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Ethiopian Airlines Boeing 737 pilots 'could not stop nosedive'

bbc.co.uk

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Re: Ethiopian Airlines Boeing 737 pilots 'could not stop nosedive'

#221

Post by matt4077 »

Yetanfou wrote: post #177
CaptainZapp wrote: post #122

Earlier quoted context omitted.

Totally agree. Some of the sentiments expressed here was borderline racist. (badly trained, overworked cluelless third world pilots not even capable to follow a checklist). One of the worst smear jobs was actually by the New York Times accusing the captain of the Ethiopian plane not having trained in a 787-MAX simulator. Hello? Wasn't that the whole sales pitch that the plane requires no training at all for certified…

Please stop looking for racism in each and every aspect of public discourse, it does way more harm than it has the potential to do good. The harm lies in the ever larger focus on things which have the potential to divide people, be they race or sex or gender or religion or any other section. In this case there may have been a suggestion of the pilots having undergone less rigorous training and the aircraft being main…

Just check the bottom of this threat with “show all comments” enabled in your preferences.

Re: Ethiopian Airlines Boeing 737 pilots 'could not stop nosedive'

#222

Post by DigiMortal »

guylepage3 wrote: post #35

I’m a social capitalist. IMO, it seldom happens that the free market does not punish companies who make serious errors. For those times, logic, common sense & societal regulation should step in, punish the company with fines ratcheting up until free market clearly loses confidence.

The biggest issue with these massive commercial aerospace companies is a huge barrier to entry, like I can only think of Boeing and Airbus that are really legit in this space.

What these companies do/build are insanely difficult, require decades of expertise, infrastructure, so much goes into...are these institutions or companies lol

Re: Ethiopian Airlines Boeing 737 pilots 'could not stop nosedive'

#223

Post by segmondy »

I thought this was a software failure initially, but upon following the case, I have come to realize it's not. I still see plenty of people saying this is a software failure in this thread. This is not a software failure. This is a system/process failure on many level.

The plane was rushed to beat a competitor.

A mismatch between the plane & engine happened which can cause it to be off balance.

A system was added in place to correct it, but this system only used one sensor instead of 2.

The display could have displayed angle of attack which is a safety gauge, but it's optional and was charged for. $80k on a $120 million plane. It's now standard.

The display could also display a disagree light if the 2 sensors disagree, but that is also an optional feature, which will now be made standard.

The MCSA was only suppose to adjust for .5 degrees and when Boeing & FAA worked together, this was the agreed parameter, but Boeing changed it after the fact to I believe 2.5 and never informed the FAA. FAA only discovered this after the Lion crash.

This new system was not documented. It was not in the flight manual or training.

Boeing lied to pilots when they asked if there's any new system they should know about.

FAA wasn't through in certification process and allowed Boeing to sign off some things themselves.

The failure was on so many levels it's ridiculous. It's a whole collapse of a system.

Boeing, FAA, certification, QA, hardware design, etc.

If anything I won't even blame the software team much, software has no choice but to rely on the signal it's reading from the sensor if invalid. My concern is that the plane wasn't tested with faulty sensor. A happy path was followed. Testing with faulty sensor data might have shown the tug of war that would have happened between the pilot & plane. All in all, failure is across so many levels, it's terrible.

Re: Ethiopian Airlines Boeing 737 pilots 'could not stop nosedive'

#224

Post by sseth »

matt4077 wrote: post #12

I’d love to see those people who accused the airline and crew of being incompetent to apologize in the light of these reports. It was shameful to see Boeing actively encouraging that narrative behind the scenes. Especially considering it plays on racist stereotypes equating „Africa“ with bad training/bad safety record/…. The idea of „dingy third world airline“ was ridiculous on its face, considering how bad a fit fly…

Agreed.

After the Lion Air crash, Boeing basically asserted the plane was perfectly safe, and that the pilots should have followed the runaway trim process - this means turning off the electric motor which moves the trim, and having the pilots move it manually using a wheel provided for the purpose. Boeing has tried to imply that in the midst of an emergency which looks very different from a runaway trim, pilots should have followed this procedure and this was in some way their fault.

The Ethiopian Airlines crash has shown that Boeing was being disingenous. The problem is that turning off the trim motors at this stage of the flight leaves the pilots unable to move the trim fast enough manually before they crash and they are forced to switch on the electric trim - which again allows the MCAS to kick in. When pilots who are fully informed of MCAS still were unable to control the plane following Boeing's procedures then imagine the plight of the Lion Air pilots who recovered from the fault 26 times before crashing but had no idea anything called MCAS even existed. An honest admission by Boeing after the first crash would have prevented the second crash and the loss of further lives.

Re: Ethiopian Airlines Boeing 737 pilots 'could not stop nosedive'

#225

Post by treis »

mhandley wrote: post #7

Will be interesting to see the details when the report is actually public. It does sound like the scenario that Mentourpilot explored in the simulator is close to what happened, namely: Bad AoA probe causes MCAS to trim down, and also to indicate IAS disagree. Pilots increase throttle as per non-normal checklist to reduce the risk of stalling due to unreliable airspeed. Pilots disable electric stabilizer trim, as per…

>Pilots increase throttle as per non-normal checklist to reduce the risk of stalling due to unreliable airspeed. Pilots disable electric stabilizer trim, as per Boeing's advice, without trimming back to neutral trim. Pilots likely started to trim up with the manual trim wheels, but that's very slow, and gets harder as airspeed increases.

I can see that at extreme trim and high speed that it could be difficult to manually trim. What I don't see is how MCAS puts you into that situation. MCAS is supposed to be limited to 2.5 degrees (out of the ~17 degree range) change every 10 seconds. So if you identify a MCAS issue and hit the trim switch, you should still be in a relatively normal flying envelope. I find it hard to believe that manual trim is impossible then. It would have to be a monumental design flaw.

