Back to the thread on pilots setting QNH for local acro work.

I was in the trusty Pawnee this weekend and checked the altimeter, I can
only select settings from 28.10 to 31.50, so.. following the others advice
of setting QNH. I could not.

I attempted to find this information in my personal library but could not
readily find a source.. so the best source available was to "go to the
instrument".

The lowest I could set at 28.10 still gave me 750ft MSL on the dial, and
obviously 2077 feet below the current terra firma, no way to set ZERO.

So, fly with the correct QFE and do the mental math, precompute your
altitudes required to give the terrain clearance you need.

BT