[Bane]

[quote="Sgt Stryker":1a5ec]I would think that cargo carriers such as UPS, Fed-Ex, or the US Postal Service fly fully pressurized planes.[/quote:1a5ec]

I can't say their entire fleets are pressurized, but at least some are. The planes are passenger jets converted for hauling freight. When they haul, say, an F1 racing team or horses for a show they use the same planes as when they're hauling inanimate cargo.