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Airbus' Fly By Wire To Blame For AF447?  
User currently offlinekcljj From Hong Kong, joined Apr 2012, 17 posts, RR: 0
Posted (2 years 7 months 3 weeks 3 days ago) and read 12542 times:

http://www.telegraph.co.uk/technolog...7-Damn-it-were-going-to-crash.html

Having lurked around for many years, I finally decided to register. However, I rather hoped that my first post would be about happier matters.
Recently, the Telegraph published the above article. I thought it made for a fascinating read. Basically, they tried to link Airbus' fly by wire system to the horrible events of AF447.
Without trying to create any A v B nonsense (which the article is filled with), I just wanted to know what you guys think. Normally, news articles on aviation are sensationalised and inaccurate. In this instance, even though it jumps to conclusions which have not been verified yet, I think they have a point.
I did a search and it seems no one has brought this up yet. So it would be nice to get some objective feedback on this? If what they argue is true, I do believe that procedures should be changed in light of this.

71 replies: All unread, showing first 25:
 
User currently offlineAirbusA370 From Germany, joined Dec 2008, 253 posts, RR: 0
Reply 1, posted (2 years 7 months 3 weeks 3 days ago) and read 12409 times:

There was an almost identical crash of a 727 in the 70's (Harriman State Park). 727s are the most un-computerized and un-flybywired aircrafts you can imagine. So I don't think that Airbus' FBW was among the main or contributing causes of the AF447 accident.

Let's rather talk about bad/non-existing CRM in AF447's cockpit. With a properly working crew this whole thing wouldn't have happened...


User currently offlinegarpd From UK - Scotland, joined Aug 2005, 2716 posts, RR: 4
Reply 2, posted (2 years 7 months 3 weeks 3 days ago) and read 12414 times:

I've stated this a few times before, of the 9 pilots I personally know, 5 of them are Airbus pilots, 3 are Boeing pilots and 1 is a senior instructor at a flying school.

All of them agreed that if the A330 that night had been equiped with the traditional yoke, the other pilots would have been able to see precisely what the PF was doing, namely pulling back on his stick for almost all of the descent, and would have corrected his actions.
The flight instructor says that outside of the simulator it is difficult to appraise an Airbus pilot trainee's handling of the flight controls for this very reason. He has to crane his neck and unbuckle his seatbelt to see what he/she is doing.

Is this the fault of FBW? No.

Further to above, the Airbus pilots also agreed that their should be some sort of mechanism installed that moves both sticks in tandem, giving the PNF or an observer an overview on the movements the PF is making.

I should stress that neither of the pilots mentioned above are suggesting this was the cause of the accident. They are just making observations from the preliminary reports which suggest the PNF and eventually the Captain had no idea the PF was pulling back on his stick for almost the entire descent.



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User currently offlineAirbusA370 From Germany, joined Dec 2008, 253 posts, RR: 0
Reply 3, posted (2 years 7 months 3 weeks 3 days ago) and read 12364 times:

Quoting garpd (Reply 2):
All of them agreed that if the A330 that night had been equiped with the traditional yoke, the other pilots would have been able to see precisely what the PF was doing, namely pulling back on his stick for almost all of the descent, and would have corrected his actions.

And how do you explain the 727 accident I mentioned? When both pilots think that the plane is in a dive and close to overspeed, pulling back the yoke/stick seems the right action.


User currently offlinetrex8 From United States of America, joined Nov 2002, 4869 posts, RR: 14
Reply 4, posted (2 years 7 months 3 weeks 3 days ago) and read 12365 times:
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Correct me if I am wrong but my take on what reports have so far been made public on the crash is that the issue wasn't the PNF not being aware of what action the PF was doing but neither realizing the correct action was to put the nose down.

User currently offlinegarpd From UK - Scotland, joined Aug 2005, 2716 posts, RR: 4
Reply 5, posted (2 years 7 months 3 weeks 3 days ago) and read 12244 times:

Quoting AirbusA370 (Reply 3):

And how do you explain the 727 accident I mentioned? When both pilots think that the plane is in a dive and close to overspeed, pulling back the yoke/stick seems the right action.

