Of course. I have no real position re: what, where, why.... From the outset, I have faulted BEA for not providing the evidence they supposedly possess; their data is based on something not in the record.
Instead of looking at that, most people do dig in, I hope I am not one, for as above, I do not KNOW.
The report is unacceptable.
1. In reporting some of the CVR, BEA leave open the suspicion that Airbus is at fault.
2. The suspicion exists also that the pilots are at fault.
3. The "Conclusion" (one of) exists that there is a blend of responsibility for this tragedy.
Without a jaundiced eye, BEA escape their responsibility, and play the politician.
Que sera? Strange attitude from a line pilot...
The only hope of getting to the evidence is to hope that the CVR still exists, or certifiable transcripts...
This can be done via FOIA if/when the FAA get access to the record...
Til then, my hope is that people do not give up, NO MATTER THE INTENT.
I don't expect the info to ever come out. Therefore, Que Sera Sera. I feel that I now know enough to deal with the "it flies like any other airplane" airplane when it quits flying like any other airplane. That's all I wanted to know when I started looking for info.
Whatever will be with the investigation, or with the PPRuNe discussion, will be.
xxxx will still pretend to be unbiased. xxxx will still pretend to be the best pilot ever. xxx will still pretend that it will never happen again because it happened once to AF447. etc, etc, etc, but we don't seem to be adding to the body of knowledge. In the mean time, Airbus birds will fly and I'm content with my ability to fly mine. Whatever else happens, so be it.
Ordinarily, your case would be persuasive, but BEA leave the entire product in doubt, imo.
How? By not printing a remark from the crew that was once alleged by the press and therefore may not have been accurate?
Look - if we combine the more colourful language used in the book with the CVR transcript in the report, I think it's fair to say you've got probably 98% of the total CVR content in the two, and if you use the book to determine language that the BEA omitted it quickly becomes apparent that only non-pertinent language was omitted (as the report itself makes clear).
@Organfreak - The point I'm making is that there's a good chance those words were never said, given the origin of the claim.
Also given that the transcripts we do have show no cognizance on the part of the Captain that they were stalled at any point - not just in the BEA report, but also in the controversially- published book on the subject. How likely is it that the captain would enter, immediately diagnose stall and appear to forget that he'd diagnosed a stall for the remainder of the sequence?
Last edited by DozyWannabe; 3rd Oct 2012 at 18:55.
If it was the case the THS would have reach its physical NU stop. What did stop its operation ?
I seem to remember that you have already conceded that A33Zab's proposal that the PRIMs prevented any further NU of the THS after the ADRs returned NCD at around 02:11:50 [or while they returned NCD].
If that was correct, the alternative may also apply to SS ND in the same circumstances, whereby the THS may not follow the ND demand until the PRIMs allowed it. In that case, the use of the Manual Trim Wheel would be needed to resolve the situation quickly.
This situation was apparently not foreseen, and the clarification you are seeking would be welcome.
"Also given that the transcripts we do have show no cognizance on the part of the Captain that they were stalled at any point - not just in the BEA report, but also in the controversially- published book on the subject. How likely is it that the captain would enter, immediately diagnose stall and appear to forget that he'd diagnosed a stall for the remainder of the sequence?"
The time has come, the walrus said, to talk of many things
Ladies and gentlemen, dear fellow PPRuNers.
First I'd like to remind you that "blame" and "pilot error" are not phrases included in any properly made accident report, (except in the legal notice clearly stating it is not the job of investigation board to blame anyone or anything). Fault is also seldom used and then only in mechanical or electronic sense. Accident reports only state that pilots did so-and-so and occasionally can add it was in contravention of such-and-such rule or procedure. This is what folks not very well acquainted with aviation safety, or more often with aviation at all, wrongly condense into term "pilot error", which by itself wouldn't be so wrong if it didn't always come with the notion that they who erred are the ones to blame for the calamity. Such a ignorance-based mistake usually comes from media or lately, bless internet, from anonymous fora.
Since AF447 crashed into international waters, BEA was appointed as the official investigator as the country of registration was France. In its final report, it has thoughtfully provided CVR transcript from the autopilot disengagement till AoA went over 40°, superimposed on some FDR parameters (page 60 English report, page 64 French), to make it more readable than it would be the case if one would need to constantly switch from CVR transcript to DFDR graphs in order to get exact chronology of who said and did what. NTSB style animation would be even better but I guess we have to do with what we have for the time being.
