Training
 

Link Trainers did not attempt to simulate any ONE kind of aircraft. It was used to train many thousands of pilots in what it COULD do, teach and then PRACTICE some aspects of flying on instruments.

At that time, there was nothing better.

The Stratocruiser simulator had a model landscape with a "small" television camera, which then moved in sympathy with the pilots inputs to give a visual image, initially for the Captain, probably in black and white !

The point that I was trying to make, was that PF, (any PF ?) might have made a better show, if he had had practice. I do not know how many hours a year Simulators are used, 3,000, 4,000 or 5,000 hours - or more ?

If some bean counter queries the cost, just say 447.

Yes. I agree that PF was confused at best. What concerned me was that he could have hit his head as stated in the BEA report, which has never commented on in this forum (unless I missed it).
Someone did mention Laural and Hardy as far as communications. I am incredulous/perplexed by their sloppy communications in such a grave situation. It looks like they got into some very bad verbal habits and could not switch into professional comms mode when things went wrong.

PNF was not much better at his role. He should be pulling out the correct high altitude UAS checklist and making some direction to the PF. None of them ever mentioned the word stall / décrochage even if only to dismiss it as being false. What more important warning do you have on an aircraft when it tells you that it is now a falling lump of metal and no longer a flying machine. At least someone should happen to mention it amongst all the bickering and confusion. If the house is on fire do you ignore it and carry on fixing a leaky faucet/tap?

Too bad they didn't learn from that little experiment. We used to run my favorite fighter up to 600 KIAS, then set idle thrust and speedbrakes to see how much eyeballs out g we could generate. :}
A negligible effect would strongly indicate low airspeed.

'Arrogant' takes double 'R' I think but I’m not sure about 'Pretentious' is it double 'T' ?
Let me see, if rudder control is electrical does it mean it can be mechanically-controlled too … ?

JD-EE,

Your post (#636) about spammers and malware, though it will be considered OT by some, contains very helpful insights for those of us less knowledgeable in these things. Thanks!

HM:

High fidelity simulation of post stall 'beta' effects (in all configurations) is an area of concern that is currently being aggressively addressed...

(by people much smarter than me. Like yourself. :))

Cognitive Overload of a Team
 

Dozy..
I think there is a mix of overload impacts that affect each crew member differently.

First there is what is called the 'classic inverted U curve (Yerkes and Dodson 1908) which balances arousal and performance. The crew were at the lowest point for attention and arousal at 2am in a relatively boring and benign cockpit environment. This is the worst level of attention and alertness the bottom of the inverted U and poor performance. Ideally, the crew need to be engaged so that their arousal/attention is at the top of the curve of the inverted U and performance is best. However, instead, what happened was a sudden burst of emergency activity both mentally and physically demanding with instruments and techniques routinely used in Normal Law not working. Learned sim ride behaviors seemed to make things worse. This moved the PF at least, right to the other end of the Inverted U where the level of arousal was so high that performance drops off. At that level the cognitive overload that we had discussed could lead to 'attentional tunneling' (or cognitive tunneling) where the PF concentrates on a few aspects of the task and is not conscious of anything outside those aspects.

The PNF has a similar jump to the wrong side of the U but as you state has a problem as he finds that what he says is not being listened to. This is probably due to the PF attentional tunneling, but PNF may think that it is some lack of authority on his part - the authority gradient. He may also be aware that he is overloaded with all the various aural verbal analysis, visual verbal analysis trying to read ECAM listen see what PF is doing now. So PNF wants the captain back. It is noticeable, that PNF is not making it plain shouting that the aircraft has stalled get the >deleted< nose down!! - no, PNF is muttering about the delay getting the captain.

When the captain does arrive, instead of a peaceful cockpit that he left, it is a cacophony of alerts and wind noise. PF is 'making mayonnaise' with the SS and presumably staring fixedly at the instruments. I did not see any transcript of a succinct briefing from PNF to the captain giving an order of events detailing the problems - only the captain being asked what did he think is going on? Was the captain even told that the aircraft was in Alternate Law? (is it immediately obvious if you are not told?) Would the captain have identified the stall if he had just a three sentence briefing on events?

I have said elsewhere that this turned into a human factors nightmare. Books will be written about this incident. Procedures and training both live and simulated will be changed I hope for the better.

Not so sure the crew was just sitting back and enjoying the ride, Ian.

