• 1
  • 3
  • 4
  • 5
  • 6
  • 7
  • 59
 
User avatar
JetBuddy
Posts: 2246
Joined: Wed Dec 25, 2013 1:04 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Thu Oct 03, 2019 7:23 pm

morrisond wrote:
mjoelnir wrote:


So in regards to the cockpit alerting system, Boeing has not even moved the 737 to their own 1980s standard, introduced with the 757/767. Not with the advent of the NG nor with the coming of the 737MAX. Solidly stuck in the 1960s. To be able to do that, Boeing uses grandfathering and needs the FAA to relax its rules.


Talk to Boeing's biggest Customer - Southwest - they were adamant through the NG and MAX generations that not much changed.


I've read most of your posts, and you seem to want to blame anyone but Boeing. Of course Southwest told Boeing what they wanted. Yet the portion of 737 MAX going to Southwest is vanishingly small compared to the world market. And one could easily argue that Southwest would have bought whatever narrowbody Boeing produced. At least that's what has happened so far.

The responsibility for this entire mess falls squarely on Boeing - and the FAA for allowing it.
 
User avatar
par13del
Posts: 9197
Joined: Sun Dec 18, 2005 9:14 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Thu Oct 03, 2019 7:36 pm

JetBuddy wrote:
Of course Southwest told Boeing what they wanted. Yet the portion of 737 MAX going to Southwest is vanishingly small compared to the world market.

Well in that case, we could go visit any of the other threads we have on this site related to the 737 PRIOR to the MAX and you will see all of them have the same central theme, that the 737 is Jurassic and still in the 1960's with an out dated noisy cockpit with steam gauges and bulb lights because of WN. Perhaps the poster was being ironic?

However, it is funny to see all the love that the NG is getting in this thread in relation to safety, when we look at the threads about the AA and WN recent overruns, all we can hear is how unsafe the 737, its high landing speed, low to the ground etc etc etc. perhaps now they are just throwing jeers....
 
morrisond
Posts: 1650
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Thu Oct 03, 2019 7:37 pm

JetBuddy wrote:
morrisond wrote:
mjoelnir wrote:


So in regards to the cockpit alerting system, Boeing has not even moved the 737 to their own 1980s standard, introduced with the 757/767. Not with the advent of the NG nor with the coming of the 737MAX. Solidly stuck in the 1960s. To be able to do that, Boeing uses grandfathering and needs the FAA to relax its rules.


Talk to Boeing's biggest Customer - Southwest - they were adamant through the NG and MAX generations that not much changed.


I've read most of your posts, and you seem to want to blame anyone but Boeing. Of course Southwest told Boeing what they wanted. Yet the portion of 737 MAX going to Southwest is vanishingly small compared to the world market. And one could easily argue that Southwest would have bought whatever narrowbody Boeing produced. At least that's what has happened so far.

The responsibility for this entire mess falls squarely on Boeing - and the FAA for allowing it.


I basically agree with this statement along with the caveat that training needs to be looked at as well. I've said that a million times.
 
morrisond
Posts: 1650
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Thu Oct 03, 2019 8:07 pm

par13del wrote:
JetBuddy wrote:
Of course Southwest told Boeing what they wanted. Yet the portion of 737 MAX going to Southwest is vanishingly small compared to the world market.

Well in that case, we could go visit any of the other threads we have on this site related to the 737 PRIOR to the MAX and you will see all of them have the same central theme, that the 737 is Jurassic and still in the 1960's with an out dated noisy cockpit with steam gauges and bulb lights because of WN. Perhaps the poster was being ironic?

However, it is funny to see all the love that the NG is getting in this thread in relation to safety, when we look at the threads about the AA and WN recent overruns, all we can hear is how unsafe the 737, its high landing speed, low to the ground etc etc etc. perhaps now they are just throwing jeers....


You are right - the NG actually doesn't have that great a track record if you look at all the landing incidents it's involved in.

It's high landing speed is an issue (same thing is happening to A320/321 as they get heavier and wing stays the same) along with I would have to guess an over reliance on Auto throttle in trying conditions ( it not being able to compensate fast enough?) and you can see this one coming from me - more training is needed and better crew decisions need to be made to get these incidents down in number.
 
