EMIT, hopefully the BEA final report will be a lot more informative than their last one. It lacked any meaningful information for some reason. They had all the data but it was like the guy who wrote it was getting off shift in 15 minutes and had a hot date and couldn't be bothered by details.

Quoting Lonewolf_50:-

Blowed if I know for certain, Lonewolf - I'd be surprised if even 'Bus-drivers' are absolutely certain, from the extraordinarily-complex documentation, what the systems may do or not do in different circumstances. But, according to this, in Alternate Law 'Alpha Floor' is lost, but AoA monitoring continues:-

http://www.smartcockpit.com/data/pdf...light_Laws.pdf

Quoting EMIT:-

I fear that you're now just making things up, EMIT. 'A lot of backstick' was not applied, leave alone 'maintained' - even the BEA states that the PF did exactly what he should have done, applied forward stick, controlled any tendencies to roll, and levelled the aeroplane out:-

No 'backstick' at all?

RWA

You are now the one making things up.

Your previous quote from post 1994

My bolding and colour change.

Pray tell why if the aircraft was in Alpha Prot it would increase the AOA by pitching UP!! Plus in ALT LAW 1/2 Alpha Prot is not available. Roll is direct which is why there could have been slight over-controlling in roll. High AOA and High speed protections could also have been lost. Once the AOA had been sensed greater than 30 degrees Abnormal Attitude Law would have been in place to allow recovery of the A/C. (Pitch control alternate law with no protections as mentioned before and Roll would now be direct - NO auto-trim from that point on and Manual Pitch trim required. This would be displayed on the PFD.)

You are like a dog with a bone and need to just relax and wait for further information to be given out by the BEA. With your continued misinformation and lack of understanding you seem to be trying to prove your own conspiracy theory.

See footnote 17: Protection totally lost if DUAL ADR failure or ADR disagree.
If there had been AoA protection we wouldn't have this thread.

What speed does the "Low Speed Protection" kick in?

Edit: Ah i see footnote 18

"If dual ADR failure then low speed stability is lost"

A330 has a Horizontal Stabilizer.

It articulates, making it in essence also a variable incidence wing.

With aft fuel, the THS must work against its primary function, that of keeping the Nose UP.

If the THS AoA increases too much it will STALL

If it STALLS, the NOSE will drop like a stone, and the a/c will likely ROLL as well.

A pilot, seeing the NOSE DROP, and roll right. WILL INPUT NU AND ROLL LEFT.

IF Pilot overcontrols, the a/c will CLIMB, perhaps alarmingly, and said climb may become unrecoverable.

just a thought.

RWA:
Based only on my understanding of the resource you cited, and a slightly dated training manual on the A330, the automatic feature (alpha protection) would induce control inputs (you could say "fight the pilot" or "help the pilot since what he's doing is heading in the wrong trend") in normal law, but in alternate law, that AoA related feature doesn't (should not?) do that. Stall warning should sound if the AoA is deciphered as a value approaching stall. (It appears that it did ... but also that there are some quirks at very low airspeeds regarding that feature).

What is frustrating in understanding this incident, for me, is the number of parameters that need both Airspeed and AoA as inputs, and the coupling of Airspeed to AoA, and problems this poses for the flight control system when those fundamental inputs are spurious or obviously erroneous, or "voted out." (Note: since the mishap was reported, there has been a Greek Chorus of pilots who point out that flying pitch and power is where one begins to deal with erroneous airspeed problems ... and there is also a considerable body of pilot experience that points to hand flying at altitude becoming a lost art ... )

Systems complexity considered, once in alternate law the speed protection can be overridden by pilot. Whether or not the computer sensed an overspeed protection requirement (and thus a kick off of the autopilot) has been discussed at some length. The consensus seems to be that AP kicked off due to crap airspeed inputs, not due to overspeed sensed (erroneously or otherwise).

