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AF 447 Thread No. 7

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AF 447 Thread No. 7

Old 28th Mar 2012, 18:28
  #1041 (permalink)  
 
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Originally Posted by CONF iture
For now the BEA is selective ... but the Judge is withholding data from the proceedings.
The sole objective (of BEA's investigation) is to draw lessons from this occurrence which may help to prevent future accidents. Obviously it needs to be selective in presenting the data that have a bearing on that objective, both in the interim reports and in the final report. I know nothing about the Judge's actions, and why would you blame BEA for those - perhaps you can explain?
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Old 28th Mar 2012, 20:14
  #1042 (permalink)  
 
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Cool

Hi,

I know nothing about the Judge's actions,
HazelNuts39 .. as you are (mostly) located in Françe .. this will give you some light about the judges action
Hope it's help .....
Some news there: (audio included)
Rio-Paris : les familles réclament une enquête transparente - RTL.fr
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Old 28th Mar 2012, 20:43
  #1043 (permalink)  
 
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jcjeant,

That's about the lawyers request (Les principaux extraits...), nothing about the judge's response, nor about BEA's responsibility in this. Doesn't the judge makes his or her own decisions, independent of BEA's investigation?

Last edited by HazelNuts39; 28th Mar 2012 at 20:56.
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Old 28th Mar 2012, 21:18
  #1044 (permalink)  
 
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BEA's responsibility is non-existent, vis-a-vis the Court case. One must read the Mission statement, and realize that there is sufficient discretion in it to frustrate even the most Liberal Magistrate, imho.

If there is a superior authority to both the Judge and BEA, that is where disclosure reposes.......Even then, the Judge can frustrate disclosure. Monkeys play football.
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Old 28th Mar 2012, 21:50
  #1045 (permalink)  
 
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Originally Posted by Lyman
To constantly insert AoA in the record, knowing the pilots had no access to it, is dishonest on BEA's part.
BEA simply describes the condition of the airplane, and doesn't in any way suggest that the pilots had that information.

Between 02:11:00 and 02:11:45 PF applied nose-up and nose-down inputs to maintain a pitch attitude of 15°, which required full travel of nose-up SS at 02:11:45. He then pulled the thrust levers back to idle, which caused the airplane to pitch down to -10° against full NU SS maintained until 02:12:15. Did I refer to AoA?
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Old 28th Mar 2012, 23:20
  #1046 (permalink)  
 
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HazelNuts39

"Between 02:11:00 and 02:11:45 PF applied nose-up and nose-down inputs to maintain a pitch attitude of 15°, which required full travel of nose-up SS at 02:11:45. He then pulled the thrust levers back to idle, which caused the airplane to pitch down to -10° against full NU SS maintained until 02:12:15. Did I refer to AoA?"

If I ask you who was PF during this time frame who would you say was flying?

Bonin from the RHS?
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Old 28th Mar 2012, 23:40
  #1047 (permalink)  
 
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Open minded

Hi Captain

PJ2:

I understand your rationale and must admit, it is robust. HF (being addressed) probably is the major "component" of this accident.

When investigating something "different from our expectations" (i started to learn long time ago doing corrective maintenance in a powerful NDB (RR 375 Kc/s ) we must be open minded to all possibilities.

Your thinking (on why's) i understand is concentrated in the crew (unexpected behavior) and considers the machine "performed as expected". As a designer i always question the design. It can have 'flaws". Better when we detect first. Cost less.

I understand your thinking that crew actions were "unexpected" before and after facing the consequences of the "inadequate inputs=large stimuli to the plane, zoom climb, etc." An "entire group failure": PF, then PM and finally CPT being unable to deal with the issues and not showing any useful timely "response".

Considering the "effective aircraft" (Machine+PF) failed VERY FAST (degraded) without any "useful reaction" (showing ZERO resilience) and considering (probably) there are some (perhaps important) factual information we don't have, I prefer for now (as safer):

To consider the man machine interface "performance" as a possible important contributing factor why the crew failed completely (acting unexpectedly).

