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Malaysia Airlines flight MH370 makes it clear: we need to rethink black boxes

theguardian.com

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Re: Malaysia Airlines flight MH370 makes it clear: we need to rethink black boxes

#151

Post by phaemon »

masklinn wrote: post #150
phaemon wrote: post #147

Earlier quoted context omitted.

No, he's talking about "evidence-collecting computers in the cockpit". I know that because that's a quote from the article. You can tell that because I used "quote marks". He also says that there should be a permanent data link to ground. At which point you say (paraphrased), "there is one, except there isn't".

> No, he's talking about "evidence-collecting computers in the cockpit" No, he's mentioning them. He's not talking about them. You could know by having read the article and noted he says nothing about them outside of the subtitle. > At which point you say (paraphrased), "there is one, except there isn't". The actual paraphrase would be "there is one except physics". There is a link, it can't magick reliability which…

> No, he's mentioning them. He's not talking about them.

Yes he is, in the part I quoted. That's the part I'm talking about, which is why it's the part I quoted. Learn what the word "context" means. It's the part that the comment I was replying to quoted. Try and keep up.

> The actual paraphrase would be "there is one except physics".

Use the existing wifi connection to send additional information that at least would give you the location of the plane to the nearest kilometer. There are no laws of physics that prevent this.

Re: Malaysia Airlines flight MH370 makes it clear: we need to rethink black boxes

#152

Post by wglb »

fnordfnordfnord wrote: post #111
wglb wrote: post #107

Earlier quoted context omitted.

How would that work?

When the aircraft stops receiving signal from the ground on one channel, it searches for a beacon on another channel.

And what I am saying is that in bad HF conditions, it won't hear anything, and thus won't say anything. Putting the likelihood of a missed communication higher.

Duplex doesn't fix no propagation.

Re: Malaysia Airlines flight MH370 makes it clear: we need to rethink black boxes

#153

Post by smackfu »

Even if you know exactly where the airplane broke up, finding debris can be very difficult:

* There often aren't many big pieces left after a breakup at 550 MPH.

* The debris is falling 7 miles, so where it actually lands is pretty random and dependent on the shape / weight of the debris. Lower density debris probably travels further.

* Most debris sinks when it does get to the ocean.

* The lower density debris that floats moves in currents.

* You can't search at night, so the floating debris might move considerably before you can start searching.

Re: Malaysia Airlines flight MH370 makes it clear: we need to rethink black boxes

#154

Post by Already__Taken »

masklinn wrote: post #144
akiselev wrote: post #53

I totally agree with making black boxes more advanced to phone home and such, but this line annoyed me: "Your iPhone is more powerful than the evidence-collecting computers in the cockpit. Simple changes could mean faster answers for plane crashes" You're talking about the black box for a airline jet. This thing is supposed to survive plane crashes; not just being dropped a meter off the floor, but smashing into the…

> You're talking about the black box for a airline jet. This thing is supposed to survive plane crashes; not just being dropped a meter off the floor, but smashing into the ground going 100's of meters per second. Just so everybody understands, here are the specs advertised by Honeywell Aerospace for the type of box on e.g. AF447 (the Air France flight which crashed in 2009): Advanced Recorder (AR): available as Cock…

How can something only survive under 20,000 feet for 30 days and not 60, or a year. 30 days is a long time.

Re: Malaysia Airlines flight MH370 makes it clear: we need to rethink black boxes

#155

Post by fnordfnordfnord »

wglb wrote: post #152
fnordfnordfnord wrote: post #111

Earlier quoted context omitted.

When the aircraft stops receiving signal from the ground on one channel, it searches for a beacon on another channel.

And what I am saying is that in bad HF conditions, it won't hear anything, and thus won't say anything. Putting the likelihood of a missed communication higher. Duplex doesn't fix no propagation.

Under what conditions in an airplane's flight routine is there no radio propagation on any frequency?

Re: Malaysia Airlines flight MH370 makes it clear: we need to rethink black boxes

#156

Post by wglb »

fnordfnordfnord wrote: post #155
wglb wrote: post #152

Earlier quoted context omitted.

And what I am saying is that in bad HF conditions, it won't hear anything, and thus won't say anything. Putting the likelihood of a missed communication higher. Duplex doesn't fix no propagation.

Under what conditions in an airplane's flight routine is there no radio propagation on any frequency?

