Thanks for posting several articles that provide very useful information about flying an A/C of this kind.

One element that drew my attention in the last article you've posted was the mentioning that the A/C reaction to pitch and roll commands is amplified at high altitude.
...

Regarding the climb from FL350 to FL380, there are several elements in the BEA text (marked in italic, and/or color) that attracted my attention, and perhaps are worth mentioning:

Sometime between 1:59:32 and 2:01:46, the PF said, “…turbulence that you just saw…. We’re in the cloud layer unfortunately we can’t climb much… because the temperature is falling more slowly than forecast… and the logon with Dakar failed”.

The text marked in blue can be considered as implying that going to a higher flight level, above FL350, was considered as a possible solution, had the air temperature and the Dakar logon been OK.

At 2:08:07 PNF said “you can maybe go… to the left” airplane …. change ….about 12 degrees possibly because the increasing turbulence …. The level of turbulence increased … the crew reduce the speed to about Mach 0.8.

At the moment the A/P and A/THR disconnected, at 2:10:05, the A/C needed a correction command, and I think it is also possible that the PF thought, that it is worth trying to go at a higher flight level - we don't know if the air temperature may have decreased?

The BEA text indicates that the A/C climbed (from FL 350 and speed 275 kt) while rolling left and right between 12 and 10 degrees to FL 375, at which time the speed on the Left indicator increased (came back) to 215 kt, Mach 0.68, and the AoA was of 4 degrees (with stall warning stopped).

Based on the vertical speed of 7000ft/min mentioned by the BEA's text, the A/C climbed the 2500 ft to FL 375 in about 20 seconds, which left about another 20 seconds of flying approximately at this FL375 and A0A of 4 degrees, before the stall warning was triggered again at 2:10:51.

Note the left speed indicator seems to have been back OK right before the stall warning was triggered again at 2:10:51.

Did the PF, at this moment of stall warning again, decide to go a bit further up, as gaining altitude seemed to him to help with the turbulence, but also be a help with the coming back of the speed indicator? We don't know what he saw through the windshield - ice? - that may have been another contributor to the decision.

....

Recently, on a cross continental flight, as passenger, during the heavy storm season, at about ½ way into the flight, at cruise altitude, and clouds way bellow, out of nowhere, the A/C entered a high altitude cloud, and hit heavy turbulence. After a couple of seconds in the cloud and turbulence, the plane climbed, and I could tell, as soon as it came out of the cloud, after not too long, that it was at least several hundred feet higher.

Your reasonably can be interpreted as having the thought that other things could be done.

Based on elements pointed out on the AF 447 threads, there could be for instance:

a) provide a "better redundancy" of the sensors, as at the moment, they are all of the same kind, and positioned quite closely to each other, and thus providing a high probability of sharing the same failure fate, in similar conditions.

b) resolving the "lack of", or "confusing information" provided by the "A/C to Pilot Information Interface", by diversifying the parameters used to calculate certain extreme dangerous/fatal conditions, like Stall, and provide a separate and distinct "approach to Stall", and a "A/C is Stalled" Warnings.

The important resources dedicated by the French Government, Airbus, Air France, and others for two years... .to find and recover all what was left of AF 447, for a good understanding of what happened, and what caused it, seem to show the commitment and determination in adopting a wide range of solutions to avoid a repetition of an AF 447 type accident in the future.

ChristiaanJ :For those interested the report has leaked here:
http://jonathan2.blog.lemonde.fr/fil...se-Externe.pdf

Regards

airtren, I am puzzled at one of your suggestions.

I am also intrigued by your trying to follow a reasoning process based on what we know, the idea that the PF was keen to change altitude.
Hadn't considered that line of thought previously.
But wouldn't he have added power with his pitch up input if it was his intention to climb two or three thousand feet? :confused:
But wouldn't he have added power to climb in the first place? Cruise climbs typically are a change in both power and attitude. Is there evidence that he assumed A/T would follow his stick input (nose up) and that he noticed (late?) that the A/T had not followed his nose up for a climb command? I cannot recall that having been covered in the BEA report. Is that another reason that the pilots noted "Alternate Law?" If so, why not comment on what the auto throttle was, or wasn't, doing?

OK, then answer me this: why was TOGA applied when it was applied? See the timeline a few pages back?

Also, if I get a stall warning, is my first thought "I need to climb a bit to avoid ice?"
You are able, in pax mode, to measure/sense at cruise altitude a change in a few hundred feet of altitude? :confused:

Hi,

Seem's AF adopted already a measure
Some time after AF447 event AF made a general recall of the pilots for simulator training for such situation as AF447 was involved
So .. one can ask if it was refresh trainings or a completely new training ?
Again .. I suggest to read the external audit report for better comprehension ....
http://jonathan2.blog.lemonde.fr/fil...se-Externe.pdf

lonewolf

The initial NU I take to be PF directed. The Left Roll command as well. So does BEA. So the a/c was ND, Rolling Right at the switch? Logical?

As to the Rolling (L,R, between 12 and ten degrees). It would be interesting to know which direction the Rolls were. If one was consistently of different input than the other, one could infer an asym configuration of some kind.