They had just told the flight attendants to be ready for some bumps, and they were turning a bit to left of course.

The human factors should play a large part of any recommendations, and the crew coordination/procedures should also be addressed.

Most simulators are in near 24/7 use - the ones I typically work on once in service are most often on a 20 on, 4 maintenance cycle, so are running 24/7, generating revenue for 20 hours a day. Many times I have tried to book a slot to perform an update and found the sim has been booked full-up 24/7 for several weeks. There is a massive demand for sim time and not enough simulators. The problem is often there is time on the wrong simulator....

Cognitive Channel
 

Clandestino
Each of the cognitive channels in YOUR brain can only handle one input at a time. There are discussions about how many cognitive channels there are but if you really think you can concurrently read a text, while repeating a well known rhyme correctly, listening to someone talking and accurately writing down what they are saying - then you are NOT human.

I suggest that you google 'Wickens cognitive channel' and read the research there much of which was carried out with pilots. You will see how easy it is to initiate cognitive tunneling in professional pilots.

It is the poor designs and procedures that do not take account of human cognitive limitations that can lead to accidents.

Ian W knows of what he speaks.

Any of you who think you can always multitask in a highly demanding environment have forgotten your early days of instrument training where it was easily possible to break down your scan.

We try to plan ahead to prevent overloads, but occasionally stuff can snowball.
There is no pilot alive who's scan cannot be broken by the right circumstances.

It is how you recover from this mess that separates the men from the boys.

Judging from how little actual stick time airline pilots seem to be getting, I am amazed that loss of control incidents are not more prevalent.

The term scan as I am using it refers to the multi-sensory process of acquiring information regarding your flight from all sources. It is very close in meaning to situational awareness.

airbus once had solved the problem to fix a vertical stabilizar on a fuselage.....

tape will work very well, but also this: open the window, hold a lace out, close the window....... will fix it for a test

yes please

vertical speed tape
 

What are the limits, within those the VSI needle displays vertical speed?
And what is the picture, when vertical speed is greater then the display available?
Could somebody post a picture with VS pegged?

02:11:50 PF: ........"I have a problem, it´s that i don´t have vertical speed indications"
..............Captain: ."OK"

Alpha Max for M=0.65, the Mach number at 02:10:56, is 7.6 degrees. The lift coefficient and AoA versus time are shown in this graph. The lift coefficient is calculated for the normal acceleration and airspeed calculated from ground speed and vertical speed in still air, which fits the recorded airspeed prior to stall. I can't explain the strange variations of cL and AoA after 02:10:58,4 when the airplane is evidently stalled.

Look at the bank angle. The aircraft was rolling and probably yawing and the ailerons had been deflected at the reversals of the roll from PF SS input. It is normal, that overall lift is reduced, and the wings will produce different amounts of lift.

RetiredF4;

That doesn't explain that the sum of two wings, plus tail and fuselage looks like this.

At least that what it feels like in real life (with different aircraft though).

In bank we loose lift on both wings, in a stalled environment with disturbed airflows anyway. Same with yaw. The bank reversal points correlate with the decrease in CL in that timeframe.

But i´m open for a better explanation.

A very good question RF4

Let's hope for a good answer... whatver it is

@RetiredF4:
Thanks for your perspective on things...
I was catching-up with the thread yesterday after some time away, and I saw you mentioned the VSI / VVI a few days ago also. I've searched for the info on the VSI display, but can't find it yet.

I remember reading (I think in a BEA report?) that when some barometric parameters are exceeded (including CAS < some value???) that VSI display is inhibited and a flag was shown instead of a value. So there were times when the PF had no valid VSI shown (my memory is that NCD was set in the SSM of the ARINC data, to indicate it was not valid, but I'm happy to be corrected when the actual reference is found). I'll look again when I have a bit more time.

This might also be what is shown on the graphs in BEA report 3 (English) pages 106 and 111 (but that is not the presentation which I remember reading) - we can see that at times, the recorded VSI is shown switching to zero, then back again to a high value. At the times when the FDR trace records zero that will be NCD in the ARINC stream since, of course, the VSI was not really switching rapidly to zero and back to a high value.

Personally, I think this intermittent VSI indication also played a part in the PF's behaviour. As well as intermittent airspeed indication, he also had this intermittent VSI and, at some times, intermittent (counter-intuitive) stall warnings e.g. ND = stall warning, NU = no stall warning.

