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AF 447 Thread No. 12

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AF 447 Thread No. 12

Old 26th Feb 2019, 15:31
  #1621 (permalink)  
 
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Flogging a dead horse

Oups, sorry Mods but we clearly have here a flagrant case of flogging a dead horse
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Old 27th Feb 2019, 00:42
  #1622 (permalink)  
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Conclusion

The most seminal crash ever supplanting SR111.
The case is yet to come court and with the social mayhem that rocks every France evert Saturday, at earliest will be in 2020!
A top French attorney told me (not specifically about AF447) that the longer a case gets to court, one forgets why one is in court!
Doubtlessly, the media frenzy will return and the question of Bonin's frozen licence will come to the fore as AF still refuse to release his payslips as to whether or not they tally.
An angry Father will not concede on the aforementioned.
Ipso facto, 11 years is too long and AF447 now resembles a cold case.
The pitots froze for 2 minutes but the wheels of justice still can not get any traction.
2020 is just the start but with appeals we are looking beyond 2025 not surprising that France's budget for the justice system is 1% GDP being the lowest of any G7 member.
When an air crash happens, it reflects a nation's status.
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Old 27th Feb 2019, 02:02
  #1623 (permalink)  
 
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Originally Posted by llagonne66 View Post
Oups, sorry Mods but we clearly have here a flagrant case of flogging a dead horse
I would describe it more as "foaming at the mouth" or "throwing a handfull of spaghetti at the wall and see how many noodles stick."

Coherence, on the other hand, is a stranger to W's posts.
I dropped in to see if anything new was in the offing.
Not really.
gonebutnotforgotten
or as one wise ex-boss, and very good engineer, once told me, 'this [thing] is fool proof, but it's not bloody fool proof'.
True of many aircraft. I may keep that one for future reference.

The question on this accident that concerns me most is:
Are lessons actually learned?
Is better training in play today for A330 pilots?
Do pilots better understand their aircraft systems?
Do pilots get more training time and flying time hand flying?

These would hopefully be worthwhile action items after the final report was produced.
Originally Posted by Winnerhofer
When an air crash happens, it reflects a nation's status.
I guess that the US needs to pull the plug and let itself drown in the Gulf of Mexico now that a 767 went down near Houston the other day.
Valueless spluttering like yours adds nothing to a discussion among pilots.

Last edited by Lonewolf_50; 27th Feb 2019 at 02:12.
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Old 27th Feb 2019, 13:36
  #1624 (permalink)  
 
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Lonewolf 50 et al, Re #1622: ‘The question on this accident that concerns me most is:’

Are lessons actually learned?
Depends on what is identified as a lesson and the willingness to learn.
You can always ‘find’ error, but what else might be learnt as meaningful action. Whereas the limits in certification processes - unforeseen weather threats, could be alleviated with more technology, triple systems become quadruplex (dual become triple), but at what cost.

Is better training in play today for A330 pilots?
After replacing the pitots (revised design) what do you train for, … recovery from a situation which should not reoccur.

Do pilots better understand their aircraft systems?
No, and with increasing complexity is unlikely to improve. Understanding complex systems and the consequences of rare failures challenge the fundamental limits of human performance; we are unable to deal with situations which machines cannot manage on our behalf - because we were unable to manage … …
Also consider ongoing social changes, less teaching of critical thinking, instant communication, the desire and expectation for instant answers.

Do pilots get more training time and flying time hand flying?
Why propose a ‘training’ solution for a problem which might not exist. Hand flying or not, the industry appears to be managing safety very well so far; … perhaps train for awareness, self management, and the avoidance of complacency, … if only we knew how.
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Old 6th Mar 2019, 22:11
  #1625 (permalink)  
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Indeed.
Did you know that NONE of the BEA's recommendations have been implemented?!
A total disgrace!
So that means the accident costed hundreds of millions, 228 lives lost for nothing...
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Old 6th Mar 2019, 22:35
  #1626 (permalink)  
 
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What would you expect from the french?
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Old 7th Mar 2019, 09:34
  #1627 (permalink)  
 
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Originally Posted by testpanel View Post
What would you expect from the french?
Most of the recommendations were to EASA and/or ICAO, so the implementation is not under the control of the French.
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Old 7th Mar 2019, 13:15
  #1628 (permalink)  
 
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Winnerhofer,
You may have overlooked section 5 ‘Changes made since the accident’ page 215.
Also, perhaps misinterpreting the context of a recommendation, including ‘review’ and ‘evaluate’.
The report is published according to ICAO Annex 13. Specific points can be directed to the aircraft certification authority, or the operations regulator; elsewhere a wider view is given e.g. EASA / FAA.

