>>>What would the Max Altitude be in a Commercial Aircraft [eg B737] if it has to Ferry fly from A to B with U/s Pressurisation & Oxygen system.
It also depends upon what you're authorized for....
For unpressurized ferries, we usually stay at 9,000 or 10,000 depending upon direction of flight, but if MEAs/terrain are an issue, we have the option of operating up to 17,000 (with the flightcrew on oxygen) not to exceed one hour's time between 10,000 and 17,000.
Unpressurized revenue flights at/below 10,000 are rare, but still possible in some cases, as long as pax count is low (for cabin temp considerations) and that MEAs can be complied with. The flight that Silver1SWA mentioned in post #15 is a good example, and SJC
is one leg where it's possible to be done. You wouldn't have the same luck coming out of RNO
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