
China's Search Vessel Picks up Pulse Signal in South Indian Ocean - fla
http://english.cri.cn/6909/2014/04/05/189s820764.htm
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podperson
Interesting how effective the Chinese have been (relative to the US and
Australia) in the search thus far.

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podperson
Odd to get downvoted for suggesting this is interesting.

1) If China feels it necessary to fabricate sightings in order to mollify its
population (also note the way it has tried to manage the bereaved families and
focus their anger on Malaysia including providing coordinated t-shirts etc.)
then that's interesting.

2) If China, not usually noted as outstanding in air, naval, or orbital
surveillance capability is able to outperform Australia (which is both very
experienced with ocean searches and is operating on its doorstep) and the US
then that's interesting.

3) If China is more willing to reveal its capabilities than the US or
Australia that's also interesting. (E.g. I suspect the reason the Australians
were so willing to commit to the current search area based on one satellite
image is because they actually tracked the flight via Jindalee, but were
unwilling to reveal that system's capabilities given there weren't going to be
any survivors.)

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headShrinker
> The signal, at 37.5 kHz per second, was picked up by a black box locator at
> 25 degrees south latitude and 101 degrees east longitude.

Hz per second? Hertz is a per second unit of measure...

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wglb
Yep, but they did get it right a little further down the article.

But what is the _monitor an acoustic wave_ \--isn't it a radio signal?

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dannypgh
No, it's an acoustic wave. Salt water is a good conductor of electricity, as
such only ultra low frequency radio has any chance of penetrating more than a
few feet, and the antenna needed to pull that off is prohibitively large for
an aircraft.

Recommended reading:
[http://en.m.wikipedia.org/wiki/Communication_with_submarines](http://en.m.wikipedia.org/wiki/Communication_with_submarines)

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daturkel
Incredible last minute discovery considering that they're only relying on it
to continue pulsing until tomorrow.

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kapkapkap
30 days is not by any means a firm deadline for the blackboxes. They are
designed to last a _minimum_ of 30 days and usually do last a lot longer.

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mschuster91
I think it's time for the FAA/JAA to make a regulation that blackbox batteries
have to last 3 months or longer. Should not be too much of a cost to retrofit,
compared to stuff like live FDR transmission via satellite.

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peeters
It's hard to design for outlier data. This is the most unusual search in
modern aviation history. It is the outlier. With a couple of exceptions, all
crash zones are found within days.

What makes you think that increasing the battery by a couple of months will
deal with the next extraordinary case? What you're suggesting isn't even an
order of magnitude more, though 30 days is already a couple of orders of
magnitude more than what is needed 98% of the time.

Hindsight is 20/20.

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kenrikm
Or just automatically eject floating GPS beacons on impact. You only need one
good ping to the satellite to define the crash area.

This is not the first time this has happened. After Air France there should
have been some added location method, it took two years to find the black box.

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CamperBob2
This. It's crazy that it doesn't already work this way.

Don't even wait until impact... it should just be the first part that
(intentionally) falls off the plane when a critical sink rate threshold is
crossed.

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HeyLaughingBoy
Are you seriously suggesting that a passenger airliner deliberately eject an
object from itself based on nothing more than the rate at which it is
descending?

Hazard to people or structures below? Hazard to the airplane if it impacts a
control surface? Hazard to the airplane caused by a misfire of the eject
mechanism? Inherent danger of the eject mechanism (I'm assuming it would have
to be a chemical explosive due to the need to get it far away from the
airplane so it doesn't cause the second hazard above)?

Ejection seats have the same problems, but at least their deployment is pilot-
actuated.

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EliRivers
_Hazard to people or structures below?_

Given that they're about to get an aeroplane in the face anyway, an acceptable
increased risk :)

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HeyLaughingBoy
You're assuming (a) no false triggers and (b) the path of the airplane is the
same path the ejected box will take.

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CamperBob2
You'd probably be genuinely disturbed to learn just how often stuff falls off
of planes.

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HeyLaughingBoy
Actually, no: having been a student pilot at one time, I spent a lot of time
reading about the many things that went wrong with airplanes.

That doesn't mean I still don't think this is a bad idea.

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analog31
Dukane Seacom... is that the same company that made the filmstrip projectors
that we dreaded so much in elementary school? Maybe that's where they got the
idea for the beep from.

