the interim report no 1 in English - AF447

https://www.bea.aero/docspa/2009/f-c...90601e1.en.pdf

and an excerpt re ACARS p50-51


and the flow...

Attachment 415

Will the Egyptian authorities be able to analyse the FDR and CVR or does this need the expertise of the units' manufacturer? If the French are not given access directly I don't think we will ever learn the truth. Who is the manufacture of the CVR and FDR on the A320?

Surely whatever happened could also be seen by the British military radar on Cyprus. The crash site seems to be approximately equidistant between Crete, Cyprus and Egypt.

@vmandr
 

Thanks for retrieving the English version of AF447 Interim 1 report.:ok:
I feel the answer to Ranger One's query is contained in pages 25 to 27 where the BEA explains the one minute "correlation window" principle that regroups alarms upon priority.

You would think so. Even Nicosia probably had it.

@mross The Egyptians have stated earlier that the recorders would be read by the Egyptian authorities. Unless the damage would be too severe. Then the recorders would be sent to a 'foreign' specialist/manufacturer. Which is normal practice in cases like these.

Also note that the BEA and other parties are represented in the investigation. These parties will know. But in the case of AirAsia, in spite of explicit requests from the BEA, for instance the CVR data was not published 'en plein publique'. So lessons learned are not shared in full, which of course detracts from the value of a safety investigation.

My impression is that ACARS information would not have been adressed by the parties involved if they had not been 'leaked' earlier. Also, I think that modern day requirements for earlier public disclosure of known (and checked) and unknown facts is something that cannot be ignored by authorities. The case of MH370 has shown what it does to the credibility of authorities if they do not act properly in this respect. If the authorities do not publish these fact, then they run the risk of information being leaked that contains information that should not be leaked, like for instance privacy and such details.

I know what the Egyptians said, but wondered if they had the capability? Much of what they say seems ill-informed!

@mross - what an Egyptian spokesman said is that they have the read-out capability. Which is getting more and more common. What they also said suggests that they do not have a large specialist lab. When you have to go there, then you are often close to going or working together with the manufacturers of the recorders anyway. So that is normal too.
I have no inside information on what they actually have. But it is clear that more countries are working on getting more capabilities in this field.

Indeed. And it is very re-assuring they are being discrete about it. If they have anything it is reasonable to assume that conversations through the appropriate channels have been had.

No need to add to the feeding frenzy of amateur conjecture on here.

It depends whether it's actually switched on. My last source was about three years ago, but at that time the cyprus Watchman radar had been switched off for years because interference from egypt (allegedly) created a picture that the SATCO didn't like.

Also looking at the projected location it would have been, what, a couple of hundred miles from Akotiri? Would that be within PSR or SSR range? (I genuinely don't know - hence asking the question!)

With respect...

sitigeltfel did not suggest "a high speed inpact was the definitive prime force" etc. What he, and klintE and myself were pointing out is that the statement by the Egyptian "forensic expert" -- that the condition of the remains proved the existence of an explosion -- was both incorrect and premature. That's all.

Contrary to your assertion, we (aviation professionals), at least those of us with experience in accident investigation, are not accepting any cause at this point. And I certainly have no problem accepting that foul play could be involved. Or not. Time, and the evidence, will tell.

Most airlines these days have quality assurance programs based on QAR readouts and analysis, the data on the FDR-s is identical, if the interfaces are not compromised then with the right software the data readout is as straight forward as looking at pictures on a SD card. It only becomes tricky if the interface or the memory module itself is damaged (which could be the case given the intensity of the impact). Similarly the CVR records digital audio, it can be easily read out by the right software with the appropriate interface.

Are things really that bad in Egypt?

Please read all thread before posting!!!!!
 

Exactly Scott. You have answered your own question. The reason your post has likely been removed is this was all discussed much earlier in this thread so your query is a duplication.

