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Ethiopian airliner down in Africa

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Ethiopian airliner down in Africa

Old 12th Mar 2019, 16:02
  #741 (permalink)  
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Originally Posted by Speed of Sound View Post

On the subject of a 'software fix', as well as possibly feeding data from both AoA sensors to the microprocessor concurrently rather than consecutively, would adding another precondition to MCAS operation affect certification?

What I am suggesting is a >minimum altitude to be achieved before operation of the system.

The stabiliser is a very powerful control surface and having a system which can repeatedly trim the nose down at an altitude where time to recover is limited has the potential to cause more harm than it can prevent. A system which can require both pilots to simultaneously apply greater than normal elevator control added to the need for either the system to be disabled (one hand off the control column to operate two guarded switches or selection of flaps), opposing the MCAS trim by repeated manual trim control, or all three is quite frankly an ergonomic mess!

Despite the 'it wouldn't happen in a Western/white airline' nonsense we keep hearing, as many people on here have said, MCAS operates normally most of the time and even the best forewarned crew would (and should) not immediately respond to every upset as though it was an MCAS problem. Even a very quick and efficient diagnosis of the problem could still take the same length of time as it takes for the automatics to put your aircraft in a potentially fatal nose down trim. This is not primarily a training issue, it is a systems issue which Boeing now seems to be accepting despite the 'making a very safe aircraft even safer' statement.

This is a general observation, regardless of the cause of this particular incident. As mentioned above, the best time to have an AoA sensor failure is just after take off (even at night) when there are still some visual references to help you decide whether to believe either what your instruments are telling you or what you are seeing outside the cockpit.

So if we don't get a rethink of the whole system, would putting a minimum altitude requirement for its operation pass existing certification or is MCAS protection required for all phases of clean flight? As MCAS is intended to provide protection in low energy situations a great deal of thought would need to be given to how the minimum operating altitude would be determined.
Well, you wouldn't want to stall low as well. And MCAS is there bc MAX couldn't be certifed w/o it. To put it harshly, with MCAS one* dives, w/o it one* stalls.
*Applicable to some, not all pilots.
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Old 12th Mar 2019, 16:06
  #742 (permalink)  
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Originally Posted by Cows getting bigger View Post

Iím not sure theyíll be with Boeing!
According to the BBC news site:

What happens next?

The investigation will be led by Ethiopian authorities in co-ordination with teams of experts from Boeing and the US National Transportation Safety Board.
Does this mean the boxes are being processed in the US?
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Old 12th Mar 2019, 16:07
  #743 (permalink)  
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Lion Air FDR has been found on Nov 2nd and read on Nov 4h - 2 days. ET recorders were found yesterday, but LOTS of parties are VERY interested in what data they have. Is it technically possible they have been read?
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Old 12th Mar 2019, 16:07
  #744 (permalink)  
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@22/04 ... Question is if Ethiopia will take the lead or delegate the whole or part of the investigation. There was a photo with Ethiopian CAA and other investigators going aboard a plane to the location. But their labs and technical backup will probably not be sufficient to lead this one (with all due respect).
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Old 12th Mar 2019, 16:09
  #745 (permalink)  
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Originally Posted by Brake Fan View Post
It's looking like we are witnessing the first aircraft to be killed by social media since the Hindenburg.
Not quite - the EC225 suffered that fate, albeit one with the offshore industry lobby factor. Similar parallels with the UKCAA (and Norwegians) acting fairly promptly and EASA dragging its heels. The Eurocopter/Airbus strategy on dealing with that one would be a salutary lesson for Boeing.
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Old 12th Mar 2019, 16:09
  #746 (permalink)  
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Originally Posted by PaxBritannica View Post
Does this mean the boxes are being processed in the US?
Why don't you ask the Ethiopians?
It's their investigation.
They'll either want to do it in house, or somewhere else, based on their view on what gets the best results.
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Old 12th Mar 2019, 16:13
  #747 (permalink)  
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Originally Posted by PaxBritannica View Post
According to the BBC news site:[h2]

Does this mean the boxes are being processed in the US?
i read in an article yesterday that a lab in Israel may me used. Sorry I canít recall where I read that.
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Old 12th Mar 2019, 16:13
  #748 (permalink)  
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Old 12th Mar 2019, 16:13
  #749 (permalink)  
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Holland has joined in.


Is the European regulator doing this? There is also news that Turkish Airlines are grounding them (not yet confirmed).

Now confirmed: https://www.apnews.com/94c19abef66d4a0e977a1286d779ba22
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Old 12th Mar 2019, 16:14
  #750 (permalink)  
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Originally Posted by loob View Post
RE: Comments that the pilots don't know how to fly. If this was true the issue would not be concentrated on this aircraft.

RE: Comments that flights should continue until the problem is identified. This is backwards and people who believe this obviously don't understand basic risk management. The fact that you may be a pilot is irrelevant, pilots are not trained in data analysis and risk and a lot of you seem to be allowing your personal politics and biases come into your opinions.

