AF 447 report out

[BOAC]

I would surmise that at the AoA's we are looking at here one could 'forget' any form of 'classic' lift considerations and we are really looking at the moments generated by a 'flat plate' (the tailplane) plus any added force generated by a lowered elevator which would effectively increase the flat plate area. What is unknown at these attitudes is the nose-up pitching moment generated by the wing/body combo (and I suspect we will never know) but I would expect the overall pitching moment of the a/c to be nose down, so we are left only with the thrust couple to spoil the results, and, of course, any applied 'up' elevator reducing the flat plate area - and I think the FDR shows that to be so.

[A-3TWENTY]

Quote:
Originally Posted by A3Twenty
There is no doubt pilots failed to comply with procedures , but in my opinion, the airplane showed three design failures, some known long ago.

1.The side sticks are not connected.

2.Pitots getting iced.

3. The stall warnings stops before you are reaaly out of stall.

My 2 cents.
Yes, they failed to comply with procedure and the key lies in why.

Would you care to speculate as to why the crew failed to recognize the need to follow the UAS procedure?

I think the only real design failure is in allowing stall warning to stop while the aircraft was/is still stalled.

1.Why did they fail to use the UAS? Probably lack of experience , but I don`t want to expeculate.It`s going to be never ending discussion.

2.Don`t you think pitots getting iced is a design problem?? Airbus does , even before the accident when they recommended operators to change it.

3. About the sidesticks , well , is something you get used to , but nobody can say it is great not to know what your coleague is doing until it has already done.The proof is this accident. Was it a boeing and the other pilot would know from the very begining his coleague was constantly puling the column.

Note:I fly the airplane for almost 10 years and like it , but I assume it has imperfections.

[mm43]

Effective tailplane area versus pitching moment

Since the subject has been brought up again, this AF447 - Thread No.3 link also includes two further links relevant to the subject.

Owain Glyndwr in one of his posts indicated that the THS was never stalled, so adjust the amounts of "pepper" or "salt" to suit your specific taste.

[TTex600]

Originally Posted by A-3TWENTY

1.Why did they fail to use the UAS? Probably lack of experience , but I don`t want to expeculate.It`s going to be never ending discussion.

2.Don`t you think pitots getting iced is a design problem?? Airbus does , even before the accident when they recommended operators to change it.

3. About the sidesticks , well , is something you get used to , but nobody can say it is great not to know what your coleague is doing until it has already done.The proof is this accident. Was it a boeing and the other pilot would know from the very begining his coleague was constantly puling the column.

Note:I fly the airplane for almost 10 years and like it , but I assume it has imperfections

Most everything you are bringing up now, such as the sidestick vs column debate, has been resolved or at least discussed to a standstill in the thousands of posts in these last two years. I do suggest a review. In short, plenty of Boeings have crashed with the stick full back and the Airbus advocates will inform you of that very quickly.

The pitot issue may or may not have been a "design" fault; but I think everyone agrees the pitots were not up to the task, whether by faulty design or by failure to perform as designed.

Regarding why. Until we understand how and why they failed to recognize UAS and apply the proper UAS procedure, we will be doing those dead pax a disservice.

Whether it be training, procedures, background, experience, culture, social norms, etc, it really needs to be puzzled out to a reasonable conclusion. Otherwise, as the pool of aviators dries up, and more programmers enter the workforce, the potential for another AF447 grows greater every year.

[mm43]

In addition to the comments made by HazelNuts39 in #627, the following graphic portrays most of the events described.

To my mind, the pitching oscillations that occurred after passing CLmax are indicative of the CL shifting in the final moments prior to complete airflow separation. From 02:10:57 until 02:11:12 the aircraft was in the "mush", also semi ballistic and not responding positively to SS commands.

[jcjeant]

Note:I fly the airplane for almost 10 years and like it , but I assume it has imperfections.

As non-pilot .. I wish you a long and successful career
I hope you will not have to suffer the imperfections that you assume exist on the Airbus .. for to assume means not knowing exactly who they are and therefore you risk finding yourself in a situation that you will not understand ..

[TTex600]

Originally Posted by jcjeant

I hope you will not have to suffer the imperfections that you assume exist on the Airbus .. for to assume means not knowing exactly who they are and therefore you risk finding yourself in a situation that you will not understand ..

"What's it doing?"
"Why's it doing that"
"Look, it's doing it again"

It's an old joke, but too many Airbus pilots laugh for it to not contain some truth.

[DozyWannabe]

Originally Posted by TTex600

It's an old joke, but too many Airbus pilots laugh for it to not contain some truth.

Two of the deadliest early mode-confusion crashes relating to automation actually occurred in an L-1011 and a B757. It's far from an Airbus-only problem and always has been.

[TTex600]

Originally Posted by DozyWannabe

Two of the deadliest early mode-confusion crashes relating to automation actually occurred in an L-1011 and a B757. It's far from an Airbus-only problem and always has been.

We get it buddy. You have no sense of humor and you're on a mission to uphold the good reputation of Airbus against all of us haters.