Sure enough, same company!

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myth_drannon
to see it on the map try
[http://itouchmap.com/latlong.html](http://itouchmap.com/latlong.html) with
lat: -25 long: +101

Sorry I couldn't find a map service that I can share the point

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bdz
[https://www.google.com/maps/place/25°00'00.0"S+101°00'00.0"E...](https://www.google.com/maps/place/25°00'00.0"S+101°00'00.0"E/)

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davidw
Interesting - there's a bunch of detailed satellite imagery in the general
area they've been searching:

[https://www.google.com/maps?q=25%C2%B000%2700.0%22S+101%C2%B...](https://www.google.com/maps?q=25%C2%B000%2700.0%22S+101%C2%B000%2700.0%22E&ie=UTF8&ll=-40.245992,95.844727&spn=30.18728,67.631836&t=h&z=5&iwloc=near)

I'm guessing that this is because of the crash.

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supernova87a
I would suggest to the regulatory/FDR/CVR manufacturers a change to the black
box spec, which causes the pinger to only begin pinging 7 days (or some
threshold) after the crash.

The first few days of pinging are generally useless anyway, because I have not
seen any search where a sea vessel was remotely prepared to search in the
right area or with the right equipment.

Incorporate this delay period (in the absence of anything else), and at least
you get an extra week out of the search potential time window.

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dredmorbius
Your assumption is false. There have been a few notable cases of flight-over-
water crashes in which the correct zone wasn't found quickly, but in the case
of flight 137, ships were over the _presumed_ crash zone within hours of the
aircraft turning up missing.

In other cases, particularly where the crash itself was visually observed (US
Airways 1549, Ethiopian 961, and others) where a multi-day delay in starting
pingers would have been counterproductive.

It's also useful to realize that any change you make on flight recorders
applies to _all_ equipment, needs to be replace on _existing_ aircraft, and
concerns a system which has to work with _very_ high reliability.

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tzs
In some cases a delay in starting the pinger would delay finding the
recorders, but does that actually cause any noticeable harm?

It is important to find the crash site quickly, in order to help any possible
survivors, but the pingers do not help with that, do they? Aren't survivors
found visually or by the emergency locator transmitter?

It could delay the forensics investigation, but that usually takes years to
reach a conclusion anyway and depends on inputs other than the recorders, so
it is not clear that getting the recorders is even on the critical path for
that investigation.

On a different note, I wonder if it would make some sense to have echoers
instead of pingers? That is, instead of automatically sending out a periodic
pulse, they would listen for a pulse and then respond.

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dredmorbius
At best you might want to delay the system by a few hours. Which in the
extreme case doesn't buy you much time.

You've also _really_ complicated the system, as it now has to determine how
it's crashed and where and when to start the pingers. All parts that might
fail.

Simpler to either resolve the time component by 1) installing a larger batter
(or more efficient pinger), or 2) by creating a jettisonable independent
locator beacon, or possible a set of scatterable data recorders.

In the latter case (say: a set of microsd cards), the problem _still_ becomes
"how do you find them*. The size, color, and beacons on existing data
recorders all assist in their recovery.

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lutusp
Quote: "The signal, at 37.5 kHz per second ..."

I haven't seen this construction since the early 1960s, when the new SI units
came into use and people were still confused about the meaning of "Hertz".
"KHz per second" literally means "thousand cycles per second, per second".

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zmanian
Ever since it became clear that MH370 fell through a gap in the civilian air
traffic control system. This has been a story where various nation states
cautiously disclose surveillance capability in order to satiate public demand
for information.

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yogevyuval
Is this 37.5 kHz is a standard frequency for black boxes?

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daturkel
"The pulse signal with a frequency of 37.5 kHz is the standard beacon
frequency for both so-called black boxes -- the cockpit voice recorder and the
flight data recorder, CNN quotes Anish Patel, president of pinger manufacturer
Dukane Seacom, as saying. "They're identical.""

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ttflee
Could it be possible that another black box happened to be found there?

EDIT: I'm just asking a question. Why the down vote anyway?

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InclinedPlane
You seem to be implying that commercial aircraft go missing over the ocean
routinely. That's not the case.

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ttflee
The missing of MH370 itself is an outlier(, unprecedented according to the
Malaysian officials), too. BTW, I was not implying anything.

