[ceejayoz]

Being able to rapidly depressurize is fairly critical; the doors are prevented from opening in flight by a pressure differential and their construction. In an emergency, being unable to depressurize would mean being unable to evacuate the aircraft.

Passengers would've had their oxygen masks deploy, which works in normal circumstances, but they only last 12 minutes; intended to give the crew time to descend. When the pilot has no intention of taking that measure, you're screwed pretty fast, but they could fly into a mountain too if they felt like it.

[Gare]

> but they could fly into a mountain too if they felt like it

Don't know if you said that with this crash in mind or not, but: https://en.wikipedia.org/wiki/Germanwings_Flight_9525

[ceejayoz]

Yes.

Fundamentally, if the pilot of an airliner wants to crash, they will be able to crash.

With very rare exceptions: https://en.wikipedia.org/wiki/Cornfield_Bomber

[dehrmann]

There's a lot of automation around commercial air travel, so autonomous commercial flying is an easier problem than city driving. The argument against it tends to be that you need a human behind the stick in cases like the miracle on the Hudson. The other side of this is it's about as likely a pilot intentionally crashes the plane.

[loeg]

In an evacuation event, the aircraft would be at sea level and the interior would not be pressurized relative to outside air. You only need to depressurize if you're going to parachute out, which... is not an option in commercial aviation.

[edrxty]

Pressurization is relative, aircraft can end up pressurized on the ground. Next time you fly, note the warning beacons in the windows of all the doors. They indicate the cabin is pressurized alerting rescue crews that attempting to open said door will either A: not work or B: kill them, as has happened before with a G150 [1]

Also, there are other situations where you may be inclined to disable bleed air, such as in a fume event where an engine is releasing turbine oil into the bleed air stream due to a mechanical failure or fire.

[1] https://www.flightglobal.com/g150s-pressurised-door-fatally-...

[loeg]

> Pressurization is relative

I mean, that's literally what I wrote.

[ceejayoz]

Unless you, say, make an emergency landing somewhere like Denver or La Paz.

[loeg]

Aircraft are pressurized to 8k feet above sea level. Denver is only 5k. La Paz, specifically, sure. It’s a lot less broadly useful than your original language made it sound.

[Merad]

DB Cooper would beg to differ: https://en.m.wikipedia.org/wiki/D._B._Cooper

[jki275]

They specifically fixed that problem after his escapade.