A33Zab

Very valuable contribution by PJ2

@JCjeant:

Although a legimate request, the RAW FDR data (translated into a readable format) will not give the answers.
The final BEA report is not based solely on FDR and CVR data.
System byte(e.g. FMGEC) is an used source but requires both Airbus as manufacturer specialists with in depth knowledge of the system and equipment.

PJ2

Okay. Not very clear or specific but I understand what you meant.

"Raw" data is understood as binary data which is the form it arrives at the recording equipment in from various aircraft systems and sensors; the flight data we are accustomed to viewing has been translated by proprietary software into engineering units.

As A33Zab has previously, correctly observed and which apparently still requires emphasizing, because no consumer software is capable of processing flight data, there will always be the accusation that the data has been in some fashion manipulated upstream of any software that is capable of displaying the data. The decades-long nonsense over Habsheim abundantly illustrates this fact.

A33Zab

To give one an idea of RAW data:

1 word = 12 bits (Harvard BiPhase Code)

• not all bits used for value, some words contains only discretes, a combination of value and discrete is also possible (depends on attached computer/equipment)

1 subframe contains 256 or 512 words.

1 frame consists out of 4 subframes (= 4 sec. of data)

• not all frames are used identical, e.g. the sample rate for acceleration may be once a second while documentary type may be sampled once every 4th second.

1300 parameters (330 mandatory) are recorded for 25 hrs.

jcjeant

Reminder:
I'm already at the episode 2 .. I will say the trial
It is not a question of quantity of data or complication for analysis or answers given or not ... it is a question of law
All parties must have access to the same documents as part of the trial
If Airbus and Air France have access to the FDR data .. the plaintiffs have the same right (fair trial principle)
What they can do with those data is the problem of their lawyers and experts

PJ2

jcjeant;

I won't argue the specific case for protecting the data against use in courts any further.

I see and understand the point you are making, and it is that exact point with which I take issue. This data has not been used in a court of law by the parties mentioned in your note. There is no reciprocity here.

DozyWannabe

Precisely. Those parties will be going to court with the same publicly-available report as everyone else. A report that highlights possible deficiencies from both of those parties.

jcjeant

I would be more cautious about using the word "precisely"
Await trial ...

PJ2

jcjeant;

re your response to Dozy's comment, "I would be more cautious about using the word "precisely"
Await trial ... "

Oh, I and most everyone recognize that the courts will attempt to, and will in many cases do what they may in accordance with "the public interest". Nothing would surprise me in any jurisdiction after Canada's, (actually a Quebec Court's), conditional release* of the "so-called 'protected-by-law' " CVR recordings from an accident a number of years ago.

I am arguing a caution as regards ultimate outcomes in areas of specific interest, namely the aviation safety system which has delivered unquestionably spectacular and enviable results for users and corporations alike due in large measure to the industry's unequalled-in-no-other-venue principles and efforts to protect safety information, gathered both voluntarily at great corporate expense and also as a result of legal SMS data-capturing requirements, from use in narrow legal prosecutions.

I am not arguing that it won't possibly be done, even as it may after much visceral political and legal wrangling at tremendous expense and collateral damage to the aviation safety process.

*TSB opinion on the protection of safety information

CONF iture

Accidents don't exclusively happen to crew members with an "agenda".

WillowRun 6-3

While perhaps well-known to legal counsel whose practices are situated within the air transport industry, the protection against discovery for flight safety data is not, I believe, well-known to litigators in general, or to corporate counsel. Just curious - to any who have posted and esp. PJ2 - could you kindly provide a citation to a section of the FARs which establishes this (or is it statutorily established?), and also, do you know whether the non-discovery protection has been the subject of any litigated court rulings?

AlphaZuluRomeo

Excellent post. Thank you PJ2.

PJ2

WillowRun 6-3;

United States:
Canada:
Europe:
It is worth noting within the present context that data gathering and analysis by experts is a relatively new approach to flight safety and human factors for North America - the Brits have been doing this since the 50's and share data quite differently.

I know that you will very likely appreciate the complexities inherent in these and any such statutes and policies.

Notwithstanding these complexities, the intent is, as far as is practical and reasonable, to prevent safety information which in many cases, (ie., United States, and for example, ICAO and IOSA "best practises), is collected under one set of goals, intentions, requirements or recommendations, from being formally employed by processes which contemplate precisely the opposite in terms of goals and intentions and requirements.

Now I know that that statement and what is occurring in some jurisdictions is arguable both philosophically and by example, (notably most of Asia and some European countries), but I am a safety person and (retired) pilot not a prosecutor and as far as I am concerned the long view in terms of the viability of safety programs as presently constituted outweigh short-term, specific demands for specific data particularly when it is largely though by some observations not exclusively demonstrated that overall, the safety process works quite well.

