They're definitely confused!

I suspect the "10 PSI" that they quoted was the "pressurization differential" for the airplane, the max. allowable difference
between inside and outside pressure. 14.7 as you probably know is normal sea-level atmospheric pressure.

As another poster indicated, typical "cabin altitude" for airliners is around 8000 feet. You'll definitely see above 4000
feet in a jet, and very likely in a commuter turboprop too.

I think the options are probably limited to ground transport, traveling on another airline with supplemental O2, or maybe if
it's a short trip one of the small "air taxi" carriers that usually fly low with piston-powered airplanes.

Eric Law

wrote in message oups.com...
I just got off the phone with Southwest Customer Relations asking a
question about cabin air pressure. Two separate people informed that
cabin air pressure in flight is 14.7 psi (sea level equiv.) and that it
is 10.0 psi (about 10,000 ft equiv.) on the ground.

Obviously, this has to be backwards, right? Even so, don't regulations
require cabin air pressure to be between 5,000 and 8,000 equiv.
altitude? Wouldn't that mean one of the numbers they gave me would
have to be between 12.23 psi (5,000) and around 11.0 psi (8,000)?

The reason I ask is rather important. My friend has a heart condition
and needs pressure of 4,000 ft or less. Southwest does not allow
supplemental oxygen, and he'd rather not use it anyway. The numbers
they give out seem suspect, and I can't take chances here.
Thanks,
Josh