1) You posted that as I was typing my post.
2) Apart from the plane crashing and the Pitot freezing, there is no similarity. The crew could SEE what each other was doing. Something which does not appear to have been the case on AF447.

Quoting AirbusA370 (Reply 1):
Let's rather talk about bad/non-existing CRM in AF447's cockpit

Agreed. I believe non existant CRM did play a much bigger part in this crash. If Bonin had told Robert he was pulling back on his stick, Robert would probably have barked corrections at him.
The fact that Bonin didn't say anything does constitute a lack of skill and CRM.

In the confusion of the alarms, buffeting and wind noise, both Dubois and Robert did not look over to look at what Bonin was doing, nor did they ask him. Bad CRM? Perhaps.

However, you cannot just ignore fact that Robert or Dubois could not easily see Bonin continuing to pull back on his stick. Had he been pulling on a yoke, his actions would have been very clear to see.

As in all crashes, there are many elements to this one. The inability of the crew to easily see what the PF is doing with his stick does, IMO and those of my pilot friends, constitute a contributory element to this crash.
Again, I'm not saying it was the primary cause of the crash or the only tripping point, merely that it was part of a chain.

[Edited 2012-04-28 11:43:18]


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User currently offlinezeke From Hong Kong, joined Dec 2006, 9229 posts, RR: 76
Reply 6, posted (2 years 7 months 3 weeks 2 days 23 hours ago) and read 12030 times:

Quoting kcljj (Thread starter):
So it would be nice to get some objective feedback on this?

I do not think the article is that bad. They have to make the article somewhat less technical for the public to digest

Quoting garpd (Reply 2):
All of them agreed that if the A330 that night had been equiped with the traditional yoke, the other pilots would have been able to see precisely what the PF was doing, namely pulling back on his stick for almost all of the descent, and would have corrected his actions.

Does not matter what they can see in terms of control inputs, none of them was able to identify the attitude, or identify what instruments had failed. One needs to know what inputs to make first. If they have just let go of the control column, the FBW would have actually recovered the aircraft.

A lot of people sware black and blue if it was them, or of it had conventional yoke, or this, or that, after the event it would not have happened, however they have the hindsight of knowing the nature of the problem in a zero g, zero airspeed environment. You put a person in an unnatural environment like a cockpit on a dark night, in cloud with no visual clues, they are actually significantly disabled, none of their sensors are working for them. The ONLY information that will save them if the flight instruments.

No event is ever the result of one action/feature. The common theme in these type of incidents is the pilots fail to recognise the problem in the first place.

Quoting trex8 (Reply 4):
Correct me if I am wrong but my take on what reports have so far been made public on the crash is that the issue wasn't the PNF not being aware of what action the PF was doing but neither realizing the correct action was to put the nose down.

Yes.

And this is not just AF447, it has happened a number of times in the past, some with fatal, some with non fatal results. This is from an NTSB report of a 717 that had an unreliable airspeed event in 2005, "Contributing to the incident was the flight crew's improper response to the erroneous airspeed indications, their lack of coordination during the initial recovery of the airplane to controlled flight, and icing conditions.”

Sound familiar ?

Even if you look at the 737 crash on approach in AMS, 3 pilots monitoring the aircraft, none of them were able to detect the problem. Before someone recovers an aircraft, they have to know what the issue is.



We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
User currently offlineDaysleeper From UK - England, joined Dec 2009, 873 posts, RR: 1
Reply 7, posted (2 years 7 months 3 weeks 2 days 23 hours ago) and read 12032 times:

Quoting kcljj (Thread starter):
Having lurked around for many years, I finally decided to register. However, I rather hoped that my first post would be about happier matters.
Recently, the Telegraph published the above article. I thought it made for a fascinating read. Basically, they tried to link Airbus' fly by wire system to the horrible events of AF447.
Without trying to create any A v B nonsense (which the article is filled with), I just wanted to know what you guys think. Normally, news articles on aviation are sensationalised and inaccurate. In this instance, even though it jumps to conclusions which have not been verified yet, I think they have a point.
I did a search and it seems no one has brought this up yet. So it would be nice to get some objective feedback on this? If what they argue is true, I do believe that procedures should be changed in light of this.

