Hi Organfreak,
Me too!

The report of July 11, page 29 shows quite clearly that the AP (probably No2 (FO's side)) disengaged at 02:10:05. The FO's IAS is not recorded, but the ISIS shows a speed drop from 02:10:06 and the Capt's IAS shows a drop from 02:10:07. I assume the FO's IAS showed a speed drop at 02:10:05 which caused the AP to fail.

I suggest you disregard the "The pilots noticed it by reference eleven seconds AFTER the Cavalry Charge, yes?" red herring.

http://www.blackholes.org.uk/pp/AP disconnect.jpg

What caused the AP to disconnect also caused alternate law. When the ADR monitoring sequence began the AP disconnected as a consequence. The same process caused the switch to alternate law.

I have no interest in entertaining a small child.

If required, which it was not. Deflection of the roll spoilers occurred after AP disconnection.

Oh dear.... Lieman is back.

I thought the mods got rid of him and his unbased theories?

Hi,

ChristiaanJ
I do not dispute
But you find this lack of interest on the part of regulators and certification bodies as something satisfactory?

Read NPA 2011-03, p. 60 "CS.1324" (all new), and p. 75 "Appendix P" (all new).

A thread about the conversation between/among the piots? All PF says at a/p loss is "I have the controls"?

Does this suggest the pilot also knew the Flight Law had degraded? No. My point is that the all important question is what he knew, and when. He makes no mention of the Plane's conversion to Alternate? No mention of the loss of AirData? Does he illuminate the type of Alternate? No. Does he believe he is still in Normal Law, and speeds are not unreliable? This all is first verbalized many seconds later. Red Herring?

Neither does he call for the book, and establish other than a mundane reversion to manual control.

This raises no questions amongst the illuminates here?

The salient point is not what has been discovered, it is of no meaning to the crew/pax. What is important is if he was flying without a basic set of start points, how could such a thing happen?

There is also, of course, the possibility that the ironclad conclusions of some are in an area that not even the BEA has ventured, nor will they.

http://oi43.tinypic.com/2d6nmv.jpg

The proposed EASA amendments (NPA 2011-03 ~ Appendix P) have been added in green, plus 3 UAS events are plotted.

EDIT :: Some additional background:-

A common characteristic in most Unreliable Air Speed (UAS) events was the proximity to deep convective/tropical storm cloud formations; hence the EASA NPA 2011-03 Appendix P proposal is primarily a "deep convective cloud" extension to the existing JAR intermittent maximum envelope. This hypothesis is based on the often rapid onset of UAS events, the lack of airframe icing, some observations of strong moisture on the windscreen (e.g., rain reported but suspected to be melting ice crystals), and the proximity to such cloud formations, is that the aircraft are likely encountering an area of high ice water content[1]. The observations of low or no reflectivity on the pilot’s radar are consistent with flight through ice particles, possibly concentrated at small sizes[2].

Refs:- (BEA Interim Report No.3 - p.77)
[1]The background noise changed rapidly around 2 h 09 min 46. This change in the background noise was identified as possibly being characteristic of the presence of ice crystals but did not give rise to any specific comments from the crew, the phenomenon being little known to pilots at the time.
[2]The conversations in the cockpit did not reveal any malfunction of the weather radar and indicate that the latter displayed a usable image.

Many thanks, HN.
I've skip-read it and will read it again, even if it is not quite my field.
But at first sight, I've not seen an unequivocal requirement for re-defining the pitot tube certification requirements.

Sub heated AS probes and GIGO*
 

Hi,

It seems almost ridiculous the fact the aviation industry is still today using sub heated Pitot's.

A very simple device, so important, an essential input to the A/C complex IT Systems, seems to be not advancing to a "changing environment".

And clearly, the trigger of a serious accident where the System and the crew were not capable to deal with the consequences of it's VERY BRIEF failure in presenting consistent output.

Another almost ridiculous fact was a DESIGN FLAW that allowed Garbage In generate Garbage Out affecting an essential System output, the aural Stall alarm. An essential input to a crew facing an unprecedented situation.

