Go Back  PPRuNe Forums > Flight Deck Forums > Tech Log
Reload this Page >

AF 447 Search to resume (part2)

Tech Log The very best in practical technical discussion on the web

AF 447 Search to resume (part2)

Old 17th May 2011, 19:01
  #1641 (permalink)  
Join Date: Aug 2009
Location: Texas
Age: 64
Posts: 7,042
Received 251 Likes on 162 Posts
Respectfully, SaturnV, I'd say the priority starts about 15-20 minutes prior, to see what the crew were discussing and doing as they approached the time where things began to go wrong. Without the stage being set, some very wrong assumptions may be made regarding how and why crew responded as they did ... response being more along the lines of your timeframe. That allows the first run through of the synched "crisis period" to dispense with a variety of "they did what? why? how did that get into the equation" questions ... and this means fewer errors in various utterances coming out of BEA.

Regarding conflict of interest and the BEA.

It's there, the question is in what degree. It may be small, or large, and if it stays close to small, would be low risk to a quality investigative finding.
Lonewolf_50 is offline  
Old 17th May 2011, 19:04
  #1642 (permalink)  
Join Date: Jun 2009
Location: VA, USA
Age: 58
Posts: 578
Received 0 Likes on 0 Posts
They don't simply connect a laptop to the FDR and CVR and download a PowerPoint presentation.

It takes quite some time and effort to derive the most accurate transcription possible from the CVR.

Once finalised by the working team, the transcript may be matched up to the FDR traces using the synchronised time code.
Hahahaha... well done.

Firstly, please don't tell Microsoft... really no Powerpoint?

Ok, so now the comedy is finished... right?

It DOES NOT take weeks - I routinely handle test flight data - audio striped with a timecode on one track on the audio recordings, and performance data striped on the data captures. Synching the two is not difficult, particularly since in this case the encoding is well known ahead of time.

What will take time is ensuring the exact transcription is provided, since in many cases the audio is not exactly the clearest, particularly when things are not exactly going as planned.

However, and this can be argued, the primary content of the CVR will be easily determined from the first few listens through I'm pretty sure, and it doesn't take a rocket scientist to copy/format convert the recording to .WAV format to allow analysis on a standard soundfile editor (Adobe Audition or Audacity for example), which gives you simple view of the waveform against time. Since the recording is realtime, timing does not have to be millisecond accurate to make sense of the key events.

Whether or not, those initial broader findings can/should be released is not my place to argue, but I would be dumbstruck if it were not very easy to determine who was in the cockpit (FO1 and FO2, or some other combination of occupant) for example. But now my point is drifting.

It does not take weeks to synch the FDR to the CVR. And at that I will exit stage left...

Last edited by Jetdriver; 18th May 2011 at 06:39.
GarageYears is offline  
Old 17th May 2011, 19:14
  #1643 (permalink)  
Join Date: Dec 2010
Location: Middle America
Age: 84
Posts: 1,167
Likes: 0
Received 0 Likes on 0 Posts
BEA Press Release - English

Flight AF 447 on 1st June 2009

A330-203, registered F-GZCP

Press release on 17 May 2011

According to an article that appeared in « Le Figaro » on the evening of Monday 16 May 2011, the « first elements extracted from the black boxes» would exonerate Airbus in the accident to the A330, flight AF 447, which killed 216 passengers and 12 crew members on 1st June 2009.

Sensationalist publication of non-validated information, whilst the analysis of the data from the flight recorders has only just started, is a violation of the respect due to the passengers and the crew members that died and disturbs the families of the victims, who have already suffered as a result of many hyped-up stories.

The BEA repeats that, in the framework of its mission as a safety investigation authority, it alone has the right to communicate on the progress of the investigation. Consequently, any information on the investigation that comes from another source is null and void if it has not been validated by the BEA.

