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AF 447 Thread No. 12

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AF 447 Thread No. 12

Old 12th Jan 2018, 14:43
  #1601 (permalink)  
 
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It may be something worth quoting when in front of a beancounter's leather top desk, being berated for FOQA showing a period of manual flying in cruise and the potential extra 5kg fuel burn... deskilling and the potential issues with the extra stress of an incident while less confident is a threat that everyone should be aware of.
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Old 14th Jan 2018, 22:11
  #1602 (permalink)  
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wfpalmer 15/01/2018 at 8:47 am
It’s not like Airbus has done nothing. Have they gone back to redesign and recertify the A320/330 flight control and airspeed indication systems? Well, no. But, they have designed and implemented a much more robust airspeed indication scheme for the A350 where data on the PFD automatically switches between sources and if all the pitot tubes are blocked will then switch to a system that displays airspeed based on data provided by the FADEC (engine cowl pressure sensors)and AOA data.

Additionally, the autopilot doesn’t just click off when the going gets tough but enters an extended protection envelope where it will attempt a recovery back to the normal flight envelope. This extended envelope includes extremes in speed, AOA, pitch (50° up!) and bank (120°). Indeed, the A350;s autopilot can remain engaged (or be reengaged) even in cases of dual engine failure, complete hydraulic failure and emergency electrical configuration!

>> For example in the Airbus design although AoA and Mach number are calculated by the ADR and transmitted to the PRIM fourteen times a second they are not directly available to aircrew.<>For example in the Airbus design the current procedure is to reach up above the Captain’s side of the overhead instrument panel, and deselect two ADRs…which ones and the criterion to choose which ones are not however detailed by the manufacturer.<<

This procedure applies when the AOA probe is stuck/frozen and the airplane inappropriately enters an alpha protection mode (i.e., it wants to pitch down to correct a high AOA). This is not an unusual airspeed recovery procedure. It doesn't matter which two ADRs are selected off, as the objective is to force the airplane out of Normal law where that protection operates. Perhaps the crew will have had some indication from prior failures which of the ADRs is most likely to blame, but for the immediate action it doesn't make any difference. The objective is to regain positive control of the airplane.
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Old 16th Jan 2018, 13:58
  #1603 (permalink)  
 
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@Winnerhoffer

Is any of that your own work, or did you just cut and paste again? Please use quote blocks using the square brackets {quote} what you are quoting {/unquote} around that which is what someone else posted, or use italics.

What you present to us is barely coherent.
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Old 17th Jan 2018, 15:12
  #1604 (permalink)  
 
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Winnerhofer,

“Additionally, the autopilot doesn’t just click off when the going gets tough but enters an extended protection envelope where it will attempt a recovery back to the normal flight envelope. This extended envelope includes extremes in speed, AOA, pitch (50° up!) and bank (120°). Indeed, the A350;s autopilot can remain engaged (or be reengaged) even in cases of dual engine failure, complete hydraulic failure and emergency electrical configuration!”

As an answer to 447? Save TRIM, wasn’t the 330 eminently controllable with loss of (displayed) speeds? Wasn’t the loss of data the exact reason the Autopilot quit?

So, with bad airdata, autoflight is a good idea?
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Old 25th Jan 2018, 23:03
  #1605 (permalink)  
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https://www.ladepeche.fr/article/201...is-proces.html

For the father of a victim, "the truth broke on the crash, I'm waiting for the trial"
Flight AF 447 Rio-Paris disappeared - Michel Mommayou, the father of one of the victims of the flight Rio - Paris

Eight years after the crash of the Rio - Paris flight, the latest judicial expertise confirms the serious mistakes of the Air France pilots. A decision that, unlike the president of the asso families of victims, relieves, the father of Virginie Mommayou. The 35-year-old Tarn-et-Garonnaise had died with the other 227 passengers.

In front of Michel Mommayou's office, Virginie's radiant smile contrasts with the tragedy that the sexagenarian has been facing for almost nine years. On June 1, 2009, the life of his daughter who returns with a friend of a trip to Brazil, stops abruptly. She is one of the 228 victims of flight AF 447, one of the largest air crashes of the French company. Relentlessly, this entrepreneur who, from simple plasterer is now at the head of a flourishing construction company in Saint-Aignan, has continued to want to know the truth about the death of a girl. Is this a technical problem of the A 330 that caused the tragedy? A human error of the team of pilots of this transatlantic flight? Michel Mommayou did not wait for the two reports of judicial expertise to get an idea. With the support of his lawyer Jean-Lou Lévi, the contractor assembled a team to obtain his own expertise of the accident. Surrounded by a former Air France pilot, a former air traffic controller and a mechanic of the company, all settled in Castelsarrasin ... This trio of aeronautical experts spend months peeling, studying all data. They will go so far as to give justice the place, long unknown, of the crash. An incredible story that Michel Mommayou, who has also become an aeronautics enthusiast, unveils us today. An investigation that led him to an intimate conviction: the heavy responsibility of the commander of the AF 447. A thesis that the latest forensic expertise confirms to the chagrin of the president of the association of victims of the crash, Danièle Lamy . The latter hopes that this report essentially involving the pilots of Air France, exonerates neither Airbus nor Thales of their responsibility. Michel Mommayou has a different opinion ... Interview.