We now know that these behaviours all had a single cause (low CAS inhibits some data & warnings), but he/they may not have made that "connection" (and may not have been trained to know that). With 3 different sources of data all behaving "strangely" to him, (not only UAS) perhaps he simply did not know that he could (and should!) trust the artifical horizon?

At the moment, I'm not sure whether the PF (and PNF) didn't hear the repeated "Stall Stall" due to cognitive overload, or whether they heard it but chose to not believe it, thinking it to be spurious due to having other (apparently) incomprehensible indications as I mention above?

@Ian W:
Just wanted to also say thanks for the human factors comments, very interesting and fits with my experience about cognitive overload. I do also see a significant variation between people in this respect (I overload more quickly than some other people I know - I can't give commentary to an instructor in full sentences without the flying suffering :ugh: - but other people manage it fine!).

Maybe this picture from a sim gives a rough idea?

I disagree, here.
Had they followed the same drill as in their sim check (Rio depature) they would have :
- indeed seeked for 15° pitch attitude
- but also set TOGA at the same time.

TOGA was selected around 02:10:50, i.e. 40" after the NU first input, and at a time where the PF was lowering the nose, and just after the stall warning begun.

VSI
 

Thank you, that´s what i´m looking for.

If i read it correct, it shows a descent rate of 1.800 fpm (number 18 besides the needle)

Would it look the same and would there be the number 100 for a 10.000 fpm descent rate?

VSI needle is green and it beautifully simulates looking at the needle hinged to the right of the scale and being looked at through narrow slit - it appears to thicken with deflection from zero. Scale limits are 6000 fpm up and down, when they are exceeded needle is stuck at maximum deflection but it turns yellow as the digital readout adjacent to it. I don't recall any limitation to digital VSI value.

It's possible, though I can't say how probable it is, that VSIs blanked out sometimes during the descent. Someone with engineering expertize of A330 ADIRS and displays would be better suited to answer that than me.

Rudder actuators are mechanically connected to pedals via mech mixer. Yaw damping, turn coordination, trimming and travel limit are achieved electrically. THS actuator is mechanically linked to trimwheels. FCOM chapter 1.27.10 and 1.27.30, part that describes mechanical backup refer.
I couldn't have put it better myself, sir.

Seemingly they forgot everything they ever learnt about high altitude aerodynamics and performance. Actually, they needed not to know anything about it, it would be enough just to follow the procedure in order to survive. If your notion is proved to be true (which I mildly doubt) crew applied part of UAS drill that was not to be used above acceleration altitude (most of the time 1500 ft above runway) at FL330. I say it was incap.

I prefer to have the opinion that he does not. It is much more comforting to think his biased views stem from the ignorance of the matters aeronautical, rather than from agenda. Basically he claims that the cognitive overload of AF447 crew makes the whole Airbus man/machine interface wrong and disregards tens of thousands normal flights made by FBW Airbi crews every day. He disregards 32 UAS that ended as very minor incidents. Applying such a hasty generalization is something that we have used to expect of politicians every day, yet it doesn't make it a lesser logical fallacy.

Multitasking, whether it involves human or electronic brain, is not about doing many things at once. It is about properly managing cognitive/computational resources in sequential manner. Of course I can do just one thing at the time but in proper instrument scan, that one thing can be done a couple of times a second.

Pilots who don't show improvement of their instrument skills during their initial training to the point where they meet minimum applicable standards, don't get IR and are therefore unable to fly airliners. In a perfect world, anyway. Curves of pilot skill required vs pilot skill available are as important to flying as power required vs available. When skill required exceeds available, trouble is guaranteed.

To borrow the phrase from Peter Garrison: most of them will be written by the folks with "movie rights" stenciled on their glasses.

JD-EE
There is no evidence that data presented to the pilots was inadequate and even if it was this is another training issue. There are procedures for dealing with loss of information which should be followed. It is not a problem with the aircraft or its displays.

I am interested in the idea that humans can only handle one cognative input at a time. Under certain circumstances this is true but only during times of stress. Outside such situations the human brain can handle several. The point of proper training, CRM and well defined procedures is that they put the pilot into a situation where the cognative input is controlled and directed towards solving the situation. All of these factors give the pilot the ability to overcome the narrowing of inputs and continue to function normally. Iain W's reference to Wickens MRT Model though could be thought of as misleading - it is a much more complex theory than the element presented and in fact as Wickens talks about people having problems when handling more than one task which requires the use of the SAME resource. This is slightly different to a statement that we are able to handle only one cognitive input at a time. Visual perception and auditory perception would in fact constitute two different resources. Thus conducting a proper instrument scan and hearing the stall warning would not be mutually exclusive. I do not feel that this can be an adequate explanation for the accident and in fact would even go as far as to doubt it especially as Wickens also notes that as workload increases performance can also increase.

