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Comment by sliverstorm | Hacker News Reader

Could they not simply have looked out the window and understood? Or simply felt gravity in their bodies? A 40 degree incline is pretty severe, wouldn't it be obvious?

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Our bodies are horrible when it comes to spatial awareness.

Pilots are trained to ignore sensory input like the feel of gravity, the feel of being in a dive/climb/bank and use the instruments to make determinations about what the aircraft is doing. Usually those feelings are dead wrong.

It's amazing how flying into a cloud bank, even though you've been flying straight and level, suddenly your body screams at you that you're in a descending bank or something. You just learn to disregard those senses and trust the instruments.

As far as looking out the window, it was cloudy, at night, and at high altitude. At high altitude in straight and level flight your nose is pointed at blue sky, not the visual horizon.

Ah, that bit about being trained to ignore their body is interesting. I was not aware of that, and it answers my question pretty well.

There is an unstable mode in some aircraft (maybe only small aircraft?) where it enters into a kind of spiral dive. When you are sat in a plane where that is happening (I have done this in a training exercise) you really cannot feel anything unusual at first - the forces you experience from the different accelerations cancel out. Until all of a sudden you do feel it - at that point you are pitched with the wings at about 45 degrees and the nose pointing about 45 degrees towards the ground. Suddenly you feel it a lot. That is a very scary experience, and one of the reasons to ignore your body if you are a pilot.

When I experienced it it was in clear skies, so it would be rather obvious that it was happening just by looking out of the window, but apparently this can happen to inexperienced pilots in clouds.

See http://en.wikipedia.org/wiki/Graveyard_spiral

when instruments were first introduced to planes, most people thought that something caused all instruments to malfunction like crazy as soon as they entered clouds due to the ghost spatial effects the pilots assumed were true ("I can't be turning, I feel like I'm going in a straight line!" or "I can't be going straight, I feel like I'm turning").

If I remember correctly, the average lifetime of a non-instrument trained pilot in instrument only conditions is measured in seconds, because these ghosting effects are so strong.

There was a thread on here recently about this: http://news.ycombinator.com/item?id=3144099

I think my comment on the subject is near the top: to summarize, it's not as dramatic as all that. :)

that's the article i was thinking of! i still think 178 seconds is insanely short, though.

Unfortunately, no. They could not look out the window because it was dark and they were in the middle of a storm. I doubt the sky looked much different IN the clouds as opposed to 10 ft above the ocean. Presumably, it would also be too dark and stormy to see the ocean even if they were right above it.

To understand why the answer to the rest of your questions is also "no", you have to understand the psychology of vertigo in situations like this (http://www.studentpilot.com/articles/medical_articles/articl...).

In the dark, in a storm, you have no reference points. In a moving plane, your reference frame is further confusing. There are stories of pilots making a nice, 1-g bank turning the craft upside down and not noticing until it was too late due to white-out conditions. Gravity is only one of the forces acting on the pilots' bodies.

Aka a graveyard spiral:

http://en.wikipedia.org/wiki/Graveyard_spiral

This is what killed JFK Jr.

Yes, thank you. I was also thinking of a second well known example that happened in South America I believe.

The nose was "only" pitched 15 degrees up. The descent was at 40 degrees. With considerable turbulence, and a storm raging outside even the rapid descent may not have been apparent (body-wise).

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