In contrast to the president of AF 447 - the association of families and relatives of the victims of the crash Rio - Paris - are you satisfied with the conclusions of the counter-expert report published last week?

When I read the report last Thursday, I was alone in the office of my company: I screamed, I cried! I have been waiting for that for almost nine years. I was afraid the truth would never break that it was stifled. With this counter-expertise, the investigating judge can not return to it.

For you there is no doubt it is a negligence of the drivers who is the cause of the crash?

I do not dispute that there was a problem with the probes (Pitot, manufactured by Thales for the A330). These were frosted and blocked for less than a minute. Many planes are equipped with these probes and they do not fall. Still, when the counter of your self loose, it is not for that that you necessarily end against a plane tree. What is certain is that the pilots and especially the captain were not up to the task. They were not able to cope with this incident and, more importantly, they did not divert early enough to avoid the storm cell on which the aircraft was heading.

How can you say it?

From the beginning of this business, I had the chance to know a former Air France pilot certified A 330 who is retired in Castelsarrasin. With my lawyer Jean-Lou Lévi, he has set up a work team in which we find a air traffic controller and a former Air France mechanic. They worked on the subject, sifting through the data, redoing the flight simulations, they came to the same conclusions as the counter-expert report that it was a pilot error and, above all, a carelessness. captain.

This is a serious accusation ...

It must then be explained why on the 9 aircraft that were in this sector, 8 were diverted to avoid the storm. Only AF 447 continued in this direction.

How do you explain it?

We have never heard of the pilots' briefing before take-off. This particular allows to check the weather ... Why? We simply doubt that it took place. It is a serious negligence of the Cdt especially in this intercontinental zone where it moves a lot. It is known that he slept only 1:30 the day before the flight. In the records of the black boxes, we hear him fourteen minutes before the crash telling his co-drivers: "You know what will happen in front of you (talking about the storm). I'm breaking myself (resting). " It is not because he is dead that he is not telling the truth. He has shown lack of professionalism.

What are you expecting now?

When the truth has exploded, I hope nothing more will happen, that the trial we all expect will take place. The experts who made these two reports agree ... Now it's enough!

The asso AF 447 is afraid that Airbus and Thales are not on the dock ...

My engine in this case: it's Virginia. My daughter would not let herself be done, nor me. The association since 2001, I do not belong there, I do not know where they are ... But we will not do an expert every two years. Stop!
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Old 29th Jan 2018, 21:19
  #1606 (permalink)  
 
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I suppose from my PAX view, given that everything has been hashed over so many times, looking back on it all, it was crew action that caused the zoom climb and crew action that failed to recover even though simulations showed recovery was possible with 10k ft loss. Elevator control was present despite THD at limit. No horizon, counter intuitive non-latching stall warning limit compound an erroneous mind set focussed on a presumed inability to stall but not in that control law. Actual control law and limited protections clearly displayed for eyes that looked and could focus. Bad day at the office, maybe bad night the night before.
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Old 17th Feb 2018, 22:44
  #1607 (permalink)  
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https://www.aerotime.aero/en/civil/2...air-france-447
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Old 17th Feb 2018, 23:13
  #1608 (permalink)  
 
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From the article in Aerotime:
And there is another factor, which is also very important. One lawyer I spoke with, who is actually advising the families of the deceased people on the Air France crash, told me, there is a co-dependent relationship between these organizations and the big airplane constructors.
(my bold, underline)

I think the author may have a conflict-of-interest.

He believes the software that controls the pitot heads maybe faulty?! Also states that because Airbus made changes to their software proves they thought it was faulty. This is what lawyers always seize upon.

Last edited by jack11111; 17th Feb 2018 at 23:27.
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Old 17th Mar 2018, 18:51
  #1609 (permalink)  
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https://www.flightglobal.com/news/ar...at-now-377433/
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Old 20th Mar 2018, 12:50
  #1610 (permalink)  
 
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The point of linking to an article published in 2012 being?
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Old 23rd Mar 2018, 00:02
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Does anyone here know about Norbert Jacquet ?
He's a French pilot who's, to say the least, against the concept of fly by wire.
He commented extensively on previous crashes, which, according to his own website, led him to be sacked by Air France (where he was a boeing captain)

He's got a website here, you can use the english flag or google translate to read it.
Airbus - The lies / by Norbert Jacquet

I really don't know what to think about all of this
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Old 23rd Mar 2018, 13:04
  #1612 (permalink)  
 
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Originally Posted by KayPam View Post
Does anyone here know about Norbert Jacquet ?
[...]
I really don't know what to think about all of this
My 2cents, probably worth less: It is fairly simple really, he is either a mentally ill conspiracy theorist, or he is an outstandingly persistent whistle-blower fighting against an entire system including his own lawyers to bring to our attention the dangerous flaws in Airbus' FBW systems (and/or FBW in general).