On the other hand, it may have been an attempt to slow down, due drag.

Also BEA are not clear about the timing of "Continued ND inputs". When were these? After entering this climb? As written, the Stall is linked to the climb, initiated (?) by the Pilot.

The Stall could have easily been the result of the PF trying to recover the a/c from the climb.

The PF knew what was going on. The BEA know what was going on.

WE don't know what was going on. I am trying to come up with a way to understand what happened, by entertaining possibilities. BEA knows. BEA is not giving it up (at their discretion, no problem).

I am not trying to predict the Truth, I am trying to keep as wide as possible the discussion. Not least to keep and encourage an open mind.

Mostly, after expression of surprise and disgust at the "reported" conditions, the opinion here is too often too harsh and too conclusive (!) re: the PF performance.

Fine aircraft, fine Pilots. Always my starting point. What happened?

I do not know the motive of BEA with their note. Their distinct challenge if being devious with it, is to continue to withold data except the bare minimum to support a finding that is suitable. Cynical? Yes.

1) at least subliminally, the PF words indicate what he may have or would consider, 2) BEA's mentioning of those words, among a quite careful and succinct "selection" of "word exchanges" between pilots, must have a significance.
....
I think both pilots understood the relationship between the cloud/turbulence, possibly ice in contact with the windshield, and the loss of speed, and considered the first Stall Warning at FL 350 in light of that, and possible the one following at approx FL375, as only the left speed was showing a reasonable speed, as the ISIS came back in sync with the left speed indicator only a minute and some 10 seconds or so later.

Note: this is within the limits of the interpretation of the correspondence between actions/events and time scale in the BEA text,

Measure? SURE NOT, I didn't have on me any measuring device.

Sense? Yes, of course.

It was not only the clear sense that the plane was climbing, during its short climbing, but also the clear difference of the level of clouds with many holes, which was bellow the flight level before, and after the exit of the short presence in the high cloud, heavy turbulence.

Dehaene, jcjeant,
Many thanks for the link to the report.
Haven't quite finished reading it yet, especially since it needs an awful amount of "reading between the lines".

airtren: ah, visual cues. :cool:
OK ... but ... if the intent is to climb, where in the sequence is the initial power and pitch change to climb from 350 to 370/375?
Consider: they had recently slowed down to turb air penetration speed. (I presume by using A/P functions).

That is why I asked: do you believe that the nose was used to climb on the assumption that auto throttle would pitch in on time and allow the aircraft to climb at appropriate airspeed/Mach/energy state, rather than by trading airspeed for altitude? :confused:

bear:
Maybe, but if there was a roll/nose drop at AP disconnect, would not the FDR give BEA a hint of that?
Configuration asym ... such as ... what control surface(es)?
What? Use wing roll to slow down?
They have a throttle quadrant.
They have nose attitude control.
I don't see rolling as a deliberate "slow down" maneuver, no.
I wonder. They are trying to piece it back together.
As above, not sure what they know, and what they've been able to infer to fill in the holes where facts are not available.
Yet.

"Corporate Culture" at AF hasn't changed, audit or no audit.
CC on strike the coming weekend, pilots the weekend after.

Holiday departure/return weekends especially for France.
Classic ploy.

This isn't related to the famous AF "internal audit";

[Edit:] Sorry, disregard my above statement (I had too many open windows and messed up with another report) , this one is related with AF "external audit", not with the other one I'm talking below which is another report from "Judicial Experts":
See report (in French) here: rapport d'expertise Rio-Paris

this "expertise report" (linked) is from the Justice inquiry which is in charge of the procedure. Anyway, they interwieved 22 crews from 9 flights belonging to Air France about those previous UAS events - and that's what I was trying to translate in English. Too bad, all annexes are lacking in this linked report.

Flights:
#01 10-05-2008 A340 AF675 PPT-LAX F-xxxx Papeete -> Los Angeles
#02 14-07-2008 A340 AF279 NRT-CDG F-xxxx Tokyo -> Paris
#03 16-08-2008 A340 AF908 CDG-TNR F-GNIH Paris -> Tananarive
#04 20-08-2008 A340 AF101 CAN-CDG F-xxxx Guangzhou -> Paris
#05 10-09-2008 A340 AF488 CDG-SXM F-xxxx Paris -> St Maarten
#06 31-10-2008 A340 AF012 CDG-JFK F-GLZN Paris -> New York
#07 30-03-2009 A330 AF459 GRU-CDG F-GZCB Sao Paulo -> Paris
#08 07-08-2008 A340 AF422 CDG-BOG F-xxxx Paris -> Bogota
#09 30-03-2009 A340 AF607 CAY-ORY F-GLZH Cayenne -> Paris

@PJ2
Would you pick any of these?

The list was in reference to the stick backs during the stall rather than in the flying zoom climb earlier. The stick back during the stall is harder to explain IMHO. The zoom climb could be explained by many reasons e.g. PF wishing to climb out of the warm air he spoke of in the BEA report.

Reasons Why "Generally" Stick Back for Final Mintues?