A significant weakness in the overall safety process is the time delay both in reporting and implementation, the judgement of cost effectiveness against the continuing risk (e.g. pitots fixed), or how to validate the effectiveness of intervention.
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Old 13th Mar 2019, 21:35
  #1629 (permalink)  
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https://www.aerotime.aero/aerotime.t...ed-with-boeing

Air France 777 captain appears to misunderstand how the Airbus works. His statement "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."

Autotrim only serves to align the elevators with the stabilizer. In Normal and Alternate laws it has NO EFFECT on how the airplane feels or behaves. In the flight control law where AF447 found itself (ALT2) and the sidestick demands g-load. As a result, it's basically a point and PROT) the stick changes from g-load demand to full back law the hard protection is replaced (due to various failures) with a "stability", which is the airplane's natural aerodynamic stability to pitch down when very slow.

However, the transition from g-load to stability mode is based on indicated airspeed. In the case of AF447, the airspeeds were rejected by the flight control computers because it had become unreliable due to the pitot tube issues. This left the airplane in full-time g-load demand.

When at least 2 of 3 airspeed sources were deemed unreliable, the autopilot disconnected. This dropped the job of hand flying the airplane into the laps of the unsuspecting and very-soon-to-by confused pilots, when they least expected it, and probably least prepared to handle it. "Startle factor" is the term used here that describes their diminished mental capacity to perform.

He said "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)." This is not correct. At least not for the fist full minute with the stall warning going off. All they had to do initially was to point the airplane down. It did not require any trim action. Now later on, when the angle of attack was extremely high (>45°) and the trim was full nose up, my own tests indicate that manually reducing the nose-up trim may have been required for a successful recovery from the 20,000 ft/min descent they put themselves in.

But instead of nose-down input, which would have worked, they instituted the only stall recovery action they apparently remembered: full power. Except at cruise altitude, they were pretty much already af full power and the extremely minor amount of power still left would produce no results.

Unfortunately, Bonin's initial actions on the stick (be then intentional or as a consequence of something else) were to pitch the airplane up. But the airplane's neutral stability allowed the nose to just stay there.

It did not require trim to hold it there. That was its job. If he had pulled it back and then just let go completely, the result would have been much the same. The lack of the low-speed stability meant that as the airplane approached the stall AOA, there was nothing to pitch it down except the pilot - who was probably trying to follow the ever-reliable flight director which was telling him to continue the climb.

As the airplane began to stall and lose lift, the airplane started to sink, and thus the actual g-load was reduced. The airplane responded to this less-than-demanded g load with all it had at its disposal to increase the g load: Up Elevator. This obviously just made things worse and within a few seconds, the angle of attack increased to 45° and more (though the pitch attitude remained at 15° or less).

What this required from the start was for the pilot flying to FLY THE AIRPLANE. That is, command a pitch and power setting commensurate with level flight (2.5° & 83% N1). Any pitch and power setting remotely close would have kept the crew out of trouble for a long time. It only took about 40 seconds for all of the pitot tube issues to resolve themselves, and they could have been on their merry way like the dozens of other crews that employed that strategy in similar circumstances. However, by the time the pitot tubes were clear, the flight was in a far worse position, having climbed 3000 feet and lost over 100 knots of indicated airspeed. A recovery at this point required far greater skill than the minimal skill required to fly straight and level just 60 seconds earlier that they failed to exhibit.

It is further interesting to note that Airbus seems to have taken this accident to heart in the design of the A350. It has extremely robust airspeed backups (even if all pitot tubes become unusable), and Alternate law maintains all of the same hard protections as Normal law (assuming the physical flight control surfaces are not damaged beyond carrying them out). Further, the autopilot remains engaged in an extended envelope (right up to the abnormal attitude parameters (120° bank, 50° pitch, etc) So, in this case, the AP/FD would not have disengaged at all.
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Old 14th Mar 2019, 09:05
  #1630 (permalink)  
 
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Interest of quoting this paper almost one year after its distribution?
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Old 14th Mar 2019, 22:08
  #1631 (permalink)  
 
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Salute!