This first issue IMO should be addressed earlier by Airbus SAS and the patent filed (of a LASER based sensor) shows a tentative to face the problem.

And the 30+ UAS incidents shows the (previous) vulnerability.

GIGO

(*) "Garbage" generated in the design :}

Sub heated Pitot's
 

Hi,

These companies no longer invest in R&D? And the bureaucrats do not rely on the TECHNICAL experts or not pay attention to the REGISTERED incidents?

Remember the patent filed by Airbus SAS using OPTICAL approach.

The problem is above Engineering level, you know. The HIGH ROCKS failed and probably are still failing to solve the problem.

And the short duration of the "inconsistent output" of current probes suggest we are near the required electric power.

IMHO this is a typical INERTIA of bureaucrats. It seems lack of diligent Technical experts in order to KILL the problem.

Analog devices are no longer "attractive"? The Engineers are losing the ESSENTIAL feeling due the "Digital revolution"?

Like pilots under the FANTASTIC digital paraphernalia losing the basic ability to fly safely when they need it most?

A design that put triple redundancy to deal with (sensor) failures that OBVIOUSLY will occur SIMULTANEOUSLY is RIDICULOUS, IMHO.

And after all, not train adequately the crew to operate these A/C is :mad:

The Blame Game
 

Hi,

Organfreak,

The human machine interface (during crisis) has not a place in your list? The fact that the entire crew failed to even understand timely what was occurring is not important?

Or your

Quote:

---

7. Deficiencies in the Airbus instrumentation and control design in terms of stall warning behavior, angle-of-attack display, auto-trim, and the list is long.....

---

includes this issue?

:ok:

Sensors reliability and GIGO (garbage "per design")
 

wheelsright

:ok:

The Blame Game
 

@RR_NDB:
Yes, of course, and you're right that I was careless when I assumed that was taken into account in point seven (quoted below), as well as my remarks about poor training. Point seven:
Guess I was thinking that the above deficiencies, IMO of course, were a part and parcel of their lack of situational awareness. Anyway, nothing meant to be definitive about what I wrote, just the musings of a bystander trying to make sense of it all. When the final report comes in summer, it'll be none too soon, eh?

Sorry, but I don't understand that. Isn't the proposed (new) CS-25.1324 just that?

The basis for the proposed CS-25 Appendix P ice crystal certification environment is described in FAA Technical Report DOT/FAA/AR-09/13

HN39,
Thanks for the link! Oops, another 80-odd pages to plow through.....
The FAA tech report seems to deal with engine icing at first sight, but I'll refrain from comments until I've read it.

Human machine interface and the K.I.S.S. principle
 

Hi,

Organfreak,

Quote:

---

...were a part and parcel of their lack of situational awareness.

---

Antagonic factors poses important challenges to the design of the “interface" in complex Systems.

CRM, developed after DC8-61 flight 173 in Portland is IMO closely related to the interface design challenge:

1) What is happening? (relatively simple to present)
2) Which are the priorities (a complex task for the interface and the crew)

The crew always should be helped to deal with the issues.

Based in what we learned (not so much) on AF447 we may say the crew barely understood what was happening. And only realized (partially) in the final moments of their plunge.

This is a very important fact. We may say the System failed, at least in three important points:

1) In order to deal with, and present fast and precise information on the SIMPLE (and BRIEF) failure of an important "input" (AS data) to the STABILITY of the plane System. AS probes with a previous history of problems. (Simultaneous "failures")

2) In order to present CLEARLY and with all necessary methods, the REAL EMERGENCY: Plane plunging near TERMINAL SPEED. With ETA to sea level in just 4 minutes.

3) In order to provide "automated" resources to allow the crew fly the plane.

Actually the crew never learned the trigger factor and the short duration of the sensors failure.

And they never elected the top priority, very probable due current deficiencies in the human machine interface.

The silent move of THS made things worse instead to help the crew with useful output to facilitate the urgent need to "make the plane fly again".

The probable "pilot error" in the end, IMO could be applicable during sections of 350 to 380 climb. To PF (absurdly) not trained for hand flying at cruise level.