Planetalk
Posts: 451
Joined: Thu Aug 27, 2015 5:12 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Thu Oct 03, 2019 8:25 pm

morrisond wrote:
aerolimani wrote:
StTim wrote:
Why oh why are people arguing around this?
Firstly the plane as certified and delivered was flawed. That is Boeing and the FAA’s baby
Secondly the pilots might have been able to recover it if they had made different choices/had more experience/ had better training.
This thread is about the grounding to resolve the first issue. Why do we keep coming back to the second which will be covered in the specific accident reports.

Indeed. For a thread about grounding, it's astounding how few words are taken up with the discussion of the aircraft, and how many are spent on discussing the pilot's actions. It's a serious imbalance, IMO. Unfortunately, people want to shout from where they think their voice is likely to be heard by the most people. This, as opposed to exercising some self-control and posting in the correct threads. If I were a moderator, I might start sorting people's posts into the correct threads. I realize there is some blur between topics, but when we start discussing specific pilot actions of one crash or the other, then that really doesn't belong here.

Here are all the correct and still active threads:
• grounding, ungrounding, root cause of grounding: this thread: viewtopic.php?t=1432067
• pilot culpability in Lion Air crash: Lion AIr thread: viewtopic.php?t=1407217
• pilot culpability in Ethiopian AIrlines crash: Ethiopian AIrlines: viewtopic.php?t=1417519
• discussion of improved pilot training: viewtopic.php?t=1431655


If people would stop shouting that there was nothing that pilot's could have done to save the flights and that the training system is perfect and does not need to be looked as part of the un-grounding then people like myself would have no reason to post in here.


I don't think anyone is saying that, that's a strawman. I think the issue is actually that some people keep saying the same thing over and over again, without any actual evidence to justify their conjecture about the pilots actions. We know you think the pilots made flawed choices, everyone here knows it. But until the reports are released there is nowhere more for that discussion to go. As of now, you have no actual evidence the pilots made flawed choices because the reports, which will explain some of the 'why' behind their actions may refute many of your claims. Right now we only know the 'what', not the 'why'.

For instance, it appears possible the electric trim wouldn't function beyond a certain point, which would negate all the criticism of the pilots for seemingly releasing the switches too soon. Accident reports often provide explanations for seemingly inexplicable pilot actions, so its best not to jump to conclusions. Of course, it will likely find things they could have done better, but will never be able to say any other pilots in the world would have done any better. (and any pilot who says for sure they would have done better, is full of ****) So I think the issue people have is criticising the pilots' action - people who died because of Boeing's design decisions remember - when we don't even know why they made the decisions they did, and whether there may have been explanations for some of it.

I think everyone agrees more training is/was necessary, after all it was Boeing and Southwest who agreed a stitch up so that there would be no sim training and pilots weren't informed of MCAS. That wasn't the fault of either airline involved.

The only thing really known for certain is that this plane was not airworthy as it was, should not have been certified as it was (hence having certification revoked), and that the pilots were pretty much test pilots of an experimental type, the operation of which was not even correctly disclosed to the aviation regulator during certification. If additional training is required, the blame for it not having been reqired before lies with Boeing, Southwest, and the FAA (and possibly EASA depending on what emerges about what they knew, or whether they too were not given the full picture).

You may note that the plane has been grounded and the only recommendations in the preliminary report were to the airframe manufacturer, not the airline or its training.
Last edited by Planetalk on Thu Oct 03, 2019 8:32 pm, edited 3 times in total.
 
asdf
Posts: 496
Joined: Tue Mar 18, 2014 12:03 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Thu Oct 03, 2019 8:28 pm

Waterbomber2 wrote:
This is taking the proportions of a scandal, akin to VW's dieselgate.

If I were Muellenberg, I would order to stop producing MAXes and start producing B738NG's again. The B738NG may not be as competitive but at least it is a well proven design and many airlines will accept to switch back to it at the right price.


they would probably go for the NEO

boeing is doing the only possible now
play a high card
produce as many MAX as possible
every single brand new MAX increases the likelihood that the government will eventually exert political pressure to let the birds fly quickly, regardless of a fix of the problems

if its 200 MAX to reconvert to NGs boeing will have to to that
if its 2000 MAX to reconvert potus will hold his hand over boeing and there will be found a solution anyway ...


lets be clear
boeing has done NOTHING in the meantime
we all know that it isnot enough to make those AoA sensors redundant because if they dont show the same value you dont know which is true
electronic would have to quit MCAS and the plane would need to operate now outside certification parameters
this is not accaptable

and we are not even looking at the bit flip, the non usable manual trim wheel ....
 
rheinwaldner
Posts: 1790
Joined: Wed Jan 02, 2008 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Thu Oct 03, 2019 8:52 pm

Revelation wrote:
You can compare statistics from dissimilar populations all you want, but you can't reach any valid conclusions by doing so

The conclusion is absolutely valid. The MAX fleet was large enough and flew long enough to give sufficient data. You just seem to dislike the result of the calculation and the comparison.