1. Failure to recognize stall condition (PF responded correctly to the first stall but not subsequent stall).
2. Correcting for perceived overspeed/dive.
3. Ignored flight attitude data.
4. THS trim interferance?
5. Pilots executed wrong stall recovery procedure although they did it right the first time ???
6. Failed flight attitude data on PFDs, no backup steam guage style AI instrument installed. [A330 ADIRU failures: 21 May 2009 Miami-Sao Paulo TAM Flight 8091 registered as PT-MVB and on a 23 June 2009 Hong Kong-Tokyo Northwest Airlines Flight 8 registered as N805NW]
7. Sidestick input fault with nose up bias. Failure to diagnose and overide.

CJ;
Having seen this kind of report before, I think that this kind of writing is well within what is usually done.

If I may comment generally...- a 'reading between the lines' here isn't intended to diffuse or obscure meaning, (I know you know this...I'm writing generally).

Rather, the Report is expressed in terms that clearly indicate that it is not intended to be specifically linked with any accident. This team did not do a "safety audit" and left large areas of AF unexamined. A safety audit is quite a different thing than an operational safety review.

I think the report accomplishes what it sets out to do, which is to honestly, bluntly, examine areas that work and areas that need change, some "quickly". To me the report's language only appears "soft" - it most certainly isn't but it does not "criticize" either. It is substantively "frank".

The group is a blue-ribbon panel of experts on flight safety processes and I trust their work in this Report. This is a courageous piece of work on the part of Air France when it didn't have to be done. I am completely familiar with many of the organizational issues which the report discusses including "siloing" of departments, lack of respect for others' capabilities, complexity of processes, inability to effectively assess, highlight, communicate and use safety and risk information gathered through programs such as FDM, and so on.

These issues are not unique to Air France and the caution from the authors not to link the report with any one accident is wise and appropriate.

In fact, connecting parts of the Report or linking the Report to one accident would be the same as linking, say, one runway or a specific route, to an accident and concluding that, "we shouldn't use that runway, or fly that route anymore". The Report is far broader than this.

Edited to add:
Corporate culture takes almost a generation to change, unless done with a heavy hand informed by an unusual ability to comprehend the issues and go beyond mere commercial priorities. I know about the issues between management and union having lived with them for 35 years and won't comment further in public except to say that only one can lead and that "soft" responses to safety matters do no one any favours in the long run, but getting there can be extremely difficult depending upon the cultural milieu in which the organization functions. It is easier in Singapore to get something done "quickly" than it is, say, in France, Canada, Italy or even the US, but what is given up in the exchange?

xcitation;
No, I wouldn't pick any of those, not because they may or may not apply but because there is no single "cause" and we can't stop at answer a, b, or c yet.

In these discussions about climbing, there is something that has been missed in airtren's and others' here of "climbing out of warm air", etc etc.

An aircraft on a routing which has been flight planned is not just climbed out of one altitude for another. One needs an ATC clearance to do so, as one needs an ATC clearance to deviate off course. It is not mentioned in the BEA Update that the crew obtained a clearance either to deviate from course or later, to climb out of FL350. You simply don't deviate from your flight planned routing and altitude without an ATC clearance unless it is a dire emergency, which, given all available information including the loss of airspeed information, this was not an emergency.

This relates to my earlier point about SOPs. While we do not have all the information, the BEA Update does not indicate any standard communications with ATC took place (for the climb), nor does the Update indicate that the crew followed SOPs for an Abnormal or Emergency event. The PF just started the climb, essentially on his own without coordination with the PNF, and the PNF appeared to just follow along. Now this may not be the case at all but it is what the BEA Update either says or leaves out from which we must draw interim notions. One simply never, ever "launches" into an abnormal or emergency drill on one's own, period. I have discussed this at length elsewhere.

The discussion between the two/three crew members about altitudes and temperatures is pretty ordinary stuff for flight crews and, if I may, I think airtren and others may be reading far too much into the communication/discussion...they're parsing it far too finely and perhaps looking for justifications of the pitch-up and climb where there are none. I've had such discussions many times and while an operational decision (to climb or not), it isn't unusual, ominous or even significant that they decided not to climb at that moment.

True, the ICAO Flight Plan (available in the Appendices of the First BEA Interim Report and reproduced below), indicates that after NTL the routing was UN873 INTOL/M0.82 @ FL350, then SALPU at which a climb to FL370 was flight planned, with the Mach remaining at M0.82, (see the ICAO Flt Pln below).

Standard procedure is to cross the waypoint at which the higher altitude is planned, AT the higher altitude (vice beginning the climb at the waypoint).

They were relatively heavy (not "too" heavy...the discussion was a recognition that it was a bit too warm to climb even though I suspect they could have...I've done it sometimes, when it's close but still operationally doable because if one doesn't take the higher altitude one may not get it for the balance of the trip - it's as much a judgement call as it is an operational one).

Their clearance at that moment was to maintain FL350 and they would not climb to/maintain FL370 without ATC clearance to do so even if the Flight Plan indicated such - one simply doesn't climb without a clearance unless it is a dire emergency when communication with ATC is not possible in the time available. Again, this was not the case at this point in the flight, (prior to SALPU). That climbing to FL370 was on their minds was obvious but there was nothing unusual in that - it was on the flight plan and they were assessing the need for the climb and, at that point, were content to stay at FL350, with a possible request to climb to FL370 a bit later than flight planned.

