Rolf,

From the inception of the club to about 5 years ago, we flew and
taught AGL only. No self respecting power pilot would fly AGL.
Flying AGL is a crutch intended to help new pilots. But It is better
to learn it right from the get-go than to have to relearn it later and
maybe getting into an accident.

So about 5 years ago my Club's flight chair said that flying AGL was
wrong, dangerous and (if I am not mistaken) illegal. So the board
made an edict and we changed overnight at the start of a season. We
marked all altimeters in club ships "MSL Only Club Policy". There was
some, but not a tremendous amount of, consternation ... such as "But
it is so flat around here." or "But I always land back home."

We did have one incident related to the AGL/MSL switch that might be a
good to read about. One day yours truly flew a club ship and set the
altimeter to MSL. The next pilot was an die hard AGL'er. The AGL'ers
were used to finding the altimer not quite at zero due to barometric
changes and would "tweak" the altimeter to zero at the start of each
flight. Our field elevation is 888 feet. So the next pilot tweaks
the altimeter to "zero" but instead of subtracting 888 feet (by moving
the hands CCW), he tweaks it CW and adds 112 feet! Can you see where
this is going?

He then takes a tow to what he thinks is 3,000 feet AGL but is only
really at 2,000 feet AGL. The tow pilot doesn't think much about it
as people get off tow early all the time. About to enter the pattern
the AGL'er thinks, "Gee, the ground seems to be kind of large
today ... but I am still at 1500 feet AGL so I'm must be OK." He then
almost lands short as he was 1,000 feet lower than he thought. End of
story? Nah.

The AGL'er gets back on the ground and complains that the altimeter
must be wrong. We look at the altimer and see that it is showing
1,000 feet. Putting 2+2 together we figured out what he did. So get
this ... an old timer CFIG says it was my fault as I should have reset
the altimeter to zero when I got out. Sorry, wrong-o. Who was the
PIC on the second flight? The AGL'er of course. It is his
responsibility to ensure that the instrumentation is set correctly,
not mine. Can you tell that it still grates a bit? Ok, I feel better
now.

Anyway, my suggestions are to;

1) Do it!
2) Convert "big bang" all at once, not by dribs and drabs or over a
"transition" period.
3) Mark the altimeter with an "MSL Only" sign to reenforce the new
policy each time a pilot climbs into the cockpit.

Good luck, John DeRosa

PS Early in my soaring career, I remember flying at a commercial
operation while on a business trip and was told to set the altimeter
to MSL. I started sweating worrying about all the math I would need
to calculate in my head. Luckily I was in Miami at the time and the
field elevation was all of 20 feet - not much of a problem.