Collection of all of the information from the audio recordings and from the flight parameters now gives us a high degree of certainty that everything will be brought to light concerning this accident. The BEA safety investigators will now have to analyse and validate a large quantity of complex data. This is long and detailed work, and the BEA has already announced that it will not publish an interim report before the summer.

At this stage of the investigation, no conclusions can be drawn.
Turbine D is offline  
Old 17th May 2011, 19:16
  #1644 (permalink)  
Posts: n/a
A final point, and off to other things.

In any human endeavour, but especially those involving great investment, profit, and competition, there is a palpable corporate and institutional culture in play.

BEA is not feverishly working in isolation, they carry vectors of concern into the Lab. This investigation has hundreds of players, and thousands of close and privy PEOPLE. Keep an open mind, but please entertain that these are people, like you and I. Protect the Guilty? Line one's pocket? Keep quiet when to speak is demanded? Shade ever so slightly a finding in the interest of what may be ultimately security and survival? (and not for clients and personnel?).

All respect for all, keeping in mind that all data belongs to the people, and especially where the Public Safety is concerned, there is NO PROPRIETARY

edit... "Sensationalist publication of non-validated information, whilst the analysis of the data from the flight recorders has only just started, is a violation of the respect due to the passengers and the crew members that died and disturbs the families of the victims, who have already suffered as a result of many hyped-up stories."

my turn,
Old 17th May 2011, 19:33
  #1645 (permalink)  
Join Date: May 2010
Location: Boston
Age: 72
Posts: 443
Likes: 0
Received 0 Likes on 0 Posts
It does not take weeks to synch the FDR to the CVR. And at that I will exit stage left...
Although a "quick look" is likely just a few hours for the CVR the FDR probably will take a bit longer.
Have lost the link (buried many pages back) to a DFR problems report that discussed the dismal state of the documents that link the raw bits from the DFR to measured paramaters. It also discussed the typical process and problems with using the data:

Before using the DFR data it must be carefully checked to ensure that the calibration values are valid since there have been many instances of wrongly documented "gain/offset" valies or calibration drift after last inspection (which are also inadequate), not to mention totally incorrect channel to parameter maps.

This vetting is in partdone by comparing all 30 hours (or whatever it is) of normal operations to retrieved values - flap position on take-off etc).

Only after this is done can the CVR be synchronized to DFR tracings in a meaningfull way.
I suspect that is where most of the "weeks" will be spent the actual time stamp linking as you point out is very quick.
MurphyWasRight is offline  
Old 17th May 2011, 19:49
  #1646 (permalink)  
Join Date: Jan 2002
Location: USA
Posts: 286
Likes: 0
Received 0 Likes on 0 Posts

BEA has already announced that it will not publish an interim report before the summer.
Anyone care to comment on when BEA might think summer is? Officially, it is the day of the year when the Sun is farthest north (on June 20th or 21st). This day is known as the Summer Solstice.
wes_wall is offline  
Old 17th May 2011, 19:52
  #1647 (permalink)  
Thread Starter
Join Date: Jun 2009
Location: florida
Age: 81
Posts: 1,608
Received 52 Likes on 15 Posts
Cause, contributing cause(s), findings, et al


I have to lean with Wolf, Bear and others here.....

- We shall finally see that no single design deficiency or crew action had the end result. As with most losses, it will be a chain of events. Hopefully, we will see procedural changes and mabe some "design" changes implemented to prevent future incidents.

- "design", as Wolf says, has lots more than basic airframe characteristics. The human interface with the "system" is an important component of the "design". To this old dinosaur that flew the first operational FBW system, seems that the 'bus has a convoluted sequence of reversion to basic control laws that are closely coupled to the autopilot and other considerations when things turn to worms. Seems that the crew should be able to use a single switch or button to get to the basic FBW control laws and let the plane do what it is aerodynamically and structurally capable of doing.

- I won't argue with the certification process. The FBW control laws for the 'bus appear to be in synch with the basic "requirements" for certification. This is a point I can wait to discuss over a few beers and "there I was" war stories.

