AF 447 report out

[airjet]

age old

wow a lot of "monday night quarter backs" are out in this thread, --the capt should not have been in the back, while the aircraft was approaching a line of storms, also according to the sat pic at the time there was a clear path thru the wx 50 miles to the left, I flew airbuses for the last 10 years of my career and NOBODY ever said you could not stall the plane, in normal law you couldn`t but in this case they were def Not in norm law. also i don`t care if your control is a yoke, stick, or a dick, pulling back when the stall warning is shouting "stall stall" is madness.

[infrequentflyer789]

Originally Posted by qquantum

Quite true — IF he recognized and corrected the egregious THS setting. Should note that some bottom rudder with 90° of bank would also be helpful to get the nose pointed in the direction of energy (and therefore recovery).

Nose down side stick would have "corrected" the THS whether they recognized the setting or not. Recognizing that nose down was required was the issue.

As to 90deg right bank - why would you try for that in an a/c with bank angle protection ? [or have you changed your previous conclusion htat they had not recognized loss of protections ?]

[Carjockey]

@NigelOnDraft

Disagree. Many systems on aircraft are duplicate, but identical systems. Not just ASIs, but Altimeters, Engines etc. If we followed your logic, on a twin engine aircrraft, one would be RR, one GE etc.

Now that is definitely not logical! My point is that since airspeed is such a critical factor for the AP to function, an effective alternative backup method of feeding back airspeed to the AP should be incorporated on aircraft. Pitot tubes are exposed to outside elements, they can freeze up or otherwise be damaged and as such they are obviously a weakness in the AP system.

Diaagree. Pilots are on aircraft to fly them, and the ability to be cope when the automatic systems fail. Not v-v. APs are there to reduce fatigue, increase capacity & accuacy (RVSM). After any major / multiple failure, if the integrity of the AFS cannot be assured, it should audibly and clearly "give up", as it did here, not try to fly the aicraft with incomplete / inadequate / non-verifiable data.

Agreed, but when 'giving up' the AP should clearly indicate the exact reason for it's 'giving up' and the pilots should have an established procedure available to them to enable them to recover from any given situation. Why didn't that happen in AF 447's case? Why didn't the pilots understand what was happening? Over confidence in their automated systems perhaps? Or simply a failure to understand the automated systems?

As an aside, I have a military background, both jet instructing, and fast jet flying. I tend to manually fly, at work, to/below 20K'. I fly / display / compete and teach GA inc aerobatics and upset training. I teach / fly display ex-mil jet trainers / FJs. I am very lucky to be able to do that, and to have had the opportunity / luck to have the training I got. It is not available to all. It might be that background that leads me to hope I could have coped with the situation these guys found themselves in. It is that background to realise that many might not fair much better than this crew did. The report covers it under "startle factor". Unless and until we take crews, in sims or aircraft, and regularly (say a <6 month cycle, not ~3 yrs) give them unanticipated multiple systems failures and expect their raw handling and management skills to cope, we will get (a few) such accidents.

'Startle factor' eh? Well that's a real good one. Do you mean to tell me that when flying a planeload of passengers at 35k feet, today's pilots are complacent and unprofessional enough to be 'startled' if a problem arises? Are they not sufficiently trained to handle such situations? Maybe yet another indication of operator / pilot over confidence in their aircrafts auto systems?

FYI, I have no connection with the airline industry, other than flying frequently as SLF, which is apparently the standard and wonderfully respectful aircrew term for paying passengers.

[NigelOnDraft]

Carjockey

My point is that since airspeed is such a critical factor for the AP to function

It is not "that critical". APs need many other functions far more importantly than airspeed - many APs (in smaller aircraft) will have no IAS input at all.

...an effective alternative backup method of feeding back airspeed to the AP should be incorporated on aircraft

Well, we'll have to disagree then. Not sure there is any aircraft out there with such a system? Where we disgaree is that to me the AP is not a "critical system" - it is "luxury" to help the pilots, and if it drops out, well the pilots just have to fly. In all types, quite often relatively minor system faiilures lead to a requirement to manually fly i.e. the pilot is the backup to the AP, not v-v.