There are some reasons for this.

I sincerely hope the lessons of this case (all possible) are learned and implemented with no "trade offs".

The user wants to travel not just in "competitive carriers" operating "competitive machines". The user really need "Uncompromised Quality". Safety as a direct result. This is what the users expects indirectly (or directly).

This case, a complex one presents a great opportunity to advance further toward the objectives of every one professionally conscious on these issues.

IMHO the man machine in these "advanced flying systems" should be reviewed specially when working under "unusual conditions". Exactly when you need most it's resources.

With the information we have so far in this case we have reasons to consider this as a possible and probable important factor.

Actually the authorities should pursue this objective, in the interest of all involved in the industry.

I am anxious to see the results of the HF study and the role of the man-machine interface on crew (lack of) "performance".
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Old 29th Mar 2012, 00:35
  #1048 (permalink)  
 
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Cool

Hi,

HazelNuts39
That's about the lawyers request (Les principaux extraits...), nothing about the judge's response, nor about BEA's responsibility in this. Doesn't the judge makes his or her own decisions, independent of BEA's investigation?
We should try to make an effort to understand what the lawyer says in this interview
It simply says that BEA has passed the entire FDR to Airbus company
He also said that Airbus is one of the parties named in the lawsuit .. as are other civil parties that is to say the associations of families of victims and people with right
Also it is not normal in terms of law that either party has the intelligence and the other does not ...
And it's even more weird that the judge handling the case should not take a decision to correct the imbalance .. as she refused to join the FDR in the instruction process (so far)
The families associations have the right (as civil party) to have their own experts ... but how they can make expertise with no datas ???
Hope it's help to understand what happen there ...

Last edited by jcjeant; 29th Mar 2012 at 00:48.
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Old 29th Mar 2012, 01:48
  #1049 (permalink)  
PJ2
 
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RR_NDB;

I try very hard to leave hindsight bias behind and go where the available evidence and my experience and knowledge of the airplane take my thoughts. It doesn't always work, so disagreement, based upon further information and not just opinion, is always part of the process.

Believe me it is not pleasant to contemplate what has happened to this crew but as so many have said, it is crucial to find out what happened and why so that prevention takes place. In fact many things have already changed in the past year as a result of the available data in the form of recurrent training and so on.

It is a fact that airplanes, their systems and engines rarely fail mechanically, that navigation is extremely accurate, that autoflight is very good, that CFIT's and mid-air collisions are rare thanks to GPWS/EGPWS and TCAS, that satellites have made communications over vast areas of ocean almost routine, (though not here even though such wasn't likely an important factor), and that SOPs, CRM and things like checklist design have all contributed to the remarkable safety record of the industry.

It is therefore a fact that a very high percentage of accidents are HF accidents.

This is a primary reason for safety programs such as FOQA/FDM, which also have a crew-contact element (by a pilot's peers, not by management!), which is designed to address human factors issues and prevent untoward events.

So it is extremely important to understand what happened here and why, especially in Phase 2, and with two first officers and the ill-defined command and experience gradients which, I am sensing, may possibly also had had a cultural aspect.

These are SMS, HF and organizational areas of accident investigation and prevention. So, with reference to your comment, "Your thinking (on why's) i understand is concentrated in the crew (unexpected behavior) and considers the machine 'performed as expected'. ", I was not so much focused on the crew so much as it is where the available data is drawing attention. That means that new information, when or if it arises, always has the capacity to draw attention. This does not mean that design, and the machine is not the focus but that one places such attention in the context of the man-machine interface.

Designers cannot reasonably be expected to anticipate everything that will occur in an aircraft either by mechanical incident or crew action so it must be designed to fail gracefully as some have pointed out here, and this airplane failed gracefully - a loss of speed information does not necessarily result in a loss of control or loss of the aircraft. I don't think it is at all reasonable to expect that a designer will, in the course of such anticipatory processes, design against all outcomes that may or may not obtain in a fully-developed high altitude stall by line crews.