For now, I can say my point is that all the reversion sequences do not seem to be considered in the certification process, and that is what is bugging me. Where's the consideration of reasonable crew actions when things go wrong? It's Wolf's point about "design".

All for now, and hope we get to see some "real" data versus speculation soon.
gums is offline  
Old 17th May 2011, 20:48
  #1648 (permalink)  
Join Date: Mar 2002
Location: Florida
Posts: 4,569
Likes: 0
Received 1 Like on 1 Post
This thread seems to have taken a turn to damn the torpedos full steam ahead.

The press leak is not the responsibility of the parties neither goverment investigators nor manufacturer experts, The BEA has already stated their opinion in this regard.

The public can clamor and fret about the data, but it is not them who have to fully understand it before releasing it. We already have enough folks on internet sites specultaing from all sides, less about technical things and more about somehow the answer may harm their pet theory.

What will happen is that when the data begins to point at major contributors, then begins the challenges to the data by the experts within the investigation Only after the challenges have been vetted will major releases occur, not necessarily as final findings, but more of areas being explored.

The time line for this is probably with a week or two, not months and not days.

It does not help an investiagtion to allow itself to become sidetracked by clammoring for data outside of the experts within the investigation.

If you want to turn this process into a coverup or political forum then there are other sites where it can be taken (JetBlast anyone?)
lomapaseo is offline  
Old 17th May 2011, 20:49
  #1649 (permalink)  
Join Date: Apr 2000
Location: SNA
Posts: 70
Likes: 0
Received 0 Likes on 0 Posts
I think the problem w your assumption Gums is that any "procedural" or "design" changes will be perceived as an admission of some level of culpability. The last thing Airbus wants is ANY question regarding their system logic as this has far reaching implications across their entire fleet. Any design or even training change would be a billion euro plus event. The lawyers would have a field day.

Likewise Air France (albeit at a far less euro payout) wants to avoid any mention of maintenance issue or shortfall in training. The foundation per today's leak is pointing squarely at the pilots who are no longer able to present their case.

The importance of a full release of data is obvious and as others have said can be presented as necessary to present a credible picture.

My hope is that we all have an opportunity to continue what this forum has done so well since the accident which is is question the available data and understand the conclusion the BEA comes too.
KATLPAX is offline  
Old 17th May 2011, 21:08
  #1650 (permalink)  
Join Date: Mar 2007
Location: Here and there
Posts: 2,783
Likes: 0
Received 1 Like on 1 Post
Bear the pb is above the AP engage pb but is of a different design.
I would say that for most pilots if an AP disengages that they will take control of the aircraft and then try and re- engage the AP.They do not have experience in hand flying these aircraft at high level with a rearward c.g and many simulators do not replicate tnis very well and in my experience it is never practiced. There may have been some repeated button pressing until they realised that it would not engage or function properly
I do not believe that selection of the fpv was accidental. Airbus philosophy is that if you are hand flying you select fpv and I would imagine that this is what they selected whilst they tried to cope with the situation before them.
The problem with this selection is that the Unreliable Airspeed checklist advises against its use if altitude information is unreliable. We will find out in the coming months what was the root cause of the upset and the wisdom of the selection of fpv.
The A330 is a beautiful machine and many of its systems have been developed to cater for shortfalls in the design of earlier Airbus types.When I first flew it I was very impressed that the designers had put a lot of effort into getting it right. It is an immensly complicated aircraft but also extremely reliable . I would imagine that this crew were aghast by how quickly their perfect machine turned ugly and their atrophied stick and rudder skills failed to cope

Finally I have not seen an A300 with four pitots,which operators aircraft did you see?

Last edited by tubby linton; 17th May 2011 at 21:38.
tubby linton is offline  
Old 17th May 2011, 21:14
  #1651 (permalink)  
Join Date: Aug 2009
Location: Texas
Age: 64
Posts: 7,042
Received 251 Likes on 162 Posts

Your post raised a worry, even though I had no friend or family on AF 447.