It's still funny and it still illustrates my point that A3-TWENTY is not a bad pilot just because he assumes the aircraft has imperfections. jc quoted him and implied that he might find himself in a situation sometime that he didn't understand. My point was that he wouldn't be the only one. It's called being human. I'm not perfect, nobody is. Get the chip off your shoulder.

[A-3TWENTY]

Quote:
Originally Posted by TTex600 View Post
It's an old joke, but too many Airbus pilots laugh for it to not contain some truth.
Two of the deadliest early mode-confusion crashes relating to automation actually occurred in an L-1011 and a B757. It's far from an Airbus-only problem and always has been.

Again.
I like the airplane , I like the sidesticks(there is no reason nowadays to keep the column in front of you for 12 hours to use it for 5 minutes) , I love the table, just think like a lot of airbus pilots sidesticks should be conected.

In a smaller scale we feel that , when the FO is approaching.We only know what he is thinking and doing after he has already done.With a column or conected sticks we would be able to correct his actions in an earlier stage.I have almost 10 years flying airbus , but I have been flying for 24, so I have bases to compare.

Just that , as simple as that.

Regarding the surprises from the airplane . I had some in the begining like everyone , but not from long ago.
If it happens?? Well two golden rules os airbus state that :
The airplane can be flown like any other airplane
When things don`t go as expected , take over.

Simple.

TTex600,

There were lots of accidents in the aviation history which were atributed to pilot errors and their failure to act as expected.This is just another one.
But it`s also true that through out all these years , the industry has made changes in the new designs to minimize the chance of pilots doing the same mistakes again.Airbus just implemented the BUSS.And I keep thinking that doing something so simple as conecting the sidesticks would be one of them.Despite I`m very used to it.

I completely disagree when you said the pitots were not one of the factors contributing to the accident. They were the first one in the chain.Why? Because they were designed by humans ,and those who designed it didn`t do it properly, the same way the human pilots didn`t perform properly after the pitots got iced.
And this is so true that Airbus recomended operators to change them even before the accident.

[DozyWannabe]

Originally Posted by TTex600

We get it buddy. You have no sense of humor and you're on a mission to uphold the good reputation of Airbus against all of us haters.

Huh?

I'm British - if you want to see my sense of humour I suppose I could do a silly walk and drop my trousers!

As I said on the other thread, as someone who does 99.9% of his flying as SLF it does me no good whatsoever to defend a problematic or bad design. What I do have a problem with is falsehoods being repeated with no supporting evidence, and it'd be the same no matter who made the aircraft concerned.

One of the biggies for me is conflating FBW (which is the technology used in the flight control systems of the A320 through A380, as well as the B777 and B787) with FMC/FMS (which has been a standard component of every major airliner for the last 3 decades or more). The latter of which is essentially a fancy term for advanced autopilot and is the exclusive domain of the "what's it doing now?" problem.

As an analogy, it's as wince-inducing for us as systems engineers as it would be for you to hear a cadet or a journalist talking about AoA and pitch attitude as though they were the same thing.

It's still funny and it still illustrates my point that A3-TWENTY is not a bad pilot just because he assumes the aircraft has imperfections.

Wha? I wasn't even referring to his posts! I've responded to some of the points he raised years ago and have no intention of revisiting them now...

jc quoted him and implied that he might find himself in a situation sometime that he didn't understand. My point was that he wouldn't be the only one. It's called being human. I'm not perfect, nobody is. Get the chip off your shoulder.

If that does happen (and I fervently hope it doesn't), I don't think the type he's flying will have any impact on the situation. The idea that the airliner design consensus from the late '50s to the early '80s was some kind of golden era is provably false. Likewise, the idea that the FBW Airbus types are any more difficult to understand when in an unexpected failure mode than their brethren from other manufacturers is simply not supported by the evidence of the last two decades.

@A-3TWENTY - I've asked this before and I'll ask it again. You remember the incident when the sidestick controls were inadvertantly connected in reverse, and it took quick action from the pilot in the opposite seat to remedy? Now imagine what would have happened if the sticks were connected and the pilot in the correctly-wired seat could not overcome the force-feedback.

The sticks are not connected for several reasons, and it's worth understanding what those reasons are before asserting that the design decision was a mistake.

[A-3TWENTY]

@A-3TWENTY - I've asked this before and I'll ask it again. You remember the incident when the sidestick controls were inadvertantly connected in reverse, and it took quick action from the pilot in the opposite seat to remedy? Now imagine what would have happened if the sticks were connected and the pilot in the correctly-wired seat could not overcome the force-feedback.

.

Yes , it happened with Lufthansa.

Easy solution.
The button we nowadays use to take over could be used to disconect them and make them independent.

[bubbers44]

That is why I stuck with the 757. The controls worked the same way on both sides. You could see if the FO was out out of bounds and fix it. As I understand in the Airbus you have to see the airplane respond before you can correct it. In the Boeing you don't have to wait.

[TTex600]

Originally Posted by A3-TWENTY

I completely disagree when you said the pitots were not one of the factors contributing to the accident.