My sense of their discussion is, therefore, that it was about managing the flight, not about any concern about altitude and weather or temperature. I think things were "ordinary" in the sense that there was weather around and they were doing what everyone else was likely doing - discussing it, and deviating where necessary and monitoring temperature for their climbs.

PJ2


ICAO Flight Plan from the 1rst BEA Report:

Hi xcitation,
PF responded correctly?
Do you mean that climbing at 7,000 ft/mn could have been a correct answer to stall warnings at FL350? A correct reaction seems to me to descent to lower flight level, not a try to out climb the weather.

There is no certaincy about the reason causing the stall warnings to sound due to BEA narrative style (was it at 0210:05 or slightly later?); Consequently, there is only two possibilities:
1. Caused by switch to Alternate Law and subsequent change of Stall Warnings threshold.
2. Pull up by the pilot => g-load induced warning by his first sidestick order.

Any subsequent sidestick nose down order was only applied between 0210:16 and 0210:49. Moreover, not enough ND was applied to stop the climb as she climbed again 500 ft after this point. Hence, this is hard to believe that it would be a reaction to those previous stall warnings, and it seems to be confirmed by the second reaction.

Lonewolf

Asym config. At first blush, a jammed or unstowed spoiler. Consistent with a RL input at handoff. Or an hung aileron. Rudder issue?

Isn't it possible? Also, BEA do not state much of anything re: aspect at handoff. There is perhaps nothing of note to report, or there is, and it remains unreported. Nodata. "No soup for you........"

The Path shows a chronic right biased descent, and BEA in first Interim state a "rotation right" at impact. I think it is early to foreclose on all mechanical issues.

If PF input "SLOW" (turbulence pen speed) to auto pilot, it would be in NORMAL LAW. As such, at a/p drop, He would be in NORMAL LAW. As such, if he input NURL, he HAS Protections in PITCH and ROLL. In ROLL to 30 degrees, and Pitch to STALL nibble. The approved recovery from CFIT is full BACK and full ROLL (And full THROTTLE). Not suggesting CFIT, only to demonstrate the LAW in effect at a/p LOSS. If I was expecting STALL protection with my Pitch UP, the dual chirp of STALLSTALL would be more reassuring than worrying.......Remember, at this point NORMAL LAW.

It is here, during the last ten seconds of a/p, and the first ten seconds of Hand flight, I believe the a/c was lost.

BEA state the a/c did not begin to climb until she was passing through ten degrees NU. (PITCH). So there was a lag in response to PF's "First Input".

Did he become impatient, and just as she started to rotate, input everything the Stick had left? The elevator responds faster than THS, did he have too little back stick with his first input? As the THS caught up, she "overrotated"? Is there a STALL WRN on the THS? Because this climb wants to tell us that ND (at least 'effectively'), was unavailable for the time she was zoomed?

Please, could we have a quote from those flight reports showing an Attitude data failed on PFDs?
Where did you get that? Those are UAS reports, no trace of IR faults.
No backup steam gauge? Well there is an ISIS, which is the 4th source of Attitude indication! (considering that the backup ADIRU3 may be displayed in either PFD in case of 1 or 2 IR channel failure)
http://takata1940.free.fr/isis0.jpg
http://takata1940.free.fr/isis1.jpg
http://takata1940.free.fr/isis2.jpg

You could save the bold for something sensical, it's so embarrassing.
Quite simply, AP would not go OFF while EFCS would stay in NORMAL law.
When AP kicked off, it was ALTERNATE 2. Before, it was NORMAL, right?

Hence, when the pilot entered Mach 0.80, this was between 0208:07 and 0210:04... so, call it before event (NORMAL) with autopilot ON... while at 0210:05, it was ALTERNATE 2, after event, with autopilot OFF!
Get it?

Event = UAS.

In Normal law, if something happened (attitude, speed) protections will kick in and EFCS will set itself in "protected" law (high Alpha, High Speed, bank angle, pitch attitude...) without any need of pilot imputs, the aircraft will recover automatically. They won't be "STALL STALL" sounding if entering the high Alpha mode (Alpha-lock) because the aircraft would not go as far by itself (pilot needs to help up to Alpha_Max, where it doesn't sound either).

After EFCS dropped NORMAL for ALTERNATE 2, anything could happen as protections won't kick, and everything would have to be done manually.

It looks like a motto!
BEA is covering up that, at 0210:05, she was at 90° bank angle, while "starting" to roll to its right... or was at -90° pitch down while "starting" to climb at 7000 ft/mn!

Hi,

More and more I read this BEA"note"(french or english language) and more and more it make non sens for me (for many reasons and principally a erratic chronology and a syntax of bad first grade student)
Best is to stay stick with the two first interim reports and wait the FDR (I don't think the CVR is crucial)
Unfortunately I think (personnal feeling) the next interim report will not include any FDR parts ... :uhoh:

takata. Thank you for the data. I appreciate that you respond, and your response is important. The invective and attitude is wasteful, though. I am old enough to have learned to smile instead of frown. No offense taken, but save your upset, it must be unpleasant for you. It isn't to me!