During the descent, the many facts we learned, suggests important deficiencies in an essential sub System, the man-machine interface.

Thus compromising the ability and the performance of the entire crew. IMO, the human machine interface must be improved urgently and a complex R&D is required for.

K.I.S.S. principle

Mac

PS

Complex CRM issues (involving plane System) inducing entire crew to important errors. Plane System being imho, the most relevant factor, from apogee to sea level.

to present what the a/c did right, and what the pilots (obviuousy, not even
 

RR NDB

Frustrating. All along, here, I have noticed a tendency for many to present what the a/c did right, and what the pilots bitched up. Odd, since there is ample fuel to go around both ways. I appreciate your take on the matter at hand. I recall that the UAS here, was the 33rd in a recorded sequence, and yet there seems a lack of urgency on the part of the line and the airframe side to give it proper credence.

No awareness of the cause of the a/p drop is apparent in the CVR. Yet wouldn't both pilots be quite aware of the progress of the flightpath and attendant parameters? "What's with the speeds"? "G is constant, noise level is ok, wtf?"

Hamburt says the a/c was in ALII immediately, yet the pilot makes no mention of the degradation in Law, merely, "I have the controls." Something so important, along with a notice of fluctuating IAS deserves not a mention? No discussion of the handling differences twixt NL and ALII? "Watch your lateral, remember the bank is touchy in this regime". No Protection, etc. Only, "Lost the speeds, Alternate Law". And that many seconds after the PF has started hand flying?

What about the several seconds prior to a/p drop? Would the a/c, in autoflight, not react to ADR with "corrections" noticeable on the flight deck? No flight path changes? Nothing untoward due faulty sensors, just a cavalry charge instant? And wouldn't these excursions produce a heightened sense of awareness in our pilots?

It is so hard to imagine such a quiet, passive, and reactive flight deck. It only starts to appear real when the a/c is already in dire trouble, banking to and fro, climbing way too quickly, etc. Something is missing here, if only a completely lacking CRM. Reading for on toward three years about this has not lessened my sense of a very incomplete story presented by the authority.

Ultimately, not even BEA will present "This is what happened".

(And my favorite. "Less is more." Mies van der rohe)

I don't think these two flying pilot had a clue what was going on and the captain was taking his required rest. Sad. Hate to say it but I think it is time to put this crash to rest. Bye.

Hi,

You are right .. put all this into hibernation and set the alarm clock to the release date of the final report of the BEA.
We have time to take a well deserved rest as the report will be published in a few months
Although for those who are impatient and curious .. they can certainly have the final report by reading everything that was posted in this forum.
The key is to choose the right things .. but certainly the analysis and recommendations to be made by the BEA are already written in this forum
Some may say "I told you so"

HF, CRM & TEM
 

The speed/mach flag was shown on the PFD.
How many clues are required?

This tragedy wasn't caused by the UAS but by the reaction upon.

Said it before but will say it again, there was no input from ADIRU to the SW logic inside FWC.
The ADIRU output design needs to be considered not the SW logic,
as AIB did with offering the BUSS option. (AoA input available to SW logic supplied through IR output)

AF (Pilot organisation) didn't opt for the BUSS enhancement,
Why?

The BEA is absolutely on the right track with the Human Factors workgroup, 'all' visual and audible clues have been missed without any sign of CRM or TEM.

I don't know for sure whether or not the following has been linked here (I did a search and the search returned a null) but I found the
following Aviation Week article 'High-Altitude Upset Recovery" most informative. There are even some comments by Captain C.B "Sully" Sullenberger.

High-Altitude Upset Recovery

Middle of the book.
 