Why don't people read THE WHOLE THREAD before posting duplicate BS? Most questions being asked here have been answered more than once already.:{

Looking at the "marinetraffic dot com" web site the vessel "PMS Burullus" is engaged in what has to be a search pattern! About 200 miles NNW of Alexandria. Shows as a pale blue diamond on the web site, but look at its recent track.

goeasy,

People don't generally have all day to read 40 pages worth of nonsense?

According to the marinetraffic web site the vessel "PMS Burullus" has spent the past 10 hours in a rectangular grid pattern searching an area just 1Km by 400 metres. You have to zoom right in to see the pattern. All done with the vessel pointing NE, which means it has been reversing and crabbing its way around most of the time moving very very slowly.

I wonder if they are "on to something"?

Fingers crossed for the sake of all involved.

goeasy is correct..it was discussed..but as long as chunks of discussion ( no doubt deemed to be off topic) are being deleted there's bound to be an on going game of whack-a-mole....

The airport radars may have been switched off but the larger ones higher up on Cyprus almost certainly were not. I would be very surprised if that area of the Mediterranean was not in solid radar cover from several sources other than the normal ATC systems. However, none of them will be eager to publicly declare their coverage.

True enough, but what people can do (should do) before posting a question, or media quote, is do a quick word search of the thread. That takes but a minute or two and saves the rest of the readers having to endure multiple repeats, and perhaps saves the poster being embarrassed, or exposed to the slings and arrows of other ppruners...

Screen Grab of the PMS Burulla track for the last few hours.

(Courtesy AIS Vessel Tracking)

Attachment 417

Dark Matter

It is worth pointing out that the "grid" you can see is approx 1km in the North South direction and just 450 metres East West. Each sweep is just over 200 metres from the last.

It strikes me that this is too "fine" a grid for a pinger search - and rather more a sonar search. Each pass would have to sweep a 200 metre or so wide path, but I rather hope somone with undersea submerisble/sonar expertise might step forward.

Not an expert, but with a little experience, yes, AT1, that's a sonar search pattern.

I believe that either during or subsequent to the accident where the Egyptian authorities violently disagreed with the NTSB conclusions (the suicide vs flight controls failure one) that the Egyptians bought a FDR etc lab capability from FlightScape, now CAE-Flightscape, which is the software provider to a number of the "big" accident agencies (if you've seen a recent "official" FDR plot, chances are you've seen a Flightscape plot).

While having the kit doesn't always equate to having the expertise, I think it's safe to say they do have the ability to do what they say, unless, as has been mentioned, the units are so badly damaged only the original manufacturer can read them (which can be the case with the "big boys" as well)

Mad F S: " While having the kit doesn't always equate to having the expertise."
Agree. Take the example of the A320's FBW flight controls. If an FDR trace shows a given sidestick input and a control surface moving in a certain direction, how to know whether the plane behaved as designed? I'd venture that the way to know is to ask Airbus not the Egyptians.

'decoding' digital FDRs
 

I found a fascinating article on 'decoding' digital FDRs on BEA's website. Even if the Egyptians have the equipment it may not be plain sailing. The CVR is probably much easier. Article is in English.

Correct me if I'm wrong but AF447 ACARS was received via Satcom. In Egypt Air 804's case the ACARS was received by a ground station via VHF or VDL mode 2. For this reason it would not be ideal to draw too many comparisons. But there are a few points that are in line with the AF447 report:

ACARS does not transmit all ECAM's it is a subset that is programmed by the operator. This may introduce some differences between operators.

The messages are not real time, the data is processed before transmission and placed in a queue. This may result in a delay before a message is transmitted.

In addition, ACARS in VHF mode only transmits at 2400bps and there is no round trip confirmation in any mode.

If the aircraft was severely damaged (fire, decompression, bomb etc.) one would not expect comprehensive ACARS messaging; only a short burst that is a subset of the faults or cautions that existed. The ACARS transmissions may well be consistent even with a rapid decompression. However, the evidence points to the aircraft colliding with the sea at high speed and largely intact.

Many of the theories proposed in this thread are not consistent with the "evidence" so far (if any of it is true?!). There are quite a few things that can be ruled out as very unlikely already.