The problem with the latter view is that FBW Airbuses have been flying now for 30 years and are not obviously falling out of the sky at a greater rate than non-FBW airliners - you can slice and dice the stats a million ways, there is no signal that stands out from the noise or isn't more than covered by correlation with other variables.

It is still possible that FBW has had some effect on safety, good or bad, but there are other far more important things that have happened in the same time frame - EGPWS and TCAS for instance. If choosing flights (as pax) for safety, airline / operator, region and airports may be far more important than A or B (certainly easier to get a idea from the stats) - for instance I personally would avoid Air France before I avoided Airbus...

The most telling thing for me though is that behind all the fuss about airbus fbw, FADECs seemed to sneak in without a murmur. Yet many/most of the arguments against also apply there (e.g. there are 100k+ lines of code in typical FADEC, maybe far more these days, and as far as I know they are the same lines of code on each engine, and if "computer says no", it don't go - whatever type of thrust levers you have).

Norbert Jacquet seems to have very little to say about FADECs, possibly because he doesn't have that much of a clue, or possibly because Boeing uses them too - doesn't inspire any confidence in his output either way.
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Old 24th Mar 2018, 12:57
  #1613 (permalink)  
 
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This post was a real grammar exercise for me because everything is written in the conditional tense !

He points out very troubling things regarding the Habsheim accident.
He shows pictures and newspaper articles for both of the following :
- The pilot (Asseline) would have received not one but two fake licenses, after his license was confiscated (by the same authority)
- The black boxes would have been tampered with by the BEA, and they would even have given the judiciary investigators fake blackboxes (he shows pictures with different marking patterns on the black boxes)

He also says things very troubling about France :
- He would have been declared mentally ill by state doctors, whereas private doctors signed several certificates saying he was not crazy*
- He would have been followed and threatened by state agents**
- He would have been forcefully sent to mental asylums even though he was not crazy*
All that because he said things that were obviously causing a trouble.

*Of course, staying focused on the same topic for 30 years despite all the problems it caused him is the sign of a slight deviation from the norm. But not the kind of deviation that would justify denying him his medical, or sending him to an institution.


Like you said, today, it certain that FBW is not outright dangerous in itself.

So I think we can conclude that one of several hypotheses is true :
1 - The Habsheim crash revealed a small defect with the 320 (either the normal law, or the fadec, or the engine itself..). Jacquet was too much of a pain in the ass, so the state decided to shut him up. Then even though the 320 problem was solved (with a simple software update), the man never changed his mind. At this stage, his mind and jugement could also have been polluted by several years of fighting against something he cannot beat (the state and airbus), and it's plausible he won't support any airbus system for the rest of his life.

2 - Or, there was never a problem with the 320 to begin with, and the state just destroyed this man for no reason.

3 - Or, everything could be made up bullshit, but that seems improbable since there are many articles proving at least 2.

**You can google things like "rainbow warrior" to find that the French state was not always "white as snow" as the French saying goes.
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Old 2nd Apr 2018, 09:14
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Can pilots be asked to perfectly control a trajectory without speed indications with a non-compliant airplane with the regulations of the certification basis (no static longitudinal stability and no low speed protection)?
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Old 2nd Apr 2018, 11:24
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Originally Posted by SPA83 View Post
Can pilots be asked to perfectly control a trajectory without speed indications with a non-compliant airplane with the regulations of the certification basis (no static longitudinal stability and no low speed protection)?
Hi. Presumably you meant to say "... an airplane non-compliant with the basic certification regulations (no static longitudinal stability and no low-speed protection)." ?

Am not conversant with the contemporary certification requirements affecting the A330-200 but, as far as I know, the A330 does enjoy static longitudinal stability. As for low-speed protection, that had become ineffective or spurious on AF447 only due to a significant system failure, so I don't see in what way the aircraft type could be considered non-compliant.

Regarding the PF's task - in the sudden absence of reliable airspeed indications - of maintaining straight-and-level flight, together with a suitable thrust setting: that matter has been discussed at considerable length in the pages of this thread and its predecessors.

EDIT
Further to the issue of longitudinal stability (see above) and the handling qualities available to the PF after the effective loss of airspeed indications, some readers may not be aware that the FBW had downgraded from Normal Law to Alternate Law in pitch, with Direct Law in roll. Although several pitch-related protections were lost, the feel and handling of the aircraft in pitch, known as C*, would have been identical to that in Normal Law. (The same cannot be said of the handling in roll.).

The aircraft's aerodynamic longitudinal stability would only be a relevant issue if the FBW had downgraded further to Direct Law in pitch. It did not.

Last edited by Chris Scott; 2nd Apr 2018 at 19:55. Reason: Added brief description of post-failure pitch control.
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Old 30th Oct 2018, 22:57
  #1616 (permalink)  
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Airliner pitot tubes provide redundant inputs for indicated airspeed and altitude readouts as well as inputs to all the various computer systems used for flight management. GPS provides groundspeed and GPS altitude information independent of pitot tubes. Angle of attack vanes provide angle of attack information (AOA) - a plane will not stall/spin if it is flying at less than stall angle of attack. As a retired Navy carrier pilot who used AOA exclusively for carrier approaches and didn't even scan airspeed except for a crosscheck at the beginning of an approach, I have always questioned why airline pilots aren't trained to use AOA and GPS speed readouts whenever any questions arise about pitot static systems reliability. AOA/GPS may not be accurate to the knot (groundspeed is a function of variable windspeed and direction) but they will both keep you comfortably within stall margin. Another mystery of life - why do folks who have no clue about aviation and aerodynamics feel qualified to display their ignorance on TV or in forums like this?