It's called ET 302 and serious Boeing problems.

Gums...
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Old 15th Mar 2019, 13:12
  #1632 (permalink)  
 
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Not sure that the causes of these two accidents are the same or even similar. In fact, I am almost sure that they are not for a lot of reasons, such as phase of the flight including altitude, day/night, mature aircraft ...
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Old 15th Mar 2019, 15:43
  #1633 (permalink)  
 
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.....Both with planes perfect flyable, both with banal sensor malfunctions, both with inappropriate responses from PF, both with crews untrained for those flight circumstances, both with manufacturers purposefully understating training requirements (do you remember the concierge ?) both with aeronautical authorities closing eyes at serious things for industry's sake......., and comparable number of deaths!
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Old 15th Mar 2019, 16:53
  #1634 (permalink)  
 
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It is my understanding that the A350 also no longer has the autotrim function in alternate law, is that correct?
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Old 16th Mar 2019, 16:26
  #1635 (permalink)  
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I will not comment on the technicalities of both accidents , not my area of expertise. although looking from the outside that is a lot of preventable accidents happening due of the failure of one sensor , or of one instrument/IRU ( i.e west air sweden ) and inability of crew to recognise it.
Whether it is a design issue , a training one, or other I leave the discussion to you guys.
But on the French Judiciary system , I agree with W. it is a scandal . Last week the trial of the people responsible for the collapse of CDG Terminal 2E , took place, that is 14 years after the event !
The worse ( that i know of) is the UTA DC10 bombing/accident that took place in 1989 in the Libyan desert. The last appeal , closing the case was done in 2008 , almost 20 years after the event , and the suspected perpetrator , a Libyan national. received a pre-trial in Tripoli in 2013 , still awaiting the full trial, we are now 30 years later..
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Old 21st Apr 2019, 21:34
  #1636 (permalink)  
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https://www.telecablesat.fr/actus/31...-le-crash.html

New documentary out on 31 May 2019
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Old 17th May 2019, 17:02
  #1637 (permalink)  
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From AF447 to AI447
What if the cockpit stall warning had said, “Pierre-Cédric (the co-pilot primarily responsible for pitching the plane’s nose upward for the entire six minutes) you are ignoring my warning that the plane is in a stall and losing altitude. Please take immediate corrective action by pitching the nose down or give me control so that I can rectify the situation.”

https://www.innovationexcellence.com...-intelligence/
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Old 17th May 2019, 17:09
  #1638 (permalink)  
 
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Originally Posted by Winnerhofer View Post
From AF447 to AI447
What if the cockpit stall warning had said, “Pierre-Cédric (the co-pilot primarily responsible for pitching the plane’s nose upward for the entire six minutes) you are ignoring my warning that the plane is in a stall and losing altitude. Please take immediate corrective action by pitching the nose down or give me control so that I can rectify the situation.”
They'd have all still died, since auto pilot was off due to airspeed unreliable .. pitot tube icing. So Pierre-Cedric "gives" the plane to an autopilot that has already gone on holiday.
W, sometimes I wonder if you only post after a few pints.

Last edited by Lonewolf_50; 17th May 2019 at 22:32.
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Old 17th May 2019, 22:13
  #1639 (permalink)  
 
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Originally Posted by Lonewolf_50 View Post
They'd have all still died, since auto pilot was off due to airspeed unreliable .. pitot tube icing. So Pierre-Cedric "gives" the plane to an autopilot that has already gone on holiday.
W, sometimes I wonder if you onlly post after a few pints.
You on the other hand are a little malicious , since we all know very well that the autopilot it's only one of HAL's avatars on the flight deck
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Old 17th May 2019, 22:29
  #1640 (permalink)  
 
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@alexd10, there is no value accrued to encouraging a bloviating fool to post on Tech Log, but there may be some value in discouraging the same.

You get what you incentivize, condone, and encourage. Psychology 101.

(and yes, on the technical side, you are correct. Brevity in this case was being used to respond to low quality garbage.)
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