Nuts!!

How in hell do you expect them to do that when the facts are not yet in evidence.

At least in a technical forum we get to debate speculations with some degree of balance. and we sure as hell don't yet agree with the news article.

When a newspaper prints statements as this,without being vetted by broad experts, it can cause great harm.

the BEA was correct in their response

One of the considerations is that the typical FDR output really is not suited for publication as is. Generally it needs a bit of tidying up to end up with something which makes reasonable sense.

I guess the short term problem is the usual one resulting from social acculturation by media to desire a quick ten second news bite .. rather than the traditional boring, tedious, do all the work, engineering analysis in between input and output.

"...When a newspaper prints statements as this,without being vetted by broad experts, it can cause great harm..."

Yes, that is a given. It is also the baggage that comes with a free society. A large net catches many different fish.

The argument, I submit, is where is the line drawn in disclosure of information, 'data'? It is not about Trust, but Choice. Who makes important decisions for us? Hopefully, we do. We also put Trust in agencies and bureaus whose mission it is to represent the People. The Client of these constructs is the People.

To the extent that publicly supported agencies engage in spin or favor to individuals (Corporations included), this mission is subverted. In any large group, there are miscreants and those whose mission is other than the common good, it is legend.

Data, belongs to all the people, any resistance to disclose can and should be met with great suspicion. It is a fundmental principle.

John- The Press is a pain in the ...elbow. But it is our elbow. I don't disagree with the timing at all, there are different needs for different disciplines. Ultimately, everything should be on the table, "tidying up" should be open to critique, yes?

I have the impression you've never seen or had to work with raw flight test data or FDR data....
They are just long meaningless tables of initially meaningless numbers.
(Read the earlier posts (a few pages back) about coding and scaling and calibration and time-stamps.)

"Tidying up" is a misleading term.

All those numbers are first "decoded" and "translated" into "real" values, such as speed, altitude, control surface position, etc., then plotted. and checked and correlated for verisimilitude.
The "tidying up" then consists in extracting the "story", and finally in producing a legible report, usually with info-graphics that are understandable by the public, and non-specialists.

You are right and I stand corrected on that point. I based that on the fact that many crew reseted their PRIM after ADR disagree events, but the procedure is mentioning clearly that Alternate can't be cleared until after landing.

On the other hand, RTL (Rudder Travel Limiter) rule out the reversion to alternate in AF 447 case. The fact that the rudder settings were still frozen after impact imply no reversion from ALT2 because it would also have cleared the RTL fault (having now two "good" ADRs back, even if both "wrong").

Consequently, IMO, it means that ADR DISAGREE situation was also not cleared until impact: they would never have had the opportunity to re-connect either autopilot or autothrust after 0210, while no other flight envelope protection other than "g load" would have been active before crash time. In this context, the possibility for a supposed induced "aircraft system upset" happening after 0210 is more than very thin. Don't you think?

To give technical explanations or reasons why is energy wasted. From the very beginning the course chosen by some have been to cast doubt on everything and anything, to suffer from a selective memory and other pretenses. Not due to cause but for own purpose.

Less of a principle, more of a condition.

[/B]Hi. I wouldn't know what in the world to do with raw data. I would need help understanding the final product. That is not to say I think you or CONFiture should be excluded from making the attempt. I think in this is a minor misunderstanding. Any agency acting in the Public behalf must be subject to scrutiny from whoever has the desire to. Here is the rub. The Public is complacent, and in technical things, generally also ignorant. On top of this add a poor memory, and the Field belongs to the sly, or the greedy.

Here, a distinction. BEA is not likely the source of any potential problem. It is the unseen players whose power and influence are acceded to, to the detriment of Public safety. I am disappointed BEA played into the clumsy tactics of the Figaro. Choice before Trust, and Trust is subject to change.

Cockpit sound analysis and not just voice recording
 

JD-EE,

As you know CVR are useful not just for voice.

We as Engineers MUST optimize our Designs and in this issue you can provide better info for the investigators just improving at a VERY LOW COST the recorder.

This is related to Engineering and not to radio operation. And could be discussed in engineering details in another thread being planned.

Bottom line:

There is room for (low cost) improvement in existing CVR´s.

KBPsen

"...From the very beginning the course chosen by some have been to cast doubt on everything and anything, to suffer from a selective memory and other pretenses. Not due to cause but for own purpose...."