Agreed, but when 'giving up' the AP should clearly indicate the exact reason for it's 'giving up' and the pilots should have an established procedure available to them to enable them to recover from any given situation

They do to an extent, and it did. But the reason the AP "gave up" it is not relevant, what is relevant is it clearly says it is diconnecting, and they acknowledged that ("My controls" or similar). What is important is the systems failed indicate to the pilot(s) they have failed - which again they did in various ways.

'Startle factor' eh? Well that's a real good one

At one moment you say you are SLF, and now you have the expertise to criticise the report 'Startle Factor' is the exact phrase used in the BEA report (repeatedly).

Are they not sufficiently trained to handle such situations? Maybe yet another indication of operator / pilot over confidence in their aircrafts auto systems?

Clearly they are not sufficiently trained, else this would not have occurred. What I tried to illustrate to you in my earlier post is I cannot see "how" we will ever get to the stage where airline pilots can reliably cope with such events. Not whilst it is such a cost driven industry, where we recruit pilots who have hardly handled the controls, and who both by choice and company rules, are actively discouraged from doing so to keep/gain experience. And also whilst said pilots have never flown aircraft in anything other than the nice gentle flying you have a right to expect as a passenger.

[qquantum]

Originally posted by infrequentflyer789

1. The loss of airspeed information caused a change in the FCS mode, which the pilots seemed not to notice, as they made no mention of it;
False. Mode change noted and read out. Read the CVR in the report.

I'll concede that — at 2h10min22.1 it was indeed mentioned, but the import was lost in the confusion that followed. I'll amend my post. Thank you.

False. The THS didn't wind up until they were already stalled, and there is no evidence autotrim failed - with nose down control inputs the THS would have followed allowing recovery (plenty of SIM sessions and theoretical models covering this on the tech log thread).

Stall Warning occurred at 02h10m45s – at that time the THS was already moving ANU from its cruise trim condition; what sort of sane FCS/SW engineering logic will allow ANU movement of the THS in a stall?
Without Aural/Visual warning to the pilot?
We've seen that before — A300-600R Nagoya, A320 Perpignan.
In fact The algorithm controlling the stabilizer has accumulated a large value on a forward integrator and this value is much larger than the actual stabilizer deflection limit. Because this integrator has built up a value well past the actual stabilizer limit, the stabilizer did not come off the ANU stop when the pilot reversed his input – as happened several times – until the integrator wound back down to the limit value. The integrator never unwound over the rest of the flight (fall) to impact.

Since you appear to consider this phenomenon to be OK (Designed as required for certification.??) I don't deem it necessary to address the remainder of your comments.

[Carjockey]

@NigelOnDraft

It is not "that critical". APs need many other functions far more importantly than airspeed - many APs (in smaller aircraft) will have no IAS input at all.

Not that critical! This was the reason for AP disconnect on AF 447 which subsequently led to the demise of the aircraft and all on board!

Well, we'll have to disagree then. Not sure there is any aircraft out there with such a system?

I know that there is no such system, my point is that there should be.

At one moment you say you are SLF, and now you have the expertise to criticise the report.

I am SLF and I am entitled to form my own opinion, regardless of what any 'experts' may say.

[infrequentflyer789]

Originally Posted by deggers316

can you quote to me the accident report this paragraph came from ?

It's three sentences from three different reports. All Boeing. All stalled into the ocean/sea.

Ethiopian Airlines Flight 409
Birgenair Flight 301
Aeroperú Flight 603

Really these accidents should come immediately to mind for anyone interested in airliner LOC/Stalls (and UAS), but some people seem to have a block which prevents them getting on their radar because they were Boeings, with yokes. Adjust your tilt / gain and look beyond the small side-stick shaped problem in front and see the big yoke shaped one behind, otherwise you risk avoiding only the small storm and flying straight into the big one.


