deSitter

NASA had an orbital configuration display software one would often see during slow spots in Shuttle mission coverage. One glance at this screen and the configuration of the craft relative to the Earth was instantly obvious. In the open areas of the display one found all the necessary data to have a precise description of the Shuttle's configuration.

Why cannot a modern aircraft have such a display for itself?

Lyman

Not one proposition offered to mitigate the THS fatal flaw here was NOT looked at by Airbus.

One thinks one can solve a problem that one assumes to have been OVERLOOKED? By AIRBUS?

3hl : perhaps the solution to a "go to your room" command to THS in other than NORMAL LAW is not necessary afterall.

Airbus, in their wisdom created AL2 with ROLL DIRECT. PITCH NOT DIRECT.

They still wanted the a/c to have some "say so"

The pilots can be trusted with ailerons and spoilers, but not the TAIL.

Initially, when the THS did NOT contribute to the zoom climb, it looks like a good idea.

Let the elevators nudge the a/c into a crazy climb with the Computers help? YES. The climb is a pattern of UP nibbles and retreats, in thrall to the PF's STICK. With each nudge to a higher AoA, the computer forgot the last one, and the zoom climb resulted. Then at the top, it forgets its last nonsense, and tries to maintain a load.

Going up, maintain load, at the top maintain load. The PF is not the only one who appears to have lost his "mind".

So the THS was not "Jammed"? Baloney. Two powerful motors were holding it against the Top curb. It was free to move only upon command, a command of NOSE DOWN. It recieved plenty of these, but the computer disallowed them v/v THS.

Pilot responsibility? Of course. AIRBUS? You make the call.

If elevators can (and should be) used to recover, or maneuver, or maintain, etc. Whose idea was it to throw in a silent partner?

Flying is NOT inherently Dangerous, that is a bromide, and demonstrable for those of us who hang on to the hero pilot meme.

It is inherently SAFE, as the statistics PROVE.

airtren

jcjeant,

If I read again your previous post, I think it is quite a bit about semantics.

It is easy to agree with your saying that the "pitot tube was not faulty", as I take that as the "pitot tubes were not defective", as the pitot tubes functioned normally in different conditions than those when they failed.

But even if they were not faulty, they did fail, as a device can fail, without being defective, when in an abnormal operation conditions.

But, IMO, you're raising a high threshold for yourself in saying: "The pitot tube operated normally .. as required by its specifications and certifications". The "required" implies IMO that the language in the specs/certifications is strong, some wording that is equivalent to the combination /MUST/MUST NOT/, i.e., mandate the freezing in the conditions of their failure, and mandate the providing of inaccurate information in the condition of their failure.

Are you sure about meeting that threshold? ...

OK465

From post #101:

@USMCProbe:

There's one small problem with this. At 16 degrees pitch attitude and AOA in excess of 35 degrees, do you know where the "bird" is on the PFD?

(Any 'stall prevent' use of the "bird" would have required monitoring and honoring FPV ("bird") thru the "ballistic" portion of the "zoom", the caveat of course, it must be selected and available.)

edit: BTW there are a lot of pilots trained to use FPV.

jcjeant

Hi,

The language used in certification .. the words used must be accurate and not misleading and should not allow an interpretation that could afford not to keep strictly to these specifications
If this is not the case these certifications are useless and therefore the classification societies and certifications societies (and regulators) must be submitted to an external audit to detect problems .. skills or organizational
Trials and penalties can be at the corner .. as those specifications concern not only technical matters but also human lifes.

airtren

As a clarification, I think, like you, I expect the specs/certs to be non-ambiguous in defining the operational conditions, and functions within those conditions.

Without the specs/certs in front of me, I don't know if that non-ambiguous language extends to the range of conditions which is outside the operational conditions, as that's outside the scope. Therefore, I asked my question, as the possible ambiguity for the outside operational conditions range creates the difficulty of meeting the threshold, which I think you've set for yourself, with the wording you've used.

HarryMann

Ok, enough of this THS speculation.. I (and others) mooted extreme concerns over this (misuse case) style of behaviour hundreds of posts ago... a few others didn't agree, or thought we were grasping at straws - fair enough.