Precisely.

takata;

Regarding the F/CTL RUD TRV LIM FAULT message, BEA Report #1 states:

takata

Did the RTL go fault due to lack of reliable IAS? Does the Rudder become functionally unavailable at lower speeds, then? Would that have any effect on recovery from roll, or Yaw in upset??

The Rudder was limited to 7.9 degrees sweep all the way to the Ocean, per BEA report. Is that a mechanical condition that may need to be addressed post 447?

At some point in the descent, would you have selected slats to release the Rudder? At what airspeed would the slats have been susceptible to separation?
Would slats have hindered recovery?

If too fast, and Rudder was needed, would you have selected spoilers?

Rhetorically, would Protections have limited any of the other controls?

Global picture of the crisis phase (>02Z til impact)
 

John,

The "circonstances" report could be "enriched" by FDR data fed to SIM. For sure will not happen. The time now is for PR content.

BEA/Airbus SAS and investigation team had opportunity to "see the global picture" very soon.

And also about important facts (and decisions) before 02Z.

You are answering your own question.
If slats are used, full rudder deflection become available (that's the way to go out of the limitation, on purpose, if it becomes inapropriate). In AF 447 case, everything points at an aircraft staying in a clean configuration until impact.
Do not ask me why as I don't know.

Bearfoil,

you are talking about two different things here.

One, and I completely agree here, is to make raw (and processed) data available to the public. I'm all for it (as long as there are no national security, trade secrets or other plausible reasons for non-disclosure involved) - it's good policy, it can be easily done in the internet age and it may help to shut up some of the constant harping about "bias", "pressure" etc.

Two, independently of the point above, BEA is still the authority with the sole mandate of investigating the accident and determining the causes. Not Airbus, Air France, the leaker or Le Figaro. That's the point they were making with the press release (along that causes have not been determined so far), and I think it may have been necessary (alas, probably unsuccessful) to stem the tide of daily leaks.

takata

I think we may be jumping to a conclusion or two. I don't see conclusive evidence that she "stayed clean all the way down." The BEA say she was intact at impact, fine. Intact does not mean clean at impact, neither does it mean she was not using control surfaces on her way down. BEA have said Flaps were stowed, fine. Stoweds flaps likely means retained spoilers, but does not preclude their deployment. All of the surface recovered pieces have yet to be conclusively demonstrated to have been on the a/c at impact. Please don't extrapolate from that, it is merely a statement of fact.

Still, "Clean at impact"? "Clean all the way down"? If speed is a problem, dirty is good?

wozzo

BEA is not the only authority responsible for conclusions. If the data is disclosed, "duty" can be assumed by any independent. You are confusing duty with ownership. The findings, though ennabled by BEA, are not the property of BEA. Likewise, "proprietary" or "Patent" considerations are secondary to Public good, would you not agree? National security perhaps, but what about Public carriage has to do with espionage?

I just mentioned the same thing.... been there, done that.
That is a fairly normal procedure, so why "will it not happen"?"
That's a separate issue. I can read FDR traces, the general public can't, and I think a lot of pilots can't either, or at least not draw conclusions from them.
Doing a 'PR job' means translating a lot of highly technical information into a statement (I will refrain from calling it a sound-bite).
I respect the BEA for not being suckered into premature and incomplete statements, other than refuting the Figaro crap......

ChristiaanJ

"...I respect the BEA for not being suckered into premature and incomplete statements, other than refuting the Figaro crap......"

On that we agree. :ok:

RTL still limited at this settings means no slats used all the way down as, if used, its settings would be quite different from Mach 0.80/272 kts. IMO, it also means that two ADRs were turned off after ADR disagree and that this fault was not cleared. No flaps, spoiler at impact is no proof they were not used at one point, but no proof either of any use and later retractation.
If two ADRs (with blocked pitots) were considered reliable by the crew, then turned ON at any point, they could not have remained frozen from FL350 to sea level, hence, at one point in the descent, the airspeed displayed would have been the "real" one and it would certainly not be 272 kts at impact (as shown by RTL) following the BEA description.

Managing an important and sensitive issue for France
 

Originally posted by ChristiaanJ

A "SIM picture" (complete or even a fraction) i guess will not go public now.

PR is critical now. The decision making, IMHO is being made at gov´t level.

The global picture with all details will be available in the end.