This issue has been covered more than once in the many AF447 threads posted over in tech ops.
Here are the three most recent ones;

AF447

AF447

AF447

But, if you want to save yourself a little time, the general consensus is that AF447 crashed because the crew not only allowed the aircraft to stall, they then performed the wrong recovery method further exacerbating the issue

It’s also worth bearing in mind that the FBW/Side stick system used by airbus has now been in service almost 30 years, any inherent design issue would have come to light a long time ago.

[Edited 2012-04-28 11:56:54]

User currently offlinePGNCS From United States of America, joined Apr 2007, 2858 posts, RR: 49
Reply 8, posted (2 years 7 months 3 weeks 2 days 23 hours ago) and read 11936 times:

Quoting Daysleeper (Reply 7):

This issue has been covered more than once in the many AF447 threads posted over in tech ops.
Here are the three most recent ones;

No kidding...

Quoting Daysleeper (Reply 7):
But, if you want to save yourself a little time, the general consensus is that AF447 crashed because the crew not only allowed the aircraft to stall, they then performed the wrong recovery method further exacerbating the issue.
Quoting Daysleeper (Reply 7):
It’s also worth bearing in mind that the FBW/Side stick system used by airbus has now been in service almost 30 years, any inherent design issue would have come to light a long time ago.

I've flown both and the general consensus among people who have actually FLOWN Airbus FBW is that it's a nonissue.

Quoting garpd (Reply 5):
The Airbus pilots I mentioned all took a long hard look at their flightdecks and did some soul searching. They all agreed that for all of it's benefits, it does lack something other flightdecks do not: The ability of both pilots to know what the other one is doing by sight alone. For only on Airbus flightdecks are the control sticks positioned in such a way that the a pilot cannot see what inputs his/her opposite number is inputting into their stick. This obviously was not deliberate, but a natural limitaion owing to their positions.
Quoting garpd (Reply 2):
The flight instructor says that outside of the simulator it is difficult to appraise an Airbus pilot trainee's handling of the flight controls for this very reason. He has to crane his neck and unbuckle his seatbelt to see what he/she is doing.

I have flown and instructed a LOT in the Airbus (and lots of Boeing, Douglas, and Lockheed, too,) and it is difficult to see the actual stick position from the jumpseat or from the IOS in the simulator. It is generally not difficult to see the stick displacement when looking across the cockpit. There's no soul searching required here: recognizing the attitude of the aircraft and making appropriate corrections were the problem with Air France 447, not the fact that it had no yokes.

Quoting zeke (Reply 6):
No event is ever the result of one action/feature. The common theme in these type of incidents is the pilots fail to recognise the problem in the first place.

Couldn't be said better. Thank you, zeke.


User currently offlinegarpd From UK - Scotland, joined Aug 2005, 2716 posts, RR: 4
Reply 9, posted (2 years 7 months 3 weeks 2 days 23 hours ago) and read 11838 times:

Quoting zeke (Reply 6):
Does not matter what they can see in terms of control inputs, none of them was able to identify the attitude, or identify what instruments had failed. One needs to know what inputs to make first. If they have just let go of the control column, the FBW would have actually recovered the aircraft.

Partly agreed. At the onset of the incident, neither Pilot appears to have understood the situation.
However, later on it seems they did identify their high rate of descent as a stall. Yet Bonin kept his stick planted in the nose up position. Neither Robert or Dubois appear to have noticed him doing so until Bonin himself said what he was doing.

Quoting PGNCS (Reply 8):
There's no soul searching required here: recognizing the attitude of the aircraft and making appropriate corrections were the problem with Air France 447, not the fact that it had no yokes.

I am not saying it was. Please, read what I write, don't just skim. I have made it abundantly clear that the lack of control input overview may just be a contributory factor. As the linked article in the OP focuses on that point, so does my reply.

Quoting zeke (Reply 6):
No event is ever the result of one action/feature. The common theme in these type of incidents is the pilots fail to recognise the problem in the first place.

Again, I am not, I repeat, NOT saying the lack of side stick visibility was the single event resulting in the crash.
But I do agree with the second part of that statement.



