AF 447 Search to resume
 

NOSJOURNAAL - Nieuwe zoektocht naar Franse Airbus

The search for the FDR and CVR is to resume according to a French junior minister during a commemoration service in Brazil.

He stated the renewed search will commence in February.

AFP: Vol AF 447: crmonie sobre Rio en souvenir des 228 victimes

According to this document the statement is to be attributed to Maarten, a spokesperson for the victims. His statement (at the bottom) is however not a request or hope but seems to be a statement of fact.

Tailstrikecharlie,
Acting your age, I see. Your remark is so infantile .....

Apart from that, I suppose there is already a discussion about the likelihood of finding a widely scattered wreckage field at a depth in the order of two to four thousand metres, after months, with any clues like the under-water beacons now silent?
Leave alone finding a couple of small rectangular boxes, similar in size and appearance to a lot of other "stuff" .... AFCS computers, for instance? ... which by now have probably sunk into the bottom silt.

Any link to a halfway sane discussion would be welcome.

CJ

Although extremely remote, the possibility of finding the boxes exists. It's been done before ( SAA off Mauritius ). It would an incridible strike of luck and a more than welcome one. I can understand the families want answers but the aviation community too. Whatever the findings, it will be something to act on and will put a stop to these pathetic drivels like the senile one above.
Seeing the commoration on Tv only triggers thoughts of sadness, anger and frustration at not being able to provide answers and corrective actions.
I never gave 2 thoughts about travelling on a 330, but now and time isn't helping, I have to admit that if given the choice, I'd rather fly on a 777. That's one of the reasons I'd really like to see those boxes found.
Tailstrikecharles, french kids often say " celui qui dit, c'est celui qui est " which translate like :
You are only projecting your own sick and wicked thoughts.
Maybe you're in the habit of cooking the books in your professional life ??

A day or two after this accident one of the top salvage experts was interviewd on BBC Radio 4's Today programme. He was adamant that the recorders could be recovered. He also said the task would not be easy but said that it had been done before. I suppose it's possible he was touting for the business but it didn't come across that way.

From my perspective as an employee of an OEM, finding the boxes is incredibly important. National or Manufacturer prestige is secondary to determining the cause. There is so much more at stake.

Also, since it will likely come up, in my two plus decades of experience, there is no personal animosity between the two primary OEM's from honorable employees. While there is pride in our respective products, there is also a mutual respect, as well as sympathy when the other has an event.

I've found that the A vs. B arguments -as a rule- are not instigated from folks who actually work for A or B, rather, they are championed by those who have very little, if any, "skin in the game" and are generally dismissed by those of us who do.

This article mentions that the 3rd phase of the search was expected to start before year´s end but is now postponed "until at least the end of February":

Air France crash memorial in Rio amid criticism | ajc.com

That´s four months away. While a delay of a few months may not matter much at this stage, what might be the reason? Bad weather conditions this time of the year? Boats and equipment not available right now? Nobody wants to pay Christmas bonuses to the searchers?

RE the timing for resuming the search.

I would guess (and it's only that) the main reason for the delay is due to arranging for the most appropriate equipment for the task. The actual search equipment used for the first search, though very good at what it was intended for, was not necessarily the best for that specific task. In the past couple of years (months even) several new submersibles have been developed that would be significantly more effective. The main problem is these vehicles are not just sitting around waiting for someone to call and book them. Once developed and available they very quickly get booked full time for research (usually academic) for years.

I would suggest that it has taken a great deal of negotiation (and money of course) to secure the appropriate equipment, and to do so for the length of time needed to complete a thorough and adequate search.

grizz

Who is paying the cost of the extended (new) search?

Does anyone know how deep manned or unmaned subs can go; I thought it was less than a mile. I know the Titanic was fairly deep.

Why do they not make responders for underwater "listen" , rather than sending out pulses when no one is listening . This way the recorders could "live" for months in listen mode . Hear a sonar and then respond with a stronger beacon signal.

Best suggestion I've heard for a long time. Any manufacturers here like to comment?