That said, even with a full NU THS, there was sufficient elevator authority and upwards force on the horizontal stabilizer and aft fuselage to lower the nose and un-stall the airplane albeit likely over as much as a 20,000ft loss of altitude. I think that is a remarkable bit of engineering. A level D simulator may not have the exact algorithms for post-stall behaviour but nor is it entirely without data and fidelity in such conditions.

Crew confusion must be examined very closely in both Phase 2 and 3. Post-pitch-up the PM was confused by the initial two very short stall warnings for example. Who knows how that may have influenced subsequent perceptions and input? The other aspect which I expect will be examined in the final report is the behaviour of the stall warning system below 60kts but this has been widely discussed.

It remains a concern as a former transport pilot that potentially irreversible actions were swiftly, unilaterally taken without adhering to SOPs, CRM communications standards and the handling of abnormals. Cockpit discipline and TEM (Threat/Error Management) processes are drilled into crews in each simulator session and are causes for failure of the ride if not executed to high standards. These processes intervene to prevent rushed actions while providing a basis for calm, measured and coordinated responses by both crew members. This isn't some elusive ideal, this is the normal standard by which transport aircraft are flown, so any unexpected divergence from this standard requires explanations and a willingness to closely examine crew actions where the data supports that kind of an approach. That is why I seem focused on the crew.
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Old 29th Mar 2012, 02:03
  #1050 (permalink)  
 
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Heavens to Betsy, is this still going on?

Originally Posted by Lyman View Post
To characterize post apogee Pitch inputs as "mostly nose-Up" is not fair.
Yes it is. When talking about average positions over time the inputs were *overwhelmingly* NU.

The a/c wandered NU/ND between -3 and +17 several times.
Yes - in response to the stall. Speed decays, nose comes down, speed increases but the aircraft pitches up and stalls again due to elevator/THS position.

The co-pilot input ND several tmes.
Not enough, and for nowhere near long enough. When we ran the scenario in the sim, the SS needed to be emphatically forward and held there for at least 8-10 seconds to correct the THS position and control the aircraft. This is speculation on my part, but having seen the PFD myself I suspect the PF was "chasing" the ADI indication in the same way he'd follow the FD.

The key aspect is that in order to perform the correct recovery procedure, the pilot in control needs to first understand what the problem is, and then perform a recovery based on the information they receive. For whatever reason the flight crew of AF447 didn't even get to understanding the problem, and the PF's responses were instinctive and consistently reactive.

It was PNF (LHS) who was doing the flying when the Captain entered and said "Er, what are you doing" LHS continued to fly during the initial phase of three pilot command.
No, he was never in control for more than a few seconds at a time, because the traces show the PF taking back control almost immediately without announcing his intent to do so.

And remember, the STALLWARN is WARN, not STALLED, necessarily.
I'd say if it's been sounding for a minute, there's a good chance that you're in the stall regime. This is immaterial however, as there's no acknowledgement that they ever even heard it.

At one point, both sticks were to the stops, left, and the a/c was Rolled right 4 degrees, and when one stick relaxed, it immediately Rolled right to 7 degrees. I still think there was a problem with the airframe, Rudder/Lateral, that favored Right Roll, chronically.
I don't know how much more simply I can put this. Lateral control via the ailerons is not reliable when this or any other aircraft is in the stall regime. Basic aeronautics - ailerons work by directing the airflow over a section of the wing. If a wing is stalled, it cannot produce lift, ergo if an aileron encounters stalled air it will not respond as expected. This is why full stall training at PPL level has the pilot use the rudder to level the wings via the side-effect of roll if necessary.

I think it is reactionary to dismiss the possibilities of 'desperate' measures, taken by crew. Also to 'assume' 'most' displays were 'working'.
...
I would think that a fair position would be: "With so much confusion, how could the instruments possibly be working?
Simple - these were FOs trained in the glass cockpit era. Most of their airline hours have in fact been with autopilot engaged. On the occasions they've flown manually, it has been done with the FD engaged and with the speed tape on the left clearly marking the safe range. They've not done any manual handling on basic instruments in that type other than possibly in canned simulator scenarios. It's like riding a bike or playing an instrument - the knowledge will always be there, but unless it's practiced regularly you will not be able to perform at your best in a scenario where you're suddenly called upon to do so.