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User currently offlinestrfyr51 From United States of America, joined Apr 2012, 1398 posts, RR: 1
Reply 10, posted (2 years 7 months 3 weeks 2 days 22 hours ago) and read 11529 times:
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as the side stick is not inherently easy to see from the opposite Pilot position there IS a solution To the delimma.
I'm SURE Airbus apologists will disagree but this IS Simple. Install a position indicator on both sides that take voltage or resistance readings from the side stick transducers to generate a position signal to the opposite crewmwmber.. The indication would be: for the SSTK in neutral.. T he light inside the position indicator would show dead center in a round 2" guage. Any displacement from Neutral would move the indication light to the bottom for full Nose UP and to the top for full FWD or Nose Down. to the Left for left wing down and to the right for Right wing down, This would also be backed up by the ECAM flight control page where the opposite pilot might review to what position the flight controls are displaced to minimize expenses this COULD only indicated on the PIC position. the SIC has the ecam screen . But! More effective is installed on Both pilot positions . the flight control page could also have a momentary contact switch on each side of the pedestal that switched the Lower ECAM display to the Flight control Page when pushed for as long as it's pushed.


User currently offlineEPA001 From Netherlands, joined Sep 2006, 4934 posts, RR: 40
Reply 11, posted (2 years 7 months 3 weeks 2 days 22 hours ago) and read 11509 times:
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Quoting zeke (Reply 6):
Even if you look at the 737 crash on approach in AMS, 3 pilots monitoring the aircraft, none of them were able to detect the problem. Before someone recovers an aircraft, they have to know what the issue is.

And that crash happened in much, much better weather conditions and on a fairly low approach speed.

So it is clear these events can still happen in modern airliners. But developments in training (CRM) and better instrumentation will continue to strive for making the chances that such events can happen, smaller and smaller.


User currently offlineEPA001 From Netherlands, joined Sep 2006, 4934 posts, RR: 40
Reply 12, posted (2 years 7 months 3 weeks 2 days 22 hours ago) and read 11510 times:
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Quoting strfyr51 (Reply 10):
as the side stick is not inherently easy to see from the opposite Pilot position there IS a solution To the delimma.

There is no dilemma on that part. Read the previous threads and the ones in the Tech/ops section. Then you will know that the side stick is not the issue. Never was, and never will be.


User currently offlineDaysleeper From UK - England, joined Dec 2009, 873 posts, RR: 1
Reply 13, posted (2 years 7 months 3 weeks 2 days 22 hours ago) and read 11503 times:

Quoting strfyr51 (Reply 10):
as the side stick is not inherently easy to see from the opposite Pilot position there IS a solution


Nothing personal, but given PGNCS's experience I'm inclined to agree with him in that this isn't an issue.

Quoting PGNCS (Reply 8):
It is generally not difficult to see the stick displacement when looking across the cockpit.


User currently offlineSSTeve From United States of America, joined Dec 2011, 733 posts, RR: 2
Reply 14, posted (2 years 7 months 3 weeks 2 days 22 hours ago) and read 11432 times:

The article is fairly good, I think. It just doesn't pull any punches at all.

Quote:
Meanwhile, Bonin’s instinct was again to pull back on the control stick. He left it there despite the stall warning that blared out some 75 times. Instead of moving the stick forward to pick up speed, he continued to climb at almost the maximum rate. If he had simply set the control to neutral or re-engaged the autopilot, all would have been well.

However, is the above true? I've thought he was fighting the planes tendency to roll. Was any relaxation towards neutral making him feel like the plane was rolling strongly? What would letting go really have done to the plane's attitude? I've felt that it sounds like Bonin shut off his mind and tried to keep the wings level while deferring to someone else to tell him what went wrong-- does that make any sense given the previous 8000 posts on this subject? The recent tech ops threads dive much farther into CRM and instrument minutiae.


User currently offlineairmagnac From Germany, joined Apr 2012, 321 posts, RR: 52
Reply 15, posted (2 years 7 months 3 weeks 2 days 22 hours ago) and read 11387 times:

Quoting garpd (Reply 2):
and would have corrected his actions.

