Altimeter Setting

In article
,
ContestID67 wrote:

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?

I did pretty much the same thing in my MSL-only club. Atmospheric
pressure had changed by 6-700ft from the last time the plane had flown,
and I did the nearest-thousand thing you describe. Even better, I
actually managed to do this twice in a row in our ASK-21! Discovered it
when I got off tow. Casually asked my passenger what his altimeter said,
and this discovered I'd managed to screw up both of them. Easy fix in
the air once I realized what I'd done.

Watch that thousands hand when you set your altimeter, and know what
your altitudes look like outside the cockpit!

--
Mike Ash
Radio Free Earth
Broadcasting from our climate-controlled studios deep inside the Moon