As the bits and pieces of info come out of the investigating team, the discussion on Tech Log forum has been skeptical of initial (via the high speed protection feature?) NU input commanded by the robot. Part of the support for that skepticism has been the kinetic energy tradeoff (q) and the recorded pilots back stick inputs (along with roll inputs). These inputs look to have accounted for the pitch attitude and altitude gain (and of course, actual airspeed loss, versus displayed which was for a while all wrong).
What I glean from this is:
if all three of the sensors that feed airspeed info to the flight computers and displays went pear shaped -- the evidence points to this based on pitot icing -- then the automatic pitch up would NOT happen since in Alt 2 that feature is disabled. This presumes that the flight computers more or less were functioning as advertised.

Whether or not a suprious voltage or oddball computer decision entered into this cannot be known as of today. It may be unknowable, if such transpired. There does not seem to be much of any evidence to support that class of malfunction. If such did happen, it didn't leave much of an audit trail.

Svarin has made some thought provoking posts and analysis in that regard, recommend taking a look at his inputs if you have not already.

Cheers

Lonewolf50

From the outset and per BEA the PF made one NURL at a/p drop. It was not continuous. The climb is unexplained, although High speed Prot is a candidate, certainly.

Thanks bear, I just read PJ2's latest Tech log post on how much SS deflection it takes to start a climb. He related to about six inch control deflection on a yoke controlled jet. Most enlightening. Also the deciphering of the BEA reports on when the inputs to the nose began to drive the nose higher, in concert with TOGA. Paints a different picture.

I think it well to bear in mind that, per the basic systems information publicly available, unless you counter any nose up input you makes on the SS, your nose up input remains within the system.

Put another way, if you put a little nose up in, you need to take the same amount out to restore level flight, unless you are attempting to trade airspeed for altitude. As I understand the Law they were in, (Alternate) the computer won't think through that for you. You must mind your pitch attitude and counter correct for your various inputs.

More than one pilot who flies at high alt has pointed out to how delicately one must handle the big jets at high Mach numbers and high altitudes. Hand flying. (Seems to require some practice to master, like any sort of flying).

If I misunderstand the controls, please correct me.

Yes. And NO. In a powered system, especially one with a tagalong "Trimmer" (also described as a variable incidence wing set), it is a bit more complicated? "Stop the Roll". "Relax back stick".

Ab initio complaints from the CFI? Once rolling an A330, or Pitching it, with a "helper" as big as my house, the Physics is different? Not really, perhaps surprising is more accurate.

IF PF's first NU was in some way additive to an existing rotation of some description, it explains a bit how the rotation could have been emphatic enough to elicit 7kfpm? If he held it enough (before the seat started to really push him up!) to allow that big slab to acquire the power to really move her tail, Bob is then someone's uncle........?

The BEA later mention "repeated ND inputs" by the Pilot, but have they attached these to an attempt to recover from the climb? BEA's bon mots need to be sorted by time on a linear graph, perhaps that is forthcoming.

Not quite as simple as "relax back stick." That leaves the "up" command in place. Worth reviewing the on line resource, A330-A340 Flight Crew Training Manual . pdf. (Dated, June 2005) regarding SS and high speed protection, if Alpha Prot isn't working. (Seems not to have been, else no stall, right?).
See pages 27 and page Page 34 of that .pdf.

Note: pull side stick up, release. Nose stays up, up you go. Push side stick forward, and then release, to change pitch. If you don't, up you will keep going ...

IF the magnitude, in displacement and time, of your nose up command isn't equaled by the magnitude, in displacement and time of the nose down command, THEN your nose will stay more "up" than "level." (See the pictures).

I have been intrigued by the discussion about what happened deep into the event, when the AoA had gone high, plane was falling, and questions on control effectiveness in well developed stall arise. But we are not talking about that time, the concern at hand is upset initiation.

I honestly don't think it's that complicated.

The complexity begins when one sorts through laws that rely on the AoA input, and Airspeed inputs, and being aware of which law is operating. Some of the laws do some work for you. Some hundreds of posts into this discussion, we have the pilot's own words to tell us which law state to examine: alternate law. Fewer things at work for you.

I'll await further input in re Abnormal Attitude law. Some parameters were met. But some information (leaks?) to date suggest that due to airspeed being erroneous, AA not in play. I hope that gets officially addressed.

Quote:

---

Ab initio complaints from the CFI? Once rolling an A330, or Pitching it, with a "helper" as big as my house, the Physics is different? Not really, perhaps surprising is more accurate.