I believe that when he says "we don't have any displays", he is referring to the displays that he has come to rely on for the entirety of his time in manual control of that type, namely the FD and max/min speed tape. I believe that the basic instruments were still available, but that he had come to rely on the electronic guides to the point that he was afraid of having to go back to basic panel flying.

I believe that the initial NU demand was an overcorrection to the turbulence that left them a touch ND in pitch, which started a series of instinctive panic reactions, complete breakdown of instrument scan and failure to calmly assess the situation. I don't believe this was entirely his fault because he was not properly trained for the situation that confronted him.
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Old 29th Mar 2012, 02:51
  #1051 (permalink)  
 
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Dozy,
Heavens to Betsy, is this still going on?
Hell, we're just warming up!

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Old 29th Mar 2012, 03:02
  #1052 (permalink)  
 
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Lyman,

You are still concentrating on the examination at 10,000X magnification.

Does it really make a difference who was piloting the aircraft between 2 hr 11 min 00 and 2.hr 11 min 45 and which seat they were seated in? The BEA made it clear on Page 20 of IR#3 the AoA was not directly displayed to the pilots. Further, if you read Pages 29-31 you will see some of the data you say was not presented to the pilots that was presented as they referenced it in their conversations. I will let it up to you to decide which ones, although it is pretty clear.

PJ2 & RR_NDB,

You both have hit on some very important aspects of this event IMHO. The question of "Why?" is of paramount importance in problem solving any situation or event that is out of the ordinary. The machine - human interface is always an important aspect to look at and review. There is a technique to be applied when asking "Why" to get at a root cause. It is a matter of asking it five times, giving a response between each "Why". At level five is generally found to be the root cause from which corrective action can be taken. It is a process that works. However, it is more complicated when you can't interview a key person in the problem loop. When this happen, you have to make a list and go through the process. So PJ2, lets take your first question and explore: "Why, when the autopilot disconnected, and manual flying was demanded did the PF pull the sidestick back commanding a continuing climb, Why? Well, there can't be an interview, so we have to provide multiple answers for consideration:

a. He was shocked it happened, the "Startle Factor".
b. He responded based on his training and SIM experiences
c. He responded based on his recollection of the "Memory List".
d. He --- --- --- ---

For each of these you ask "Why" four more times and what you will come up with is a rather concise short list, sometimes, one item that defines the root cause. Now I can't contribute to this as only experienced personnel intimately familiar with the aircraft (the pilots) need to compile the list and ask "Why". Once you have determined (or think you have) the root cause, you can then turn the root cause over to experts to begin the process of providing the solution, along with your input as to the quality of the solution decided as being best.

A simplified example would be this:

The power failed on climb out at 1,700 feet on a Boeing 767, Delta's Flight 810 from Los Angeles to Cincinnati on June 30, 1987.
The Captain with 29 years of commercial flying experience failed to coordinate with the First Officer and reacting to an amber light, warning him of a fuel-flow problem, pulled two round knobs cutting off fuel to the plane's two engines instead of pushing square buttons two inches away that would have corrected the problem.
"Why"?
To make a long story short, he had flown the B-727 for years and had transferred to the then, new B-767. When this event occurred shortly after liftoff, he applied from his "experience and memory", without looking, exactly what was required on the B-727 but not the B-767. The initial fix was to cover the knobs and square buttons with a plastic cover that you had to "look at" to open, but the real solution was to move the engine control panel to the overhead console. Training was also found to be defective at the time at Delta regarding entry into the B-767 which was corrected.
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Old 29th Mar 2012, 03:57
  #1053 (permalink)  
 
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TD

A friend drives FBW, not Bus. He was cruisin along, sippin coffee when the a/c started a sweet turn to the right. Both pilots noticed immediately, and switched off the data drive, and flew HDG to the destination. He bird dogged the event with others in company, and no one could explain what happened. He did run across others it had happened to.