In the specific case of the Ethiopian flight, unless I'm mistaken they went through at least a couple cycles of MCAS -> Pilot Correction -> MCAS. Even if they timed their cutoff switch to the end of the MCAS cycle they should only be 2.5 degrees off where they wanted. I would be surprised if that position wouldn't be level flight let alone a situation where they can't manually trim.

I wonder if there is a second issue cropping up. The Lion Air crash saw a similar cycle of MCAS -> Pilot Correction -> MCAS that eventually stopped.

Re: Ethiopian Airlines Boeing 737 pilots 'could not stop nosedive'

#226

Post by Yetanfou »

calcifer wrote: post #202
Yetanfou wrote: post #177

Earlier quoted context omitted.

Please stop looking for racism in each and every aspect of public discourse, it does way more harm than it has the potential to do good. The harm lies in the ever larger focus on things which have the potential to divide people, be they race or sex or gender or religion or any other section. In this case there may have been a suggestion of the pilots having undergone less rigorous training and the aircraft being main…

"I don't see colour, it's not about race" said the white Western European guy...

You're implying I am 'white', 'western-European' and '[a] guy' even though this is irrelevant and there is no indication of either my race, origin or sex in my post. Please stop doing that, it only serves to create strife where no strife is needed. It is almost as if you did not read the comment you responded to or - worse - decided to ignore it because it does not fit a given narrative.

Re: Ethiopian Airlines Boeing 737 pilots 'could not stop nosedive'

#227

Post by peteradio »

Xixi wrote: post #213
peteradio wrote: post #154

Earlier quoted context omitted.

Why is nobody looking at the manufacturer of the sensor?

Disclaimer: I'm not an aeronautical engineer, just a software "engineer". But between harsh atmospheric conditions, bird strikes, hornets deciding to nest where they should not [1] and mundane human/maintenance errors, sensors can and do fail. I've been taught that reliability is not achieved by building bug-free systems on top of can-never-fail hardware. Quite the opposite actually: reliability is achieved by assumi…

Thanks that makes sense.

Re: Ethiopian Airlines Boeing 737 pilots 'could not stop nosedive'

#228

Post by treis »

phire wrote: post #178
mhandley wrote: post #7

Will be interesting to see the details when the report is actually public. It does sound like the scenario that Mentourpilot explored in the simulator is close to what happened, namely: Bad AoA probe causes MCAS to trim down, and also to indicate IAS disagree. Pilots increase throttle as per non-normal checklist to reduce the risk of stalling due to unreliable airspeed. Pilots disable electric stabilizer trim, as per…

> Now, from what I understand, appying nose-up electric trim should override MCAS, and so this course of action should be possible. I'm not so sure. Will have to wait for the final report to be sure, but I feel like the Lion Air flight should have survived if the pilot's trim up commands took priority over MCAS's trim down commands. They were fighting it with trim up commands and they lost. I fail to see how they cou…

You're right, but since 10 > 5 the pilot should always be able to "win". You can see it happening in the Lion Air flight:

https://spectrum.ieee.org/image/MzE4Mjg2OQ.jpeg

I count 20 cycles of MCAS -> Pilot correction. It's not clear why the pilots lost the 21st cycle. It could be that they stopped making corrections or another yet to be identified airplane failure.

Re: Ethiopian Airlines Boeing 737 pilots 'could not stop nosedive'

#229

Post by Tsubasachan »

Yetanfou wrote: post #177
CaptainZapp wrote: post #122

Earlier quoted context omitted.

Totally agree. Some of the sentiments expressed here was borderline racist. (badly trained, overworked cluelless third world pilots not even capable to follow a checklist). One of the worst smear jobs was actually by the New York Times accusing the captain of the Ethiopian plane not having trained in a 787-MAX simulator. Hello? Wasn't that the whole sales pitch that the plane requires no training at all for certified…

Please stop looking for racism in each and every aspect of public discourse, it does way more harm than it has the potential to do good. The harm lies in the ever larger focus on things which have the potential to divide people, be they race or sex or gender or religion or any other section. In this case there may have been a suggestion of the pilots having undergone less rigorous training and the aircraft being main…

I think a lot of people still have this idea that everyone in Africa is poor. The reality is that Africa has flagship carriers that are as old and prestigious as those found in the West and that the African economy is booming.

Re: Ethiopian Airlines Boeing 737 pilots 'could not stop nosedive'

#230

Post by JshWright »

treis wrote: post #218
JshWright wrote: post #207

Earlier quoted context omitted.

The original comment you were replying to referenced Boeing's smear of the pilots, not Lion Air the company. The pilots would have no knowledge of the first two items on your list (the ones I did not address, as they weren't relevant to the comment you were replying to). You're absolutely correct that Lion Air might have had the opportunity to prevent Boeing's design failure from bringing down this plane (this time).…

>The original comment you were replying to referenced Boeing's smear of the pilots, not Lion Air the company. I responded to: >the Lion Air crash (they were busy smearing the airline an the pilots instead) Which clearly references Lion Air the company. >You're absolutely correct that Lion Air might have had the opportunity to prevent Boeing's design failure from bringing down this plane (this time). That still leaves…

> Which clearly references Lion Air the company.

Ah, yep, I misread that (can I blame the typo...? ;) )

My point is that is that it is appropriate to call out Boeing for their attempt at deflecting blame. The pilots apparently did not take an action that _may_ have saved the plane (we now know it may not have). That doesn't change the fact that the issue they failed to correct was a faulty design in the first place, and would have resulted in a crash at some point.

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