You could also of course have this one for mishandled stalled Boeing :

From the NTSB report's abstract:

...the probable cause of this accident was the loss of control of the aircraft because the flightcrew failed to recognize and correct the aircraft's high angle of attack, low-speed stall and its descending spiral. The stall was precipitated by the flightcrew's improper reaction to erroneous airspeed and Mach indications which had resulted from a blockage of the pitot heads by atmospheric icing.

When investigators analysed the 727's voice recorder, the recording revealed that the pilots believed that the shaking of the stick shaker mechanism was caused by the airliner reaching the speed of sound, and not a warning that it was going into a stall.[2]

Northwest Airlines Flight 6231. Didn't end up in water though, which was the original criteria.

[Clandestino]

Originally Posted by Case One

What?

One can pass ATPL theory exams by learning the answers from the question databank by rote. Some even try. Some succeed.

Originally Posted by Case One

Well, they turned through 180 degrees on the way down, I wonder if they really were IMC the entire time.

They turned while stalled with alpha exceeding 30° all the time! CM2 fought the right bank with full left stick, to no avail. He even didn't comment about inability to control the roll.

Originally Posted by Case One

Don't be silly, how about downgrading to another mode such as attitude hold?

It downgrades to modes considered basic: as Airbus flight director has far less modes than e.g Dash-8's, it can't revert to attitude hold but to heading select and V/S. It's pilot's responsibility to recognize F/D are no longer able to guide the aeroplane reliably and shut them manually down. If nothing else, checklist says so.

Originally Posted by Case One

I don't think you can read that as the FCS would demand minus 1g

FCS demands nothing! It tries to comply with demand coming from autopilot or sidesticks! Full forward stick gives you low g limit of -1 in manual flight, clean.

Originally Posted by Case One

However Airbus manuals are cr@p, so I can't be certain - can you?

Pretty lame excuse for ignorance. It might have helped my Airbus groundschool CBT was made in Germany but it was telling the same story manuals did.

Originally Posted by Case One

When someone is panicing I think you can have it both ways, they are not thinking logically, and this design feature does not help

So it was panic and not design, after all?

Originally Posted by Mac the Knife

Because they thought it was

Any signs of rethinking from the powers that be? Could be that FAA won't rethink Airbus certification just because hundreds of posters on anonymous forum want it to?

Originally Posted by noske

Michel Asseline, possibly slightly misquoted, but I'm not going to look up what exactly his claim was.

It was statement made in post-crash shell-shocked state. Investigation found out engines worked as expected, capt Asseline concurred and retracted it. Of course, noticing this would damage the strong belief of anti-FADEC brigade so they keep trusting the old newspapers instead of competent technical inquiry.

Originally Posted by noske

This must refer to the Bangalore crash.

Bangalore crash was caused by selecting the altitude below the airport elevation into FCU and making OP DES towards it. Unsurprisingly, descent was broken by hitting the golf course short of threshold. Selecting the altitude below planned landing elevation is a very big no-no on any aeroplane equipped with altitude selector.

Originally Posted by Carjockey

Pitot tubes are exposed to outside elements

Well, they measure air pressure, it is natural they have to be exposed to... air.

Originally Posted by Carjockey

Do you mean to tell me that when flying a planeload of passengers at 35k feet, today's pilots are complacent and unprofessional enough to be 'startled' if a problem arises?

If you paid attention to other aviation incidents and accidents instead of making a whole world-encompassing theories based only on AF447 case, you would not need to ask that question.

Originally Posted by qquantum

what sort of sane FCS/SW engineering logic will allow ANU movement of the THS in a stall?
Without Aural/Visual warning to the pilot?

The one which is behind every aeroplane certification since certification business has started: pilot is the master. If he demands nose up, nose up he will get as long as the aeroplane is structurally and aerodynamically capable of performing the feat.

Fact that THS would go nose down if nose-down input were made doesn't sit well with "evil autotrim" myth, eh?

Originally Posted by qquantum

We've seen that before — A300-600R Nagoya, A320 Perpignan.

For beginning: A300-600R is not FBW, it has conventional control columns so anyone seen same thing at Nagoya, Perpignan and AF447 is likelyy suffering from cognitive bias.