So this a/c will climb "unexpectedly" and Uncommanded, (to QUOTE Airbus) when UAS happens. Instead of "Inferring" proper instrumentation for 447, and without any conclusive rejection of "AUTOZOOM", I'd like to keep an open mind. In the meanwhile, the HF, which I have been trying to discuss (from a defensive pov, I'll admit), wants a clear and microscopic overview.

So far we have a too quick PU from RHS, a consequent loss of orientation (both airframe and crew) and that's it. This wreck can be argued to have happened within several seconds of autoflight loss, since all sense of PITCH and AOA slithered away through the fingers of our impatient pilot. POSSIBLY. The entire public perspective misses that fact. For want of a breath, and a count to five, the flight was lost. Fully half of the culpability for the crash after this time frame belongs to AF training, AIRBUS complacency and overconfidence, plus an arguably criminal case against AF for deferring a non deferrable.

I haven't even cranked up the dark field, or the scanning EM. Not to mention the gas chromatography room. Sometimes it is simple. Did I just frame the dilemma, simple to impossibly obtuse?
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Old 29th Mar 2012, 04:07
  #1054 (permalink)  
 
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Graceful Degradation of the "effective aircraft"

Hello PJ2,

Thank you for your very good answer. Sincere and constructive.

Concerning this segment:



I would like to comment something now (and think and elaborate later):

It seems very, very important to have ALWAYS available a basic set of resources in order to allow the very basic need to just aviate when facing extreme conditions. This is mandatory for a "Graceful Degradation" of the "effective aircraft" (A/C+PF/PM). The incomplete factual information we have suggests the crew may not had this may be adding to the difficult conditions they entered (by their own errors, e.g. "entering WX", lack of perception after AP and A/THR quit leading ultimately to stall, etc.). IMHO the interface design (a real challenge due the complexity of the Systems) may be improved (using lessons from this case) if the HF study being developed and the analysis shows that. The AoA indication may be a result of this process. I am not expecting the need (or possibility) of a major redesign or change in Airbus SAS FBW "protections philosophy", obviously.

Crew confusion must be examined very closely in both Phase 2 and 3. Post-pitch-up the PM was confused by the initial two very short stall warnings for example. Who knows how that may have influenced subsequent perceptions and input?
Important facts that were "important inputs" to the crew (and their perception).

It remains a concern as a former transport pilot that potentially irreversible actions were swiftly, unilaterally taken without adhering to SOPs, CRM communications standards and the handling of abnormals. Cockpit discipline and TEM (Threat/Error Management) processes are drilled into crews in each simulator session and are causes for failure of the ride if not executed to high standards. These processes intervene to prevent rushed actions while providing a basis for calm, measured and coordinated responses by both crew members. This isn't some elusive ideal, this is the normal standard by which transport aircraft are flown, so any unexpected divergence from this standard requires explanations and a willingness to closely examine crew actions where the data supports that kind of an approach. That is why I seem focused on the crew.
Well put, i agree with you. This "organizational aspect" is paramount.

I must admit your "focus" seems correct.

Please, regard my "man machine emphasis" as a very important input to the crew "output". (e.g. the stall warning system below 60kts, etc.). And very probably to be considered as a "contributing factor" in the final report.

Despite having a "technically oriented mind" () i learned very early the importance of the "organizational aspects", certainly with "higher hierarchy".
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Old 29th Mar 2012, 04:20
  #1055 (permalink)  
 
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If a pilot can follow each "degrade", well and good, otherwise "Graceful Degradation" can be a plot in the cemetery. Think about it. It sounds wonderful, but to synch each degrade with its counterpart, its replacement, describes a dance, no less. Here, the pilot should have hesitated to suss Attitude (so we are told). What was graceful about a cavalry charge, Master Caution, and a maneuvering a/c? ECAMS? Turbulence? Duff speeds? Say PF got it right, there followed three more instances of UAS, at a time when Airbus had not decided what to tell each crew. Reselect Autopilot? Or NOT? Careful, one chance only.