From my comment ancestor to this thread:

Keep in mind that over-the-horizon radio communication is subject to the vagaries of the ionosphere and is not totally reliable.

Non-line-of-sight radio communications are short wave (well, also medium wave and long wave, but those modes require significant power). If ionospheric conditions are bad, as they are at many times of day (worse at night for some bands), at many times during the sunspot cycle, and during a solar storm, and sometimes during atmospheric events, then you won't get a radio signal through. One famous example of this was just prior to the Pearl Harbor attack, communications via radio between US and Hawaii were very poor or nonexistent for key parts of the time.

So to put a number to your question "likely better than half the time".

Re: Malaysia Airlines flight MH370 makes it clear: we need to rethink black boxes

#157

Post by sliverstorm »

fnordfnordfnord wrote: post #155
wglb wrote: post #152

Earlier quoted context omitted.

And what I am saying is that in bad HF conditions, it won't hear anything, and thus won't say anything. Putting the likelihood of a missed communication higher. Duplex doesn't fix no propagation.

Under what conditions in an airplane's flight routine is there no radio propagation on any frequency?

http://en.wikipedia.org/wiki/HF_radio#Propagation_characteri...

I'm no expert in HF, but my general understanding is that while auto band-hopping could be helpful, you are never guaranteed there is a usable band.

Re: Malaysia Airlines flight MH370 makes it clear: we need to rethink black boxes

#158

Post by masklinn »

phaemon wrote: post #151
masklinn wrote: post #150

Earlier quoted context omitted.

> No, he's talking about "evidence-collecting computers in the cockpit" No, he's mentioning them. He's not talking about them. You could know by having read the article and noted he says nothing about them outside of the subtitle. > At which point you say (paraphrased), "there is one, except there isn't". The actual paraphrase would be "there is one except physics". There is a link, it can't magick reliability which…

> No, he's mentioning them. He's not talking about them. Yes he is, in the part I quoted. That's the part I'm talking about, which is why it's the part I quoted. Learn what the word "context" means. It's the part that the comment I was replying to quoted. Try and keep up. > The actual paraphrase would be "there is one except physics". Use the existing wifi connection to send additional information that at least would…

> Yes he is, in the part I quoted.

No, he's not talking about these systems.

> Use the existing wifi connection

The fuck are you talking about, planes don't have wifi connections. Do you think they've got a a wifi antenna outside connecting to an AP on land?

> to send additional information that at least would give you the location of the plane to the nearest kilometer.

That already trivially fits in the ACARS, and is completely useless since it's available from radars in the first place, until radar and data links become unavailable.

Re: Malaysia Airlines flight MH370 makes it clear: we need to rethink black boxes

#159

Post by masklinn »

Already__Taken wrote: post #154
masklinn wrote: post #144

Earlier quoted context omitted.

> You're talking about the black box for a airline jet. This thing is supposed to survive plane crashes; not just being dropped a meter off the floor, but smashing into the ground going 100's of meters per second. Just so everybody understands, here are the specs advertised by Honeywell Aerospace for the type of box on e.g. AF447 (the Air France flight which crashed in 2009): Advanced Recorder (AR): available as Cock…

How can something only survive under 20,000 feet for 30 days and not 60, or a year. 30 days is a long time.

It can and most likely will (the AF447 black box was retrieved after almost 2 years at ~12500ft). That's just the speccing, the warranty if you will.

Re: Malaysia Airlines flight MH370 makes it clear: we need to rethink black boxes

#160

Post by phaemon »

masklinn wrote: post #158
phaemon wrote: post #151

Earlier quoted context omitted.

> No, he's mentioning them. He's not talking about them. Yes he is, in the part I quoted. That's the part I'm talking about, which is why it's the part I quoted. Learn what the word "context" means. It's the part that the comment I was replying to quoted. Try and keep up. > The actual paraphrase would be "there is one except physics". Use the existing wifi connection to send additional information that at least would…

> Yes he is, in the part I quoted. No, he's not talking about these systems. > Use the existing wifi connection The fuck are you talking about, planes don't have wifi connections. Do you think they've got a a wifi antenna outside connecting to an AP on land? > to send additional information that at least would give you the location of the plane to the nearest kilometer. That already trivially fits in the ACARS, and i…

> The fuck are you talking about, planes don't have wifi connections.

Yes they do. I'm talking about the connection that is used to provide wifi to passengers on the plane. It's a satellite connection.

If the location is available, how did they lose the plane?

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