Originally Posted by qquantum

Because this integrator has built up a value well past the actual stabilizer limit, the stabilizer did not come off the ANU stop when the pilot reversed his input – as happened several times – until the integrator wound back down to the limit value. The integrator never unwound over the rest of the flight (fall) to impact.

Bold statement. Couldn't find in the final report. Can you name your sources or would you rather keep them anonymous?

Originally Posted by qquantum

Since you appear to consider this phenomenon to be OK

Phenomenon of airing good-sounding and completely false hypotheses on PPRuNe is just something we have to live with if we want to keep the discussion open.

Originally Posted by carjockey

I am SLF and I am entitled to form my own opinion, regardless of what any 'experts' may say.

You are absolutely entitled to your own opinion, not to your own facts.

[Organfreak]

From one SLF to Another

Carjockey opined:

I am SLF and I am entitled to form my own opinion, regardless of what any 'experts' may say.

Everyone is entitled to their own opinion, of course, but it's well to remember a simple axiom:

Some opinions are more well-informed than others.

Experts have gotten a bad name in recent years (see Warming, Global -- and the reason is poor education and political brainwashing) and we ignore them at our peril.

[The Dominican]

You are running in circles gentlemen, making the same arguments from just a few posts back again and again, that is by all accounts the definition of lunacy

[DOVES]

Clandestino
You who are so conceited why did you ignore my sentence:

6: If I remember well some fuel had been transferred to the tail (which I suppose happens automatically during cruise, like on MD11, to reduce fuel consumption) making it even more hopeless, if they wanted and had tried, to exit the condition of deep stall they were in.

Is it true?
On MD11 the Tail Tank had to be empty during Approach & Landing for obvious reasons.
Fly Safe
DOVE

[Carjockey]

@Organfreak

Everyone is entitled to their own opinion, of course, but it's well to remember a simple axiom:
Some opinions are more well-informed than others.
Experts have gotten a bad name in recent years (see Warming, Global -- and the reason is poor education and political brainwashing) and we ignore them at our peril.

Agreed. But we should remember that those experts who deny 'Global Warming' tend to be associated with companies who are (in theory) complicit in it's proliferation and stand to lose lots of cash if controls were implemented.

Whereas those experts who warn of the dangers of 'Global Warming' have no such agenda.

So who are you going to believe?
Sorry for the thread drift...

[BOAC]

Originally Posted by The Dominican

You are running in circles gentlemen, making the same arguments from just a few posts back again and again, that is by all accounts the definition of lunacy

- indeed. Cue the 'OOZLUM BIRD'. Obviously returned from its migration. Flap flap. flap flap..............

[Lyman]

@DOVES...

6: If I remember well some fuel had been transferred to the tail (which I suppose happens automatically during cruise, like on MD11, to reduce fuel consumption) making it even more hopeless, if they wanted and had tried, to exit the condition of deep stall they were in....

You are correct, the Tail tanks were full at the time of a/p loss (2:10:04.6). 10.5 thousand pounds of fuel. Initially the Cg computed by BEA was released to be right at the margin for flight (37.6?). Later, that value was retracted and replaced with ~ 28.7. In turbulence and experiencing rolling and pitching moments, the Cg may have been well aft, and exacerbated the inability to recover from the initial upset at a/p quit.....

Salaries and benefits of employees at BEA are partially paid by the revenue stream at Airbus...

The standard of investigation Stateside is the "mandatory avoidance of even the appearance of impropriety". It does not matter the acceptance of such a blatant conflict by apologists, the standard is the standard.....

Relying on the assumed honesty of the players is insufficient to exonerate the conflict, the report is tainted, has been right from the start.

[Anthony Supplebottom]

AF447 Conclusion: The pilots pulled instead of pushed. The end.

[Organfreak]

@ Carjockey

Agreed. But we should remember that those experts who deny 'Global Warming' tend to be associated with companies who are (in theory) complicit in it's proliferation and stand to lose lots of cash if controls were implemented.
Whereas those experts who warn of the dangers of 'Global Warming' have no such agenda.
So who are you going to believe?