Arthur Murray can teach dancing in the studio, but two years hence, when the music is still, and the orchestra on leave, will John remember what to do with his hands? With his feet? Dancing is not natural to most pilots.

A fading away of a/c response must be synchronized with a building skill set from a pilot? Each gentle nuance recognized and bade farewell? It's a freaking machine. Fix the wrong stuff, train the right stuff, and let's keep moving. ffs.
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Old 29th Mar 2012, 04:20
  #1056 (permalink)  
 
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Interesting approach

Hi,

Turbine D:




Will use the tool to test with some problems.

Please, references on it. Thank you.
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Old 29th Mar 2012, 04:54
  #1057 (permalink)  
 
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The old gang comes together again, huh?

Long time, and long time for many of us.

I salute Doze for actually trying the profile in a sim, and I think that another here has access to the sim.

RR and PJ and Doze and others have conferred on PM's, so my observations are for others.

The human factor aspect of this tragedy is a big factor. Why is that, Gums?

- "You can't stall the jet, but you can overspeed the jet". Need inputs here from Okie and Rudderrat and maybe PJ2. So maybe the PF was more worried about mach than stall. And my personal choice when airspeed goes FUBAR is to not worry too much about overspeed as much as under speed. Of course, a valid AoA indication is immensely helpful, but the 'bus seems to ignore the sensors if airspeed is below "x".

Before exploring all the manuals those here have made available, I was not aware of the small AoA margin that the 'bus has between cruise and stall. I have to admit that I was shocked at the low AoA values I saw, as my experience in bent wing jets exhibited much higher AoA values before getting into trouble, the VooDoo being the big exception ( ask me about that beast offline, heh heh).

Ditto for mach limits when at 35K and above.

- The stall warning was there, but for some reason was not given attention by the crew. Did I read all those paragraphs and recordings correctly? Could they have been more concerned with overspeed than a stall? Remember, "you can't stall this jet", but there's no "protections" concerning overspeed. Hmmmm.....

- Some old pilots here harp on attitude and power to stay where you were when things went FUBAR. I am one. But seems like the jet has this auto-throttle feature, and I am not sure when the pilot can tell the "system" that throttle position commanded by the human in the cockpit should be obeyed.

Make no mistake, I flew the Viper with the electronic engine control that did things when we were real fast or slow ( not for us, but for the engine!). It was NOT an auto-throttle, and our PLA ( power lever angle) command was just that. It commanded a level of power that we mortal pilots desired/commanded.

Is there a way to tell the "system" that you want the throttle(s) to provide a direct power command and not be connected to all the flight control modes?

- "TOUCH" ----- I mean that sometimes your "touch" or your "feeling" counts as much as all the fancy indicators and displays( apologies to Doze, but trust me, I had/have touch). I flew thousands of hours with Joe Baggadonuts in three different jets and had many that could not "feel" the jet entering a stall. "Can you feel that?", I would ask. "Nope". So I then trained them to be "mechanics" and read the instruments and not horse the jet about.

I get the impression that many of the low-time 'bus drivers have never been close to overspeed or a stall. As Retired and 'bird and Smilin' and others here will attest, the plane always talks to you. The "feeling" of the jet and the gauges/indicators come together so you can confirm what your state is.

But you have to train the crews to "feel". If they can't "feel" then you must help them to interpret the gauges and such.
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Old 29th Mar 2012, 10:02
  #1058 (permalink)  
 
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Hi dozywannabe,

Good to read you back again and I agree with your post.

