grumpyoldgeek:
Maybe they did . . .

@grumpyoldgeek / grizzled

The French Nuclear Attack Submarine "L'Emeraude" (Emerald) was involved in the Phase 1 search using its sophisticated acoustic detection system, which was fine tuned during the search for maximum gain at 37.5kHz using test data developed by retuning a similar detector fitted to another Rubic class sub in the Mediterranean. The detection range was then over 3,000m, but the depth that the sub operated at is not known - "classified?"

The US Navy, US Coastguard and Brazilian Navy were also involved using hardware deployed from the surface. This consequently involved the setting up of UTC (Underwater Traffic Control) to avoid any conflict, particularly with the sub.

mm43

Location of wreckage
 

Would it not be possible to add the GPS coordinates to the ACARS data stream?

It wouldn't appear to take up too much bandwidth.

mm43,
If your "3000m range" figures are roughly in the right ballpark, we're still knee-deep in the soft brown matter.

Add slant range.
Add the fact that the pinger may be over 3000m down, in silt.
Add the directional characteristics of the "acoustic detection system".
You could pass right "overhead", and still not hear it.

CJ

ChristiaanJ

Quote:

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If your "3000m range" figures are roughly in the right ballpark, we're still knee-deep in the soft brown matter.

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Agreed, except as has been pointed out previously, ducting is also possible due to inversions caused by salinity/temperature. Hence the call for the lower pinger frequency to mitigate some of the potential signal loss.

The BEA report,
When it comes to the directional characteristics of the acoustic detection system, I would be surprised if an x/y axial scanning method was not employed by the sub. Would leave it rather vulnerable, if that wasn't the case.

I don't think that a fuselage containing lots of composites within it is going to go to the bottom at such a speed that it is going to dig a hole and bury itself. No, more likely a very gentle bottom landing.

What is missing, is where the fuselage or parts of it landed on the surface before commencing their passage to the bottom!

mm43

mm43,
Apologies, I hadn't yet read the full BEA report.

Any news on the resume of the search?

It was scheduled to February.

An association representing families of victims of the crash of the Air France A330 from Paris and Rio has again denounced on Wednesday a "crisis of confidence" with the BEA deploring in particular the "lack of transparency."

A Vice-President of the association, John Clemens, lamented about the lack of information on the third phase of research at sea which was to begin in early February. "mid-December, the BEA had promised he would get the families to explain the startup of this new phase. Since, there is no news, radio silence.''

Keep in mind Lebanon
 

For those who may wonder how hard it is, keep in mind how long its taken to find the Ethiopon CVR's off Lebanon, and they had half an idea where that went down.

It seems the search will resume at the end of february:

Transport aérien - Reprise prochaine des recherches de l'épave du vol AF447 ::: AEROCONTACT

Here is an English translation of the story linked above:
PARIS, Feb 5 (Reuters) - The search for the wreckage of Air France Flight 447, which was 228 dead in sinking down into the Atlantic on 1 June 2009, will resume in the coming weeks with an international team.

Three vessels specialized in research into shallows very uneven, ranging up to 8,000 meters deep, will be sent on an area of about 1,500 km2 located offshore Brazil, at least ten times larger than that explored in June, at we learned a judicial source.

"Our goal is that research start at the end of February, confirmed on Friday a spokesman for the Office of Investigations and Analysis (BEA), the French agency in charge of administrative investigation, which n has still not made any final conclusions on the causes of the disaster.

The tender is not finalized and the final device is not official yet, "she said.

This will be an operation almost unprecedented in the history of aviation, "very heavy and very complex to rise," said the spokesman.

A working group composed of international experts was formed in October. Air France and Airbus have a budget of ten million euros but it could be far exceeded.

A police officer will be integrated into the device to ensure that the parts that are found are placed under seal.

Two investigating judges in Paris, Sylvie and Yann Zimmermann Daurelle, are charged with a criminal investigation into the accident for "involuntary homicide and injuries".

NOT YET CONCLUSION

Associations of families of victims, which include 72 French, have instituted civil and say they fear that they hide the truth if it proves troublesome for the French aircraft.

They bring into question the independence of BEA and feel uninformed.

Until now, only pieces of the aircraft, including its tail, were rescued at sea, and about fifty bodies. The remains were stored in a research center in Toulouse.

The BEA said in its interim reports that these factors do not suggest the cause of the collapse of the device.

However, Air France was replaced after the accident probes measure pitot speed produced by the French group Thales at the request of the pilots' unions.

The latter believe that freezing at high altitude, the pitot probes can transmit false information to the computer system of the aircraft.

However, the court considers any conclusion impossible without the discovery of new elements, particularly the "black boxes" of AF447, the recording flight data and cockpit voice drivers.

"Without the black boxes, all conclusions on the probes remain in the literature," said a judicial source interviewed by Reuters.

I suppose most people will get the essential from that computer translation.

One detail: "The remains were stored in a research center in Toulouse." The french word "débris" in the original just refers to the debris, or fragments, that have been recovered, not to human remains.

CJ

Reuters has an english short version for the same news:

Air France crash search to resume end February | Reuters

Crashed Ethiopian
 

They've got the FDR.

Black box from crashed Ethiopian jet is found 150ft under the sea - The Scotsman

Please see Ethiopian thread.

I know i'm not really supposed to be in this area as i'm not a professional but could someone tell me what the chances are of data being able to be recovered from the recorders if they have been in the sea that long, or is this irrelevant?

Also, what are the chances do you think as a Pilot or an Aviation Expert, Engineer, etc. of the recorders actually being found by search teams?

Modern flight data recorders use solid state storage for the data - think 'flash memory' chips.
Those are pretty sturdy, and will probably have survived even at the depths we're talking about, even if the "black box" itself is crushed or otherwise damaged.
It's been done, and there are a few specialised labs that can take this on.

Speaking as an engineer, I think all bets are off. It's still worth a try, in case some of the wreckage is still in one place. Otherwise, with the 'pingers' now silent, it'll be the proverbial needle in a haystack, or worse.

CJ

Black boxes may be superseded:
Aero-News Network: The Aviation and Aerospace World's Daily/Real-Time News and Information Service

Quote from the article linked in the previous post...
"Wi-SKY Inflight is engaged in deploying ground stations throughout North America and Europe to support the first phases of their air-to-ground network. Base stations are needed every 200 miles, which is about 125 to 150 stations in both North America and Europe".

Could somebody remind me how wide the Atlantic is, or how far AF447 was from land?

CJ

Not again, please! :ugh:
It's pointless putting substitute data provision where is not needed (FDR lands on the ground), instead of where it is needed (FDR falls into the ocean).