What can be seen is interesting, to say the least. CM2 has promptly arrested the roll, while unnecessarily pulling and properly announced he has controls. Next thing CVR recorded is stall warning, followed by exclamation of surprise from the CM1, next both pilots commented they have no display of speeds. To digress a bit: there was a theory put forward that they were unconcerned about sudden massive indicated speed drop but rather with characteristic protection speeds being removed from from the displays. To accept it as plausible, one has to be massively unaware of the importance of the IAS in any flying, let alone airline one. Basically: speed is life. For advanced users: while in itself it is life, we can live without it being properly measured and displayed.
So far so good, there are two pilots who promptly and correctly diagnosed the problem so what should have ensued is application of proper procedure, life goes on, no one notices except perhaps FDM, etc.
However, with the benefit of 20/20 hindsight we know that it took less than five minutes form the first sign of trouble till the aeroplane impacted the ocean.
Ten seconds after he concluded there are no good indications of speed CM1 warns CM2 to watch his speed. CM2 replies with "Okay, I'll redescend" as if he were warned of climb but he doesn't. CM1 now realizes they are climbing and only then prompts CM2 to descend. CM2 agrees but doesn't reduce the pitch enough to stop climb so busts practical ceiling. Aeroplane loses energy, stall warning goes off, CM2 attempts to pitch the aeroplane even more up so seals his and 227 other fates.
Not a reaction expected from professional pilots. Perfectly understandable if we assume ones acting so are scared mindless.
There was an occasional "we steam gauges pilots did so-and-so while these new EFIS kids on the other hand..." which usually made some sense but was more often than not garnished with a plenty of nonsense as it would compare theoretical perfect pilot of yesterday with the tragically underperforming modern crew, while the unspoken but presumed narrative would be that what was discussed were the average representatives of both species. There was many a classic cockpit crew who lost the situation awareness and ended smashed against the mountain or at the bottom of the spiral dive following disorientation as there is many a wonder-electric-jet crew that turned potential catastrophe into incident (e.g. QF32). So yes, there are still pilots flying those machines overhead us and given the number of incidents that did not end up tragic (or in newspapers or PPRuNe at all) I'd venture a guess they still outnumber mere system operators by quite a large margin. Now take this statement with a grain of salt: circumstances can catch any pilot out of his depth. Trick is to be so skilled, knowledgeable, conscientious and calm to make chance of it astronomically small.
It was mentioned there was thirty-something other incidents very similar to AF447 that ended without any damage or injury. While it can be used as a definite proof that Airbus is not lethal by design, conclusion that other crews knew what happened and what they are supposed to do is so far-fetched to be patently untrue. This is the tragic part: not every did but they did manage to avoid the traps that AF447 failed into. Many survived by doing nothing while trying to figure out what is going on and so exited the area of ice that clogs the Thales pitots in the process. There were those who pulled but they didn't ignore stall warning so pushed. There were those exposed to brief stall warning as they hit updraft. After every updraft must come a downdraft so they, wrongly but not fatally, assumed warning was false.
There was many a heated argument of how this or that automated feature should have been incorporated into Airbus to prevent the CM2 from wrecking the aeroplane. Well, Einstein once observed that the good thing about thought experiments is that they always succeed. In real life, safety devices have to be designed (and demonstrated) to acceptably cope not just with the occurrences thy are supposed to deal with but also the two failure modes: 1) failure to work when required 2) activating when not required. Number 2 is dealt with by system being overridable (stickpusher) or shutting itself down when risk increases (Airbus protections and control laws). Certification authorities assume that even the crew that has barely passed the obstacles of the type rating course has good situational awareness and will recognize failures and react to them properly. There is never an assumption that crew will get totally incapacitated for prolonged period. Pilots that get detached from reality are faced with simple choice: timely regain SA and act correctly or meet thy maker. Airbus protections (which incidentally started with A300, only got more sophisticated with introduction of FBW) can only buy a bit more time for crews to regain their wits but it was repeatedly demonstrated that you can still crash while staying away from protection parameters.
What are the chances that the pilot who gets so freaked out to forget just about all the basics of flying - pitch & power, performance ceiling, that heavy buffet and failure of the aeroplane to respond to controls is indicative of stall (since warning just got ignored) would pay attention to AoA gauge or use manual pitch trim? In real world: zilch. We can indulge in wishful thinking if we find it emotionally satisfying but it won't prevent the recurrence of AF447.