Mr. Jockey,
Don't be confused: I am on the side of the vast majority of experts who do believe that global warming is real and is leading us to disaster. And, I was referring to the way you dismissed piloting 'experts.' The technical term here is, 'not cool.'

[Lyman]

@carjockey

"Agreed. But we should remember that those experts who deny 'Global Warming' tend to be associated with companies who are (in theory) complicit in it's proliferation and stand to lose lots of cash if controls were implemented.
Whereas those experts who warn of the dangers of 'Global Warming' have no such agenda.
So who are you going to believe?"

You are accepting of the "experts" who warn of disaster due "climate"?

I am glad you brought this up. People sometimes rely on comfort rather than critical thinking when venturing into an agenda laden minefield. That is what "consensus" is all about: comfort, validation, and 'safety'.

There is always an agenda, if only the fuzzy feeling "agreement with others" may bring.

Dispassionate and pure objective analysis is as rare as bananas in the Arctic. There is always the prevailing politics of the perceived outcome that drives the deceit dwelling in the person of our "guardians". You trust Government? Without rancor, the concept of a trustworthy politic is laughable. It is only when we put on our G issued blinders that we start to slide down the slippery slope. People tend to bud and bond with those with whom they affiliate, it is a given in a social society. This is especially true of the professions.

Government entities/agencies are wildly expensive, all the more when something as important as public safety is involved. The fealty derives from who signs the paycheck, pays the retirement; government is no exception. Loyalty, therefore, is to the politic, not the citizen.

BEA dances to the tunes selected by the powers that reign in the arena in which they operate. This is not surprising, and the standard of any market.

Think of the structure: a standing army of professionals, biding their expensive time between a/c accidents. You think they are best used in compliance? Any agency responsible for the public safety must be dependent on independent resources as to gathering and analysing evidence. Remember the "Memo"?

A purer and more damning bit of proof of weak and 'kept' personnel cannot be found. The actual process is frequently simply tacit, allowing for wildly blatant wet kisses such as the memo.....

[chubbychopper]

AF447 Conclusion: The pilots pulled instead of pushed. The end.

Indeed, but why? And the answer, which is plain to most, except perhaps those who earn their remuneration flying the Airbus, and dare not admit the aircraft's shortcomings, is:

One pilot pulled. The other pilot, as a result of not being connected to the loop due to Airbus design, hadn't got a fkucking clue what the PF was doing, so he just let him pull!

[robertbartsch]

Are there too many recommendations in the offical report? ...seems like these two could be sufficent:

1. Don't fly into a storm
2. Don't pull back on the stick and ignor stall warnings....

[Clandestino]

Originally Posted by DOVES

Clandestino
You who are so conceited why did you ignore my sentence:

Sorry, missed it. Beg your pardon.

Originally Posted by DOVES

If I remember well some fuel had been transferred to the tail (which I suppose happens automatically during cruise, like on MD11, to reduce fuel consumption) making it even more hopeless, if they wanted and had tried, to exit the condition of deep stall they were in.

Almost accurate but largely irrelevant.

It is true fuel was transfered to trim tank to move CG aft and thereby reduce trim drag. It is true that aft CG tends to exacerbate the problem of stall recovery. It is also true that crew did not recognize unreliable airspeed. It is true stall was completely CM2 induced. It is true no one on flightdeck ever verbalized the recognition of stall warning or need to perform stall recovery. Term "deep stall" has very specific meaning: it denotes stall that can not be recovered from by using controls normally available to crew. While no A330 before AF447 has ever ventured into such a high alpha range, there are indications in FDR data that nose could be lowered and AoA decreased as there were three occasions where the nose nodded downwards: first time when power was reduced briefly, second and third time when elevators just moved from full nose up to half nose up position as first right, then left stick briefly went ahead of neutral so it seems A330 are not prone to deep stalls/locked-in condition.

Originally Posted by robertbarsch

1. Don't fly into a storm

They never did.