Angle of Attack. It would have saved the Air France flight had pilots been trained to it too. AOA is the only thing that matters regarding wing stall and insufficient lift. It’s been around longer than airspeed measure, too. I believe the Wright brothers did it with a piece of yarn compared to a mark though they had pusher props. Flight control computers use AOA at relatively low speeds and Mach at higher speeds. It’s time we stop teaching airspeed and teach AOA. AOA is consistent no matter the weight load or angle of bank. While not familiar with the 737, I’ll bet it had AOA.

As a active commercial pilot for a large airline and a retired military pilot (20+) year flying fighters I want to throw in my 2 cents. In every military aircraft I've flown there is a AOA (Angle of Attack) indicator. Most commercial aircraft do not have this indication available to the pilot which shocked me when I started flying for the airlines. The data is provided to the flight computers but not displayed the the pilot in what I've experienced. If you lose airspeed indication then defaulting to the AOA indication will prevent you from entering a stall. Air France flight 447 that crashed into the Atlantic Ocean killing 228 passengers in 2009 could have been saved if the pilots had AOA indictions. Their pitot system experienced icing temporarily kicking off the automation. Inexperienced pilots put the jet in a full stall from 38,000' until impact. The FAA needs to mandate all air carriers have an AOA indication in the cockpit and ensure pilots are trained to use it. Secondly, many of these foreign carriers just don't have the quality of pilots we have here in the US coupled with the fact that there is a pilot shortage world-wide.

The account of the Air France tragedy that I read in Vanity Fair was rather damning for the captain (who did have a lot of experience). He apparently had spent the day golfing and perhaps partying a bit with his GF and seemed more intent on staying out of the cabin and trying to get rest during the turbulence--which did leave younger pilots in charge of the flight. I asked my now late father (10 years USN; 25 years Pan Am) before he passed if he thought 447 could have been saved. He sighed and said "if they [pilots] understood exactly what was going on". He further explained that hand flying a sweep wing jet is very difficult without reliable instrumentation or a visible horizon (447 was a redeye) and that the "coffin corner" (approaching the speed of sound w/o reliable air speed readings) is something that is real. He also told me that if rough weather hit during one of his rest periods he would always end it and go into the flight cabin.
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Old 10th Nov 2018, 20:15
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Winnerhofer. ... As a active commercial pilot for a large airline ...
Why does your public profile show you as having no flying license and no current type?
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Old 25th Feb 2019, 21:05
  #1618 (permalink)  
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Would Air France AF447 have happened with Boeing? On June 1, 2009, Air France flight 447 from Rio de Janeiro (Brazil) to Paris (France) suddenly entered an aerodynamic stall and crashed into the Atlantic Ocean, killing all 228 passengers and crew onboard. Although the initial reports on the possible causes of the disaster evolved around the malfunction of the plane’s pitot tubes, the investigation concluded that the main reason for the tragedy was pilot’s mistake.It is often debated whether the accident of Flight AF447 from Rio to Paris was partly a consequence of the Airbus flight controls. No linkage between sidesticks, lack of feedback, a deceptive Flight Director, auto-trim and a flawed stall alarm. Two Air France Captains share their opinions. One of them is Gérard Arnoux, now retired, who for many years flew Airbus 320 for Air France and is now a technical advisor in the criminal court case. The other captain, who prefers to remain anonymous, flew Airbus 320 aircraft for many years and is now currently commanding a B777.The Boeing 777 is known as the competitor of the A330 and is also a fly-by-wire aircraft. What’s the difference?

Air France B777 Captain: On the B777 we have fly-by-wire flight controls but Boeing philosophy is different from Airbus. On a Boeing you see the input of the other pilot on the flight controls, as you see the autothrottle inputs at a glance. On Airbus you must search for information. For the throttles you have to “read” engines N1 (rotation speed in %) like you would read a digital clock.Having a yoke with physical feedback is quite different than having a joystick...

Air France B777 Captain: A Boeing-777 will always give you a physical feedback of your pilot action and physical evidences when your pilot actions are wrong. On Airbus the G-load piloting law erases a lot of that physical feeling.The G-load piloting law is why the Airbus is so easy to pilot when everything goes right, because the aircraft is always in trim, and you realize it’s like you would pilot through an autopilot: just look at flight director and make corrections through small inputs and that’s enough. I have flown the A320-family and it’s very easy to fly once you have understood that your inputs, with your wrist on the joystick, must be very accurate and minimal. The less you touch, the better it works. When you are very gentle and accurate on the stick, it’s a pleasure to see it flies alone. You can’t do that on Boeing 777.Until something goes wrong. Like unreliable speed readings, for instance...