If that does not convince you, would you agree, that we could compare the MAX just with all other aircraft two years after EIS? Do you know what? The result would not be different.

morrisond wrote:
AvroLanc wrote:
There seems to be a lot of chatter here about poor pilot skills. If this was the root cause of the accidents then length of the grounding would have been considerable shorter. If pilots had sim time and training on this I doubt these incidents would have happened. I look forward to seeing the Max back in the air soon, but it must be safe for the public and pilots.


No one is arguing it was the root cause - Bad MCAS design was the root cause - however the crashes uncovered deficiencies in training that need to be corrected as well to ensure we have the safest air system possible.

If you are flying an aircraft, that has 260 times higher crash causing failure rate than any other aircraft (for Revelation I add: all aircraft just compared over the first 2 years after EIS), there is not much realistic benefit to be gained from crew training (the so far unchallenged mathematical derivation of the figure can be read on page 2 of this thread).

Let me ask precisely: do you a) demand to reestablish and sustain the "one crash in 4.7 million flights by crew error"-figure* or do you b) demand to improve the "one crash in 4.7 million flights by crew error"-figure?
*one crash in 4.7 million flights by crew error was the 5 year global failure rate before the MAX appeared.

If a): simply fix the MAX and you will get that.
if b): a noble goal which has nothing to do with the MAX and is off topic in this thread. You could have entertained and pushed this topic all the years but you did not. Why push a huge "improve aviation safety globally"-agenda in the MAX grounding thread? Currently by far the largest leverage to improve aviation safety globally is in Boeings hand by fixing the MAX.

morrisond wrote:
If people would stop shouting that there was nothing that pilot's could have done to save the flights and that the training system is perfect and does not need to be looked as part of the un-grounding then people like myself would have no reason to post in here.

Nobody said that the pilots could not have saved the flights. Any bragging and over confident pilot off course would have been able. But saying that the pilots play no role in the MAX grounding does not contradict it. As the statistics, that I made above became evident to the regulators, the grounding became an urgent necessity and the pilot performance completely lost any priority.

The only area where more training would be warranted is more specific MAX training, but that would break Boeing's business case. And improving aviation safety beyond the "one crash in 4.7 million flights by crew error" will be unpopular in many places because it will break the business case for many companies.
Many things are difficult, all things are possible!
 
jollo
Posts: 383
Joined: Mon Aug 08, 2011 7:24 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Thu Oct 03, 2019 8:54 pm

morrisond wrote:
If people would stop shouting that there was nothing that pilot's could have done to save the flights

Really, I’ve been reading these threads for a while and I can’t remember anyone claiming that the accidents could not be avoided. On the other hand, I remember you repeating over and over that any halfway competent pilot would have found it easy, bordering on trivial, to save both flights.

morrisond wrote:
and that the training system is perfect

Ditto.

morrisond wrote:
and does not need to be looked as part of the un-grounding

Now, finally you do have a point: training will probably be an element of RTS because a 1 hour iPad presentation was clearly insufficient as difference training. On the other hand, manual flying skills and basic airmanship will hopefully get more attention and sim time globally, but they will most probably NOT play any part in the ungrounding.

morrisond wrote:
then people like myself would have no reason to post in here.

So basically you’re telling us you feel compelled to to write your repetitive posts... because of your posts. Talk about solipsism.
 
frmrCapCadet
Posts: 3219
Joined: Thu May 29, 2008 8:24 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Thu Oct 03, 2019 9:08 pm

Two planes crashed. Were both of them at overspeed? And if they were, would have cutting engine thrust back have prevented the crashes, or at least given pilots more time to regain control? Was cutting thrust back a recommendation for other versions of the 737, or was that new for the MAX?
Last edited by frmrCapCadet on Thu Oct 03, 2019 9:10 pm, edited 1 time in total.
Buffet: the airline business...has eaten up capital...like..no other (business)
 
Planetalk
Posts: 451
Joined: Thu Aug 27, 2015 5:12 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Thu Oct 03, 2019 9:09 pm

[
morrisond wrote:

Please ignore then the calls from the FAA, NTSB and Airbus that Pilot training needs to be improved.

