Life of Leisure...

La Depeche by any chance :ok:


"...Le signal détecté par la Marine française est bien celui d'une des boîtes noires du vol Paris-Le Caire d'EgyptAir qui s'est abîmé le 19 mai en Méditerranée, a annoncé mardi le Bureau d'enquêtes et d'analyses français (BEA).

"Le signal d'une balise d'un enregistreur de vol a pu être détecté par les équipements de la société Alseamar déployés sur le bâtiment de la Marine Nationale Laplace", a indiqué dans un communiqué le directeur du BEA Rémi Jouty, après l'annonce par les autorités égyptiennes de la détection par un navire de la Marine française de "signaux émanant probablement" d'une des deux boîtes noires de l'A320 d'EgyptAir.

And no, I'm not going to do an a full "in English, please", other than emphasise that the BEA boss is saying the signals probably come from from one of the two black boxes...

Lonewolf 50

Yes, it is the solution in search of problem on hand. A0283 explained it well.

Even after 14 days if SAR teams are not sure where it went down, how long it is going to take to recover FDR/CVR. There is near zero possibility of recovering human remains.

Arial search happens at 150+ knots, underwater search moves at 3 knots. DFIRS eliminates the FDR/CVR search part, gives exact coordinates where it went down, so SAR teams can work on recovery and aviation accident investigators can start their investigation immediately.

BDS P8-A (a B737 platform) sports DFIRS 2100, so why can't BCA B737/B787 or B777.

Not planning to discuss this technology on this thread, but want to share there are proven solutions for this problem.

Wiggy,

Yes, La Depeche. You are right in translating "a pu être détecté" as "may have been detected", so not definite, but intereting that he has issued a statement. The newspaper seems to be more definite in its interpretation.

Edited to add: BBC also now reporting the BEA statement.

my reading is "people have been able to detect the signal"

pax, you are right, in French we do not have the distinction can/may.
Thus the sentence is quite affirmative.

wiggy, translating La Dépèche : "The signal is definetely coming from one of the recorders..."
in the next sentence the BEA boss says the signal has been detected (like pax has emphazised), recalling that Egypt had, before that, announced it was probable.
Thats is a logical chronology : first probable (source Aegypt), then certain (source BEA)

BTW French people often make mistakes just because they use "can" for "may" or conversely !

That would have to be 5 ground stations. The satellites were shut down in 2009...

And thanks to Alain67 for explaining that 'nicety' of translation from French to English!

So, back on track - can we now assume that the BEA is saying that a signal has been identified as definitely from a flight recorder?

I think it would be fairer to say that a signal has ben received, the characteristics of which are typical of a flight recorder, and the probability of picking up a false signal in this area is small so it is very probably a flight recorder..

not sure what satellites you are referring to...

the copas-sarsat satellite system is fully functional

I agree, O Ancient One. But I would like to know if the BEA is actually saying something firmer than 'probability'.

Assuming this is actually it, has anyone idea how long it takes to raise it from the those depths?

Detector 6000
 

Alseamar system on H/V Laplace
Not sure how this system work, but it seems different from other trailed beacon locators. They say it's unique, and imerged at 1.000 meters deep, this system can discriminate CVR/FDR signal at a range of +4.000 m. It looks more like sono buoys.


http://www.meretmarine.com/sites/def...00%20Totem.jpg

Now that we know of u/w signals having been detected by means yet unknown and that such emissions are likely to be from the DFDR could those with knowledge and expertise please of such- sub surface searches inform us of the acoustic/detection range of these signals.

ps whilst typing the above I just read takata`s post which says 4m, but at 1000m depth. Given the wreckage may be lying at greater depth, what then would the range be.

That's for their system DETECTOR 1000 but I guess it's the same for greater depth :
http://www.acsa-alcen.com/positioning-acoustics/detector-1000

Chronus,

That's the French way of writing +4,000 m.

In that case they must be well within sniffing distance, even for someone bunged up with a heavy cold, I would have thought.

Is it not therefore time to pop something down there for a quick look see.

Ta India4, Gallic things do rather baffle me, give me simple things like feet and inches. By the look of it got excited over nothing. But there again, must say am a bit surprised that these u/w things can detect such small objects at such range. I suppose it is all to do with the Hunt for Red October type of under water going ons.

121.5/243.0 no longer used on Sats, at least by US
 

The 121.5/243.0 was shut down, at least for the US. All ELT's were supposed to transmit on 406 by 2009, so they stopped listening. Sadly, most ELT's in the US are still not on 406, which means now ELT searches require a lot more work, almost always just to find a false alarm. In the past, COSPAS-SARSAT fixes would give a working area, based on doppler processing of 121.4/243.0, and that would usually resolve to a metropolitan area where a ground team could quickly find it. Now, we get reports from high altitude aircraft who hear it on guard, and have to launch SAR aircraft just to find out the general area of the ELT. :ugh:

How deep is the seabed there anyway?

not yet reported but the " general " area is claimed to be about 3000 Meters deep

Very deep. 3000m +.