Air France B777 Captain: You must know that training on speed failure in a simulator was very rare and during my 25 years practice on French airlines − before 2009 − I must have been trained maximum 3 times in a simulator for this situation, while we were having at least 2 engine failures to deal with at every simulator session.I do not know why speed failure was not trained. This kind of failure can be very stressing when at the same time you have overspeed warning and low speed warning, even stickshaker… The basic principle is to do nothing, just keep your thrust and attitude parameters of the aircraft. In the early years of the A320 we still had an incidence-meter (angle of attack meter, not installed on the A330) but still it is not easy and to rely on instruments, when real and false alarms are raised together.On Flight AF447 the pilots should just have kept on flying level flight, which they didn’t. Erroneous readings on their instruments, like the faulty Flight Director, which gave the order to pitch up.

Air France B-777 Captain: After the AP disconnected, the FD reappeared in basic mode, which is really not a good thing because the basic mode is just a copy of what you were doing when you connected the FD. They were climbing then, so the FD connected in Vertical Speed mode and told them to climb!Also, it seems that before the AP and AT shut off, the crew had just reduced speed to “turbulence speed”, a second before the autothrottle disconnected, so the thrust was less than the thrust needed to level flight... and the co-pilot pulled the joystick not having the right thrust.Another important factor to understand the accident is how Airbus auto trim works. As the co-pilot pulled back on the stick, the pitch trim helped him going backward to trim the aircraft because the computer acts as if Bonin* wanted the speed as low as possible... The pilots were not aware of the fact that the pitch trim was trimming all the way back, because on an Airbus you don’t have an artificial feeling, no stick shakers. They should have read the pitch trim indicator, which is something you forget to do on an Airbus, because it’s always in trim! They also should have had a visual warning telling them to use the pitch trim manually (Man pitch trim).The design of Airbus sidesticks and the fact that they are hidden for the other pilot, has been much criticized, even by an Airbus-man as Captain Sullenberger. Why is this still like that?

Gérard Arnoux: It is strange, but it is part of Airbus design philosophy and they won’t change that, even after AF447. I have read that recent aircraft by Bombardier and Embraer have active sidesticks. On Airbus there is no feedback and no linkage between the joysticks. Airbus doesn’t do that. It’s something dogmatic.There has also been a lot of criticism on the dangerous logic of the autotrimmable THS (Trimmable Horizontal Stabilizer), even when the plane is in Alternate Law. It induces the pilots to leave the protective flight envelope. The pilots did not feel that they were too pitched up, because they had no feedback on the joystick.

Air France B-777 Captain: On a Boeing you could never have done such thing (pulling on the flight control too much), because the pitch trim does not trim anymore when you approach stall speed, leaving flight controls harder and harder, as long as you are in Normal Mode (“Normal Law” on Airbus).On a Boeing, in Secondary Mode there is no stall protection either, but even in this law, a pilot trims with physical feedback. That is why, on a Boeing, you cannot stall without being physically aware of what is going on. It looks much safer to me.On AF 447, the only way to recover from the stall would have been to push on the stick for more than 30 seconds to allow the trim to set itself at the right setting to help the aircraft to recover! This is not intuitive at all.Have Flight Director flaws been addressed since and fixed on the current A330’s that are still flying around?

Gérard Arnoux: Flight Director which shut off and reappeared, displaying wrong information, has been fixed. There have been 4 Airworthiness directives by EASA (European Aviation Safety Agency) from 2010 to 2012 that addressed this problem and now Flight Director does not work anymore after unreliable airspeed situation.What about the stall warning which on the Airbus is inoperative under 60 knots. You called it “counterintuitive” in your legal report.I found it strange that legal experts did not mention it in their reports, because that is actually illegal. And as far as I know, the stall alarms on Airbus still don’t work under 60 knots, this hasn’t changed. It’s clear that Airbus completely underestimated this problem. Before June 1, 2009, the pilot-chief of training and flight at Airbus, Pierre Baud, stated in the in-house magazine FAST, that anti-stall training on Airbus planes wasn’t necessary.So why are there as many accidents on Boeing aircraft as on Airbus?

Air France B-777 Captain: Today pilots are assisted by so many systems that they don’t need to be so accurate, they do not need to be performing. We have been trained and recommended to fly on AP as much as possible, which is not a problem for a senior pilot like me. It can be a great problem for a young pilot that has become a «computer pilot» as if it was a game.Many companies do not allow their pilots to fly hands-on above 10.000 feet and a lot of airlines do not encourage visual approach and that goes not only for Airbus, but also for Boeing pilots.In the B777 Emirates accident in Dubai (2014), the pilots had an instrument telling them they were too fast, that’s why they pulled up, but in a bad way because they forgot to push the throttles. Old pilots always push their throttles when pulling up. They probably could have stopped the aircraft before the end of the runway, which does not mean pulling up was a bad option.In the San Francisco B777 crash (2013), four experienced pilots crashed in fine weather because they were relying on their autothrottle. As the majority of pilots now, they never use manual throttle because it is not encouraged, so they feel uncomfortable to disconnect. These Pilots were supposed to obey systems that have been implemented for safety purposes. They’re becoming kind of Pavlov’ pilots.Automation is becoming a risk factor?