I am not disputing that the MCAS isn't flawed it is - however what the crashes have shown is that training is lacking as well.

Under the existing standards Pilots were assumed to be able to handle an emergency of this type. Obviously they were not. Neither were they in AF447 which the NTSB singled out as Airbus not having learned lessons from that either. So you either have to change the standards (lower them) or improve the training.

It's very simple.


This post actually shows the misunderstanding that is leading to this merry go round. You say 'under existing standards pilots were assumed to be able to handle emergencies of this type'. That is absolutely not true. It was the plane that didn't meet these standards, not the pilots. It has already been stated that excessive demands were placed on the pilots i.e. beyond those required by regulations. This kind of emergency was also miscategorised in the risk analysis. That's why the plane is grounded rather than a simple AD being sent round setting out what pilots should do. That is why THE PLANE IS BEING MODIFIED SO IT MEETS THE STANDARDS. I can't believe this needs to be said.

Yes you are right, more training should have been given to pilots who were being sent on test missions on an experimental type that Boeing didn't even bother being honest with the regulator about so it could sneak MCAS through.
 
MSPNWA
Posts: 3490
Joined: Thu Apr 23, 2009 2:48 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Thu Oct 03, 2019 9:11 pm

Planetalk wrote:
I don't think anyone is saying that, that's a strawman. I think the issue is actually that some people keep saying the same thing over and over again, without any actual evidence to justify their conjecture about the pilots actions.


I agree, people are saying, without any evidence, that there was nothing the pilots should, or even could, have done to prevent the crashes and subsequent grounding. The false narrative needs to be pushed back on.

If we can't say the pilots made mistakes until the full reports are revealed, how can one say that they didn't make a mistake without breaking the same rule? How can one opinion be labelled as factually wrong and smeared - because the full reports aren't out - without being a complete hypocrite in the process? You can't.
 
frmrCapCadet
Posts: 3219
Joined: Thu May 29, 2008 8:24 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Thu Oct 03, 2019 9:20 pm

This is not excusing Boeing or anyone else involved in the two crashes. Just a damning indictment of how the modern world works, quotation is from today's Guardian.


In the US, meanwhile, it remains the case that pedestrian advocates have failed to engineer the cultural process that transforms a scattered mass of dead and injured bodies into a widely recognised problem. They have not come close. When two Boeing 737s went down, killing 346 people, it triggered multiple government investigations. Crash reconstruction and analysis experts showed up. Corporate spokespeople apologised, began handing out cheques to victims’ families and swore to do better. Journalists searched for explanations. But cars kill a 737’s worth of American pedestrians every couple of weeks. Internationally, it is more than three 737s per day. And the news cycle barely stutters.
Buffet: the airline business...has eaten up capital...like..no other (business)
 
User avatar
glideslope
Posts: 1557
Joined: Sun May 30, 2004 8:06 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Thu Oct 03, 2019 9:27 pm

MSPNWA wrote:
Planetalk wrote:
I don't think anyone is saying that, that's a strawman. I think the issue is actually that some people keep saying the same thing over and over again, without any actual evidence to justify their conjecture about the pilots actions.


I agree, people are saying, without any evidence, that there was nothing the pilots should, or even could, have done to prevent the crashes and subsequent grounding. The false narrative needs to be pushed back on.

If we can't say the pilots made mistakes until the full reports are revealed, how can one say that they didn't make a mistake without breaking the same rule? How can one opinion be labelled as factually wrong and smeared - because the full reports aren't out - without being a complete hypocrite in the process? You can't.


Disconnecting your AT is always a good starting point in a recovery.
To know your Enemy, you must become your Enemy.” Sun Tzu
 
User avatar
PixelFlight
Posts: 740
Joined: Thu Nov 08, 2018 11:09 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Thu Oct 03, 2019 9:39 pm

glideslope wrote:
Disconnecting your AT is always a good starting point in a recovery.

Why is that relevant ? In both crashes the AT disconnected itself due to the airspeed disagree caused by the left AoA failure. The stupidity of the MCAS is that it put the aircraft toward the ground precisely because of the same left AoA failure _AND_ because the AT disconnected (because of the same left AoA failure) !!! :crazy:
Strangely, at that point of the flight it was safer to stay with AT enabled to prevent MCAS action...
 