:ok:

Hi folks, first post. I've been following PPRuNe for a couple of years now, Spanair , Colgan 3407, and AF447. Not a pilot but I am an interested frequent flyer. Thank you to all pilots and aviation people for the many contributions to these forums. Better training for pilots and having a clearly visible AOA indicator do seem like common sense improvements.
I do have an idea, a plan maybe, that I have not heard anyone discuss. It is this ---- Provide a shield system for the pitot tubes in potential icing conditions----. How do you do that ? The speed sensors on modern big jets are state of the art . If a more advanced design were available it would be used. Someday scientists may create a new material called unobtanium . It will be immune to ice buildup at all speeds and conditions. That would be great but that day is not here yet. In the meantime what planes need is an Apollo 13 type of a solution.

One way this could be done is to design small aerodynamic bullet shaped shields for all 3 pitot tubes. The two part shields would normally be left in an open retracted position along the sides of the pitot tubes. When a plane is about to enter bad weather one or maybe two of the shields would be moved forward and together protecting the speed sensors from ice buildup. There are a lot of different ways a shield system could be engineered. When flying through an area like the ITCZ one shield could be left open and one shield closed , that pitot tube being held in reserve , and one shield could cycle open for a few seconds, just long enough to get an accurate reading and then closed for maybe 7 seconds It would be better to get intermittent but accurate readings then none at all. You could also add a smaller diameter 4th pitot tube with no shield. It would be designed to fail in half the normal time in icing conditions and would serve as an early warning system for the pilots and computers that all speed indications and the AP may soon be lost.

Sometimes bad weather can't be avoided. If airlines are going to fly people across the ocean at night in stormy weather then the speed sensors need better protection from icing , pilots should get an AOA display like the military guys have, and some kind of real practice in hand flying at high altitude in difficult circumstances. I am waiting to see what the BEA will recommend.

I find the report quite telling. Working in a bigger company myself I háve the feeling I don't need too much reading between the lines to get an idea of the general 'culture'.

Surely it does not explain the AF447 accident in any direct way.
On the other hand it conveys a slight sense of a relatively strong hierarchy within an 'elitist' group and certain mistrust in other's abilities.
Statements coming from Pilots about Captains being 'immune' to their line managers implicitely point to a rather steep hierarchy in the cockpit.
In general such a spirit does not help a good workload sharing in case of high workload/stress.
Also mentioned is a slight tendency to 'Not go by the books', cut corners, etc.
All this doesn't explain any of the direct actions of the PF of AF447.
It might however be related indirectly to a potentially sub- optimal workshare during the crisis and maybe even reluctance to openly express any discomfort with the actions of the colleague or different impressions of the actual situation. This would especially apply if the PF was the more experienced of the two F/O's.
Knowing who actually was PF could indicate if this might have been a factor or rather not.

Edit: As a hint that CRM seems to be a very important topic in this report: They have added Sub- Items to go more into the detail for that and used up most of the alphabet in doing so. The only other items where they also chose to go a bit into details was Instruction/Training and Flight Data Montitoring, albeit to a lesser extent.
Take that for what it's worth....

barry54, that is an Interesting idea.

If you look at the discussions in the three earlier AF 447 threads, and posts that address the improved Goodrich pitot tubes, the "build a better pitot" approach seems to have in part succeeded. That this hull had not yet gotten the new probes is an unfortunate factor in this crash. The new design looks to have been begun after some years of the industry reporting issues with various pitot tube malfunctions.

From the FAA airworthiness E9-21368 of 02 September 2009:
Federal Aviation Administration, 14 CFR Part 39, [Docket No. FAA-2009-0781; Directorate Identifier 2009-NM-111-AD; Amendment 39-16004; AD 2009-18-08] RIN 2120-AA64// Airworthiness Directives; Airbus Model A330-200 and -300 Series Airplanes, Model A340-200 and -300 Series Airplanes, and Model A340-541 and -642 Airplanes
A shortcoming I see in the "shielding" solution is that if you get it slightly wrong, you interfere with airflow around the pitot tube and thus interfere with its normal function. (A fix worse than the problem makes the engineer a sad fella ... as he has to do it again and now gets funny looks due to the budget overrun ... )
Note also, from the same document:

Hi,

But ..
So .. this system worked for Apollo 13 but can't for Airbus ?
If I understand well .. the "Apollo 13" pitot type .. is NOT working (not in the measures loop) when shielded .. so it's not interference at all as the shielded pitot tube is neutralized.... IMHO

Lonewolf 50 -- The Goodrich pitot tubes are somewhat of an improvement, but they can still fail like the Thales tubes. Any shielding device would clearly need to be several inches behind the pitot tube opening when in the retracted position.
You are right about possible problems. If a shield system was not well engineered and thought out it could cause problems of its own. It would need to be as simple and foolproof as possible.
jcjeant -- I was not referring to the Apollo 13 pitot tubes . There was a problem during the mission with the ships air supply .The carbon dioxide scrubbers were inoperable because of loss of power in the main module .The astronauts could not wait for a perfect solution .They needed an immediate fix. It it involved duct tape and cardboard, but it worked

@Takata

Thanks for the superb graphic. Do you recall the posts that AF did not install all of the available backup steam guages option on this a/c?