Your reasoning, and that of the article, seems to be
- PNF did not react to the situation (did not push the SS forward) [observation O1]
- If he had seen the stick being held back by PF he would have understood the problem. That's totally obvious ! [Hypothesis H1]

From O1 and H1, we deduce that PNF did not know what PF was doing [conclusion C1]

- The **only** way a PNF can know what commands a PF is giving is to observe his stick movements [Hypothesis H2]
- On Airbus that is not possible because of non-coupled sticks [Hypothesis H3]

From C1, H2 and H3, you deduce that the Airbus cockpit architecture prevented PNF from reacting : he could not see the other side, so could not possibly know what was going on, and so could not realize what he had to do.
Therefore the Airbus cockpit ergonomy contributed to the crash. QED



However I see all 3 hypotheses as questionable:
# H3 (not being able to observe the other SS) might be true, but see PGNCS’ post in reply 8. It’s not as clear-cut as “you can’t see anything of what the other pilot is doing”.

# H2 (you can **only** observe control inputs by observing the other SS) is the main point of misunderstanding behind all the arguments about the A cockpit. It is crucial here to understand that the control devices of a FBW aircraft are fundamentally different from those in a non FBW airplane.

In a none FBW, the pilot controls directly the surfaces, which are only indirectly linked to attitude etc…through the airplane’s dynamics. More simply, there is no direct transposition between what you see (instruments) and what you command (controls).
On FBW aircraft the computers take care of this "translation" for the pilot, and so the controls are actually directly linked to the aircraft attitude, speed etc…. Which means that the pilot can directly “see” what commands are being input into the system simply by looking at the PFD.

Caveat : once the plane was waaaaay outside its envelope that did quite not hold true anymore, because the plane could physically not obey the commands of the pilot. But it was true for a relatively long time into the accident.


# H1 is the hypothesis I would be most careful with. I just don’t think one can consider as “obvious” that PNF would have seen a yoke movement, immediately shouted Eureka ! and reacted correctly to save the day.
I mean, you could state as “obvious” that any pilot flying at 35 000 ft would b every careful about the possibility of stalling if the plane suddenly climbs 3000ft with no additional thrust.
And yet, it seems it isn’t that obvious...

Actually nothing is very obvious here. Because we simply don’t know what the pilots were thinking and so why they acted as they did.
Just for the PNF :
He waited 30 seconds before reacting to the initial climb and ordering the PF to descend. Why wait so long ?
Why did he concentrate on calling the captain, instead of helping the PF fly the plane (procedures, suggestions) ?
Why did he never ask the PF to explain clearly what he was trying to do ?
Why did he not react at all to the stall warning ?
Why did he wait so long before trying to do something with the controls ?
Why did he not suggest anything, and instead made a short and feeble attempt to take over the controls ?
And so on…

I think the AF447 discussions always come back to the same thing : we need to know what was going on inside the pilots’ minds if we are to make any definitive conclusions. About Airbus ergonomic choices, or about anything else. But for that, you need to gather experts in psychology, ergonomics, flight ops, and aircraft systems …

Oh wait, that rings a bell…   
What did the BEA decide to do ?

Conclusion : the final report should be interesting !



One "oh shit" can erase a thousand "attaboys".
User currently offlinepar13del From Bahamas, joined exactly 9 years ago today! , 7625 posts, RR: 8
Reply 16, posted (2 years 7 months 3 weeks 2 days 22 hours ago) and read 11360 times:

Quoting Daysleeper (Reply 13):
Nothing personal, but given PGNCS's experience I'm inclined to agree with him in that this isn't an issue.

So having an indicator on the panel which shows the position of the stick is not helpful?
FBW and cockpit displays and positioning of equipment is an evolving issue, no FBW today is perfect, no cockpit layout is either, we learn from accidents, if one had said CRM was an issue at AF before this accident one can imagine the battle royal, go figure.


User currently offlineDaysleeper From UK - England, joined Dec 2009, 873 posts, RR: 1
Reply 17, posted (2 years 7 months 3 weeks 2 days 21 hours ago) and read 11259 times:

Quoting par13del (Reply 16):
So having an indicator on the panel which shows the position of the stick is not helpful?