This does not under-appreciate the long history which tort law and the notions of "recompense" have developed, to greater or lesser extents, within western societies. I would only argue that the history of data collection for the purposes described has not nearly as long a history and so litigation's accomodation of new information and processes, while painstakingly glacial in adapting to such accomodation still needs to recognize the successful implementation of such relatively-new "protections" in terms of the accident rates within our industry. The medical / healthcare industry and the auto industry to name just two, are envious of such a record and both have made significant progress in adopting aviation's strategies, won and defended at great human and economic sacrifice.

The is not to deny the "benefits" of tort law which, over many, many years may have exercised similar changes in safety processes mainly through the strategic avoidance of punishment, lawsuits etc. But with present approaches to flight safety, the "knowing about the nasty aspects" that is possible through the implementation of safety programs such as ASAP, FOQA, LOSA etc., it cannot be denied that the institutionalized protection of flight safety information is far more effective than the rare examples of "the public interest" which exist.

In fact I would argue, successfully, I think, that "the public interest" is already vastly better served through the present processes than through any narrow prosecutions or discovery actions. A "chill" on the flow of such information would not begin to describe the outcomes of any broad attempts or shifts in policy to make such information available to all who, for multifarious reasons of their own and a vague distrust of those who do this work for a profession, demand it.

I'm not clear regarding the meaning of "statutorily", but accepted (best) practise for the implementation of flight safety programs which collect data for the sole purpose of enhancing flight safety is the strongest possible protection of that data in terms of legal proceedings and lower matters such as pilot discipline, dismissal etc.

WillowRun 6-3

PJ2;
I thank you, sir. Thank you for the extensive quoted regulatory information and, as importantly if not more so, the extensive analysis of the underpinnings of the exclusion from legal process of the information in question.

(As a small preliminary item, my invocation of the word "statutorily" was meant merely to allow for the possibility that the legal mechanisms of exclusion were set forth in statutes, rather than the Federal Air Regulations (in the States), inasmuch as regulations, whilst having the force and effect of law (and receiving what is commonly known as "Chevron deference" in US courts), simply do not have the same legal throw-weight, if you will, as an act of Congress. I imagine that the gulf between administrative regulation on the one hand, and legislative enactments on the other, may exist similarly in other nations, but this would not be my field, and thus further comment, I shall not make.)

The analysis of exclusion from legal process of given classes or categories of information is one well-known in the law, at least in American law (as noted above, I hold no particular expertise elsewhere). Not only the privilege for communications between doctor and patient, or between priest and penitent, but indeed the privilege most hallowed in the law -- for communications between attorney and client -- all have their roots in the same general modality of analysis.

But as compared to those other privileges for non-disclosure and their genesis in the law and whatever we are to call the wellsprings from which developments in the law take place, there is another dimension here, to be sure, driven by the intensely deep state of knowledge one must have and hold in order to understand the complexities of the flight path (say) of a Triple 7 which might have been in FLCH mode with A/T armed but not on (until it was too late). These facts (if facts they are), a non-driver can recite, but there is much more to understanding the actual data, one would think, yes?

Certainly, if we are speaking of criminal law matters, I am not sure I can recall more than one instance in the States of an air carrier mishap from which criminal prosecutions took place. Maybe the Air Florida disaster in DC (failure of de-icing), but I don't think there were crimes charged. Or the - what was the name of that carrier - discounter out of Florida and the oxy cannisters ruptured in flight (DC-9, as I recall)....these are the only possible prosecution examples in the States that come to mind. Maybe I'm just not recalling.

And even more certainly, the plaintiffs' bar in the States will yell, scream, shout, make noise, and utter excitedly all manner of liberty, freedom and the rights of man, when it comes to suing someone who may be said to have caused a loss, especially a tragic one. Of course and it should be needless to say, the right to legal recompense is a bedrock of constitutional democracy. But it does not fit, and was not intended to be stretched so as to attempt to be fitted, to every loss.

I wish I had enough knowledge about the safety assurance process (a phrase which may do small justice only to the overall safety consciousness and the record it has yielded) you have so eruditely described in your recent posts, so as to discuss the process with some semblance of intelligence. Still I thank you for the informative and focused content.

PJ2

WillowRun 6-3;

Thank you for those examples where confidentiality of exchanges obtains. In fact in some jurisdictions, - Germany, I believe and I would have to confirm this, according to German privacy laws, the flight data captured on their aircraft belongs to the pilots, not to the airline or the state. I suspect in an incident or accident that does not apply and I know it would be more complicated than stated here!