J. Kitaori, "A performance comparison between VDL mode 2 and VHF ACARS by protocol simulator," 2009 IEEE/AIAA 28th Digital Avionics Systems Conference, Orlando, FL, 2009, pp. 4.B.3-1-4.B.3-8.
doi: 10.1109/DASC.2009.5347498

Abstract: VHF Aircraft Communications Addressing and Reporting System (ACARS) is the most popular VHF aeronautical datalink. It is used for such applications as airline operation and air traffic control. VHF ACARS has only a 2400 bit/s (bps) transmission rate air-ground link. The VHF Digital Link mode 2 (VDL2) system, which has a thirteen times higher transmission rate air-ground link than VHF ACARS, is very similar to VHF ACARS. Both systems can deal with messages in ACARS format. Even though the systems are well used for various operations, their effective link capacities are not so clear. Finding out effective communication performance, including real link capacity and acceptable maximum delay, is useful for the design layout of ground facilities and rebuild datalink operation guidance in the near future. We built both VHF ACARS and VDL2 protocol models on an OPNET protocol simulator to evaluate their effective communication performance. This paper gives an outline of the protocol models and comparison results of these performances by simulation. Statistics such as transmission delay and throughput have been obtained under various load conditions for up to 200 aircraft. Before starting the simulation, we analyzed message data length and the message generation interval of VHF ACARS from real communication logs in Japan. The message data length was mostly distributed randomly, below 660 bytes, and messages exceeding 660 bytes rarely appeared. The message generation interval mostly followed Pareto distribution. We assumed that the message data length and data generation interval followed uniform distribution and Pareto distribution respectively. We found the following by analyzing simulation results. i) When data traffic load generated from an aircraft equaled the load directed to the aircraft, the VDL2 system was able to process 4.6 times more congested load than the VHF ACARS. ii) When data traffic load generated from an aircraft was five times higher than the load directed- to the aircraft, the VDL2 system was able to process 8.8 times more congested load than the VHF ACARS. The load condition approximated real VHF ACARS data generation ratio between forward link and reverse link.

URL: IEEE Xplore Abstract - A performance comparison between VDL mode 2 and VHF ACARS by protocol simulator

Has anyone seen the Greek radar tapes yet. Egypt also was to release what they had.

OK, but 3 minutes between received messages means that they were transmitted exactly in that time period.
No matter how slow the messaging is because time travel is always the same. So something bad happend and systems were alive at least 3 minutes later. Correct?

Since there is no seconds information in the transmitted data, then the time span could be as low as 2 minutes and 1 second.

But yes, it would seem to imply that the transmitter remained powered and in a position to be received from for that period.

Looking at the abstract of that Kitaori paper, the typical ACARS message is going to need less than two seconds to transmit even at 2400 baud. Low data rate isn't going to explain the limited number of messages received over a period of several minutes.

It's likely, as Wheelsright pointed out earlier, not all faults are sent to ACARS for transmission. The CFDS is operator configured, so some messages will be stored, some printed (immediately or after landing) and others sent to ACARS.

As we do not know what filters were applied (if any) we can only assume other fault messages were likely to have been generated as well and were never transmitted on ACARS either because they were filtered or ACARS/VHF 3 failed.

I'm sure the FDR when its found, it will tell us what we need to know and shed some light on this catastrophe.

Some side scan sonars can produce a image of the sea floor out to 100m on a side. The sonar is usually towed from a long cable with the tow body near the sea floor. The image should show any of the larger parts and structures of the aircraft. One drawback it doesn't image directly below the tow body so you have to make sure the images overlap.