I will not here comment on "why is being managed this way", for many reasons.

I talked neither about duty nor responsibilty (I agree, anyone should have the opportunity for taking that on themselves), but mandate (by law - remember, there are judicial proceedings going on). As to reasons for non-disclosure: that was meant in an abstract way. I'm not completely sure that the complete CVR should be published (there may be non-essential parts to be kept back out of respect for the deceased and their families), but DFR data - dump them into the public domain!

Access. Somewhere between "Ere, let's 'ave a look?" and by subpoena.

In this case, and others, access by Court order is sufficient. Other than that, a standard "FOIA" should do nicely. And does. No one I know has demanded release of raw data, as yet. There are still missing some traces from the final minute of Perpignan, however.

Academic access? Certainly, and provided for. Access for commercial reasons? Probably, and unavoidable.

Accident results are in the Public domain, suredly.

You are really talking like a lawyer and one who is already working his case, something completely unrelated with those investigation findings. Now, tell us a bit more about your sources implying a Perpignan cover-up?

Or, maybe that this quote is for enlighting your claimed "objectivity"!

Public domain: those data are under justice control and nothing will be in the public domain until this case is fully settled. Only declared parties can access it. As for the raw data, NTSB, AAIB, etc. are fully involved beside the BEA with this analysis process.

The problem is that CONF iture, among others, is working from a pre-determined conclusion - that the BEA is to some extent in the pockets of Airbus and Air France - and thus one would always have to question whether this pre-determined conclusion would affect his reading of the data in any way.


But at what cost in terms of engineering complexity? The more components involved, the higher the complexity, and the higher the probability of component failure. This is one of the first axioms we learn as engineers.

Hi,

The BEA is not part of the court process.
The BEA is making an technical investigation that is completely separate from the judicial power
As tell the BEA itself .. they are not there for blame anyone.
And be sure that the final BEA report will be published long time before any judicial process begin (like Concorde case)
It is not required (no laws) to maintain silence as it is the case for those involved in the court process.
Judicial:
Another technical investigation will be conduct by judiciary experts

RTLU found "coherent" with cruise setting
 

BEA Interim report #2, pg 27:

Suppose they used slats (thus enabling change of RTLU settings)

Question: The info obtainable on the RTLU would be (high probability) different or could be the 7.9° by "chance"? The RTLU mfr. had this info "from a memorized mechanical freeze" of a mechanical limiter? Or other method?

The decoding document, supplied with this airplane, has around 1,300 parameters. Not all of them are relevant or necessary for an understanding of the causes and circumstances of this accident. The reporting will understandably be limited to those that are. From the BEA website:

Hi,
This is irrelevant. The BEA is fully mandated by the law for investigating those data which are staying (from the begining) under judiciary control (those Gendarmes are in charge of the recorders and a judiciary police officer is always staying with them). So, the BEA doesn't own those "evidences" and work on them following its mandat. What is released for the public is in the BEA report, as per the law.

Cockpit sound analysis
 

DozyWannabe,

I reiterate: At a very low cost. Let´s segment qualitatively first:

1) R&D: Very low cost.
2) Product Engineering: Low cost (We could quantify)

The integration to existing structure i estimate to be not a relevant issue.

I posted this possibility with all implications previously "self questioned" (this forum requires a fascinating degree of attention).

About "Circuitry complexity and Failure Rate" we could implement a better one with less components and simpler circuitry, just using denser Integrated Circuits.

In summary, The cost/benefit IMO is good for an improvement. For an investigator "High Quality recording of facts" is obviously good.

Hi,

You right .... this material (the black boxes) are exhibits to the prosecution of the court process.
The BEA report (the result of their analysis) is not an exhibit.
It therefore not falls under the same sections of law protecting the exhibits.
That's the point I want to put emphasis (BEA report is not part of the judicial process)

FBW Stick Philosophy
 

This puzzles me a bit. Decades ago when I was a student at Navy Test Pilot School, we were given three flights in a highly-modified "variable-stability" B-26 operated by Cornell Aeronautical Laboratories (later called Calspan). The right seat was truly FBW. Right seat control response was determined exclusively by analog computers. Students were asked to evaluate the response in various configurations. One configuration was to have the stick (or yoke, I can't remember which) move large distances for small control surface movements but with little force required. The opposite configuration was to have the stick "locked in concrete" and all control surface movements responding only to stick forces. My instructor, Nello Infanti, asked which I preferred. I preferred minimal stick motion with aircraft response determined by stick forces. Nello informed me that the vast majority of pilots also preferred that configuration. I would think that, when finding it necessary to fly current FBW aircraft using the stick, that precise control would be more difficult using stick deflection rather than stick forces. Is Garage Years correct in his characterization of the AB side stick?