Air France B777 Captain: I had a very interesting B-777 simulator session last week with the Traffic Collision Avoidance System (TCAS). I was on a collision course with another aircraft I was seeing. There was a TCAS-alert and I was waiting for a TCAS-command, because the aircraft’s computers “talk with each other”. So I was awaiting this order to disconnect the Autopilot and Autothrottle and fly the avoidance order but the command never came, due to a bug.At the very last moment I decided to disconnect and did a brutal manoeuver to avoid the colliding aircraft. I realized that I expected too much from computer systems and it was a good lesson of what happens when the computer fails.So the conclusion is that there should be limits on automation

Air France B777 Captain: There are two paths the aviation industry can take from here: One path would be more computers, better autothrottles, better autopilots, and more systems to detect whatever mistakes pilots make. Another would be to train pilots to fly manually and learn to avoid errors.In the first case, you do not need any more pilots and there always will be crashes. The computers will only prevent crashes imagined by engineers. A computer will never decide to do what Sully did with his A320 on the Hudson.People talk about pilot errors, but never about pilot solutions, which save lives by not following the checklist, like Captain Champion de Crespigny who flew Qantas Airbus 380 with 469 people to safety in 2010, after an uncontained engine failure, fuel tank leak, hydraulic failure, etc.Computers in aircraft are a good thing, as long as they serve pilots and not the opposite. Maybe I am wrong, but I feel safer in a Boeing, which is like a big solid truck with Apple computers you can disconnect, than in an Airbus, which is like a Space Shuttle with PC computers that have the last word. With Boeing, average or tired pilots will do the job, with Airbus you need the best, it’s not optional.
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Old 25th Feb 2019, 21:17
  #1619 (permalink)  
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Winnerhoffer C&P's someone else's work yet again

This article was cut and pasted by Winnerhofer from some other web site. It has been cleaned up to improve readability. The original work was compiled by Richard J. Ranaudo. (Mod)
Increasing automation has introduced new situational awareness challenges for pilots.
Increasing automation has introduced new situational awareness challenges for pilots.

We’re going to crash! … This can’t be happening!”

These were the last words of the first officer as Air France Flight 447, an Airbus A330, crashed into the Atlantic Ocean on June 1, 2009, killing all 228 persons on board.1 During the final minutes of the flight, the cockpit voice recorder painted a picture of confusion and frustration in the cockpit, likely due to the crew’s inability to understand what was happening.

The Flight 447 accident, according to the findings of the French Bureau d’Enquêtes et d’Analyses (BEA)² was precipitated by loss of three sources of airspeed indications at high altitude due to blockage of the pitot tubes by ice crystals. Subsequently, the fly-by-wire flight control system went into a degraded mode, and the autopilot disconnected, likely startling the pilots.

This required manual handling of the airplane at high altitude — a requirement for which the pilot flying (PF) had no prior training. The PF began a climb to a higher altitude and unknowingly stalled the aircraft. He continued to make inappropriate control inputs until it crashed.

Among the accident’s causal factors, the BEA cited the “ergonomic features” of the warning system design and the manner in which pilots are trained for stall conditions — using methods that would not elicit the appropriate response behaviors in this situation.

In its findings, the BEA stated: “The crew, progressively becoming de-structured, likely never understood that it was faced with a ‘simple’ loss of three sources of airspeed information. In the minute that followed the autopilot disconnection, the failure of the attempts to understand the situation and the de-structuring of crew cooperation fed on each other until the total loss of cognitive control of the situation.”

The crew’s loss of situational awareness (SA) began a chain of events resulting in the accident.
Airmanship and SA
Airmanship skills are defined more broadly as “the consistent use of good judgment and well-developed skills to accomplish flight objectives. This consistency is founded on a cornerstone of uncompromising flight discipline and is developed through systematic skill acquisition and proficiency. A high state of situational awarenesscompletes the airmanship picture and is obtained through knowledge of one’s self, aircraft, environment, team and risk.”³Maintaining SA in today’s modern transport aircraft requires attention and cognitive skills to sense and process information in a timely and accurate manner. Older-generation aircraft required a focus on motor skills, but modern, highly automated aircraft require more focus on attention and cognition skills.