Reading so many opinions over the past year about this unfortunate crash, it seems to me that the majority are picking up the story in the middle of the book. Most comments begin after the airspeed, auto pilot and auto thrust disconnect. For me, that is not where the story begins. It begins when the crew enter the flight dispatch/operations office in Rio. These 3 pilots about to take a flight at night over the ocean must have been given a weather briefing, weather maps and had to know what type of weather to expect in the ITCZ. Next, they must have checked the fuel uplift for the flight including fuel to circumnavigate the bad weather. In the CVR there doesn't seem to be any mention of the weather by anyone, neither any plan to skirt the CBs. When the captain left the flight deck, did he say anything about the ITCZ ? As the aircraft reached TOC, was the radar checked and set for inflight operation in cruise?
You see, this is where the story begins. This is the beginning of the book. I will forever hold that this accident would never have happened if they had gone around the storm. That is where they screwed up royally. All the other stuff that has been discussed for the past year has nothing to do with what really caused this crash. They flew a perfectly good airplane into CBs that iced up the pitot tubes causing the loss of control. As for the heated pitot tubes, have you ever made the mistake of touching one on the ramp check? It will give you a really bad burn if the switch is in the on position. Don't forget that after lift-off they go to high power and get much hotter for flight.
I will say again for the 10th time, you don't fly an airplane into CBs when close to the coffin corner.
I only hope that everyone has learnt the lessons from this accident and will not repeat them.
Thanks..

thermostat

I take your point, but I think you go back a bit too far. Captain did caution the two remaining pilots to expect turbulence greater than they had experienced, and the crew discussed deviating "a bit left". Bonin even briefed the cabin (Maryann?) in regard the expected turb. Your conclusion that ice caused the IAS problem is not ironclad, the pitots failed simultaneously, and that speaks to other than blockage/ICE.

I rue the lack of CVR discussion, but unlike you, I do not conclude that the flightdeck was silent. I believe the bare minimum was released, and whether or not it was by the wish to slow public suspicion of a/c problems or for "discretion", we have a most incomplete and premature picture.

The speeds were odd, but not so unusual as to eliminate Windshear. TCAS and WINDSHEAR were present on ACARS, and remain unexplained; the actual speeds are after the fact, and a lack of comment initially by the Pilot flying might show that they indeed were not "crazy speeds" , except to say that the speeds may have given him the notion of overspeed, ("we have some crazy speed") not extremely low, as would be expected with pitot blockages. He has become pre-occupied with overspeed, is this in response to IAS? Surely not, unless he has sussed UAS, which most doubters refuse to alow him, due his "lack of training".

(lie)man

Lyman, I seem to recall that the pilot declared, and it was recorded on the CVR, "alternate law" at a time close to when he took controls.

That part of the final conversation has made it into the reports.

Lonewolf50
 

Eleven seconds (a very long time!) after PF declared, "I have the controls,"
PNF said, “we’ve lost the speeds then,” then, ”alternate law protections." (From Interim Report No 3, Page 10.)

There is no indication that this was ever heard or responded to, as far as I can tell.

Begin speculation: Even if PF did know they were in ALT 2 (not in evidence), I'd bet dollars to doughnuts that he was not intimately familiar with the flight laws pertaining to ALT 2. :suspect:

Lonewolf 50

Smokin' Eddie, are you sure? That is not what I have found, and remain convinced the first evidence WE have is of PM annunciating "Lost the speeds, ALTERNATE LAW". This was at I think :16, eleven seconds post a/p loss. No?

bill

organfreak. "Dollars to doughnut......" Hmm. Right, that is not speculation, that is an accusation. We should be better than gratuitously making wagers on a dead man's training. I still get chills when I put myself there.

See, here's the thing: UAS was not in the line quiver, it was poorly understood, and even after the wreck, AB was issuing..."DON"T re-select A/P, the a/c may CLIMB unexpectedly......." No one had conclusively decided whether or not to trust the STALLSTALL !!
respect

Let's not forget the PF did two things perfectly after the loss of the autoflight.

"I have the controls". Perfect.

He input Left ROLL, and NU. Had he not, the a/c would have continued its right bank and Nose down (3degrees). I give the ship ten seconds to be rolled 90 degrees, and flight Path Vertical. DOWN

Lyman opined:
Excuse me sir, with all due deference, I know exactly what I meant when I said that. It most certainly is speculation. I accuse him of nothing, but I suspect that he didn't know, based on his driving. "Dollars to doughnuts" is simply a colorful expression, and far from a serious wager. Engaging PLONKing device; I've read enough. BYE now!