@notapilot: the wreckage is lying at a depth of around 3,000 meters; It wasn't a fix for the lack of other means, this system is supposed to be more efficient (like 20 times faster) than classical towed pinger locators. Egyptians already used Alseamar services for Sharm-El-Sheikh crash and the Russians at Sotchi.

@Coagie: detection range is said "typically 4-5 km", which doesn't mean it's under near perfect conditions but rather an operational range. But you are right, this system doesn't need either a dedicated ship to operate and can be deployed fast enough and at long distance from whatever asset available on the spot. H/V Laplace was close enough to be send there though.

ELB Run Time
 

The usual ULBs have a run time of 30 days. Certainly in the case of AF447 that run time was not adequate. In the case of MH370 there was probably no satisfactory search area to even begin looking for an ULB.

While ULB technology may seem archaic - how often does the 30 day run time and short detection range really make any difference?

After AF447 there were proposals to require 90 days of run time instead of 30. Would that have helped find any aircraft lost at sea in the last 10 years?

https://www.easa.europa.eu/system/fi...%202012-16.pdf

With the searches of recent years I would have tried for the following modest improvements in ULBs:

Very accurately controlled frequency: Not 36.5-38.5 KHz but something more like 37.5 +/- 3 Hz. Easy to attain with current technology. And this would allow use of serious digital signal processing methods to extend the range by a factor of 5 to 10 (a guess without serious calculations)

Reduced on-time after the battery gets below something like 40% capacity
Further reduction at 20% with a goal of 6 months run time.

Frequency shift modulation might be nice - encoding the aircraft ID.
Easy to do with a very slow rate and very small deviation.

Dukane has been offering a 3 month run time ULB for quite awhile.

As a design engineer I could list 5 or 10 more wonderful features... but my view is that what we have now is very nearly adequate - if not satisfying all of our wishes for easy recover of the FDR and CVR.

We have come a long way from the FAA proposed specs of 1968 - which was when I was working on avionics! Among other things: 200 foot depth range

http://www.fire.tc.faa.gov/pdf/na68-7.pdf

edited ELB/ULB error, hat tip to Coagie!

The locus of "French Warship" (LaPLace?) at 19:49:56z was 33° 25'N 29° 14'E. The water depth at that point is 3,024m (9,921').

Call it 10,000' in old money.

Think in terms of flying at FL100 and trying to find a sound, somewhere in a hundred square mile search zone below you, which to the human ear in air is pretty much like the sound volume and pitch of clacking of the backs of two teaspoons together.

As an ancient mariner, I spent some brief time standing sonar watches in a destroyer. It was important to know the sea's thermal profile vs. depth, which affects the transmission and refraction of sound through the sea. For that, a bathythermograph device was lowered into the sea. Technology has undoubtedly changed, but I wonder what devices can measure the temperature profile down to, say, 4,000m? Or maybe, past a thousand feet, or so, it doesn't matter that much?

It matters very much indeed.

A device is lowered through the water column, recording temperature, salinity and depth continuously.

The thermoclines and haloclines are then calculable and shadow zones can be identified.

The Med in summer is a bit of a bugger. Cold dense seawater flows in to the Med through the Straights of Gibraltar at depth and stale warm water flow over it in the opposite direction. This is further complicated by evaporation which itself increases salinity and therefore density. The multiple layers are a complication which cannot be ignored and must be allowed for in survey run-line planning on a job such as this.

OTOH, in the case of Air France Flight 447, they recovered 104 bodies from the wreckage lying at 3980 meters depth some 700 days after the flight was lost. ( https://en.wikipedia.org/wiki/Air_Fr...h_and_recovery )

@2ndpilot
 

Jean-Paul Troadec has done a bit more than x-raying suitcases ...
https://en.wikipedia.org/wiki/Jean-Paul_Troadec

Original statement by Troadec:

Source: francetvinfo

"Grâce aux messages des instruments de bord de l'avion" should mean ACARS, or maybe some QAR information may be available from previous flights?

Edit: Troadec quite enjoys seeing himself regularly on french television these days. He was one of the "experts" who favored the terrorist theory even before wreckage was found and called a technical defect "unlikely".

Yes, he's actually President of the BEA, France's equivalent of the AAIB/NTSB. Which makes it even more surprising that he would come out with easily disprovable nonsense. Is it possible that these "new findings" have lost something in translation?

He was President of BEA. Wikipedia article is outdated.