Additionally from the present A320 FCTM:
"The so-called "abnormal attitude" law is :
• Pitch alternate with load factor protection (without autotrim)
• Lateral direct law with yaw alternate
These laws trigger, when extreme values are reached:
• Pitch (50 ° up, 30 ° down)
• Bank (125 °)
• AOA (30 °, -10 °)
• Speed (440 kt, 60 kt)
• Mach (0.96, 0.1).
It is very unlikely that the aircraft will reach these attitudes, because fly-by-wire provides protection to ensure rapid reaction far in advance. This will minimize the effect and potential for such aerodynamic upsets.

The effectiveness of fly-by-wire architecture, and the existence of control laws, eliminate the need for upset recovery maneuvers to be trained on protected Airbus aircraft."

I think the last paragraph may have to be changed.
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Old 29th Mar 2012, 11:50
  #1059 (permalink)  
 
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Originally Posted by rudderrudderrat View Post
Good to read you back again...
Thanks, RRR - thanks guys. Although I must confess that I thought we'd be talking about something different by now and that the hamster would be having a snooze until the final report appears.

I think the last paragraph may have to be changed.
With 20/20 hindsight, I'd agree - with the caveat that the airframe never reached an orientation sufficient to trigger ABNORMAL ATTITUDE law, and to the best of my knowledge, not many have, if any. I think that the FCTM was written referring to the kind of "jet upset" that tended to happen in the early days of jet airliners, whereas what happened here was an aircraft ever-so-slightly askew but basically stable being handed to the PF, who then proceeded to control it into a stall.
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Old 29th Mar 2012, 12:53
  #1060 (permalink)  
 
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@rudderrudderrat:

Whose FCTM is this? Stating that
The effectiveness of fly-by-wire architecture, and the existence of control laws, eliminate the need for upset recovery maneuvers to be trained on protected Airbus aircraft.
is IMHO criminally negligent. FBW has known degradation and failure modes, insisting that they will always work properly when proverbial hits the fan is ignorant at the best. Chances of having to perform GPWS maneuvre in direct law are so small they can be ignored but Airbus pilot must absolutely know when to rely on protection and when it is not available.


Originally Posted by Old Carthusian
This links into what I believe are relevant cultural issues at Air France particularly in the area of crew training.
Could be but it's not necessarily so as a few AF crews have previously successfully negotiated temporary loss of all airspeeds. Question is what made crew act so differently form every other crew facing the same problem. That HF group report will be a bomb is quite safe bet.

Originally Posted by jcjeant
We certainly will have more knowledge about this accident when (if ever) the FDR DATA will be published ... instead of those graphics from the BEA belonging more to cartoons than technical graphics
(...)
I repeat ...
You have no datas in the BEA report .. only cartoon graphics ...
(...)
BEA chalkboard graphics less FDR data is partial and inaccurate information
Graphic presentation of AF447 DFDR readout is accurate, consistent and informative enough for anyone able to read it. Airline pilots of sub-average grade and above should be able to understand what is drawn. Of course, there are lot of PPRuNers who are either unable to understand BEA data or insist on misunderstanding it as graphs contravene their pet notion of Airbus being intrinsically evil. "Why" is good question.

Originally Posted by gums
From the data traces I see no extraordinary efforts by the crew to recover from a stall such as using flaps, spoilers, etc. In other words, I do not think the crew knew that the plane was fully stalled, and the control inputs do not reflect appropriate stall recovery techniques/procedures.
You are correct but it's even worse; CM2's reaction to stall warning was surprisingly consistent and fatally wrong; first time stall warning goes off as the nose is jerked up, he just keeps pulling, second time, as the energy bled off, he pulls inanely. Third and fourth times as he released the stick, AoA decreased and air data became valid again, he pulled again, sealing the flight's fate, never commenting what and why he was doing.

