Just got back to RAS after a long absence to find this thread. Great
fun!

One more data point:

I learned to fly with CCSC (original poster is CCSC Pres.). Actually
at CCSC's former airport in Richmond, IN. The club gliders and most
private gliders had the altimeters set to AGL (zero). Easier math
(just read, no subtraction required). No radios in club gliders (to
hear warnings or communicate with power aircraft or anyone else). No
Class B or any other type of controlled airspace nearby (no Class B
anywhere in those days). It's Ohio: flat as a board so any airport we
could fly to was within 100' or so of takeoff altitude. Under the
conditions I was flying in--which arguably don't exist anymore--it's
undeniable that the mental load is lighter using AGL. I flew for
years, including cross country and midwestern regional and national
contests using AGL. I can't remember when I switched but it was no big
deal. I'd already had to do it a few times at wave camps, etc., and
just decided it was time to make the change. For some years even after
I switched to MSL, before each contest flight I would set the
altitmeter to zero, write down the altimeter setting, then reset it to
MSL. On final glide, I would reset it to AGL to make the mental math
easier with my cardboard "prayer wheel" final glider computer. I need
4200' to get home, the altimeter says 4800', so I'm in good shape.
Again, no subtraction required: just read the altimeter and compare to
the calculator.

There may still be situations where AGL works fine. Yeah, it's
probably better to start off doing it "right" with MSL, but we don't
start students off with spins or advanced thermaling techniques. We
begin with the easier stuff and move on gradually. This month marks
the 45th anniversary of my first lesson. I like to think I was no less
a "real pilot" for those years I flew with the altimeter set to AGL.

Chip Bearden
ASW 24 "JB"
USA