Planetalk
Posts: 451
Joined: Thu Aug 27, 2015 5:12 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Thu Oct 03, 2019 9:42 pm

MSPNWA wrote:
Planetalk wrote:
I don't think anyone is saying that, that's a strawman. I think the issue is actually that some people keep saying the same thing over and over again, without any actual evidence to justify their conjecture about the pilots actions.


I agree, people are saying, without any evidence, that there was nothing the pilots should, or even could, have done to prevent the crashes and subsequent grounding. The false narrative needs to be pushed back on.

If we can't say the pilots made mistakes until the full reports are revealed, how can one say that they didn't make a mistake without breaking the same rule? How can one opinion be labelled as factually wrong and smeared - because the full reports aren't out - without being a complete hypocrite in the process? You can't.


I don't think many people are saying that. Most people just prefer to say nothing about it until we actually know what happened in the cockpit. If some people want to question the actions and abilities of a couple of dead guys, who were asked to fly a non-airworthy plane, before those facts emerge, I'm not sure how useful that is. It certainly has no relevance to the grounding of the plane. We have at least one guy here who is still convinced the plane is only grounded because the pilots weren't good enough to meet existing standard which is complete nonsense.
 
User avatar
Revelation
Posts: 21741
Joined: Wed Feb 09, 2005 9:37 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Thu Oct 03, 2019 10:03 pm

rheinwaldner wrote:
Revelation wrote:
You can compare statistics from dissimilar populations all you want, but you can't reach any valid conclusions by doing so

The conclusion is absolutely valid. The MAX fleet was large enough and flew long enough to give sufficient data.

Justify your "big enough" and "sufficient" statements.

How many take offs and landings were in the set of all MAX flights vs the set of all flights of aircraft currently flying?

How similar is the age of MAX compared to the age of all aircraft currently flying?

Can I feel free to use A320 data the day after Habsheim to show that the Airbus A320 is a safety outlier and to project its future hull loss rate?

Am I good if I just use the first two years of A320 data after EIS to project its future hull loss rate?

It is a certified aircraft, after all.

rheinwaldner wrote:
You just seem to dislike the result of the calculation and the comparison.

Yes, I dislike correct calculations that lead to bogus projections.

rheinwaldner wrote:
If that does not convince you, would you agree, that we could compare the MAX just with all other aircraft two years after EIS? Do you know what? The result would not be different.

Correct, it would still be bogus.
Wake up to find out that you are the eyes of the world
The heart has its beaches, its homeland and thoughts of its own
Wake now, discover that you are the song that the morning brings
The heart has its seasons, its evenings and songs of its own
 
strfyr51
Posts: 3979
Joined: Tue Apr 10, 2012 5:04 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Thu Oct 03, 2019 10:36 pm

sgrow787 wrote:
Revelation wrote:
2175301 wrote:
Have you been following the "issues" that automated cars have been having during the testing and early production phase. A number of accidents where the driver did not respond fast enough to either a malfunctioning automatic system, or to a condition that the automatic system could not handle that a normal person driving a car would have avoided...

Automation is not always all it's cracked up to be...

Yes, I have followed, you can look for some posts I made to non-av about the topic.

IMO commercial aviation is a lot more amenable to automation than amateur automobiling is. FBW shows that aircraft already have all the sensors and algorithms needed for automated flight, you cannot say the same about automobiles. The aviation issues really are about resolving air space conflicts and adding in sufficient failure mode handling. That's why we read articles such as https://www.flightglobal.com/news/artic ... -o-461135/ suggesting the first step will be single pilot freighter operation:

Lohwasser says that the eventual target is for a fully-autonomous aircraft that does not require pilots. "Even in the single-pilot operating case, you have to create dual safety. Our ambition is that single-pilot operation must be safer than current aircraft."

Airbus is investigating single-pilot operation of freighter aircraft as "a stepping stone" to this arrangement on passenger aircraft, says Lohwasser. "It will not be a one-step approach [to single-pilot passenger operations]."

The link back to the MAX: Is the MAX tragedy going to be looked back as the tipping point where the mind space of the industry shifted from dallying with more automation to resolving to get to fully autonomous pilotless aircraft?

As was written by others above, this has been on the trend line, but will we look back and see the trend accelerate right about now, partially or wholly due to MAX?