The report does not explicitly state attitude failure. However it does not state that attitude indactions were all displayed faithfully. FDR did not record speed on right PFD, so maybe not the attitude.

The BEA report does show errors on both ADIRU and ISIS. Having read some other incidents I recall that Airbus can give bogus stall warnings and PFD degradation under certain ADIRU failures (those 2 Airbus incidents near the Australian radar station?). IMHO the scant BEA reports do not eliminate the possibility of a degraded attitude indicator on the right PFD.

The list of 7 reasons are purely speculative. Probably a better title is "possible contributing factors to a general nose up/stick back". I was struggling with imagining the crew spending nearly 4 minutes looking at the +15 deg pitch and giving it generally stick back - sometimes to the stops. Which scenario(s) would you envisage to explain this?

I am trying to get a list of all factors either likely or not. Add any new ones that are missing. Identify any that are false (e.g. attitude indicator).

xcitation;

There is no evidence either in the ACARS series or any of the BEA Reports and Update that failure(s) of the attitude display(s) occurred.

Initially, (before the pitch-up), this was a simple loss of airspeed data, from which all messages from 02:10:05 until the apogee of the climb may ultimately be traced. In other words, there are no ACARS messages which indicate failure of the IRUs, which supply all attitude information, before the pitch-up.

The ADIRU to which takata's schematic shows is a dual "ADR"/"IRU" installation. As shown in the schematics below, the ADR part may be separated and otherwise shut off separately from its IRU, (as per standard fault actions set out in the FCOM or on the ECAM).

At the time you claim the "possible" effect (of loss of attitude information) to have occurred (which "causes" the pitch-up), the 3 IRUs remained unaffected by the pitot failure/airspeed loss and would have continued to display correct attitude information after the pitch-up. A change in altitude information would require that the Static ports were affected which would in turn affect both the ADR and the IRU incoming data. By all indications, this did not occur.

Therefore the "original cause" that is claimed to have caused the PF to pitch the aircraft up, is not present.

By the time the IR1 & IR2 FLR messages appear in the ACARS series, the aircraft is seriously stalled and descending at > 10,000fpm.

In different words, if IRU #1 or IRU #2 or both were functioning (we have no messages before the pitch-up that they weren't), and DMC #1 or DMC #2 or both, were functioning (again, no messages, no comments in the BEA Reports), then attitude information would be displayed normally, very likely on all three indicators.

From this, there is no basis for believing or even positing that any attitude indicator failed, causing the PF to pitch the aircraft up.

Merely saying that it is possible has no relation to whether it actually occurred or not, but the statements above show that normal attitude indications were very likely available.

I'm not dismissing your ideas outright here. I am demonstrating the way an investigative process might function.

A claim that any or all attitude indications were lost requires that the above statements be refuted.


PJ2

Here are the schematics:


ADIRS Control Panel:

http://www.smugmug.com/photos/i-Gzm5...Gzm5qvg-XL.jpg



ADIRS Schematic - information flow:

http://www.smugmug.com/photos/i-hLzB...-hLzBLCJ-L.jpg


For comparison to the ADIRS schematic - the Pitot-Static ADM/ADIRU system. Pitot-static data is fed to the ADIRS for use by both the IRU (baro altitude, and rate of baro altitude change) and the ADR:

http://www.smugmug.com/photos/i-Sp8P...-Sp8P439-L.jpg

What's this supposed to mean?

Based on the BEA text, the A/THR was OFF at the time of the climb.

The BEA text does not mention manual power/throttle changes during the climb time interval from FL350 to FL375. So, that makes the climb unintentional?

A kinetic versus potential energy conservation calculation shows that the BEA indicated height delta (2500 ft from FL350 tgo FL375) checks against the BEA indicated delta speed of 60 knots (from 275 to 215 knots). Same is true for FL380, and 185 knots.

dEk = Ek (275knots) - Ek(215knots) = dEp (2500ft)

That's clear. Thanks for the detailed explanation.

But the connecting to Dakar failed, and the contact with the previous ATC was no longer active, so there was no online ATC control/contact at the time.

A deviation of 12 degrees to the left started already prior to to the A/P disconnect, without ATC approval, which would seem to indicate that the PF (and PNF) were already in ATC bypass mode when the climb started...

Hello airtren;
I'm not clear on what is meant by "ATC bypass mode". Can you help me out? - I've never heard of it.

Just to review, from the First BEA Report, (all reports found here), the crew had established contact with ATLANTICO on HF and had acknowledged a successful receipt of their SELCAL by the ATLANTICO aeradio operator, (ATLANTICO and all radio stations contacted on HF are not ATC controllers, remember - they relay messages from overseas flights to ATC controllers who then provide clearances/instructions to be relayed back to the flight. This often takes a lot of time so one has to anticipate needs early).