I didn't say that, I said given what has been posted by PGNCS and other AIrbus pilots for that matter, being able to see the SS isn't an issue for someone sitting in either of the two pilots seats.


User currently onlinekiwiandrew From New Zealand, joined Jun 2005, 8625 posts, RR: 13
Reply 18, posted (2 years 7 months 3 weeks 2 days 21 hours ago) and read 11132 times:
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Quoting par13del (Reply 16):
having an indicator on the panel which shows the position of the stick is not helpful?

There are any number of things that you could add to the cockpit as indicators, however, this has to be balanced by whether their potential usefulness is outweighed by their potential to become a distraction.

A number of pilots who actually fly airbus aircraft have said that they don't see any issue with directly sighting the sidestick on the other side of the cockpit. Perhaps some of them might like to express their views on whether such an additional indicator would be a benefit or a potential distraction ?



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User currently offlinepar13del From Bahamas, joined exactly 9 years ago today! , 7625 posts, RR: 8
Reply 19, posted (2 years 7 months 3 weeks 2 days 21 hours ago) and read 10957 times:

Quoting Daysleeper (Reply 17):
I didn't say that,

Never said you did my friend, simply asking a question. Oft times when a post like strfy51 is made it is overlooked or lumped in with the general trend of defense or offense in a A versus B discussion or who / what is at fault in the accident.

I read the majority of the AF accident threads and there was a mass of information including some interesting observations of ways things could be improved. In time when the dust settles we may actually see some variations applied, you never know, we may be able to say the thought originated on a.net  


User currently offlinePHX787 From Japan, joined Mar 2012, 7944 posts, RR: 19
Reply 20, posted (2 years 7 months 3 weeks 2 days 21 hours ago) and read 10790 times:

From what I read about the CVRs, the aircraft had airspeed readings which weren't accurite, and the pilots were using the fly-by-wire joystick to try to "correct" whatever was happening, isn't that correct?


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User currently offlinetdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 21, posted (2 years 7 months 3 weeks 2 days 21 hours ago) and read 10790 times:

Quoting kcljj (Thread starter):
Basically, they tried to link Airbus' fly by wire system to the horrible events of AF447.

Although I appreciate that they're trying to distill a highly technical issue into one for public consumption, fly-by-wire had NOTHING to do with the crash. The exact same crash would happen in a non fly-by-wire aircraft with the same cockpit design.

When people talk about Airbus "fly-by-wire" they are almost always actually talking about either the sidestick or the envelope protection, neither of which are inherently fly-by-wire (they're just easier to implement if you already have fly-by-wire).

Quoting garpd (Reply 2):
All of them agreed that if the A330 that night had been equiped with the traditional yoke, the other pilots would have been able to see precisely what the PF was doing

Again, this is confusion about different features. There is *nothing* about a yoke that would inherently fix this event; what they're talking about is slaved controls (one control moves the same as the other). You can have slaved controls with or without fly-by-wire, with or without envelope protection, and with or without a yoke.

Quoting SSTeve (Reply 14):
I've thought he was fighting the planes tendency to roll.

There's no evidence for that in the FDR, as far as I'm aware. The plane should have still been in roll rate control (Airbus guys out there?)...if so, the flight controls would have countered any tendency to roll automatically.

Quoting SSTeve (Reply 14):
What would letting go really have done to the plane's attitude?

Airbii, like all other current airliners, are naturally stable. It should have nosed over and recovered from the stall. If not counteracted quickly by the flight crew, however, that would likely have resulted in an overspeed.

Tom.


User currently offlinegarpd From UK - Scotland, joined Aug 2005, 2716 posts, RR: 4
Reply 22, posted (2 years 7 months 3 weeks 2 days 20 hours ago) and read 10349 times:

Quoting tdscanuck (Reply 21):
There is *nothing* about a yoke that would inherently fix this even

You misunderstand. Perhaps I wasn't clear enough.
When I said yoke, I meant slaved units. I just said "Yokes" as they are traditionaly slaved. The point being made is, a slaved system may have helped in this situation by making the PNF aware of the PF's control inputs.