There is a pernicious route by which a safety investigation is corrupted by both penal and civil-tort investigations that have damages (money) and punishment (money/jail/cert revocation) as their ultimate outcomes.

Safety investigations, without those encumbrances, may uncover and report (via limdis) critical interface elements without fear of cost/lawyers etcetera. I remain eternally grateful to the judges in the U.S.A. They have time and again upheld the privileged status of mishap safety investigations (not the JAG investigations, which a FOIA can get released) in military crashes. (In which class are the mishaps I was a member of investigation teams a few years back).

As I watch the drama -- drama in part self-generated, and in part manufactured to position parties in legal proceedings -- unfold in re this tragic crash, I consider the Spanish incident (we discussed on these forums a few months back, problem with a configuration fault / flaps, leading to a crash) and the Italian incident more recently discussed on the forums.

If the aim and psychology of a party pursuing a case is not wholly air minded, the myopia and tunnel vision afflicing said parties -- flavored with either virulence or simple desire for financial gain/remedy, in my view blinds them to how complex and interrelated causal factors are (plural required here, even though we are mostly among aviation professionals). Those of you who are not, please take note.

The risk is that this whole proceeding distills down to a hunt for scapegoats rather than unearthing of root causes that can, in combination, be addressed to remedy whatever set of faults set up AF447 for arrival at the surface of the ocean ... not their intended point of landing. This wasn't a rookie crew. That they were unable to overcome a challenge presented to them, for one reason or another, must be mitigated for the benefit of the entire flying public. It may not just be an Airbus issue here, even though the mishap aircraft is an Airbus.

BEA has a hell of a challenge in front of them in terms of remaining objective. I sincerely hope they are up to it.

I worry, for the sake of getting the procedural or mechanical fixes appropriate to this event sorted out and resolved, that the cross contamination of interests previously raised will leak into their work, and corrupt the findings.

My appeal to the hard working folks of the BEA team is to be mindful of the traps and risks of contamination, and to deflect them. It ain't gonna be easy.
Lonewolf_50 is offline  
Old 17th May 2011, 21:15
  #1652 (permalink)  
Join Date: Jan 2001
Location: France
Posts: 168
Likes: 0
Received 0 Likes on 0 Posts
The BEA seems to be very unhappy and one can understand easily their reaction. To my knowledge this is the first time in its history that a communicate with such straightforward terms is published.
Since the beginning of the AF447 tragedy, "Le Figaro" has been one of the French media that always has been very well informed. I have realized that months ago and already asserted that, here, some days ago, just before the CVR retrieval. All their sources seem to be, as LF itself writes, very "close the investigation".
In one of its latest release LF indicates that their sources is closed to the "government" but not from the BEA investigation team. This is the first time that LF states the origin of its informations.
The fact that LF writes "government" indicates that someone there directly communicates to LF without the consent, or even the knowledge of the BEA.
LF being a newspaper it is not a shocking matter that their journalist(s) in charge of the case, try to obtain and publish the maximum of informations pertaining this affair. And they do it well.
Politically LF is a right hand newspaper or conservative one would say. There may have some privileged relationships between LF and the political sphere that could play some role and explain the "leaks". Who is the "insider" in the Government may stay a secret but it would tend to show that someone there is really in a hurry to establish the truth. Whatever the BEA says is not that important right now but as we say here "il n'y a pas de fumés sans feu" (there's no smoke without fire).
I was rather surprised how fast LF published its latest news (about the AFR responsibility) but still, even if the LF is not my cup of tea in a general way, I do trust their journalist for what they publish.
If the politics enters in scene we may interrogates ourself on a "struggle for influence" at he head of the ministry, to be the first to "unsheathe" and give a valuable information. Nathalie Kosciusko-Morizet, NKM, Minister for Ecology, Sustainable Development, Transport and Housing (in addition she finds time to sleep) is the minister in charge. There is also a junior minister (secrétaire d'état) specifically in charge of Transports ; Mr Thierry Mariani whom we do not hear a lot. Hopefully himself knows him as a Minister.
NKM made the announcement that there was bodies still in good conditions and attached to their seats the day after she came back from Japan, where she went because of the Tsunami and radioactivities disasters. I saw her at the television making this announcement and she looked tired. There was not an absolute necessity to communicate so quickly and the information(s) could have been delayed for a while but it was unveiled right away. By her.
Either someone at the minister wants to be the first to give the information and "short circuit" someone else or , because the AF447 disaster is an international matter, officials in France want to have the "scoop" on some important announcements before it might filter abroad. There might be a political will to bypass the necessary slow technical investigation. Hence the LF informations that are making, by the way, a "buzz" here. AFR unions are not happy at all with these latest informations.