According to a recent U.S. Federal Aviation Administration (FAA) report on human factors: “Highly automated systems in which the flight crew serves primarily as a monitor may reduce their awareness of system state, leading to longer response times in emergencies and loss of knowledge or skill. Additionally, humans are traditionally poor monitors, and as time spent in a purely monitoring mode increase[s], the ability to remain attentive decreases dramatically as does (their) performance.”4  The transport aircraft accident rate since the introduction of more automated aircraft systems in the 1980s continues to decrease, as shown in International Civil Aviation Organization Document 9683/950, Human Factors Training Manual, and illustrated in Figure 1. While automation has improved safety and reliability, it has introduced new and different challenges to achieving the goal of safe flight operations.5 Stated another way, when it comes to human error, automated systems have not eliminated it, they have relocated it.
Figure 1 — Accident Rates After Introduction of Automated Aircraft
Source: International Civil Aviation Organization and Boeing

Limits of Human Information Processing
Humans are essentially limited-capacity, single-channel operators, which means that we are serial processors and cannot attend to independent input and output activities simultaneously without suffering a performance loss on other tasks.6Human limitations in attention and memory resources, especially in a high workload or stressful situation, can have a detrimental effect on achieving good SA. Mica Endsley, a noted human factors expert in SA, defined three levels or stages required to achieve good SA: Level 1 — Perception of the Elements in the Environment, Level 2 — Comprehension of the Current Situation and Level 3 — Projection of Future Status.7 These stages can also be mapped into the stages of human information processing (Figure 2).8

Figure 2 — Information Processing Model



Source: Ranaudo, R., University of Tennessee Space Institute. “Human Factors” course notes, adapted from Wickens, C.D.; Flach, J.M., Human Factors in Aviation, Ch. 5, Academic Press, Inc., 1988, Editors Weiner, E.L.; Nagel, N.C.

SA begins with a perception of a stimulus (visual, auditory, somatosensory, etc.), and proceeds to higher levels of cognition. As shown in Figure 3, working memory, which is a component of attention resources, is called upon to assess what is perceived, and may extract information from knowledge, experience or training stored in long-term memory to define the situation and decide what action or actions are required. Based on the result of the action, and the expectation of its outcome, a determination is made either to be satisfied with the result or to seek more cues and repeat the cycle. What are not in this simplified model are effects of stressors such as time compression, confusion and emotions resulting from fear or difficult interactions with others in a team process. Further complications occur when this process is incited by a surprising or startling event. Startle and surprise, however, are terms that are frequently and incorrectly used synonymously. In reality, they are different events with different responses having different causes and effects. A startle occurs quickly, as a result of an unexpected event such as a pistol shot or the blast of a loud horn and elicits a physiological reaction — eye blinks, muscle tightening and elevated heart rate. Surprise, on the other hand, occurs when something does not react or behave as expected, such as a failure annunciation of stall warning when such a failure is not expected.

A confusing automation behavior is a common source of surprise in modern aircraft. Surprises generally manifest themselves in subtle ways, such as discovering a slow loss of cabin pressure; however, surprises can also follow a startling event. “These events are known to interrupt information processing to the point where the selection and execution of actions become reactive and sequential instead of anticipatory and proactive,” according to a 2017 report.9 “Tunnel vision” can then occur, causing a cognitive lockup. Quite possibly, this explains the continued incorrect pitch inputs by the PF in the Air France Flight 447 accident; as the BEA said, “The excessive nature of the PF’s inputs (in a stalled condition) can be explained by the startle effect and the emotional shock at the autopilot disconnection.”

Training for Better SA
The capacity for attaining SA varies among individuals. The reasons are complex, involving differences in cognitive capabilities, combined with knowledge and experience gained throughout life. Nevertheless, some people are much better at SA than others. These individuals also tend to be better at observing and extracting information from their environment, situation or activity. They direct their attention resources more efficiently, remain focused on their goals and ignore distractions. According to Endsley, 88 percent of accidents involving pilot error are due to problems with SA.10 She also believes that acquiring SA is a trainable skill11 and identifies 12 key principals around which SA training programs should be built. They include a host of key behavioral skills such as task management, comprehension, projection, attention sharing, team skills and forming mental models of systems and environments. This training would ostensibly transfer to better SA skills in the cockpit.

Michael Gillen, airline pilot and human factors expert, studied 40 airline crews receiving targeted training designed to mitigate startle and surprise. The research was conducted to assess training effectiveness in both high- and low-altitude scenarios using a Level D flight simulator. The thrust of the training was to enforce call-outs to identify and stabilize an undesirable situation. In an article summarizing the results of his research that appeared in the November 2017 issue of AeroSafety World (ASW),12 Gillen said, “The most significant factor in determining scenario success was problem identification, which was consistent with previous research (showing) when crews make an initial wrong decision, the in-flight issue tends to rapidly degrade.” He added, “The data showed that targeted training can help pilots bridge the cognitive gap when startled, and the fact that trained crews performed equally well in both (high- and low-altitude) scenarios suggested that the training had a broad array of effectiveness.” Gillen believes that startle can be mitigated with behavior-based training. The ASW article was based on a presentation Gillen made at Foundation’s 70th International Air Safety Summit in Dublin in October 2017.

Specific training requirements for airline pilots are found in U.S. Federal Aviation Regulations (FARs) Part 121.13 These training requirements are usually well scripted, involving standardized and relatively predictable scenarios. This type of training, which is termed “brittle,” does not require flight crews to have a high level of SA and may not transfer well to novel and unexpected emergency situations.14 As a result, pilots generally know what to expect during a check ride. At the highest level of information processing, SA is achieved in a perceptual cycle that evaluates and re-evaluates a problem. This high level of processing can come through training, which is why accident investigators in recent years have proposed changing the airline pilot training requirements to include more random and unexpected scenarios. A 2018 report summarized a research program conducted by Delft University, Netherlands, to determine if exposing pilots to unpredictability and variability (U/V) in training scenarios would improve their response performance to startle and surprise events. The test was conducted with 20 experienced airline pilots. A Delft research simulator, shown in the photo below (Figure 3), with a full motion base, visual display and a hybrid aircraft model, was used.