Dave

To add to what thf has said:

AFAIK Remi Jouty is the current president/director of the BEA and has been for a couple of years...and TBH I can't really argue with thf's opinion that Mr Troadec has become one of French TV's aviation talking heads who pop up on TV in the wake of incidents and accidents..

Thought: could Troudec have been referring to the A320 in general, even though the article makes it sound like he was talking about the airframe involved in the crash?

Hi, French SLF here.

Media outlets cite "France 3" (TV station) and "Le Parisien" (newspaper) as the original posters of these new "findings".

Le Parisien's article :
Vol d?Egyptair : l?Airbus A 320 avait émis trois alertes lors des vols précédents

They don't talk about emergency landings, but rather about "alert messages" related to smoke detectors happening each time at take-off from Asmara, Tunis and Cairo, and not triggering any kind of emergency procedure from the crew.
They also state that the relations between French and Egyptian investigators seem to be "bad to say the least".

They phrase everything beginning with "according to our sources", without citing any, so take it as you will.

@DaveReidUK, no doubt, Troadec was refering to this particular airframe. It looks like just another leak of maintenance data, if that's true (they don't have the specific data and and can't say what emergency caused landings).

I'm watching the interview, JP Troadec was simply questioned during the News about this information revealed by the "News staff of France 3"; he commented that he wasn't aware of that, and cautiously said that the investigators would take that into account for their inquiry but needed much more detail about it. So, Troadec, former head of BEA (the man leading AF447 investigation) is obviously not at the origin of the leak.

http://www.francetvinfo.fr/monde/eur...h_1479713.html

More details there :
Vol d'Egyptair : l'Airbus A 320 avait émis trois alertes lors des vols précédents

Three alerts probably with smoke detectors on previous flights on the same day.
The same article reports lot of tension between french and egyptian investigators.

@thf
Or French TV like questioning him, considering his background and references. Nonetheless, during this inteview, he told that terrorism thesis has been first to come to mind only based on pure geopolitical considerations, but such thesis was never backed up by any factual information. After ACARS leak and "last week informations" (no specific) this case was more likely oriented toward technical issues.

This new information from "France 3" is also based on ACARS from previous flights they put their hand on (without saying where they came from).

Which is why the ULB should modulate its signal with the last GPS location as was suggested on the AF447 thread. Just think what could be achieved by a ULB that was more intelligently designed and powered by a battery with a longer life.

And for all the 'what is the hurry we will find it' group - the huge expense of a search of 3 weeks with the possibility that the DFDR/CVR may not be found leading to significant assets being deployed, should be compared to a search that takes a few days and a simple SONAR buoy drop followed by recovery.

I still say that the costs of the search should be charged to the airline (insurance) company. That is the only way that funding will become available for a constructive approach to the retrieval of this information in future crashes. With more transoceanic routes being set up we can expect to see more of these searches not less.

@Ian W - My impression is that the points you mention (GPS mod, batt life, expense, charging, transoceanic routes, ...) all make sense. And should be included in discussions in solving the issues that have become clear with (RedSea), AF447, MH370, AirAsia, and now Egyptair.

One of the issues that has to be solved is what the cost of such a search is. You need that to focus the related solution efforts (engineering, manufacturing, operations, maintenance, training, etc). That would require a very serious effort by itself. The perception of people and parties in this respect varies wildly and is changing. The Australian government for example had the opinion early in the search for MH370 that 'we have these assets anyway, so there is no cost'. They have been forced to change their opinion since. The Fugro contract is an example of part of a possible search cost.

I have collected data during the MH370 and AirAsia searches and used that to make an estimate of the actual cost of such an effort. The numbers get very very big. How big, that depends for instance on how much of the cost of a SAR infrastructure, and shared use of military resources is allocated to a specific search. Such an allocation means that insurers and airlines would never be charged the 'full costs'. In that sense in the end it would probably look more like setting a 'price'. Where the price is lower than the cost.

DR

Having just seen French lunchtime news I suspect you (and Squawk Ident) are right - there does appear to a bit of backtracking going.

I apologise if this has been discussed previously. It has been commented on that needing the retrieve 'black boxes' from burnout wrecks in inhospitable places, or from the bottom of oceans, in 21st century seems very old tech. This scenario seems a case in point. AF447 was sending ACARS data back to base, as was the QA A380 with its engine blow up. Is there enough satellite data storage for every a/c to send back FDR/CVR data in live time? The data could be overwritten every 60/90/120mins, what ever is decided by the authorities. There would, of course, be confidentiality protocols as per OFDM's. All modern jets have GPS nav systems. Why not install at manufacture a satellite data transmitter; mandatory to counter those cost cutters. I'm sure it would not be expensive with economy of scale. What has been the cost of searching for; Air India in the Atlantic, AF447, MH370, many others & now this Egypt air?