Another candidate for the auto-ignore button.

grizz, 11fan, a couple of fine contributions to the discussion. I think your posts reflect the opinions of those who know and do this work: Finding the boxes is extremely important.

Edit: Auto-ignore button highly recommended.

Titanic is 2.5 miles down, give or take. Google Woodshole Oceanographic Research facility and Dr. Robert Ballard.

In order to listen, the beacon would have to expend constant power. By pinging, it doesn't use power between pings. I would agree that a louder but less frequent ping would seem to make a lot of sense.

As for the recorders, its not so much how deep they are as how mountainous the terrain in that part of the ocean is. If it was all perfectly flat and just really deep, I think they would find it pretty easy. With terrain to deal with, debris can shift and keeping ROV's off the bottom becomes much harder. The boxes could be between 2500 and nearly 4000 meters of water in that part of the ocean. The "Jason" ROV can operate down to 6000 meters.

Both Air France and Airbus are.

time
 

Looked at the Woods Hole site and their equipment pretty well booked out for 2010...which jibes with the poster upstream remarks about these type of top notch vessels pretty well tied up and not available on the fly routinely. I would also think that the time frame stated may be a period of better weather in the area also.

I also agree with the 'not a vs b' comment upthread...aviation accidents and their full and complete investigations benefit everyone. Incomplete investigations more often than not only create more questions than answers and thereby an even larger area of uncertainty.

I was surprised by the minimal assistance from other major military powers both right after the incident and later. Yes...it was a Brazil and French show and perhaps that held back some assistance besides the US P3 and the towed array. When the pingers were still active I would think it would have been a great training scenario....and would be even now. The US Navy brought in Cdr Ballard to find the Scorpion and Thresher...and that same Navy owns Alvin from Woods Hole....there is a lot of US parts in that aircraft and it has been under consideration as a replacement tanker for the USAF so there are good reasons for further participation.

Why do we still need CVRs and FDRs as pyhisical boxes onboard the aircraft ? Perhaps we should be looking at a better from of data recovery,would it not be possible in these high tech days to be able to fit a permanent satellite uplink from each aircraft ,that downloads to an airlines own server. Its server could constantly scan and monitor the data and possibly be able to spot a developing problem that the crew are not yet aware of and warn them ? The systems storage could be a controlled quarantine area where aircraft data could be stored for an indefinite period to aid accident investagation if needed.

Good to see there IS some sane discussion!
Even if interspersed with nonsense (I thought Habsheim was settled, except among the conspiracy bats).

As to djp's suggestion about a "listener".... I like it!
Contrary to what tuj says, "listening", with modern technology, would consume far less power than regular "pings".
So pinging for a few weeks, then listening for a few months, is a good idea. It would need a new module inside the FDR and CVR (or rather inside the beacon), which doesn't exist yet, so whether there will be enough of an impetus to update the beacons, for what is a rare occurrence, is an open question.

Totally agree with tuj's other remarks. It's almost like the search for Steve Fossett's plane, and over a similar or larger area, and a few miles down under the sea. And no way a hiker will stumble on the wreckage this time....

CJ

PS for tuj
I know it's a lousy analogy.... but look at a kitchen timer.
The very much passive timer display uses extremely little power. The battery usually would die from old age rather than being exhausted... we're talking microwatts.
Your kitchen timer bleeper puts out milliwatts of sound each time. Use it every day, and you have to replace the battery every year.

As I said, not a very good analogy, but a "listener" circuit would still use an order of battery capacity less than a "pinger.

With all the other issues of "equipment".
I would think they'd now have to look for a far larger wreckage field in a far less known location...
I would also think far less of AF447 is still in one piece, so the analogy with the Titanic or the Scorpion or Thresher doesn't really hold.
On a 'messy' rocky seabed how are you going to distinguish something the size of an FDR from the rock next to it?
I'm not even sure the tools exist....

