"Allen" wrote

The Lear does have an emergency pressurization system. When the cabin
altitude reaches (I believe) 12,000' there is a valve that opens and puts
full, uncooled bleed air into the cabin. There is no mistaking when this
happens; it is loud and it is hot.

Yeah, I'll bet that is exciting!

Let's see, death by altitude blackout, or death by cooking like a lobster.
Which would I choose? g

Interesting. I didn't know that. I wonder why the Payne Stewart plane
(Lear 35) did not have that system activate. Perhaps the sensor that
measures cabin altitude was on the fritz. What kind of backup would there
be? It would seem reasonable to have separate sensors for normal
pressurization operation, and one for the emergency system, and perhaps one
for a aural and visual cockpit warning.

Do you know how it is set up?

Thanks for the information.
--
Jim in NC