---

Zero-value-added prose. :confused:

Quote:

---

IF PF's first NU was in some way additive to an existing rotation of some description, it explains a bit how the rotation could have been emphatic enough to elicit 7kfpm?

---

Based on what data point? Were there an already existing rate of climb in progress, do you not think the FDR would have that data, and the info be part of the summary?
Do you mean "if he had held nose down" enough? Seat push him up? What means this?
Zero value added, though droll. :cool:

As you slow down, the magnitude of force acting on your airfoil reduces as square of the velocity change. Does one get to a point of lost control effectiveness? Good question.
One certainly hopes for more clarity in the next report.

Howdy lonewolf.

The "relax back stick" I qualify in the next phrase "ab initio commands from CFI?"

It is elementary in a cessna. Not so in a big rig.

I've lost [QUOTE] function, so to answer "what data point"? I would say:

Unable. If it's there, BEA have NOT stated it. Simply because we want to believe, we do. Why? Can I say for certain the a/c was not trending in rotation UP? Simply because it is not included? PF input NU and Roll Left. From BEA, we see it everywhwre. Supposedly as his first action after "I have the controls". Is it? Really? In the DFDR, did PF start with a clumsy grab at the Stick after a/p drop, and input NDRR? Was he recovering from his own mistake? No?

BEA will (IS?) living to regret the accommodation it made to Airbus. They must reveal more, and then more, each time stopping unsatisfactorily with "Wait for the final Report".

I would say... Next time: make a big glider of it... Without any doubt.

Climb
 

Bearfoil
The report does not explicitly say how long the nose-up input was. IMHO it was continuous from 2h 10 min 05 "...nose up input." until 2 h 10 min 16 "...nose-down control inputs". At most this was for 11 seconds and resulted in the climb from FL350 to FL375 which sounds reasonable.
We can speculate if/why the PF intentionally made the climb as he did not adjust the thrust during the change in FL despite announcing he had control before the manouver. This initial nose up would appear to be counter intuitive given the stall warning and desire to maintain cruise altitude. Unfortunately the IAS on the right PFD used by PF was not recorded on the FDR. Did the ADIRUs give bogus attitude indications? It would explain the bizarre "inputs made by the PF were mainly nose-up".

@ xcitation
FWIW, that quote isn't from me, it's from bearfoil. :cool:
Indeed, which leaves one wanting in terms of understading PF actions.
Ten seconds of nose up input. Continuous or intermittent? :confused: If continuous, that's quite a bit of nose up).
(What can you do with ten seconds of sustained "nose up" command in a given aircraft. ) Well, in a small plane, I could loop a T-28 in around ten seconds of continuous nose up (pitch toward stomach) input (a 3.5 g maneuver) back when the earth was nearly new ,and I was learning to fly. :cool: I doubt AF 447 pitch input was anywhere near 3.5 g, heck, the acft control system is limited to 2.5 g pull.

Aye. thanks.

Quote:
"The cases are completely different."
It is a remarkable coincidence that both zoomed at 4.2 deg AoA

Quoting excitation:-
None of the mentions of 'inputs' record the length of any of the inputs, excitation? However, the context - particularly the fact that the BEA note does not go on to record any climb, but instead quotes the PNF talking about the speeds - strongly suggests that the PF achieved his object (corrected the roll and duly levelled out). I've only flown light stuff (mainly gliders, as it happens :)) but even I know that a roll tends to produce less lift from the wings, so that a touch of 'up elevator' is often required to maintain altitude when recovering from an uncommanded roll?

And further, had the PF kept the 'noseup' on, I can't imagine ANY aeroplane taking 11 seconds to respond? Or, if any do, I wouldn't want to fly on them? :)
I believe that normal practice is for the senior first officer (and therefore PIC while the captain is on his break) to remain in his accustomed righthand seat. This is supported by the BEA quoting the captain as saying, "He's taking my place"?

"Did the ADIRUs give bogus attitude indications?"