[Edited 2012-04-28 14:36:46]


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User currently offlineamccann From United States of America, joined Mar 2008, 175 posts, RR: 0
Reply 23, posted (2 years 7 months 3 weeks 2 days 20 hours ago) and read 9727 times:

I am no pilot, and I understand that commanded flight path vector is different than control stick position, but I was always under the impression that Airbus Primary Flight Displays did show the commanded flight path vector. It would at least show where in relation to the artificial horizon the aircraft was commanded to go. Are there any Airbus pilots out there than can provide input?


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User currently offlineSSTeve From United States of America, joined Dec 2011, 733 posts, RR: 2
Reply 24, posted (2 years 7 months 3 weeks 2 days 20 hours ago) and read 9461 times:

Quoting tdscanuck (Reply 21):
Quoting SSTeve (Reply 14):
I've thought he was fighting the planes tendency to roll.

There's no evidence for that in the FDR, as far as I'm aware. The plane should have still been in roll rate control (Airbus guys out there?)...if so, the flight controls would have countered any tendency to roll automatically.

I didn't mean to revisit this, but the BEA report would make it appear that when the captain returned to the cockpit, the plane was banking 32 degrees right, and the F/O roll command position was at the left limit stop. At some point in the years this has been talked about, that amount of dealing with the roll attitude made me wonder if he was as mentally focused on a plane trying to roll as anything else. I can't find what he continued to do with the roll control after that... except that at that moment he had it at the left limit and the plane was rolling farther right. I simply don't think the article's characterization of the sidestick inputs as one-dimensional (pulled back) was totally accurate. He hit the left limit stop before he hit the nose-up stop.

[Edited 2012-04-28 15:16:28]