In terms of confidentiality and data protection, when implementing flight data analysis programs great care, expense and energy are expended to ensure the confidentiality of the individual's flight data so that it could accomplish its singular task. It was made clear that confidentiality did not mean anonymity however. If something in the data indicated a serious event, there were and are processes whereby the carrier's due diligence is served. The matter becomes delicate when the data indicates a serious and perhaps even intentional departure from standard operating procedures; very challenging to maintain the integrity of the safety process while addressing such matters effectively in an environment of competing goals and interests.

In re, ". . . there is another dimension here, to be sure, driven by the intensely deep state of knowledge one must have and hold in order to understand the complexities of the flight path (say) of a Triple 7 which might have been in FLCH mode with A/T armed but not on (until it was too late). These facts (if facts they are), a non-driver can recite, but there is much more to understanding the actual data, one would think, yes?"

It is your last comment in the quote passage above that is particularly germane.

Having done flight data work for a number of decades I know only too well that even as one may be an expert in examination, flight data, (which, despite apparent views to the contrary expressed here and elsewhere) is very much an incomplete process and subject to what I would view as "the interpretive gesture". I would venture to say that the FOQA/FDA/FDM community would concur. The flight data process is akin to making up one's mind about what is going on in a pitch-dark room in which there are many people doing things and which is lit by a strobe-light at a "sample rate" of once per second, or perhaps once every eight seconds, or perhaps once every tenth-of-a-second, depending upon how one's "strobe light" is set up. Ideally, a frame rate of 26fps would be wonderful and increasingly possible, (anything is possible with fathomless funding!). But the process of creating, programming and certifying what is called the "Logical Frame Layout" is exceedingly expensive, proprietary to the manufacturer and often the subject of what we call an "STC" - Supplemental Type Certificate, which is an addendum to the aircraft's original type certificate. While not uncommon, the process is extremely expensive and time and resource intensive.

That's just to get more data, (typically onto the QAR - Quick Access Recorder a non-crash-proof box) than is required by the State in its aviation regulations. If parameters are missing and desired, it is anything but a simple matter to fix, even with today's inexpensive and flexible technologies such as Avionica's mini-QARs. The equipment is not the problem.

Once all is up and running, an aircraft may have anywhere from a couple of hundred basic parameters to 40,000 parameters on aircraft like the C-17. The B787 I believe has far more, to the point where if a system event occurs, the recording system reduces parameter capture recording rates for non-related systems and enhances parameter capture rates for specifically related systems.

In older aircraft, the requirements for the number of parameters is tiny depending upon age, type certificate and date of manufacture. Retrofitting aircraft with the necessary equipment beyond what was legally required on the date of manufacture is so prohibitively expensive that the FAA (and other regulatory bodies elsewhere) provide substantial relief in required parameters.

Returning to your last comment then, you have apprehended the matter precisely. For those who do not do this work and therefore do not understand its complexities including the primary need for experience in order to interpret data accurately, the presumption that all one needs is "all the data" just to settle things once and for all, is misplaced.

Whether we are discussing flight data monitoring programs or data from the SSFDR and SSCVR after an accident, there are numerous documents which explain the flight data process quite well. Links to CAP 739 and CAP 731 are among those I have offered previously in order to help others understand the flight data process.

While one does not necessarily have to be a transport pilot to read the data, such experience is immeasurably helpful when interpreting the data. As with any process this complicated there are subtleties and when sample rates are not video rates, interpretation of the "raw" data, (not the binary code but the basic engineering data that is readable) is inevitable.

By the way this is my chief argument against the animations we see increasingly pop up hours or days after an accident when there is nothing but someone's imagination to guide such an exercise. I am similarly quite wary of animations-as-evidence, having done many such videos in FOQA work. The reason is simple: flight data supporting any animations necessarily will require "smoothing", so as to present a smooth flight path and readable, (non-jerky!) set of instrument readings. In fact, all FOQA software I know of will have numerous ways to smooth data, all of them legitimate in the hands of experts who use animations only as a rough guide and briefing tool. While this process is well established, understanding the process of how animations are actually created is important to a correct interpretation simply because any process which involves extrapolation of data in between two recorded data points can (and has, in my experience) led to wrong animations. Animations are extremely powerful in today's visual-image-oriented society and so have the power to convince when there may be no basis whatsoever to conclude. For example, let us say a control stick is sampled once per second. That seems sufficient until we bump up against an event in which rapid movements of the stick during a landing incident would not be captured, and in a not-rare circumstance, we could see two neighbouring control stick parameter data points indicating, say a full-nose-up position, but in between those two points (where there is no data), the stick may have been rapidly placed full-nose-down and returned to the previous position and those reading the data (and viewing the animation) are no wiser. I have seen examples of this phenomenon in ways not described here but no less challenging to interpret.

llagonne66

Thanks for your time, your patience, your competencies and your willingness to share your extensive knowledge

CONF iture

Still does not explain why the pilots are prevented to get full access to their own data ...
Same reply here.