Now that's a heck of a good question! And it caused me to look back at a summary of all those 24 ACARS messages. And yes, all three ADIRUs appear to have reported problems simultaneously:-

"34123406IR21,EFCS1X,IR1,IR3"

Looking further, I found something I'd missed earlier - even ISIS, the standby instrument system, appears to have reported problems too:-

34220006ISIS 1,,,,,,,ISIS(22FN

There's an analysis of all the messages below. I can't vouch for its accuracy, but if it IS accurate, and the pilots were presented with a mass of instruments that were either blanked out or reading wrong, the BEA (which only listed the ACARS messages in its first report, without any explanations, and didn't mention them at ALL in the note) is going to have a helluva lot of explaining to do one of these days........

http://www.iag-inc.com/premium/acars2.pdf

Attitude
 

From where suddenly come the ideas that the attitude indicators were giving false indications? Wouldn't such a thing, massively important, have been reported in the BEA note?

The "failures" that are distilled from the ACARS messages have been explained a long time ago: systems report OWN failures, but also failures FROM OTHER SYSTEMS, with whom they communicate. Because of that setup, you may encounter the system identifiers IR1, IR2 and IR3 in situations where,e.g. the Air Data units are faulty.

Quoting EMIT:-

In my case, from the very first press reports on the accident, plus subsequent amplification?

You'd have thought so, wouldn't you? But the note doesn't mention it at all. And all the original BEA interim report said about them was, basically, that they aren't supposed to have anything to do with any investigation :):-

Fine then - apologies, I must have missed it. Please post a link to the 'explanation' you're referring to?

EMIT

It would be remarkable I agree. I am trying to explain why would the pilots maintain a generally nose up attitude for 4 minutes of stall descent. There are many possibilities. I find it incredulous that all 3 simply forgot basic stall recovery. IMHO either they ignored the instruments or the instruments failed or both.
But did it record every failure? e.g. do we know what the right PFD showed for speed. It should be noted that in other A330 incidents false stall warnings have been generated and in those occasions correctly ignored. Could this be why they ignored most of the stall warnings?

Hi,

Can I suggest that if all participants in this theater were all together in the cockpit of the 447 the night of the event .. the end of the flight would be the same (splash) :confused:

jc, it would be so crowded in that cockpit nobody would be able to see, or move. Picture a phone booth and a bunch of college students trying to set a record of how many men one can stuff into one. No way to read the PFD, for one ... :p

Sources
 

Quoting RWA
"In my case, from the very first press reports on the accident, plus subsequent amplification?"
Unquote
SIGH

Wouldn"t BEA Interim report 1 and 2 be a better source of information?
Quoting BEA Interim reports 1 and 2:
"twenty-four automatic maintenance messages were received between 2 h 10 and 2 h15 via the ACARS system. These messages show inconsistency between the measured speeds as well as the associated consequences,"
Unquote

Nowhere is there a mention of ATTITUDE information problems.
Do not mislead yourself by thinking that FLAGS on the PFD mean that there is a problem with ATTITUDE INDICATION. An FD flag means, NO FLIGHT DIRECTOR, an FPV flag mean NO FLIGHT PATH VECTOR, etcetera.
The PFD in fact is a display that combines MANY flight instruments and annunciations in one display screen. The attitude instrument has not been reported as faulty in any way.
Have a look at Interim report 2, page 36 and onwards (pdf page numbering, otherwise page 35 and onwards, if you look at the report numbering - the pdf counts the cover page as a page, the report text doesn't). Report can be found on the BEA site.

Attitude indications are compared (by a COMPARATOR) between the three Inertial Reference Units. Absence of any ATTITUDE FAILURE indications mean, with a fair amount of certainty, that there were no problems with the ATTITUDE INFORMATION.
That the aircraft somehow ended up in a problematic attitude, 15 degrees nose up above FL350, is a completely different subject.

On page 48 (pdf count) of mentioned report, you find an illustration of a PFD with failure flags - in that picture, you have a completely functional attitude indication, any pilot should be able to work with that, and see through the multitude of failure flags.

So, did it crash because the system allowed most if not all data to the pilots to be false in this situation?

Is it a good thing that when you want to input a control movement you are in essence asking a computer permission, and if permission is granted it may or may not be exactly what you thought you wanted. (For you and your passengers own good of course)

Is our own training lacking in some way? Are we getting away from the basics and if we are is it a step in the right direction?