:D
Dear Ian W!

I take your comment as one of the most significant in the af 447 case and on this forum. This what it all boils down to, a human error with huge consequences. Lost in 90 seconds. What really scares me is how close you are to catastrophe as a defenseless passenger when those ones who are paid for, respected, carefully selected and appointed to deal with just this type of situations, are so near their limits of capacity. Bear in mind also those "Close call", similar cases referred to earlier.

human cognitive limitations
 

Hi Clandestino,

You will have had cognitive overload on many occasions - but probably have not realised it. Have you never missed an RT call?

These pilots are suffering from cognitive overload - and all they are doing is flying an approach:

Those who don't appreciate that it is a human limitation should not be in aviation.

Yes.
From the FCOM:
No mention of what is to be displayed when the barometric value is unavailable in the FCOM. I thought BEA wrote something about that in one of its interim reports, but cannot find it at the moment.

Look the same : almost.
As V/S is > 6000 ft/min (climb or descent):
- the needle would turn amber
- the needle would stay at the end of the scale
As V/S is > 6000 ft/min (climb or descent):
- the analog display would turn amber, too
- no mention (FCOM) of a change of value/scale with this display for 10K ft/min, so I assume it would read 100.

Hi,

Same .. but with a tragic end at take off (at 6min10)

WRZ
 

Seems to be a fascinating movie. Thanks for the link jcjeant.
I haven't read the report, so I don't know, but it looks that the crew decided to voluntary ignore the warning, or link that warning to something else they could deal with without rejecting ?

Captain Clandestino
 

As I told Dozy, SmartCockpit is not necessarily updated. I have well tried to put doubt in your mind … but what could we teach to a guy with the head of your size after all.

http://i45.servimg.com/u/f45/11/75/17/84/af447_17.png

Now, give a call to Airbus, they might reinstall a mechanic link on the rudder, just for you. Who knows ?

I make fun of you, Captain, but by reading your replies to others ... you fully deserve it. Reserve, modesty, humility … can be part of the picture too you know ?

Clandestino:
Cannot agree more. If one could get that written into an FAA training standard, and into design standards, and I believe three generations of airline pilots will thank you profusely. :)
It would be interesting to hear what this might do to training costs ... and thus ticket costs. Ya get what ya pay for, eh? :E
I agree in general, in terms of task load and cognitive channels.

I learned well how any crew can be eventually task saturated. It was done to me, and by me, in some of the more rigorous sim training events we used to do in my squadron, a lifetime ago ... some of the best training I got.

Yep.
Yep
Machinbird, I respectfully submit that scan (instrument / vfr / combined) is a subset of situational awareness. It is a critical part of what informs your situational awareness, but not all of it.

@CONF iture:
 

A330 has 2 versions of the ruddercontrol system.

1/ original system with mech cable loop (like F-GZCP) is called - mechanical rudder - altough the cable loop is a backup system.

3/ the enhanced version without mech cable loop is called - electrical rudder - the backup is here electrical by means of the BCM (Backup Control Module).

I certainly did, but as a firm believer that aeroplane flies thanks to principles discovered by Bernoulli and not Marconi, I have never dropped the aeroplane to fly the mike.

And what bearing on AF447 does it have? That it was inevitable? That we have to change instruments to fight it? That the 32 crews that didn't put themselves into stall when faced with UAS were just lucky? Of course anyone can be overloaded but simple loss of IAS resulting in cognitive overload (provided it's proven) is not something anyone reasonably informed of airline flying would be expecting to see. Besides, if cognitive overload resulted in stupor, aeroplane would probably fly itself to the other side of the ice clouds and chances are everything would be just fine afterwards.

Thank you very much, gentlemen, for kindly answering my question whether Airbus has recently modified the A330 rudder. So it did, but seemingly not before F-GZCP left the Toulouse on her maiden flight. Seemingly we can not blame whatever happened to AF447 on alleged idiosyncrasies of the new electric rudder after all.