CJ

28 days of pinging is usually sufficient to find the black boxes. Sure you could make the pings last for longer but this would mean a larger battery pack, adding weight too. Where do you draw the line at size, capabilities, amount of data held etc? So far 28 days has proved adequate on all but a handful of occasions. The Airbus that crashed in the Black Sea had its boxes recovered despite one being buried in sediment.
I am lead to believe that it is most likely to be the undersea terrain that has caused issues with finding AF447, with resembalnce to underwater Alps. If the boxes have slid into the equivalent of a ravine, they will never be found.
Look here for the Black Sea incident:
News and Events > Latest News > Press Release : Sonardyne International Ltd.

Why not have floating black boxes? After all a lot of the lightweight stuff did float up to the surface.

This was already discussed elsewhere on PPRuNe, somebody can probably post a link.
Two issues...
- The huge amount of (expensive) bandwidth needed to transmit/receive/process 99.999% useless data,
- The simple fact, that in extreme occurrences such as AF447, your "permanent" satellite uplink would already have been interrupted by an extreme aircraft attitude, total power failure, fire, explosive decompression destroying the sattelite aerial and wiring, etc. ... and the final few seconds/minutes of data would never be transmitted....

CJ

I agree that maybe the final few seconds in some instances data may lost because of aircraft break up loss of electrical power (although easily solved with built in power supply),But on the other hand the possibility remains that the ground based computer may have spotted a trend or some such and been able to avert an incident before it was critical. Bandwidh may be expensive but in real terms, the possible preventative safety issue should be paramount .

HamishMcBush, thanks for a lot for your link.
This was obviously one of those occasions....

All I can say... I wish the newly announced search effort all the best of luck

CJ

Here is what I don't understand. The French had submarines looking for the wreckage, right? Submarines have all this high tech sonar systems designed to hunt for other subs. There is a black box, transmitting a ping out there, saying "find me", and they can't locate it?

Doesn't make any sense. They can find submarines that are trying not to be found, yet they can't locate a box that is begging to be found. :ugh:

ChristiaanJ
I explained data streaming ( continuous down linking via Iridium satellites of aircraft parameters ) in some post in the original AF447 thread .

Details can be found at AeroMechanical Services Ltd. - afirs Up Time

The system already is in place but mainly for VIP jets as it is expensive indeed.
Also , as you very correctly pointed out, the last seconds , possibly even the last minute, would probably be missing in our case.

Another idea would be to have a small amount of radioactive material being released inside the recorders after a certain depth ( say 1000m or so ) enabling some military sensors to detect the anomaly and the location. Not sure of the accuracy of those sensors though. Possibly something for the future.

As to the duration of the "PINGS " I was told they weaken with time , but still can be read after a very, very long time. Much longer than 28 days.
The recorders of the KAL o7 B747 shot down over Sakhalin island was retrieved by the Russian Navy more than a year after its demise.
But they were not laying down at 4000m .

Can they even be sure the boxes can survive the extreme water pressures at those depths? Something in the order of several tons per sq inch trying to crush it

It would seem that the dustman has swept through the thread and performed some cleaning.

I'll have to say, there are some reasonable posts here. Most of these thoughts were addressed in the long-running AF447 thread, but that said, good dialogue so far.

Regarding "bursts or real time data transmission, ChristianJ summed it up well.

I would also suggest that HamishMcBush's post tells a lot of the story.

Specifically.....

Regards to all,
11Fan

Perhaps the delay until Feb. is due the depth of the thermocline in the search area? The more shallow the thermocline, the less costly it would be to get a submarine or listening device beneath it.

Quoting from that site:
"The afirs unit is an avionics component that resides on the aircraft. The afirs unit monitors the various systems on the aircraft, and when certain events are detected information is transmitted via Iridium satellite."
When certain events occur....... is the key.
Very much like the ACARS messages from flight AF447.

The continuous data stream into the FDR includes far, far more parameters, llike attitude (all axes), airspeed, engine parameters, control surface positions, etc., sampled every few seconds, sometimes even more often.
It's way, way beyond what could be transmitted via a satellite link, or stored and managed at the receiving end, for the tens of thousands of commercial flights in the air at any one time.