Hopefully, and looking at BEA wording, it will not be ignored and pushed to one side - everything is relevant, even irrevelances (in that they are tagged irrelevant!)

Now, we can look a bit further away... ?

I can certainly see that calls for some 'neutering or neutralising' THS logic in 'apparent' stall situations raises eyebrows, mine as well.

What goes right back to basic aircraft certification requirements in the 60's, is the stick-pusher. Indeed, RudderRudderRat just suggsted a stick shaker mode would be somethingt that makes some sense

So far, AFAIK, certification requirements mandated combined shaker and stick pushers for only those aircraft with deep (e.g. potentially irrecoverable) characteristics.

I would think AoA measurement has become easily reliable enough for this to become a safe option for all airliners above a certain size... the prelimary vibration itself could quite possibly have been enough to shake PF out of what may have tunnel vision.
THS activity and detected position would automatically have to be become part of stick shaker activity.

Airtren.. damn good summing up above

lomapaseo

If we intend to hold somebody accountable to fix something than semantics is damn important lest they end up saying "it ain't my job" Improving the Pitot tube or avoiding weather entirely (because we can't readily see the stuff) will not prevent the next accident when this system fails in a different way (flocking birds, volcanic ash or ice sheds from in front of the pitots or even a loss of vision or whatever powers the instruments that displays the speed) That is what I mean by a system failure.

The system failed ....l so what? To fix the problem we need to examine not just this one specific failure condition but to revisit the assumptions in the basic certification (which assumes this system would fail) and address every one of the assumptions that was violated.l

I have no respect for the assignment of cause "but-for the icing of the pitot" that is typical of the legal tort system when it comes to adressing flight safety shortfalls in complex system interactions.

IMO this problem is not going away with just the final accident report summary or all the rhetoric of PPRune "I told you so" until wide ranging recommendations are adopted..

Linktrained

Certification (s)

Of course certification must keep up with increasing experience, whether for speed or pitch information.

Under the Regulations of sixty years ago any aircraft ( A330 ?) would be restricted to flights not exceeding 1000 nm over water or 1500nm overland. Longer flights required the carriage and use of a Flight Navigator, who would need a sextant and a means of checking the compass (Astrocompass ?) and a Drift sight. (Please don't suggest an astrodome on a pressurised aircraft - I think that someone lost their Navigator through one, then !)

There was a list published of some 30 odd UAS incidents which had not had MAJOR problems. Someone ought to know why. (NWA had ice crystals and were 25 miles away from a Cb.)

Historically many/ most aircraft accidents seem to have come from the convergence of several (often three) factors, each relatively minor or individually surmountable. Each factor, when indentified or even suspected ought to be remedied, so that THAT factor does not happen again.

VGCM66

If you are pilot, you better know what you are getting into. Nobody is building any airplanes that flies by itself. If you as a pilot do not comprehend the meaning and the peril of what a stall is and it's dreadful implication and possible fatal consequence, you have no business being in a cockpit and even less being in charge.
I am no pilot but even I know that when flying the main objective is not to FALL as in hitting Mother Earth FALL. By the time Altitude became meaningful again in that AF447 cockpit, it was too late.

THS did what it was supposed to do. If the PF wouldn't have applied NU for more than 3/4 of the 4 minutes (give or take)of the incident opening and closing the THS would have never moved at all.
ND would have probably brought the THS down if application of the SS would have lasted long enough.

The pitots have already been dealt with by the industry which incidentally just acted in flight AF447 as a casual instigators of life eternal pop test quizzes.

A captain knowing that bad weather was approaching ahead, decided it was a good time to leave the cabin. Say what?

The PNF (First Officer and probably future candidate for Captain) heard at 02 h 10 min 10,4 : SV : “Stall, stall” (without cricket). And he said: What is that? EXCUSE ME? "You ain't a passenger Mr.! You should and ought to know what STALL, STALL means preferably waaaaaaaaaaaaaaaaaayyyy before that tragic night. On top, later he can be heard desperately calling for the captain to come back to the cockpit. Don't know, but I think he was supposed to have acted as replacement captain not a captain caller. A pilot might need schooling to learn how to recover from a Stall of any kind but he/she does not need a whole schooling to learn that a Stall might get you kill along with all your passengers. That's my take.

