"Kirk Stant" wrote in message
om...
OK, I'll buy that. My interpretation of the original post was that
since the GPS altitude showed him lower than the altimeter, he could
go up higher before entering Class A airspace (18000ft - I stand
corrected). That interpretation would be incorrect, for all the
reasons we both have stated.

I didn't write that I saw GPS altitude less than the altimeter. I wrote
that it was higher.

GPS altitude is NEVER less than the barometric altimeter set to a local
altimeter setting - at least in my experience.

Bill Daniels