"Mxsmanic" wrote in message
...


No, it is not. It's especially dangerous for RVSM flight, but it's so
inaccurate that it should never be used for anything,

Your complete misunderstanding of the GPS system is showing. I have two
GPS's in the plane, one panel mount and one portable. It is rare that
either one is ever off by more than 100 feet in altitude. Using GPS for
your altitude for VFR flight would be perfectly fine.