PMS BURULLUS
 

Egypt sends robot submarine to help plane crash search | The Expat's Guide To Cairo

http://expatcairo.com/wp-content/upl...-9680750-1.jpg May232016
Egypt sends robot submarine to help plane crash search

Expat CairoNews Reuters




Egypt has sent a robot submarine on board the PMS BURULLUS to join the hunt for an EgyptAir plane which crashed in some of the deepest waters of the Mediterranean Sea with 66 people on board, President Abdel Fattah al-Sisi said on Sunday.
Ships and planes scouring the sea north of Alexandria have found body parts, personal belongings and debris from the Airbus 320, but are still trying to locate the black box recorders that could shed light on the cause of Thursday’s crash.
Sisi said that underwater equipment from Egypt’s offshore oil industry was being brought in to help the search.
“They have a submarine that can reach 3,000 meters under water,” he said in a televised speech. “It moved today in the direction of the plane crash site because we are working hard to salvage the black boxes.”
An oil ministry source said Sisi was referring to a robot submarine used mostly to maintain offshore oil rigs. It was not clear whether the vessel would be able to help locate the black boxes, or would be used in later stages of the operation.
Air crash investigation experts say the search teams have around 30 days to listen for pings sent out once every second from beacons attached to the two black boxes. At this stage of the search they would typically use acoustic hydrophones, bringing in more advanced robots later to scan the seabed and retrieve any objects once they have been found.
Separately, the US Navy’s Sixth Fleet said one of its patrol aircraft supporting the search had spotted more than 100 pieces of debris positively identified as having come from an aircraft, and passed the data to the Egyptian Navy.
EgyptAir flight 804 from Paris to Cairo vanished off radar screens early on Thursday as it entered Egyptian airspace over the Mediterranean. The 10 crew and 56 passengers included 30 Egyptian and 15 French nationals.
French investigators say that the plane sent a series of warnings indicating that smoke had been detected on board shortly before it disappeared.
The signals did not indicate what caused the smoke or fire, and aviation experts have not ruled out either deliberate sabotage or a technical fault, but they offered early clues as to what unfolded in the moments before the crash.

grizzled, Spot on!When many were struggling with the very same problem of double, triple, ad-nauseum posts on the same question or topic, John Tullamarine, (Tech Log), provided the following search tool. One can use this to search any thread on PPRuNe. One can search for his/her subject or some key words which are in his/her pending contribution, to see what may have been said/posted regarding same.

The bolded words are the words one is searching for. The rest of the text points to pprune and to the forum one wishes to search in, (tech log, rumours and news, etc.)

Give it a try - it does return all instances of the search words, so be discriminating!

Make sure the entire text of the URL is included: site:http://www.pprune.org/rumours and news etc., then add your search text to the front of the URL:

Searching for ACARS af447 in "tech log":

ACARS af447 site:http://www.pprune.org/tech-log/

I'm not sure what search tool you are referring to, but you can use that syntax on most search engines, for example on Google or DuckDuckGo. You can also combine that with the normal search operators like +, - etc.

Reviewing the AF447 ACARS data received via Satcom shows a possible maximum delay of up to 115 secs between time-stamp and reception. In the event that there are widespread failures to report via ACARS one would would not expect many of them to have had a chance to propagate and transmit within a window of 2+ mins.

As has been mention previously, ACARS is designed as a maintenance aid and transmission is the systems lowest priority. It would be interesting if someone has an example of the last ACARS transmissions via VHF for an aircraft that had widespread electrical failure to see what ACARS managed to transmit.

Of course, the reason for the abrupt end to the ACARS messages could still be explained by loss of reception.

I am not sure whether it has been confirmed that Egypt Air had subscribed to the transmission of ACARS via Satcom? If they did there may be additional Satcom data that has not yet been released.

AF447 ACARS See #2431 http://www.pprune.org/tech-log/39510...esume-122.html

For those interrested in Search And Rescue, the bible in the western world is the ATP 10 rev (D) which is a NATO UNCLASSIFIED document which can be easily accessed on the internet.

http://www.navedu.navy.mi.th/stg/dat.../ATP/atp10.pdf

If the airline paid for SATCOM service for their ACARS, the VHF link would more than likely not have been active.

FMC's/FMS' can setup transmission to default to VHF when over or near land, then switch to the more expensive SATCOM service (or to a lesser extent, HF) only when out of range of a VHF ground station.