Is the system overall so complicated that a mere human cannot fully comprehend all of the scenarios thrown his way and if so what are we doing in the cockpit anyway? We are safety pilots for what?

Are we so far ahead of the game that we have lapped ourselves and now behind again?

I would like to think that this very moment those pilots are satisfied that they know they did everything correctly and to the extent of their abilities and it was the system that let them down.

Theories
 

EMIT (or anyone else willing to stick their neck out)


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.

Theory
 

xcitation

Your numbers 1 (excluding bracketed text) and 3 score high on my shortlist.

Perhaps it's time to revisit the Bea note:

2 h 10 min 05: (...) The recorded parameters show a sharp fall from about 275 kt to 60 kt in the speed displayed on the left primary flight display (PFD), then a few moments later in the speed displayed on the integrated standby instrument system (ISIS).

2 h 10 min 16: (...) The speed displayed on the left side increased sharply to 215 kt (Mach 0.68).(...)

2 h 10 min 51: (...) Around fifteen seconds later, the speed displayed on the ISIS increased sharply towards 185 kt; it was then consistent with the other recorded speed.
(...)
Note: The inconsistency between the speeds displayed on the left side and on the ISIS lasted a little less than one minute.

From all we know, they temporarily lost airspeed.

At which point do you suggest the plane didn't do what the pilot asked from it because of the FCS?

EMIT was talking about Acars messages. They're used to confuse technicians, not pilots...

IMHO, pilots didn´t fail to recognize their compromised situation.
Rather, I think they were dealing with a confused system, which missed the right
"law" switch or state change to begin with!
Bad training (read = arrogant position taken by manufacturers and company policies), contributed for sure!
The training based on following automatics improved the waste of time, wich at the end killed them all.
When the Captain reentered the cockpit the power plant was set at idle and nose-down inputs were fed...
So: Why?
Why power idle and change of pitch?

Well, I think they knew (or the Captain did), the best way to make a compromise with the (for them unkwon), airspeed was to make a glider of the aircraft.
Going back to the basics thus...
They just missed the Trim Wheel... And when they were on the right path to solve the problem, automation began blaring stall and confused them even more...
Who knows... Maybe it was far more worse than we can imagine...
I my eyes they knew their status, only FL370 is way to short to react well when your rate of descent is 10K feet/m.

And... If I had been a pax on AF447, sure I had tried, crawled on the roof if needed, with all the negative g´s on my ass to the cockpit to tell the pilots they had to decrease their AoA as soon as they could...

When the AP and AT failed would the plane have just flown straight and level with the last power setting before it disconnected? If there was an erroneous overspeed would the disconnected AP pitch up?

My neighbor says the Airbus autopilot is on even when disconnected to maintain pitch and bank. I recall it being brought up a few hundred posts ago so sorry if this has been hashed out before. I had another arguement with him last night because he said if the AP is off it is still flying the airplane using your control stick inputs. I said if you can get out of your seat and go in the back how can you say the AP is off. It might be in the basic CWS mode of the Boeing but for that you need the AP on.

bubbers44;
This is what was meant:-

http://oi53.tinypic.com/ok0486.jpg

and then:

Hypothetically it may just have made the difference needed for a different outcome and in a manner not envisaged so far.
The CG of the aircraft (which seems to have lost pretty well all means of aerodynamic and control authority) would have been brought forward to the degree that the seesaw effect might cause the nose to drop to the point where the aircraft starts to move forwards again. Effective airspeed would be recovered and a faint hope for resumption of normal flight presented. It wouldn't be pretty or pleasant and the end result may well have been the same.

All hypothetical of course. :8

There was that A320 that flew into the trees after the pilots performed a low pass...


Mine was strictly a rhetorical question.

Without going into another of those discussions, where do you suppose might be parallels to AF447 (besides an A plane being involved)?

I know. But is some internet experts getting Acars messages wrong a good case in point for your answer?