The correct approach is to ground the craft until faults are identified, the idea that the craft should continue flying until we discover the fault is backwards and seems to be a common line of thought nowadays amongst people who like to think that they are scientific but do not understand data analysis.
Your actually outlining the real issue at hand here perfectly. The "issue" is not specific to one aircraft or one aircraft type...not even one manufacturer. It's a systemic issue based on the ever increasing demand for air travel globally and the real cost involved in properly training pilots. The current reality is that the focus is on increasingly complex automation instead of pilot training. The primary fault lies in the cockpit not in the plane itself. I've seen multiple comments on defending the FO, that's nonsensical. The issue isn't the FO it's the system that allowed him in the cockpit that is at fault.
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Old 12th Mar 2019, 16:17
  #751 (permalink)  
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Originally Posted by DaveReidUK View Post
The CAA's statement is perfectly clear. It only fails to make sense if a poster arbitrarily removes part of it:

"however, as we do not currently have sufficient information from the flight data recorder we have, as a precautionary measure, issued instructions to stop any commercial passenger flights from any operator arriving, departing or overflying UK airspace."
I could be cynical and observe that a problem that seems to manifest during the take off phase with the flaps up is now deemed to pose a risk in the landing phase with the flaps down but that is not necessarily a clear distinction in terms of do operators know what does and doesn't lead to odd inputs?
I thus appreciate that their remit has to do with public due care, etc. and thus the abundance of caution approach is understood.

(Plus, it has to take off again, doesn't it?)

Last edited by Lonewolf_50; 12th Mar 2019 at 17:09.
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Old 12th Mar 2019, 16:18
  #752 (permalink)  
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“However, the Civil Aviation Authority of the United Kingdom announced in the afternoon of March 12, 2019, that as they “do not currently have sufficient information from the flight data recorder”, a precautionary ban of the aircraft within the UK’s airspace was ordered.”


So why isn’t every aircraft type banned after an accident until there is any idea of cause?
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Old 12th Mar 2019, 16:18
  #753 (permalink)  

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Absolutely right SLFinAZ. (3 entries above) Pilot experience levels and standards are rock bottom in so many places.The poor saps simply are not trained adequately on today's complex jets. Blame the accountants, the airline management, and even the operational and training management.

It was always about making bucks. But safety used to be of paramount importance. No longer.
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Old 12th Mar 2019, 16:19
  #754 (permalink)  
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Originally Posted by ChicoG View Post
Holland has joined in.


Is the European regulator doing this? There is also news that Turkish Airlines are grounding them (not yet confirmed).
Doubt EASA will move until the curve is well ahead of them.
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Old 12th Mar 2019, 16:22
  #755 (permalink)  
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Also Italy banning the Max as of 2100 local today.
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Old 12th Mar 2019, 16:24
  #756 (permalink)  
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Originally Posted by gmx View Post
I think its important to remember that the Lion crew kept the aircraft reasonably steady for 6 minutes after MCAS issues presented, continuously and manually counteracting the MCAS nose down events that occurred during that whole time. The crew knew they had a stabilizer runaway b/c they kept using the electric trim to correct it. They kept the aircraft basically level at 5000 feet for that 6 minute duration, until, for the last four MCAS nose down commands, the crew's manual trim responses occur but are just "blipped" (not sufficient to counteract the MCAS input), and assumedly resulted in the stabilizer being full forward.

No one knows why the crew were able to successfully counteract MCAS with manual trim operation for 6 minutes, and then fail to do so for the final 4 MCAS inputs. That is the mystery that we are hoping the CVR will explain.

Lastly, as I understand it, MCAS only dials in *ONE* nose-down increment (2 degrees or whatever it is) and then deactivates itself, until something happens to reactivate MCAS allowing it to dial in another increment. I can't recall all of the crew activities that result in MCAS being reactivated, but I believe one is operation of the manual trim. This is why the last four "blipped" manual trim inputs in the Lion flight result in four unmitigated MCAS nose-down events, because any manual trim input resets MCAS and allows it to reasses the AoA / speed picture and dial in another MCAS trim input.
I remember reading that the captain transferred control after 6 minutes. He had been making large trim inputs successfully counteracting MCAS. The FO made much smaller trim inputs, so they ended up with full AND trim.

Also I think if MCAS still senses high AOA after the 5sec pause, it will make another up to 10 second trim input.

Some people say this would confuse the pilot because it is intermittent and not continuous runaway trim. I feel 10sec trim should definitely be seen by the pilot as way too long, and acted upon as runaway trim, especially if it keeps doing it repeatedly.
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Old 12th Mar 2019, 16:38
  #757 (permalink)  
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Originally Posted by 22/04 View Post
The US seems to be out of step if anything by still insisting on more experience- I am surprised commercial pressure hasn't led to the same there.
Aeroplanes must be built such that they can be flown by these crews - safely operated all over the world. As I said yesterday, I am not sure certification bodies are doing their duty here.
Standards were raised (required hours) here in the U.S. after the Colgan crash in response to a huge public outcry.
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Old 12th Mar 2019, 16:38
  #758 (permalink)  
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Originally Posted by SigWit View Post
Because this is an accident that strikes close resemblance to another very recent accident -with brand new airplanes- where a faulty system was the root cause, and that system is still not fixed.
FAA says when then new MCAS software is certified and out it shall be implemented by an AD Note. I am not sure this is the right sequence if FAA feels something is very critical. Because the interim AD had nothing in it but hot air it reads like the MCAS problem is minor. Now they say it deserves implementation of the fix by AD note not by Service Bulletin. Again, this smells and the FAA does not seem to act logical and independantly but rather as the long arm of Boeing and US commercial interests. A logical step would be a grounding order by FAA until the fix can be implemented.
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Old 12th Mar 2019, 16:39
  #759 (permalink)  
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Shame these guys didn`t monitor their speed a little better...MCAS was the result. And `rushed` in perhaps? The law of unintended consequences. Bit like the locking of flight deck door...


As I understand it, some at Boeing couldn`t understand how, with 82 knots seen during the recovery, the aeroplane didn`t crash. It was literally hanging on the engines at full power.
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Old 12th Mar 2019, 16:43
  #760 (permalink)  
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To certify a system that directly controls primary flight surfaces AND that is reliant on a single..
MCAS controls the stab trim.

Stab trim is not a primary flight control.
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