Same difference....
As with djp's excellent idea, it's not in place.
And with accidents as that of AF447 being extremely rare, it's highly unlikely there will ever be any 'rule-making' about making it mandatory.

CJ

Good question.
I'm not sure what type of recording system was used in that A330's FDR.
But if it was any kind of solid-state memory recording, it might crush the boxes, but not the memory chips.

CJ

On pinger life, this website says that Dukane, the locator beacon's battery manufacturer reports battery life drops of significantly after 30 days.

On underwater search methods, the same site explains how an untethered Automated Underwater Vehicle (AUV) was evaluated to search for AF447's locator beacon.

Here is an interesting whitepaper, discussing how the Ark Royal was found, etc. (note: link downloads a .pdf file).

ChristianJ;
Depending upon the data frame programming, up to 40,000 parameters are available on later types but realistically, between 2000 and 3000 parameters can be done in a FOQA Program. DFDRs typically capture between 300 and 1000 parameters at varying sample rates. QARs, (optical disc, PCMCIA card etc) will almost always have higher sampling rates than DFDRs which for some parameters, ('g', control stick position etc) increases the usefulness - just like a strobe-light going off at ten times a second is more useful in a dark room than once every 4 seconds...QED.

I am aware from others' contributions of some technologies which can transmit such data on available satellite bandwidths which have been touted as "cost effective". Trouble is, I haven't seen the boxes and I have already commented on the Aeromechanical Services solution on the Tech Log thread. The security of the data is paramount and so far, no one advancing these "solutions" has broached or discussed the topic.

PJ2

I understand that military transports can deploy floating recorders.

Cheers,


Dick

Dick, others offering thoughts on this kind of solution;

"Deploying the recorders" is a variation on the solution (squirting out selected parameters as per the Aeromechanical model), which also relies upon the triggering of a "mission threatening event". How is that "event" or series of events defined? How would false alarms be prevented while still sending out the last critical information or deploying the recorders before catastrophic failure of the platform or loss of all electrics?

By the way, I don't think any such system (deploying recorders) exists but that is beside the point.

We are focussing far too narrowly on a solution that is trying to solve the frustration over the loss of AF447's recorders. What other problems does such a solution resolve? At what expense in terms of money and dedication of resources; with which other flight safety projects or solutions must this concept compete?

It isn't applicable to the majority of aircraft losses where either the recorders survived or were later recovered from a body of water. It has been mentioned a number of times on all AF447-related threads: the number of accidents which remain an enigma and for which we have no clue as to what happened are rare.

Real-time transmission by satellite may become a doable and accepted technology. I have already discussed the security issues which stand in the way of such an approach. They are only partially technical in nature. At some point the will to "do the right thing" will be overtaken by financial considerations and the true reason for the existence of flight data will become moot. Like cockpit video recorders, it can be done but thus far no one has ever come up with a solid process by which such data is not appropriated by the likes of CNN, Fox "News" or You-tube or in the case of flight data, lawyers.

PJ2

Let´s not forget that the entire underwater locator beacon only weighs 200 grams or so. The battery lasts for 30 days because that´s the present specification. Adding battery power for another 30 days or even more would be easily done.

From reading the papers, it would appear that a lot of days were wasted before they got a submarine on site to listen for the pings.

One suggestion already posted here somewhere is to store a copy of all FDR/CVR data in a small, lightweight and fairly "unprotected" memory compartment in the vertical stabilizer.

In recent impacts on water the stabilizer floated and was quickly found in a pretty much intact condition (e.g. AF 447, AA 587, NZ A320)

http://blog.flightstory.net/wp-conte...af447-tail.jpg

http://poneke.files.wordpress.com/20...irbus-tail.jpg

http://users.rcn.com/dderella/Images...ews/news10.jpg

At different accidents the established fire and crash resistant FDR/CVR would be available.

All-Ex
 

Um, that's the VERTICAL stab...

All-Ex,
It's still an elaborate solution for an extremely rare problem.

Ad what if the aircraft ditches more or less intact, then sinks to 4000 m with the stab still attached? Back to square one.

CJ