Another important matter is the present situation at Air France. Pierre-Henri Gourgeon (65), the CEO of Air France-KLM should be renewed tomorrow in its fonctions. If AFR is designated as the only and sole responsible of the crash, PHG might be led to resign to assume the responsibility in the name of the company. This last assumption is quite personal.
Squawk_ident is offline  
Old 17th May 2011, 21:25
  #1653 (permalink)  
Posts: n/a
tubby linton

Old 17th May 2011, 21:45
  #1654 (permalink)  
Join Date: Jan 2005
Location: France
Posts: 2,315
Likes: 0
Received 0 Likes on 0 Posts
With the "Figaro" already scoring an "own goal", who needs conspiracy theories?
ChristiaanJ is offline  
Old 17th May 2011, 22:02
  #1655 (permalink)  
Join Date: Feb 2009
Location: Worldwide
Posts: 579
Likes: 0
Received 0 Likes on 0 Posts
There are no A300 with four pitot probes. It is seeing things which are not there, again.
KBPsen is offline  
Old 17th May 2011, 22:23
  #1656 (permalink)  
Join Date: Jun 2009
Location: NNW of Antipodes
Age: 80
Posts: 1,330
Likes: 0
Received 0 Likes on 0 Posts

Thanks for that pragmatic look at the politics involved and the perceived pressure that goes both down and upwards.

At the end of the day, the BEA is just a name for a group of people charged with investigating and determining the cause(s) of an accident, making recommendations to prevent a recurrence, and publishing their findings on behalf of the French State. The people involved are professionals, and no person acting alone should have the ability to determine an outcome that is not supported by the majority.

We know full well that the justice system has the ability to turn facts around and make other determinations, but the BEA's Final Report will be the matter of aviation record.

There is one small point that will never change, and that is the time the FDR and CVR stopped recording. Neither politicians or the judicial system will ever change that.
mm43 is offline  
Old 17th May 2011, 22:33
  #1657 (permalink)  
Join Date: Dec 2010
Location: Middle America
Age: 84
Posts: 1,167
Likes: 0
Received 0 Likes on 0 Posts

Don't know if you have seen this or not, but for your reading enjoyment:


It is sort of an introduction, not up to date, but does give you some unofficial reference information.
Turbine D is offline  
Old 17th May 2011, 22:46
  #1658 (permalink)  
Join Date: May 2004
Location: Bear Island
Posts: 595
Likes: 0
Received 0 Likes on 0 Posts
Theories, media, our old friend ...

If we all look back over the postings on both AF447 discussions, fair to say the standard quality of informed input has been very high especially considering that the main wreckage was found only a short time ago.

Personal guess is that broadly the impact criteria has been quite accurately described, though truth may lay somewhere in the middle.

With the DFDR and DCVR recorder being time matched, and harmonic analysis applied, we are gonna be faced with the third thread, the last piece of cheese with the holes in it to let this happen when procedures, technology and culture were all designed to say it should not.