And then there is the young PF. What can we say that can bring some meaning, reason or just some measurement of mitigation? That he was young, maybe? Not even.

A flaw was finally found and subsequently corrected in the Comet. But no R-E-D-E-S-I-N-G was ever made except for the upgrade to the Comet 4. They serve their time proud and tall afterwards. There are almost 1,000 A330 already made and in service. Any major redesign will be just done on newer future versions of Wide Body Twin Engine Models.

Lonewolf_50

Retired, I believe we did discuss this a couple of threads ago, and the concensus was that in Alt Law

If you use the trim wheels to move the THS, it will over ride the auto trim. Once moved, and then left alone, in Alt Law auto trim will again move it in response to the usual inputs.

Is this trained in the Sim?

Again, the point was raised in re some Unusual Attitude training scenarios, which isn't the same as an Airspeed Unreliable scenario.

I think we are in violent agreement, more or less.

Lyman

A casual observation. If some 'blend' of manual/auto commands (THS) are mandated, do we have an alert then, in/out? Prolly not. "Who's on first?"

In a DIRECT LAW situation, only manual. So in between, and true to "gradual" and "graceful" degradation, a fuzzy mush of "What are WE doing now?" The Waltz, or the Lambada?

With the brain lock some see here, is that at all fair?

Just because it's too much for me to imagine, I'm sure it's just the thing.

More prompts, more recorded music, more Synthetic verbalie. Soon, a Choir, then a symphony?

When run out of ideas, make it merely more complex? There is a gaping hole in there between Cruise and recovery from UAS. Those who downplay it should be chastened by now? Perhaps not, given the onset of the academy awards for those sold on the platform without reservation.

RetiredF4

Please,

if you are new to this thread and want to contribute something useful out of your expierience as an engineer or any other profession you are familiar with, it would be appropriate to read the nearly 1.000 pages filled about this flight.
That would tune you in the loop of the discussion.

There had been failures, there had been mistakes, and there are things which can be improved to reduce the probability of similar accidents.
The big question to all these matters is "why"?

Your ranting does not contribute to this task.

Clandestino

There's no such certification requirement as it would be impractical to design aeroplane this way - please refer to DP Davies' masterpiece, page 35 onwards. Also it is entirely possible to certify passenger transport aeroplane that once stalled, cannot be unstalled by anything except improbable amount of luck, produce it in hundreds and have fly around for decades in statistically acceptable safety. It's not A330, if you wonder. Again, DP Davies' work is painfully relevant. Surprisingly to some, not me.

To meet certification requirements of stability and maneuverability at diferent speeds, altitudes, weights, configurations and CG positions.

With all three ADIRUs losing speed signal, aeroplane is so confused as to know nothing. Mind you, I 've used "confused" and "know" figuratively. No computer installed on A330 is intelligent therefore it really doesn't know anything and it cannot be possibly puzzled. It works within limits of its instruction code.

THS went up to trim aeroplane into AoA it could not possibly sustain. Triggering condition was sidestick pitch command.

There's good chance that even if there were trim in motion aural warning, it would be overridden by stall warning. OTOH, simple mechanical device like bicycle bell would be heard all the time during normal ops and probably wouldn't be noticed after a couple hundred of hours in flightdeck.

They can't. DP Davies explains why, page 35 and on.

There were at least six cases of total airspeed indication loss due high altitude icing before 447 on AF 330/340 fleet alone and allegedly there were about 30 cases worldwide. That every affected flight, bar one, continued and ended safely somewhat contradicts the notion of systemic failure.

Big chunk of my flying is done through clouds made of ice crystals and I have never had my pitots frozen. Not every ice crystal will stick to your probes or compressors and ideas when and where can we encounter the dangerous type are currently extremely vague. If we were to avoid every CB plume in the sky, soon we'd measure our deviations in hundreds of miles and schedules would become a joke.