Please go back and re-read my response. I NEVER said that the pitots were not one of the factors contributing to the accident. Here are my words, "The pitot issue may or may not have been a design fault; but I think everyone agrees the pitots were not up to the task, whether by faulty design or by failure to perform as designed. " I said that I think everyone agrees that the pitots were not up to the task. I'm just not certain that they failed due to a design failure.

[Lyman]

The only knock I have found on these specific probes was that they were prone to corrosion at the drain. That is not by design, to my way of thinking.

[TTex600]

Originally Posted by DozyWannabe

Wha? I wasn't even referring to his posts! I've responded to some of the points he raised years ago and have no intention of revisiting them now...

If you have no intention of revisiting A3-TWENTY's old points, what are you doing in this current discussion? He posted, I answered with quotes, jcjceant made a comment about something A3 wrote and I commented on jc's comment. The joke you object to wasn't directed to you, no comment was directed to you, you weren't a part of the conversation at that point. I'm only getting combative at the moment because you assume much with this "I wasn't even referring to his posts". Had you been paying attention, you would have know it was ALL about his posts. Seriously, get the chip off your shoulder.

[TTex600]

Originally Posted by DozyWannabe

One of the biggies for me is conflating FBW (which is the technology used in the flight control systems of the A320 through A380, as well as the B777 and B787) with FMC/FMS (which has been a standard component of every major airliner for the last 3 decades or more). The latter of which is essentially a fancy term for advanced autopilot and is the exclusive domain of the "what's it doing now?" problem.

Who conflated anything? I told an old joke in the context of an Airbus pilot who might not know exactly what his machine was doing at all times. A3-TWENTY said this. "Note:I fly the airplane for almost 10 years and like it , but I assume it has imperfections.". jcjceant answered with this, "I hope you will not have to suffer the imperfections that you assume exist on the Airbus .. for to assume means not knowing exactly who they are and therefore you risk finding yourself in a situation that you will not understand ..".
I followed with an old joke to illustrate that pilots do not always know what the airplane is doing. Nothing in that joke denigrates Airbus. If anything, it's pilots laughing at each other.

Next. Actually, FMC/FMS is not a fancy name for an advanced autopilot. I've flown more than one jet type with an FMC/FMS that used the same autopilot as a raw data airplane. My 737 type was flown entirely raw data on an airplane with an FMS. I assure you the autopilot was engaged as much as possible and functioned quite nicely without the FMS/FMC. I've flown Lears with FMS/FMC and without FMS/FMC and the autopilot was the same in both aircraft. I've flown DC9-83's with FMS/FMC and DC9-83's without FMS/FMC and the DFGS (autopilot) was identical in both airframes. The autopilots of those airplanes cared not whether the FMS/FMC was operable or on the DMI list.

Your comment just isn't correct. An FMC/FMS is a "flight management computer/flight management system" and most of them are simply fancy navigation computers integrated with aircraft performance computers.

The 320 autopilot flies quite nicely using selected speed/heading/vertical speed. It doesn't need an FMC, therefore I conclude that your comment isn't even applicable to the airplane you try so hard to defend.

[A-3TWENTY]

Quote:
Originally Posted by A3-TWENTY
I completely disagree when you said the pitots were not one of the factors contributing to the accident.
Please go back and re-read my response. I NEVER said that the pitots were not one of the factors contributing to the accident. Here are my words, "The pitot issue may or may not have been a design fault; but I think everyone agrees the pitots were not up to the task, whether by faulty design or by failure to perform as designed. " I said that I think everyone agrees that the pitots were not up to the task. I'm just not certain that they failed due to a design failure.

Quote:
Originally Posted by A3Twenty
There is no doubt pilots failed to comply with procedures , but in my opinion, the airplane showed three design failures, some known long ago.

1.The side sticks are not connected.

2.Pitots getting iced.

3. The stall warnings stops before you are reaaly out of stall.

My 2 cents.
Yes, they failed to comply with procedure and the key lies in why.

Would you care to speculate as to why the crew failed to recognize the need to follow the UAS procedure?

I think the only real design failure is in allowing stall warning to stop while the aircraft was/is still stalled.

I was answering this post. And here you say you think the "ONLY REAL design failure is in allowing stall warning to stop while the aircraft was/is still stalled "
Sorry but it is hard to guess which post you were especting me to answer.


Again.
Wouldn`t have they failed a couple of times before this accident (fortunately without any incident) and Airbus didn`t recomend operators to change them.
Do you think Airbus would recomend its change if they worked properly?

[jcjeant]

Do you think Airbus would recomend its change if they worked properly?

Methink they worked properly to the extent to which they were built and tested (certified)
They were not tested (or certified for) in a ice crystals environment
Immediately when the pitots were again in their certified environment they worked again properly
The multiple events before AF447 were eyes opener ... and they know now that the design must be improved and certification requirements must be upgraded to the new exigences ... IMHO
Aircrafts with actual pitots are not to be fly in ice crystal environment .. it's some risks .. until a new generation of pitots (or another probes system) is designed

[HazelNuts39]

Originally Posted by jcjeant

They were not tested (or certified for) in a ice crystals environment

That is not correct. Read the final report, in particular paragraphs 1.18.1.6 and 1.18.1.7.