There was even mention that there is no feedback from aeroplane to pilots in Airbus as sticks are not backdriven and this is supposed to be major design flaw. Well, we have mostly abandoned the feedback fifty years ago when we made the switch from power-boosted to power-operated controls. If you fly aeroplane with hydraulically operated controls and believe what comes through yoke is feedback, I am sorry to disappoint you but you have been lied to. It is synthetic pitch feel. It is there to prevent you from overstressing the airframe. It can provide clue how far you are from the trimmed state but it is not by design or purpose and folks who are mislead to believe they can use it to tell the speed error can get bitten when things get a bit pear shaped as almost was the temporarily hapless crew of G-CPAT. They were so concentrated on yoke feel they at one point believed they had unreliable airspeed - despite all three indications agreeing. Good thing they maintained healthy respect towards GPWS.
ECAM complications are another red herring. No abnormal checklists, no ECAM actions, no memory items, there's nothing that has be done before positive control is established (to be nitpicky: except items that prevent loss of control such as overcoming control jam or feathering the propeller that went into ground fine, nothing similar was involved in AF447) which seemingly never was.
It was mentioned that AF447 is a proof modern pilots have insufficient manual skills and that we should practice raw data manual flight more often. While I agree with the recommendation, I don't think it can be derived from the accident we are discussing. Indeed, most common contemporary accident scenario is not involving a crew that knows what goes on and what needs to be done but lack of manual flying skills prevents it from carrying out the plan. More common is the crew who loses SA, often through some minor and trivial distraction and does exactly the wrong thing (sometimes with astounding manual dexterity) so loses control. I am afraid manual flying when everything goes right does exactly nothing to prevent such a calamity and introducing distraction during simulator won't be much helpful either as basic limitation of it is that it is still a sim, it cannot simulate the feeling that you are flying for your life. IMHO problem here is the pilot that has many an hour and many a simulator session under his belt. He goes to the sim, does the motions, passes the checkrides while secretly harbouring deep mistrust of what he has been taught as he "knows" better than some manual written by the lawyers for the aeroplane made by the pilot-haters. So one day proverbial hits the fan and that's when he realizes that he has nothing to fall back upon.
Question that remains is how to prevent AF447 from recurring. Human factors are definitively the key but methinks in that aspect, BEA report leaves a lot to be desired. While I'm no expert in psychology so I can't meaningfully comment some findings from that aspect, I do know that notion that night makes maintaining attitude in passenger jet more difficult through lack of outside horizon to be utter tosh. You can combine it with the best psychological expertize and still you won't get anything true out of it. Even worse is lack of background data for the pilots involved except the very basic information. BEA should really follow the NTSB example with its background checks. We got informed that F/O of AA587 really misunderstood AAAMP to imply that it is proper to use rudder for any disturbance, was already warned by a captain on one of his previous flights, but was unable to comprehend. NTSB told us that captain of Aloha Islandair 1712 regularly scud-ran, he made wrong estimate of his position only once and that was enough. As for AF447 pilots, we have no idea whether there were precursors noted during their careers that would make their reactions more comprehensible or - far more scary option - their de-structurization and consequent disaster struck out of the blue.
@Clandestino - I agree with 99% of what you are saying, however there's one point that needs to be addressed -namely that the NTSB has a further-ranging remit when it comes to identifying cause than most other agencies. Usually, civil service investigation agencies such as the AAIB and BEA are restricted to determining cause from the immediate evidence, and their write-ups consequently tend to read more drily.
I seem to remember that you have already conceded that A33Zab's proposal that the PRIMs prevented any further NU of the THS after the ADRs returned NCD at around 02:11:50 [or while they returned NCD].
Thanks for the reminder, I had forgotten that one. Nothing was for certain in his answer but it was making sense. I didn't have and still don't have the knowledge or the tools to confirm or dispute his theory.
But for sure, such explanation should have already been part of a Final Report ... ?
Quote: Originally Posted by mm43
"I seem to remember that you have already conceded that A33Zab's proposal that the PRIMs prevented any further NU of the THS after the ADRs returned NCD at around 02:11:50 [or while they returned NCD]."
Sorry, that does not make sense to me. The reason for Alternate Law2b in the first place is duff ADRsX3. What difference does it make if they are duff or merely NCD?
Another thing, if the THS freezes with NCD ADR, why did it move at all after AL2b latched, never to be changed? If the THS did move, then the Controls Law should have reverted to Alternate Law 2, since ADR would have been reliable?
there's one point that needs to be addressed -namely that the NTSB has a further-ranging remit when it comes to identifying cause than most other agencies.
Then it is cultural or political issue. After FI acquaintance of mine perished in training accident, BFU traced his former students and their testimonies about the way he performed and taught the fatal manoeuvre made it into the final report.
DozyWannabe, In a reply to Clandestino you stated:
the NTSB has a further-ranging remit when it comes to identifying cause than most other agencies. Usually, civil service investigation agencies such as the AAIB and BEA are restricted to determining cause from the immediate evidence, and their write-ups consequently tend to read more drily.