Oh, and....speaking of "gratuitous," I'm speculating (again) that you are the only one here in the forum who doesn't believe the pitots were fouled by ice.
Wanna know what I think? (Probably not.) Preposterous!

Lyman: One thing....

Nothing from then on was perfect. Whatever he did to counter the right bank/nose down was certainly NOT executed anywhere near perfectly, with the end result being the same outcome as you postulate would have happened had he done nothing... just a number of seconds and wild ride later.

I have steered clear of commenting for a very long time, primarily because we have received nothing new to comment on. But you woke me up.

Back to silent mode.

Well to me it aint nearly as important to know what initiated this specific event as to what actions were taken or not taken to mitigate the result.

That's the difference between finding a causal factor of blame "if not for ..." rather than accident prevention which should have been "in spite of .... "

I still await a report on this towards preventing future similar accidents

wise words
 

Thank you for that comment, it forced me out of silent mode for this moment.

Thanks, Organfreak, Lyman, memory did not serve.

I just looked at the law matrix again, and note limitation of AOB to 67 deg is active in Alt 1. IIRC, the degradation kicked AF 447 into Alt 2, so stopping the roll (besides being standard airmanship in response to an undesired roll) would be the natural response, but also necessary since it won't stop itself.

Pilot S/A, instant
 

LW

Likewise the Pitch was trending up, from 0 degrees (-3 from a cruise setting) so not only was arresting and reversing ROLL important, but from PF's 'snapshot' of PITCH, his NU was not required, in fact, he should have left PITCH alone, but to my mind he didn't have the time to orient his inputs. So what ensued was what MB calls a potential PIO, and a robust NU that resulted ultimately in their demise. Inheriting a maneuvering a/c in those conditions may not be appreciated by the cognoscenti here. I continue to insist that the critical time frame is the twenty or so seconds either side of a/p loss. Sure CRM seems non-existent, and a basic understanding of what the sirframe was up to as well, however, once upset, the odds were long. Captain says it all: "We are going to crash, this cannot be..." "Climb", "No, No, don't climb." "Pull". "But I've been Pulling for some time". A regular CF, but the horse bolted long before this abject confusion. I am glad BEA are concentrating on HF, however, this wreck was not such an unexpected event, given the traps set for it right along. This flight was flukey, and an embarrassment to all involved. Such a loss.

Our agenda
 

Hi,

Prevention, as i understand is what most of us should be pursuing through careful analysis and thinking.

In order to be able also to verify if the final report gone well and deep to the most important points among all the involved issues.

Our effort could allow us also to evaluate the conclusions, obviously if the report brings finally all required factual information.

In the meantime, as i understand we could increase our capabilities with the natural Synergy of an interacting group.

Always necessarily unbiased.

:8

what is that ?
 

:rolleyes:

Hi,
is it this thread ?

I have never learned so much outside of mine own life, that with pprune

Deserve, THEN Desire
 

Hi,

what is that ?

I desire to understand, if possible, everything on AF447.

To do so, to deserve i use all means available.

PPRuNe and the SYNERGY of an interacting group is a good resource!

:8

Difference between systems voting among 3 or 5
 

Were they subheated ? Who had never a sudden pitot failure ?

AoA indicator is a mandatory solution after the AF447 loss of control, that has already been said by some of you.

But three systems (Airbus) may be replaced by five (Space shuttle), to have a better resolution of systems voting : With two pitots tubes blocked by ice the vote among three says these two are good :\ ! And the third not blocked is supposed to be false... :\ The vote among three is cheaper, the vote among five is much safer ! :p

tly
 

roulishollandais

Better still with two only Pitot Tubes ! These two, if designed differently, but to spec/reg, will never fail simultaneously, the fail chain cannot be identical. It does not eliminate failure, only failure in concurrent fashion.

Anomalous design.

Three of the identical design/manufacture are three blind mice, identical triplets.

Reasonably stupid.