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Comment by jodkdkd | Hacker News Reader

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I fly a lot and am very very interested in what happens in the airspace with large planes. When the plane is found there will also be detailed technical discussion, undoubtedly.

What are you interested in specifically? I'm a pilot--private, not commercial--and would be happy to explain the basics of airspace and flight rules.

Not in aircraft itself, but a technical interest in why aircraft goes down. When you are in a plane you are not flying you have zero control, and as safety measures are improved by each failure I would say I feel just a little bit safer after they learn why something failed.

There's lots of data on this. Every accident and incident are logged and analyzed:

- https://www.ntsb.gov/investigations/reports_aviation.html

- http://www.ntsb.gov/aviationquery/month.aspx

- http://www.ntsb.gov/aviationquery/

Notice that actual accidents, especially Part 121 ("scheduled airline") carriers, are rare. Major airliners are actually so safe now that there are no "common failures" anymore - every failure is new and weird in its own way. But as you can read through in the links above, there's lots of data and even small incidents are analyzed in depth.

There's another program, NASA ASRS, which are voluntary self-reports of usually minor incidents and can be interesting to read to get a sense of how seriously safety is taken in aviation: http://asrs.arc.nasa.gov/search/database.html

I was reading that at 35,000 feet, if the plane loses power then decompression happens and everyone loses consciousness. This seems like a fairly friendly way to meet the end, could you comment on this?

a) "Plane loses power" isn't that simple. There are multiple different independent "power" systems for different things, each with their own redundancies. Particularly critical systems, like engines, often don't need anything else in the aircraft to be functional to continue to work. Power failures, even fairly catastrophic ones, are trained for and there are checklists for such events. (This goes all the way to the point of losing power so badly that you have no instruments and no radios, there are procedures for using a very simple battery-powered radio transponder to alert ATC of this fact, who can flash high-powered light beacons at you to give you landing instructions when you get close.)

b) Ignoring the "power failure" question, decompression at altitude is also a known danger with its own procedures. At FL350 (35,000 feet), you'd have 30 - 60 seconds of "useful consciousness"[1]. Aircrews can don oxygen masks in much less time than that; this is trained for. Further, continuous use of oxygen masks by at least one pilot is mandatory when flying over at an altitude greater than FL410 with multiple pilots, or above FL350 with a single pilot. Again, if things fail so catastrophically that aircraft-supplied oxygen doesn't work, there are small standalone oxygen tanks on hand to provide at least 10 minutes of air, which is more than enough time to make an emergency descent to a breathable altitude.

Also, to the premise of the question, cabin pressure should never be lost in response to an electrical failure; these things are designed to fail "safe". There are mechanical components that have to be actively thrown for decompression, which can be done by hand if electricity is unavailable and won't be triggered during a loss of power. Uncontrolled decompression is usually the result of a structural failure (seal or gasket failure; metal structural failure; etc).

[1] http://en.wikipedia.org/wiki/Time_of_useful_consciousness

Thank you.

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