I believe the requirement for Commercial A/c is a 8,000 cabin at service
ceiling, but most planes can beat this figure.

"Big John" wrote in message
...
Cap

One bit of info. Commercial birds are pressurized to between 5K and
10K (forget the standard figure but someone will drop it in a reply).
If you don't fly any higher in your GA than the commercial bird
pressurization it shouldn't be a problem.