You are not mistaken. Not a little bit.

Utter lie, no, not even a lie, it is pure BS. Flying is fantastically dangerous. Statistics is hard science and can't prove inherent safety of anything at all. What your numerology that you have the cheek to call statistics fails to appreciate is how everyone in aviation needs to work his or her butt off to make potentially very lethal activity into something that the ignorant considers safe based solely on outcomes.

If only sheer ugliness of twisted bits of metal that used to be an aeroplane, now littering the seafloor or some mountainside, breaks up your dream of flight being safe because it's not dangerous in first place, don't come to PPRuNe for lullaby to put you back to sleep.

Lonewolf_50

bear
One of the reasons in getting a type rating, and qualified on a given aircraft model, is to study it, fly it and by so doing learn how it works, and what makes it work well enough to safely operate it.

Each aircraft will have some different characteristics than others. The art of design continually evolves, so it should not surprise us.

What most professional pilots do is, rather than grouse about whether a particular combination of features pleases or doesn't, is learn how it works and how to make it fly well.

The objective of a professional training program is to make the above happen.

Linktrained

RetiredF4

Just like Orville and Wilbur, many of us have started as Newbys at some stage. Some of us may have learned ( and understood ) everything in a single presentation. Others may be helped by a further explanation or example, even when the initial version may prove to have been in need of even wiser thoughts, often from people like yourself.

Mr Optimistic

There were 3 trained pilots in this a/c. Although you can argue that the man machine interface had its failings (stall warner behaviour, lack of explicit AoA, failure to scream the THS was at the limit of its authority), the concern about pilotless aircraft is that human beings are adaptable and flexible and cannot be programmed out. This accident makes you wonder about the value of human beings versus machines: did they deliver their value here ?

Lyman

Sounds good, lonewolf.

#1 It didn't work.

#2 I have the distinct impression some qualifieds here are not in synch with the A330, or with your anlaysis, which I personally find impeccable.

#3 The difficulty with this Discussion is its free flow, and that is fine.

My opinions are based on my experience, and knowledge. As such, they mean probably nothing to anyone else. So what. Tell me, as a helicopter pilot, your impressions of having a combination manual/auto Trim on your aircraft. In Alternate Law, a regime virtually unflown in these circumstances by most if not all of the pilots currently operating the A300xx. On a moment's notice. No Sim, No Button. No ReDo.

It is so easy to focus on one thing, and that, as a pilot, can be deadly, hence your excellent posts on SA.

You scold the pilot group with innuendo that "Learn the Airplane"? is what's missing, the platform shows no unscrutables?

Or was it meant for me? Either way, it is not productive, and unlike your proven and excellent understanding.

Thousands of people have DIED to make flying Safe. It IS safe. Inherently Dangerous sounds like a line from a B movie. Driving is more dangerous, statistically, and in personal experience. Not all who fly are dumb.

I watched once at a test flight prior Launch. It was a wicked new and complex machine. The Pilot was confident, no, arrogant. fifteen minutes later he was burned beyond recognition, along with his a/c.

That isn't danger, that is insanity. The bottom line is the argument at all, here. Entrenched on the one side, over confident and arrogant on the other. A finding of any kind is pounced on, and morphed into "evidence." For what? EGO, and PRIDE. To my way of thinking, in furtherance of making flying LESS SAFE.

Personalyzing the debate is irritating. There is great stuff here along with the dross. Me Dross? Obviously, according to some, even most. Perhaps in my own eyes.

Mark my words, Aviation is careering into the weeds in front of us, and absent some patient direction from a source heretofore unknown, it will succeed in its quest for BBR.

CONF iture

How stall warning didn't supercede that condition ... ?
Curious to see if the BEA will be curious about it ...

jcjeant

Hi,

Clandestino:
So certainly with the insight of the AF447 accident you must think that the pilots were in very bad luck for have the 3 Pitot tubes frozen dead ..

And also with the insight of AF447 accident .. you must think that if they avoided the CB plume by hundred miles .. the schedule was a joke .. but the passenggers and crew will be alive today .. commenting about their delay at arrival .....