QFE, we're stuck with the present system.
Like TheOddOne, I got into the habit of using QNH only when flying from Denham.