DozyWannabe

I have to jump in again and doff my cap to PJ2, who is doing a sterling job of laying out the complexities of the situation regarding flight data - not just in terms of the ramifications regarding disclosure, but also in terms of the scientific nature of forensic use of that data. To reiterate, the raw data must be processed heavily from its initial digital format into a format that can be read by humans as well as machines - whether that be the tabular format in the earlier examples shown or the plotted graph format as used in the AF447 report. Running that into a 3D animation requires further processing (e.g. smoothing) that, if not done properly, runs the risk of providing a misleading presentation of what went on. That, due to the relative ease of understanding such an animation can illustrate to non-technical people can cause widespread public misunderstanding and lead to long-running misconceptions about accidents becoming received wisdom. This is enough of a problem anyway, given the press's habit of promulgating unproven information to the public.

The irony is that flight data and CVR recordings/transcripts are so tightly regulated in terms of disclosure precisely because of the pilots' unions refusing to countenance use of these recorders unless such assurances regarding disclosure were given back when they were first introduced. A few of those same pilots unions have called for further disclosure and second opinions when the outcome of an investigation is not to their liking, and I can't help but feel that you can't have it both ways.

What is even more puzzling in the case of AF447 is that the investigation report, while acknowledging dubious actions on the part of the crew, goes to great lengths to highlight that the likely roots of those actions include improper or insufficient training on the part of the airline, insufficient oversight on the part of the regulator and possible design issues on the part of the manufacturer. Cursory use of the "Find" tool on any of the reports reveals that nowhere is the phrase "pilot error" used, nor any other phrases to that effect.

As a result of this, in a criminal or civil case neither Air France, the DGAC nor Airbus can point to the report to limit their liability because their part in the genesis of the accident is part and parcel of that report. I'd be prepared to wager that if the raw data were released, converted and parsed by the legal teams of the union and the families (which to do scientifically and correctly would in and of itself be a massively expensive undertaking), they'd find no germane information that they didn't already have.

PJ2

Dozy, llagonne66, thank you for your responses. My goal is education and learning.

In my view, flight data is "neutral" in its character.

One must go where the data leads and so your observation regarding the "irony of data" is correct; - the door of "proof" (for one theory or another of "causation"), swings both ways. In data, there is no guarantee of congeniality or favour. It is what it is, within stated limitations.

One cannot obtain and view the data with preconceptions as to how it will/should/may go. It may just go precisely where, "to one's surprise/disappointment/chagrin/delight, (name it), one wants/does not want, it to go".

Such prior conceptions certainly aren't about flight safety work, which this capturing of flight data enterprise is wholly and uniquely intended to support.

To put it in unmistakable terms, if one is seeking proof for one's theories rather than understanding of what occurred (within the limitations of the flight data process as described above), flight data is "Door #1, Door #2, or Door #3".

The foundations of this approach to flight data work regarding protections and the clear requirement for confidentiality as well as the requirement for caution in terms of reaching conclusions, should be abundantly clear.

DozyWannabe

Quite. And I'm certain that one of the primary motivations behind the agreed restrictions was precisely to keep the data in the scientific realm, and out of the hands of interested parties who would try to "spin" it.

Now it seems to me that those parties demanding the release of the data have thus far been very cagey about exactly what the grounds are for doing so, outside of a gross misrepresentation of the final report's conclusions - they claim the report puts the accident down to pilot error (when it does not), and makes scant reference to the THS behaviour (when the writeup on that aspect is not only present, but also fairly detailed).

Given this misrepresentation, I can't help but feel that said parties are less interested in flight safety than they are trying to insert a note of doubt into public opinion via the press, in much the same way they did with AF296.

PJ2

Hi Dozy;

Perhaps. I'm speaking at the level of policy vice specifics which will always have their uniqueness and therefore the need for close examination of such matters and their genesis. There will always be well-springs at the margins, and they must be examined on their merits alone, always within the context of flight safety work.

It is nevertheless disturbing that in the last four years there have been four fatal air carrier accidents due to loss-of-control by stalling otherwise-serviceable transport aircraft, adding to the dozen or so in less recent years. The Asiana accident is deeply troubling.