Both flights utilized an aircraft that was strictly FBW. All I am saying in general the system is designed to fly the aircraft better then the pilots and tell me if I am wrong here but it does have the capability to negate pilots actions. (The friggen A320 in the trees) I was not aboard flight 447 and neither were you so I do not know if there was an exact parallel however you are still controlling (somewhat) a system that is controlling the aircraft. Remember the designers have designed the system to be better then you and in doing so gave the system (whether inherent or by design) the ability to override what you ask of it. It knows best right? And I do think in a lot of cases it probably does know best since a lot of the pilots now have limited flying skills. But there is going to be that one hundredth of one percent that the software designer did not cover or the friggen hardware craps out and you you have between your hands and the control surfaces are some useless wires.
I like automation, with it I can relax a bit and in doing so I can better see the big picture. Hand flying at flight level does suck. (I flew cargo so yes we tried it on occasion) Are you totally comfortable of not have 100% control of the aircraft? I do stand by my original statement though; I do not mind FBW as long as the wires are in control tubes.

I do not fully understand your question (Or is it a statement with a question mark?) I am not an "internet expert" nor am I am expert in flying. I have been flying professionally since 1982, a healthy mix of military, law enforcement and commercial and presently instructing in the desert. So I have almost 30 years of experience, most of which have been successful, have not killed anyone by accident and not bent any sheet metal.
I am not here to compare experiences, time, licenses, type rating anything with you nor do I need to. I have not met any aircraft that can read whats is on the back of my piece of plastic. Well maybe your FBW one can. There is nothing (yet) that can replace experience and sound judgement. I am just giving my opinion.

(quoting 'before landing checklist':-

From much less experience, 'before landing checklist,' in my personal experience as a mere amateur flyer, I couldn't agree more. Both main manufacturers and the airlines are leaning more and more towards a situation where the 'systems' hold sway and the pilots are virtually forbidden to fly manually, unless they take the risk of being charged with anything from 'gross negligence' to 'manslaughter' if anything goes wrong.......

It's worth bearing in mind, too, that the 'first duty' of flightcrews nowadays is 'listening to the systems.' Someone above mentioned that the AF447 pilots shouldn't have taken as much as ten seconds or so before reacting to the 'zoom-climb' - it's fair to say that, as far as I know, the flight-crew's first duty would have been to 'plough through' all the error messages, one by one, with the PNF reading them out and the PF acknowledging and clearing them, before they actually DID anything about them.......

Sadly, I suspect that when (and if) the BEA finally comes clean and publishes the full CVR transcript, we'll hear that the flightcrew literally didn't live long enough to get through 'tic-tacking' on all those messages.......

My own view is - and always has been - that the pilot should always have the final say. And, further, that if a given aeroplane can't be safely flown manually in all conditions, the answer is not to install yet more 'systems' but to 'design the b****y thing so that it works properly......'

Nonsense. 'Systems' are there to be used by crews when appropriate just as manual flying is when appropriate.

Wrong. The 'first duty' of crews is to fly the aircraft. Whether that is done manually or via the 'systems' you tell the aircraft what you want and then monitor the response.

Then you don't know very far. The 'first duty' of any crew is to fly the aircraft. Any other actions are secondary and are to be performed when not interfering with flying the aircraft.

Being a mere amateur you are perhaps excused, but with the amount of nonsense already posted there is no need to add more.

Zero-value-added prose, as someone already noted before.

Despite all the more than 100 pages with remarks and replies: still asking myself: why did they fly into a level 5 CB? What radarsystem was in this aircraft?

In a CB you can expect anything, so how the aircraft behaved could have been far beyond its design-limits.

The mysterious zoom climb
 

Why the zoom climb?

It's very odd to me that all of the blogs seem to overlook that all of this happened at the very same time AF447 entered a monstrous thunderstorm. Which contains serious up and downdrafts and consistant warnings for pilots to avoid them.

There is enough evidence to indicate hand flying the A330 at altitude is dicey at best even on a clear day, let alone in turbulence, at night, and with no airspeed indications.

All the other aircraft in the area deviated. Why not this one?

Two posts in a row state as facts about the aircraft flight into a defined thunderstorm without deviation.

I challenge those facts

Where's the investigative data that so states?

To continually speculate for a simple explanation does nothing to furthur the understanding of a complex accident.