Perhaps you can explain what is meant in your quote as my interpretation would lead me not to agree. Here is the intro into how the NTSB does its investigations:
The Investigative Process at NTSB The National Transportation Safety Board was established in 1967 to conduct independent investigations of all civil aviation accidents in the United States and major accidents in the other modes of transportation. It is not part of the Department of Transportation, nor organizationally affiliated with any of DOT's modal agencies, including the Federal Aviation Administration. The Safety Board has no regulatory or enforcement powers.
To ensure that Safety Board investigations focus only on improving transportation safety, the Board's analysis of factual information and its determination of probable cause cannot be entered as evidence in a court of law.
Is what I have bolded the difference you are identifying? You can read the entire investigative process of the NTSB by going to this link:
To answer your question, though rather obliquely, I defer to another part of the same post where I pointed out that Airbus expected its aircraft to be flown by properly trained and competent pilots.
But the best tool I know to attain competency is proper training.
This is where Airbus has to question its lethargy - When it became obvious that UAS were adding up in cruise, especially after the Air Caraibes note, Airbus had to do something.
A red OEB had to be published :
Lately, multiple cases of UAS in cruise have been reported and seem to be related to ice crystals in the vicinity of CBs, temporarily obstructing pitot probes. The situation can be stressing as AP and A/THR disconnect, ECAM messages pill up, and multiple visual or audio warnings interact such as :
Possible sequence of ECAM messages :
Sudden decrease of a few hundred feet of the indicated altitude
Characteristic speeds may disappear.
Sudden increase of the TAT
Crews have also reported :
Smell of ozone
Recommended procedure : At first signs of deterioration, suspect UAS and call for the UAS Memory Item :
PF maintain wings level + pitch of 2.5 deg
PNF call any deviation and set thrust to 80% N1
This phenomenon is of short duration, 3 minutes at most according to recorded events, airspeeds are then back to normal.
Possibly Alternate 2 Law activates, pitch remains a load factor demand but roll is in Direct Law.
Due to turbulence, brief STALL warnings have been triggered - Maintain recommended attitude + thrust setting except if Stall warning persist in which case the STALL procedure has priority and must be followed.
Disregard the STATUS MSG : RISK OF UNDUE STALL WARNING
We still investigate and bla bla bla ...
Even better if a simulator experience can be provided. Proper training is a good tool to make us competent.
Dear clandestino, Thank you for your post from 3.oct.I trully hope you do believe me,when i tell you something you mentioned in your post was in my mind for a long time. Why did`nt i post it ? wll it may be because english is not my native language and i was`nt sure that i`m able to do oi right. You mentioned the missing backgrounds ckecks.I`m just a Slf with interest in aviation and i have reed a few hundreds of accident invest.reports.So that`s my experience and i think i know a little bit more about aviation than the common man on the street. in ca.90% of these reports there had been a background check of the pilots and i was always thinking that the cause of the accident of AF 447 may lay in the personal structure of the PF. How was his behaviour on duty,to colleagues,how did he react earlier in stress situations in the cp.How was his behavior to friends or relatives,how did he conduct his private life. I`m quite sure that it is possible there is maybe something in his past that could explain why he did react that night the way he did.
Thanks for the link to Aviation Investigation Report A08Q0051.
The report mentions:
"2.6.4 Spatial Disorientation and Interpretation of Indications of an Airspeed Indicator Error
From the start of the descent until the reduction in power, the somatogravic illusion due to the aircraft’s acceleration could have suggested that the aircraft had a nose-up attitude when in fact it had a nose-down attitude. The false impression of a nose-up attitude combined with the increase in aircraft speed may have prompted the captain into diagnosing an airspeed indication error."
Yet you say
I do know that notion that night makes maintaining attitude in passenger jet more difficult through lack of outside horizon to be utter tosh. You can combine it with the best psychological expertize and still you won't get anything true out of it.
Suppose AF447 crew experienced a similar somatogravic illusion, and the deceleration of the aircraft caused PF to "feel" a nose down sensation. It may help explain why PF was reluctant to believe his PFD.
Originally Posted by rrat Suppose AF447 crew experienced a similar somatogravic illusion, and the deceleration of the aircraft caused PF to "feel" a nose down sensation. It may help explain why PF was reluctant to believe his PFD.
- indeed it might, but do we not expect 'average' pilots to associate rapidly climbing altimeters (x3) with a loss of speed? The essence of ALL instrument training is to believe the instruments where they appear to be reliable and IGNORE 'somatogravic illusion'.