25 Ruscoe : IMO if the control sticks were connected, and if the stall warning below 60 knots was not counter intuitive the pilots would have recovered, To just b
26 Starlionblue : To paraphrase Zeke above, hindsight is 20/20. It is easy for us to sit here and say that x should have happened. The pilots seemed so far behind the
27 Post contains images kcljj : Many thanks for the links. I guess I shall have to brush up on my searching skills. Having read the discussion, I totally understand that the crash w
28 PPVRA : There may be one: a giant yoke moving between your legs is more difficult to miss than a side stick across the cockpit that may or may not be easy to
29 RickNRoll : The problem with this theory is also the crash of West Caribbean Airways flight 708. The co-pilot knew exactly what was wrong, they were stalled much
30 Starlionblue : That's the idea. One pilot flying. Regardless of yoke or stick, moving or non, slaved or non, the pilots made the very basic mistake of not being cle
31 Post contains images David L : And in the Civil forum, too. And yet: a) The PNF and Captain kept telling the PF he was "going up" and needed to "go down". b) The PNF briefly took c
32 garpd : That has nothing to do with the point being made. On AF447, both Robert and Dubois DID NOT KNOW Bonin was pulling back on his stick. When he finally
33 ThrottleHold : There is "a button". It's the same button as the autopilot disconnect on the top of the sidestick. Once again we have thread where a few posters are
34 airmagnac : How can you be so sure ? Is it explicitly stated in a BEA report, is it easily deducible from the known facts ? Maybe....And so what ? How can you be
35 Post contains images Pihero : Could one try another body part using the exact same letters ? Some thirty years after the Airbus FBW architecture was basically frozen, 25 years aft
36 Starlionblue : Basic airline pilot training: only one person flies at a time... AFAIK, there's an arrow on the screen in front of the pilot pointing at who has prio
37 Daysleeper : I appreciate your frustration, but conversely there are also many of us which do listen and are certainly willing to be educated. I don’t have a va
38 garpd : The pilots had agreed they were falling. Only after that did Bonin tell them he's been keeping the nose high. To quote the transcript: 02:13:42 (Capt
39 airmagnac : And here the captain was talking to...the PNF ! NOT the PF... It was an answer to the PNF's urge to "climb, climb, climb" I quoted myself. So it does
40 Post contains links airmagnac : I was looking at that. As far as I can tell, among the latest commercial FBW aircraft designs (excluding A & B) : BOMBARDIER - Bombardier CSeries
41 Post contains images David L : How would such a safeguard decide whether or not a take-over is justified? How would it decide which pilot should be flying? There's a procedure for
42 Jetlagged : AeroPeru 603 crashed in similar circumstances with conflicting flight instrument indications due to blocked static ports. The aircraft descended with
43 tdscanuck : That's a good point but it confuses yokes/sidesticks with slaved/not-slaved. They're not the same thing. It causes people to incorrectly criticize si
44 PPVRA : But the visual cue would be quite obvious in a yoke versus a sidestick. The way I see it, it's not that sticks are inherently flawed, but that their
45 amccann : I'm not sure I agree with that. *Again my disclaimer, I am not a commercial pilot.* Because both Airbus and Boeing Primary Flight Displays (PFDs) sho
46 David L : And yet there's been one accident where nose-up input (or insufficient nose-down input) was applied to an Airbus sidestick during an unrecognised sta
47 Pihero : Actually, it's 40 seconds ..... Thanks for that, as I was to do the same later. Jetlagged gave an exaple amongst dozens, but it's about useless to tr
48 Starlionblue : It's not an argument against per se. My point is that there is no real argument FOR slaved/interlinked control stick movements being of help in this
49 tdscanuck : Slaved controls don't do anything to tell you about flight path; they do a lot to tell the PNF what the PF or autopilot is doing. That's the argument
50 arluna : Being a Boeing fan I find myself surprised that I am defending the Airbus A330 on Air France flight 447. The aircraft did everything that it was suppo
51 Starlionblue : Fair. But paraphrasing you in the other thread, it is possible these guys were so disoriented that even moving controls would not have helped. First
52 tdscanuck : It exists today; whether Airbus has it or not I'm not sure, but Boeing now has modified heads-up-display symbology on the 787 that does exactly what
53 RickNRoll : Reading the tape transcript, the PNF seems to have been busy getting the Captain back to the cabin. He was preoccupied with other things.
54 Starlionblue : That confused me a bit. Why did it take so much of his time? If the pilots were handling a crisis, wouldn't a call to an F/A with "Get the captain in
55 rfields5421 : As discussed on other threads - there was a not optimal crew dynamic going on in the cockpit. The very experienced PNF was in the left hand seat. He
56 Post contains images Mir : And if the pilots don't have faith in the instruments (which would be completely understandable given the failures that had just occurred, even that
57 Pihero : On the 330, there is a similar philosophy on the PFD. If the pitch goes over 25° nose up - or 13° nose down - all data except the primary are blank
58 SSTeve : I also tend to think the PF shut off his brain and waited for the others to tell him what to do-- wasn't necessarily inexperience, it also could have
59 Pihero : That happens a lot of times as sims rarely sleep !
60 tdscanuck : This is true. My prior post was in reference to actual FPV (I didn't read carefully enough). There isn't really such a thing as commanded flight path
61 moo : I cant help but wonder if having a yoke would have really prevented anything here, as it wouldn't have been moving - the PF apparently had his control
62 tdscanuck : It depends on the yoke design, but the general answer is "yes". Full aft on a yoke typically puts it right in your lap; it's very obtrusive and inter
63 mandala499 : You need to talk to more Airbus pilots, and read the AF447 FDR plots. Stick was not being pulled back for almost all of the descent. And I know a hec
64 Acheron : As has been said many times before, they ignored a pretty annoying stall warning for a great deal of time. What exactly makes you think having a yoke
65 bueb0g : The stick was indeed held at the full aft stop for a large portion of the descent; it was relaxed a few times but brought back to full nose-up afterw
66 David L : Since that conflicts with the FDR plots issued by the BEA, can I ask where you're getting that data?
67 babybus : We are all professors of doing the right thing after the event. A pilot with any experience would be trying to do the best he could under the circums
68 LTC8K6 : Was the PNF aware of the initial pull up by the PF while it was occurring?
69 David L : Since neither of them mentioned it, I guess we'll never know. However, looking at Mandala499's spreadsheet, in the few seconds before the PF's first
70 rfields5421 : A pitch up is the correct memory item manuever for UAS event. So pulling back on the stick was the RIGHT thing to do. However, as Mandala499 pointed o
71 LTC8K6 : I was remembering the initial pull-up as being too much, causing trouble. I need to go over the reports again.
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