Figure 3 — Delft University of Technology “Simona” Research Simulator


Source: Courtesy, Olaf Stroosma and photograph by Theirry Shut, Delft University of Technology

The pilots were divided into two groups of 10 — a control group whose members were given non-variable and predictable training, and an experimental group whose training was U/V. A hybrid aircraft model was in the simulator, for which none of the pilots had previous experience. Variability was achieved for the U/V group by alternating the failure conditions from run to run, whereas the control group practiced the failure cases in succession (non-variable). Before a practice run, the U/V group was only told that a malfunction would occur (unpredictable failure), but the control group was told the details of what to expect (predictable failure).

After the practice sessions, the pilots in both groups were tested in identical failure scenarios that were designed to create surprise or startle. Surprise was caused by engine and control system failures. The presence of startle was assessed post-test with Likert-type opinion questions — for example, “How startled or shocked were you when you discovered the issue?” (1 = not at all, 5 = extremely). The test profile is shown in Figure 4.

Figure 4 — Traffic Pattern Flown in Surprise Test


1. Right engine loses power over 20 seconds.
2. Brief decrease in left engine power, which was restored immediately.
3. Rudder effectiveness decreases 20 percent.

Source: R. Ranaudo, Adapted from Reference 12.

A moderate nearly direct crosswind was present, and pilots were told to fly a left traffic pattern and call out failures as soon as they became aware of them. A successful landing was the success criterion. The test profile began with a right engine power loss on takeoff at 55 kt (1). After the callout (or after approximately 30 seconds), pilots were instructed to continue the takeoff and were given a lower level-off altitude. A second surprise was an engine power loss after which the pilot was informed that both engines were unreliable but still running (2). When turning downwind, rudder effectiveness was reduced by 20 percent (3). A successful landing was possible only if pilots identified the failures and managed differential thrust to offset loss of rudder effectiveness. The U/V pilots adapted their training and developed a control strategy allowing them to fly a steeper approach with reduced thrust on the good engine and landed safely. Successful landings were made by nine of the 10 pilots in the U/V group and only two of the 10 pilots in the control group. Callout times for failures were not significantly different between the two groups. Regarding the subjective determination of startle vs. surprise from the opinion questionnaires, there was no significant difference between the groups. On a scale of 1 to 5, startle was rated between (slight) 2 to (moderate) 3. Surprise was rated on average a (moderate) 3, with the highest (very) 4 for all events. Overall, the U/V group rated all events as “significantly easier to understand” than the control group. The higher surprise ratings indicated that the failure events were unexpected but not of such significance that the pilots felt threatened. Real-world conditions would likely have caused higher ratings.

Changes in Training
Following the Air France Flight 447 accident, the BEA recommended that unexpected and unusual situations — that is, surprise and startle events — be incorporated into pilot training scenarios. This training takes a behavioral approach that emphasizes problem solving through analysis of failure indicators and their meaning. The objective is to teach pilots how to make sense of a novel or unusual situation, achieve good SA and make better decisions and action responses. The results of the two studies cited in this article give evidence to the efficacy of this training. But completing the picture requires that training include manual control skills training in failure modes. These are still the most basic airmanship skills required of a pilot.

Richard J. Ranaudo was a U.S. National Aeronautics and Space Administration (NASA) research pilot for 25 years and the lead project test pilot in the icing research program for 16 years. After retiring from NASA, he spent five years as manager of Canadair flight test programs, and conducted icing development and certification testing on prototype business and regional aircraft. As a research assistant professor at the University of Tennessee Space Institute, he taught graduate level courses in the Aviation Systems Program, including human factors in aviation, flight test engineering and airport systems.
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Old 26th Feb 2019, 14:01
  #1620 (permalink)  
 
Join Date: Dec 2002
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Winnerhofer,
The debate is little more than A vs B separate from the root cause of the accident.

The simultaneous malfunction of three identical sensors confused a triple cross monitoring system resulting in an extensive and complicated disruption to normal flight deck displays. The type of sensor has been changed.

With a similar high-level systems view, the recent 737 accident appears to involve a single sensor failure and a weakness in the implementation of a dual cross monitoring system. The result was similarly confusing, with conflicting indications.

Thus these accidents - root cause systems malfunction, are conceptually very similar, if not identical, both unfortunately with the same outcome.

Outcomes, accidents, fatal or otherwise, should not be use to judge the relative merits amongst similar or dissimilar aircraft types.
If comparison is warranted, there would be greater benefit in assessing normal operations, the systems which aid safety or clarify situations, and protect pilots from ‘themselves’.

We should also recognise the problems in adapting ‘facts’ to fit a particular argument.


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