(See Nello's obituary here: Nello Infanti Obituary: View Obituary for Nello Infanti by Dengler, Roberts, Perna Funeral Home, East Amherst, NY )

DJ77
Having had another look at the French, and guided by your interpretation, I believe you are right. Thanks.:ok:

I certainly can't suppose they used slats after RTL freeze. In this case, the RTL would be at its full limit settings (no speed limit). Either this plane was flying at 272 kts at impact, either it was left frozen from 0210.

takata

It is not possible to determine as yet? The record of control deflection is at hand? If rolling and or yawing, and the Rudder was frozen at ~ 4degrees each way, unlocking it by manual action might have been tried. We'll soon see. I think we'll get an education as to how the Rudder and Pilot interface in the weeds, also. Unlocking the Rudder seems a poor choice?

bearfoil
A small factual error - one I believe you have committed before.

The RTLU set the travel to +/- 7.9° or a 15.8° "sweep" if you want it that way.

But aren't denser IC's just moving the complexity "up the chain", as it were? Denser IC's also tend to generate more heat energy, so the new components would have to be re-certified - an expensive and time-consuming process.

Complexity and lack of predictability in new hardware is the reason that digital circuitry introduced in aviation tends to be of the simpler "tried and true" designs (which would be considered obsolete in terms of consumer devices) rather than the latest generation hardware - it's also the reason I throw my hands up in the air every time I hear FBW/FMC avionics systems compared with modern PC computer technology.

The FCOM description of the rudder travel limit is ambiguous on this point. Slat limit speed is 240 kCAS, and it would seem illogical for the maximum rudder deflection with slats extended to be independent of speed. Could it be that the 'freeze' is lifted, and the normal limits apply? (I.e. 35 deg below 150 kCAS).

It's not ambiguous at all. RT Limits are computed and limited by both sec's. If both sec's fail the RTLU remains frozen at the limit in use upon failure.

Now lowering the slats won't repair the sec's so the statement is quite logical. Lower the slats and you have max deflection again (35 degrees)

So. What happens to the Rudder Travel if unlocked. Can it be re-Limited?

Or, with SECs still out, does it lock at whatever travel it had at new Lock? (including deflected?)

Can it lock at 17 degrees? Can it be re-centered and locked?

What does DIRECT LAW do to RTL ? Does it release it?

At < FL200 and < 150 KCAS the slats/flaps are available. Should the PRIMS/SECS be available, then it should be reasonable to expect the RT limit to be calculated as per normal. Otherwise, +/- 35° would seem to be the fall back compromise.

The RTLU setting was as a result of reversion to ALT2 Law, and whether other PRIM/SEC problems have intervened, or whether valid KCAS was available is simply guesswork.

EDIT :: Should the slats be extended as allowed below FL200, then any preset RTLU setting will not be cleared until < 150 KCAS, at which point the limit will be +/-35° and reducing if the KCAS increases again.

K.I.S.S. should be a design rule, when possible
 

Hi,

First, i will use some words of a phrase you posted:

To say you what happens to me when i realize the "circuitry" amount and complexity used (required) in highly complex FBW a/c.

Just a detail: You need to use 3X (acting as 5X) redundancy. Approaching the one used in the STS fleet now retiring.

(Yesterday night i was reading again on the F8 DFBW. A MUST read)

Well,

In this case, i would say: No. The complexity is about the same. And the use of more memory presents "no drawbacks".

We are talking about Audio (low power signals), so, no problem.

You are talking on the IC´s or the final product, the CVR? Anyway every change or evolution is not free. And ROI must be checked.



I agree 100%. And will use this to ask: What´s your feeling (on this issue) on the Revolution (rdware and Software/algorithms[/]) EA introduced using DFBW technology (for the first time in non military planes)? With it´s big implications. Why US didn´t introduce "in parallel"? But this is for another post or even another thread.

BTW, What is "wiring fault" (Hard) mentioned in some earlier posts regarding ACARS sent. I am curious to understand this.