A deviation off course requires an ATC clearance. As I've stated, an aircraft cannot just be taken off course without such clearance unless an emergency diversion is required, (I've done it once, on the Pacific - one lights up the aircraft, broadcasts intentions on 123.45 and if necessary on 121.5 and one might climb a few hundred feet 'just in case'). The CPDLC is a direct link to ATC but it had not successully logged on. (I have my theories on why) but communications were established and a clearance to deviate or climb is required unless, as described, an emergency exists.

Perhaps I am posting under a misunderstanding on my part: the PF & PNF had no radio communications from the time when the event started, all the way to FL 0.

They deviated to the left at FL 350, and climbed from FL350 to FL375 and then FL380 without any radio communications and thus ATC permission/approval - if I understand correctly.

Another lacunae in my reading followed by a dump, an observation, and a question.
 

In most situations roughly analogous to AF447 the crews have visual clues of one sort or another. That means the plane leaves it to the pilots to discern "too fast" from "too slow" from those clues.

Um, that brings up a probably silly question. Might the pilots be better able to guess AoA from simply turning on the landing lights or watching wing tip lights to see if they can get any hints from the variations in the clouds through which they are flying?

There were two of them who apparently learned it wrong.

--

I love PJ2's pages from Davies. Even I understood most of it. And it explains a lot. Thanks.

Now I have a question:
The plane turned to the right despite NU-L inputs on the stick. Did we ever hash this out? (If so, excuse me please. I somehow missed it.) Did the pilot fixate on the plane not being able to turn back to a straight course and forgot about stall? And why did the plane apparently never respond to the left part of the inputs?

Rolling the plane to the left with up elevator is, I believe, a left turn input. If I'm right why'd the plane go into a fairly tight right turn?

bearfoil, you should have mentioned aside from one set of alternating roll inputs all inputs were either neutral roll or left roll to make your point better. I don't suggest a reason. I simply ask "why?" Then you launched into what seems to me to be silliness.

PJ2 - in message 515 of http://www.pprune.org/tech-log/45687...ml#post6582663 you suggest you're out of ideas. Does the notion of turning right with left stick inputs key any ideas?

There are several sources of data to support these last ponderings. As above, PNF would alert by radio as to the deviation, and also the climb, and if it was inadvertent, it may have been accompanied by a M'aider.

Simply because communication is problematic, the crew would follow procedure and make the calls. The CVR, depending on ambient sound level, will support this, so I am not worried.........

The inference that could be made if notification to local traffic of a climb was not made, would mean that the PF's original input will not have been intended as a 'climb', per se, but a recapture of FL350 if low.....

For about two years, various protestations of a/c fidelity and reliability have been made by quoting design considerations.

When it comes to actual BEA data "PF input RLNU.....at PITCH +10 the a/c began to climb", the immediate response is the PF commanded an absurd ascent which led to the loss of a/c. Various adjectives are selected out of thin air to savage his training, and hold in suspicion his competence.

I find that outrageous. Is there another way to see these slanders here?


JD-EE I have no opinion on what you consider silly. If you think I made a compelling statement, acknowledge and leave the gossip in the computer. I have been hammering on the initial ten seconds for months, actually from the beginning...........

What part of airframe/EFCS failure do you seem reluctant to address? A fall off of the a/c to the right is noted by BEA, as you state. It happens again, and BEA states same. Rolls and reversals are stated on the way up the climb. The a/c is behaving unusually, notwithstanding the absurd climb.

Rudder for Roll. Rudder issues. If Left Rudder was unavailable, any out of trim excursion to the right would be un reversed, and additive. Likewise if Right Rudder was in, and not corrected (or correctable).

airtrenThey were on UN873, an unidirectional northbound airway, and even though there is comment in the BEA Note that they hadn't managed to logon to DAKAR via ADS-CPDL, they were still (12 mins) inside the ATLANTICO FIR. There are currently no known records of them attempting to call either ATLANTICO (which had their guard) or DAKAR on HF.

There were a number of "off track" deviations made that night by other aircraft passing through the ITCZ, and it is not clear how many requested clearance, or how many just deviated.

Adjacent parallel airways are spaced at 90 NM.

Bear, I honestly don't see that being either implied or said outright anywhere - in fact the only person to say words to that effect throughout the running threads has been you!

Even elite pilots make mistakes - sometimes fatal ones. *If* the PF in this case made a mistake, then there may have been extenuating circumstances. *If* his training was part of the cause through being substandard, then it must be corrected. This is not about blame or slander, it's about trying to make sure that it doesn't happen again.

I agree since you state such, that you do not see an imbalance of invective. Much of it has become tacit, part of the Thread Line Culture.

Part urban myth, at this point. The time just before a/p unlatch is not well addressed by BEA. Therefore Not mentioned=Cannot have happened? The part that is disclosed is parsed such that we look for faults in the Pilotage, and accept the a/c "AS DESIGNED". "The aircraft won't do that". "What was the pilot Up to".

Doze: Do "Elite Aircraft" make mistakes?