CONF iture, reservedly, modestly, and humbly claiming that e.g. Habsheim crash was caused by software protecting the aeroplane was never my cup of tea. I prefer to have my opinions as closely aligned to facts as it is possible and am not particularly caring about sugarcoating. I accept that many time I will be wrong but I also expect that I will be corrected by someone more knowledgeable than me. Way the corrections are delivered is of no particular interest to me. FWIW, I have no problem with them being extremely derisive, as long as I get facts straight. I have always preferred substance to style.

That's one of the main points of airworthiness certificate since the first one was issued.

Previous 32 UAS events
 

Basically, yes.

Those previous 32 UAS events (which you've mentioned a few times now, in an apparent attempt to show that AF447 was the exception), were not all identical in their effects, and many of those crews also made various mistakes in handling them (some of which were the same as AF447 e.g. not treating it as a UAS event in the first place!). Look at BEA Interim Report 2, page 51 onwards (English version of the PDF) for the evidence.

Thanks for the reply and the attached s/s graphic. Will have a good look at it shortly.

Ventus, since most of the people who fly the 330 seem to like flying it, and seem to manage flying it, odds are that in this case, it meets that standard. :ok:

Quote:

---

Originally Posted by Clandestino

That the 32 crews that didn't put themselves into stall when faced with UAS were just lucky?

---

Of course they aren't all the same, but one can't help noting a few similarities between the 13 incidences they examined more closely: IMC, cruise level, slight to strong turbulence, a/p disconnect, alternate law (in 12 cases). Sounds quite familiar so far...

"The variations in altitude stayed within a range of more or less one thousand
feet. Five cases of a voluntary descent were observed, of which one was of
3,500 feet. These descents followed a stall warning;"

That indeed makes AF447 sort of an exception, having quite involuntarily descended 48000 ft from FL350.
Whatever the other crews did - they didn't point the nose into orbit and kept it there for minutes a couple of seconds after they had to start flying their plane themselves. Please tell me that isn't considered a matter of luck these days?

Agreed, of course :)

The point I was trying to make, is that to lump the other 32 UAS together as some kind of non-events, and not the near disasaters which some could have been due to poor / incorrect handling in some cases (e.g. re-engaging A/P immediately after the disconnection, not recognising that it was a UAS at all etc.) is ignoring that some of them could have turned out differently IMHO.

As I agreed above, other crews didn't make the same major mistake as AF447 which you mention, but potentially disasterous mistakes in handling some other UAS events were made, as described in the report. That none of those resulted in crashes does have an element of luck IMHO (swiss cheese model).

Or to put it another way - I doubt that the AF447 crew were the only crew at that time, with the same lack of training/practice in handling/recognising UAS and hand-flying at cruise altitudes. If one of the other crews mentioned in the report, who didn't handle their one of the 32 other UAS well, had been in the AF447 situation at that height, time of day, flight deck situation (2 x F/O) etc. etc., would they have done better? I wouldn't bet on it. That's all I'm saying.

I, perhaps naively, somehow hope that pilots being competent to fly a plane are still the norm rather than the exception, but maybe you're right and the odds are decreasing. If so, we can only hope that AF447 will be a wakeup call, the price was high enough.

Agreed completely.

From what I read on here, training (which is where I see one of the main deficiencies in the set of "holes" leading to the tragedy) has already been improved. If the A/P can disengage at FL350 and dump the plane into the hands of the flight crew, in Alt2 law, in some turbulance, at 2am, then they had better be trained and allowed to practice to cope with that event. It may not be a common event (and that may have driven budget decisions about training), but the criticality of hand-flying at that altitude (as explained by the ATPL pilots here) makes me think that the AF447 crew were put into a situation they were ill-prepared for. Of course there were other factors too.

I also think that luck (that word again!) played a part with AF447, in the sense of bad luck, with the timing of the Captain's departure to go on his break. If only that had been delayed by a few mins, he would have been on the flight deck when the problems started, and so the less experienced F/O wouldn't have been PF. Also the Captain would have been "caught-up" with events because he would have been there as the situation developed, so he wouldn't have been left with that "information void" which he had upon re-entering the flight deck that night etc. etc.

Anyway, just to summarise, I only posted earlier as the comparison seemed to be being made of: 32 other crews performance with UAS = good; AF447 crew performance with UAS = bad. IMHO, as explained in that 2nd Interim Report, the comparison is not so clear-cut.