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Comment by pdx_flyer | Hacker News Reader

I would assume that situational awareness for those inside the plane would have actually been pretty poor. They were climbing through clouds when the dive began so seeing the orientation of the plane to the earth would have been very spotty.

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As a passenger, even if I couldn't see out the window, you'd definitely know you weren't going "up" anymore at that rate of decent. Combined with "we just took off" I'm certain that at least a few people in the cabin knew something really bad might have been about to happen.

  As a passenger, even if I couldn't see out the window, you'd definitely
  know you weren't going "up" anymore at that rate of decent.

No, you really wouldn't. Even for the pilots spatial disorientation is a real problem and they have instruments to show which end is up.

I follow most of my flights (especially takeoff/landing) with all the sensors in my smartphone. In flights without emergency events, the most useful for me is barometric pressure. When they suddenly drop the pressure by 20+% after achieving cruising altitude, half the plane shortly goes to sleep. I presume due to the lower partial pressure of oxygen.

Sure, but then you're talking 10,000 ft or more. The pressure differential between 2,200 ft and 775 ft is much smaller. It's possible some folks' ears popped, but IMO unlikely that they would've attributed it to a steep descent. Instead I'd expect folks chalked it up to the cabin pressurizing if they even noticed. If passengers noticed and thought there was something wrong this would've made news much sooner.

  I presume due to the lower partial pressure of oxygen.

Probably the lower oxygen content. My pilot friend claimed to have raised the cabin altitude a smidge back in the DC-10 days if FAs complained about e.g. noisy babies. I assume he's full of shit, but you never know.

> The pressure differential between 2,200 ft and 775 ft is much smaller.

Irrelevant. The cabin pressure is controlled independently of the Earth's environmental altitude pressure.

> Probably the lower oxygen content.

That's literally exactly the same thing as the thing that I said.

The cabin won't be noticeably pressurized at 2,200 ft. While a 777 will pressurize the cabin slightly before takeoff the max cabin altitude is 8,000 ft. So, yes, there is a bigger change in pressure during an approach (from 8,000 ft cabin altitude to roughly the altitude of the field) than there is going into a steep dive from 2,200 ft.

I might be stupid but I don’t understand what point you’re getting at?

No. In flight you are subject to variable G-forces so you can't know that you are moving in the way that you "feel" you are moving.

If you (or anyone) wants a really, REALLY good experience around this, go to your local small airport and find a flight instructor and ask them to show you "unusual attitudes" - they'll have you close your eyes and put your head down, do stuff with the plane, and then ask you what the plane is doing - you will say "turning down and to the right" and be in a climb to the left. It's freaky.

That's fair, I suppose a better way to word my point would be that any sort of "extreme" maneuver, absent some warning from the pilot about a rough takeoff or landing (or turbulence while in flight) is unusual for a passenger plane. Having that happen just after takeoff we're near the ground would give me some concern regardless of which direction I subjectively felt we were moving in, up or down. I've been through plenty of rough takeoffs and landings as a passenger and I just find it hard to believe that not a single person on the flight didn't at least think to themselves "hey, this isn't a normal climb to 10k".

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