Originally Posted by gums
So a stall may not be easy to recognize, especially if the crew is trained that "you can't stall this airplane". FBW and "protections" for another time, another thread, IMHO.
If that's indeed so, it's a good thing there's synthetic voice shouting "STALL STALL" at A330 pilots. Cricket too.
That A330 or any other FBW Airbi cannot be stalled is severe misunderstanding and if the crew were really officially told so, then their trainers should be taken off duty until retrained. There's not magical about FBW alpha protection, it's just a mechanical-electronical device which limits pitch control in order to keep alpha below critical. Just like on 'Vark or Viper. It needs valid sensory input, computer and output to elevator. Something gets banged up in the chain - it doesn't work and it's easy to promptly see if it dropped offline, if one pays attention to his artificial horizon, that is. Nothing startrekkish about it.

Originally Posted by ChrisN
There is now much more on approach to stall/buffet (but not into stall), and emphasis on recovering controlled flight including nose down if that is what it takes, and not on minimum height loss only as it used to be.
I sincerely hope this is not the whole story.

IMHO it won't hurt to repeat what must be readily understandable to any pilot at any time of day or night: there is a whole world of difference between low and high level aerodynamic and engine performance. People who keep insisting that maybe CM2 was trying to replicate extremely low level manuever at FL330 are maybe onto something but usually go tangential when they go on blaming the training for it. For Finnegan's sake, any pilot must be fully and correctly aware at any time of what his aeroplane is capable of doing - if not, he has no business being at the controls. What was so far trained was avoidance of stall at low level because final turn stall was quite common killer and still is in the general aviation. What is commonly misunderstood in PPRuNe discussions is that airliner pilots are trained to recover from approach to stall, not fully blown stall recovery. That's because the only thing that can extract any aeroplane from low level, low energy stall is excavator.

High altitude stalls were never of concern because it was assumed that pilot would readily understand that they need to keep the speed up to avoid stall and trade altitude (of which there's abundance at typical cruise level) for speed if they got on the back of the power curve. Real life with lack of high altitude stalls seemed to confirm the notion. Than we had Pinnacle 3701. That accident was quickly forgotten as it was ferry flight, so no public outrage over passengers' deaths, and ascribed to cowboyishness of the deceased pilots. Heck, on PPRuNe there was ever-present "blame it on the technology" brigade who insisted that core-lock phenomenon was main culprit in the crash. It is correct that pilots undid themselves but they were not suicidal, they were just ignorant and that killed them. Did the powers to be push for better pilot selection and training post Pinnacle and Colgan? No. Just more hours that should serve as panacea for all the holes in the pilots' knowledge. Learn as you go.

IMHO, no amount of unusual attitude or high altitude full stall recovery training is going to prevent AF447-like (or Colgan, Armavia, Gulf Air, Ethiopian, Kenyan....) accident form recurring! We are not discussing about aeroplane being thrown form the sky with crew failing to recover, we are dealing with disoriented and confused crew that kills itself and everyone on board by doing the exactly wrong thing while believing it is right! It is not about recovery, it is about recognizing one is confused and getting to grips with reality ASAP. If this is dealt with soon enough, no radical recovery actions are needed, if not, it might be too late for airframe strength or altitude available anyway.

Originally Posted by gums
I was not aware of the small AoA margin that the 'bus has between cruise and stall. I have to admit that I was shocked at the low AoA values I saw, as my experience in bent wing jets exhibited much higher AoA values before getting into trouble, the VooDoo being the big exception ( ask me about that beast offline, heh heh).
...and yet no airliner falls from the sky because of it. There are a lot of things common to all aeroplanes but some fine details are either applicable to subsonic, stable transport, some to supersonic, maneuverable interceptor bot not to both.

there's no "protections" concerning overspeed.
Normally, there is high speed protection which, very unsurprisingly, doesn't work without valid airspeed.


But seems like the jet has this auto-throttle feature, and I am not sure when the pilot can tell the "system" that throttle position commanded by the human in the cockpit should be obeyed.
To be pedantic: it's called autothrust and unlike autothrottle doesn't have servos that physically move the trust levers. It dropped off as speed become unreliable and anyway it can be disconnected by using the red button on either thrust lever. With ATHR off, it acts just as you wrote:

our PLA ( power lever angle) command was just that. It commanded a level of power that we mortal pilots desired/commanded.
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