Per previous post, it is the design interface (and all aspects of it) with the human element that has consistently proved to be the weakest link, often at the most trivial level.

Everything that we have pondered, analised and written could be overturned in a single press release, let's not forget that.
Everyone remembers landmark accidents that we have as core material on our CRM refreshers .. this may turn out to be just another one.
Who knows, but despite the conspirisy theorists, I sense that training, technology and culture may well have been a red herring here.

Having had the privilage to spend some time with investigators over the years, I know them to be dedicated people, when they have agreed a likely senario as a team, we will know much more in a substantiated form.

So lets wait on this one, and let them do their job.

Do not forget that this design, AP in or out wants to maintain zero roll rate and 1g .. it can get out of sync per the transatlantic incident, make it extreme and it's gonna be a nightmare with protections lost .. add a human in the loop, perhaps more so, perhaps being there in the first place is the best demonstration.

Last edited by Teddy Robinson; 17th May 2011 at 22:59.
Teddy Robinson is offline  
Old 17th May 2011, 23:02
  #1659 (permalink)  
Join Date: May 2011
Location: BOQ
Age: 79
Posts: 545
Likes: 0
Received 1 Like on 1 Post
New guy to these discussions. I’ve read only about 200 pages of posts, some from Part 1, all of Part 2; so forgive me if I repeat something already covered.

The FPA/TRK discussion finally got me hooked.

The FPA-TRK mode, as I understand it, is an alternate FD display with command steering available for the FPV. The HDG-V/S mode is the primary FD display option with the dual-cue command steering for pitch attitude and bank.

The validity of the command steering for either FPA/TRK or HDG/VS is always a function of proper mode selection and annunciations per the FMA.

I guess what I’m getting at is once the FPV is selected is it always valid autonomously as an FPV regardless of the mode selected and the command steering indication. At high AOA, would the FPV not be visible on the PFD when outside the PFD displayed range of attitude versus actual FPA? Are the FD's removed?

Boeing allows the selection of the FPV on either PFD individually thru the individual EFIS control panels. In the HUD, if so equipped, Boeing always displays the FPV and command steering in the HUD is always for the FPV. If the FPV is out of the HUD FOV, it ‘ghosts’ (dashed outline) to indicate non-conformal situations. (The HUD & PFD FPV algorithms are very slightly different however.)

My other question: Is ADR "unreliable" the same as ADR "failed"? My understanding is that in ALT 2 you cannot re-engage the A/P with dual ADR failure.

I may know just enough to not really know enough however.

edit: the Boeing PFD FPV's, if selected, are added symbols to the PFD, the dual-cue FD steering is still for pitch attitude & bank
OK465 is offline  
Old 18th May 2011, 00:14
  #1660 (permalink)  
Join Date: Dec 2005
Location: At home
Posts: 244
Likes: 0
Received 0 Likes on 0 Posts
It takes quite some time and effort to derive the most accurate transcription possible from the CVR.
Once finalised by the working team, the transcript may be matched up to the FDR traces using the synchronised time code.
I would also expect there to be a lot of tedious manual cross-checking between the CVR and FDR to ensure data consistency. For example, ensure that a particular sound, e.g. from a setting of some switch or control, corresponds to a change in the corresponding FDR trace at exactly the same time. If not, the data might be unreliable. Add the ACARS messages, and possible recordings from QAR and internal memories of the instruments and FADECs, and the worst case time required for all this consistency cross-checking may be quite long.

On the CVR,
I'd say the priority starts about 15-20 minutes prior, to see what the crew were discussing and doing as they approached the time where things began to go wrong.
Preferably even before. IIRC the CVR records the last 2 hours. That requirement is not there by coincidence. The Swiss cheese theory says each accident has multiple contributing factors, some of which may have occurred long before the sh*t hit the f*n.


Can anyone provide a description of the parameters recorded by the A330 DFDR? That would be interesting to study while waiting for the analysis results.
snowfalcon2 is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.