Hi airtren;
I'm just going by your post #519 where you say:

Perhaps we're talking past one another! :)

For the record, it is stated in the BEA Update that the pitch-up was the result of an aft movement of a sidestick.

To your point, all I'm saying is, you can't just "decide" to climb, or descend to a new altitude or deviate off course for weather or anything else, without an ATC clearance unless there is an emergency.

They didn't get a clearance to climb but just pitched the aircraft upwards.

Therefore we have to conclude that the PFs intention, unchallenged by the PNF, was not to just climb to a higher altitude and level off.

Therefore his reasons for the pitch up lie elsewhere and that is what we need to find out.

And to drive a point home which I have been stating for some time now, when one loses the airspeed indications, one does NOT change pitch or power. As soon as one does that, one loses the pitch and power settings in which the aircraft was stable immediately prior to the loss of airspeed indications and very quickly loses situational awareness.

Without careful attention to attitude and power, loss of control can quickly result. A pitch-up of 15degrees in a transport aircraft operating at FL350, if held and not reduced, is, for all intents and purposes, a loss of control.

Whether the PNF knew about and understood what the PF was doing is not known and not discussed in the BEA Update. We will know, I hope, in the upcoming Report.

Does this help?

@Bear:
 

All A330 Flight Controls servos are individually monitored, including spoiler servo jacks.
If one 'refuse' to act as commanded the FCPC/FCSC will take corrective
actions to prevent such an asymmetry; e.g. remove symmetric hydr.
pressure to aerodynamically stow the spoilers and at the same time
locking the extend movement (excl. 4 & 6 for roll support) to prevent
floating spoilers.

This will be notified to crew by an appropriate ECAM message:
"F/CTL SPLR FAULT"
or in case of aileron fault:
"F/CTL L (R) OUTR (INR) AIL FAULT"

Both faults were NOT present at the time.

I did mention it before, could MLA be any factor?

Manoevres Load Allevation.

The purpose of MLA is to distribute the lift over the wing to relieve
structural load on the outer wing surfaces (bending moment).
The demanded load factor is maintained.
MLA utilises spoilers 4,5 & 6 and the ailerons.
The MLA becomes active when the side stick is pulled more than 8°,
and the load factor is more than 2g, in which case:
- The ailerons are deflected symmetrically upwards:
Max 11° added to Roll demand, if any.
-Spoiler 4,5 & 6 are symmetrically deflected:
Max 9° added to Roll demand, if any.
- Deflection is proportional to load factor in excess of 2g.

An elevator demand is simultaneously applied to compensate for the
pitching moment induced by spoilers and ailerons.

The load allevation is only available:
CAS > 250 Kts
FLAP LVR = 0 position
In NORMAL or ALTERNATE LAW.

MLA has priority over the speedbrakes.

I disagree - this is and has always been a technical discussion regarding systems design and the man/machine interface, any attempt to deviate from that has generally been avoided.

Well, there's two likely reasons for that:

1) Everything appeared relatively normal up until that point, so mentioning events during that time period were unnecessary
2) They didn't know exactly what was going on during that time period, so could not put anything conclusive in the note

Not at all - that is how you seem to be choosing to interpret it. Coming at it with no preconceptions it reads as a very dry statement of events that happened at specific points in time without any implication of anything, as you would expect of what was essentially a press release to get the more lurid speculation out of the way so they could do their job.

With all due respect, you seem to choose to be very definite on occasion and then swing wildly into evasiveness and conjecture if anyone asks anything of you directly, so I'm going to ask you directly and see what - or if - you answer:

Do you believe in a conspiracy on the part of the BEA and Airbus to blame the pilots in the case of AF447?

Either way I think you're too emotionally involved with this, and I suspect a few days away from the thread might do you some good and get you some perspective - it certainly did me good a few weeks back!

A33Zab

Thanks. If aerodynamically stowed, and absent hydraulic pressure, can they flutter?

Also, RTLU. Is Rudder centered before limit is ennabled? Any chance of (R) Rudder staying with the a/c all the way, without annunciated ECAM or ACARS rpt? If jammed at (Right) would there be any ECAM, since the Rudder has (limited) authority anyway? Would the deflection be accepted as an input, not an anomaly?

Hi Dozy. Conspiracy is defined as an effort to collude with others to effect an outcome, generally for ulterior motives. A "Surprise Birthday Party" is also a conspiracy, a good one! Few people have left an ability to accept that sometimes motives are unconscious, or inadvertent. That means we can say bias instead of conspiracy. With bias, it is even more difficult to pin down, since it frequently lacks acknowledgmwent among 'buds'.

The silence of the lost pilots is a sort of vacuum. Nature abhors a vacuum, and the firstest with the mostest will fill it up. Yes, there is an element of 'blame the crew'. I think it does not rise to the definition of criminal, but merely to an excusable 'birds of a feather' sort of interdisciplinary sort of thing. I take your recommendation seriously, I have once again become too passionate, and will take your advice.

*le sigh*...

Or the CVR that is now in the hands of the BEA - the "lost" pilots are silent no more!

I'd like to see precise examples of where you're getting this idea from.

See you when you come back!