So what you're saying is if Boeing had assumed dumb Pilots to begin with, they would have designed a better system - a system with two sensors instead of one. Regardless, the two crashes were because a design failed, the company that designed the system failed, the certification process overlooking that company failed, and without pilots in the planes, the two crashes would have just been less painful, as the MCAS system would have just plowed them into the ground sooner and faster.

Automation is supposed to help the pilots. Some how we jumped from that to pilots are too dumb to be trusted with essential information on flying the plane, and then jumped from that somehow to they're too dumb to fly at all when they cant save the same undocumented automation. Amazing logic there!

How Boeing Designed that system was NOT for New Pilots. They had New Program managers doing the Stupid Profit before Safety Motive, They thought they wouldn't get caught short or they would have designed it with redundancy and safeguards as had previously been the case.
 
prebennorholm
Posts: 6998
Joined: Tue Mar 21, 2000 6:25 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Thu Oct 03, 2019 11:41 pm

asdf wrote:
we all know that it is not enough to make those AoA sensors redundant because if they dont show the same value you dont know which is true
electronic would have to quit MCAS and the plane would need to operate now outside certification parameters
this is not accaptable.

I don't agree with that. Two redundant sensors is a vast improvement. When one fails, the system will know that there is a failure and automatically deactivate MCAS.

Instead of a string of confusing failure messages plus conversion into kamikaze mode, the crew will be told that there is an AoA sensor failure, so please don't do any high AoA work.

Triple sensors with voting is better than dual sensor redundancy. But if the 737 MAX ends up being re-certified with dual redundancy only, then it makes the plane safety wise on par with the industry norm, even if it theoretically may not be the world record holder as the very safest plane in the sky.

I will gladly jump on board a 737 MAX again if it has dual AoA sensing redundancy. Yes, once I was sitting on a MAX - with an only roughly 99.999% chance of surviving MCAS. I won a second life and didn't become #347. With dual redundancy I can add five more trailing 9s to that figure for identical failures not happening on both sensors on the same flight, another string of 9s for them not happening simultaneously, and a little more for them not failing in same direction and within 5.5 degrees.

And still there is 0.000000.....% chance that MCAS 2.0 will fire more than once, making it an annoyance only to the flight crew, not a kamikaze style ballistic missile.

Equipment made by humans will fail some day. We cannot avoid that. What we can avoid, that is that a failure has serious consequences. If MCAS 2.0 failure means a flight crew annoyance once every 150 million years. Instead of a kamikaze dive once every 4 months and 2 weeks. A dive which only North American pilots are good enough to control [/sarcasm]. Then I can live with MCAS 2.0. And I would assume that so can FAA, EASA, etc.
Always keep your number of landings equal to your number of take-offs
 
morrisond
Posts: 1650
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Thu Oct 03, 2019 11:59 pm

PixelFlight wrote:
glideslope wrote:
Disconnecting your AT is always a good starting point in a recovery.

Why is that relevant ? In both crashes the AT disconnected itself due to the airspeed disagree caused by the left AoA failure. The stupidity of the MCAS is that it put the aircraft toward the ground precisely because of the same left AoA failure _AND_ because the AT disconnected (because of the same left AoA failure) !!! :crazy:
Strangely, at that point of the flight it was safer to stay with AT enabled to prevent MCAS action...


You are confusing Autothrottle (AT) with Autopilot (AP).

AP disconnected but AT in ET302 stayed engaged for basically the entire flight at Full Thrust - even when it was pointed down. Not a good thing.
 
prebennorholm
Posts: 6998
Joined: Tue Mar 21, 2000 6:25 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 12:44 am

Revelation wrote:
Am I good if I just use the first two years of A320 data after EIS to project its future hull loss rate?

If you are good? It depends. If you qualify "hull loss" into "equipment failure induced hull loss", then at least you stay on topic on this thread.

In another line you mention Habsheim, another tragedy, but different since the captain went to prison for committing a long string of failures on a fully functioning plane. For obvious reason the JT and ET captains don't go to prison, and I think that there is more than that single obvious reason.
Always keep your number of landings equal to your number of take-offs
 
User avatar
Revelation
Posts: 21741
Joined: Wed Feb 09, 2005 9:37 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 1:03 am

prebennorholm wrote:
Revelation wrote:
Am I good if I just use the first two years of A320 data after EIS to project its future hull loss rate?

If you are good? It depends. If you qualify "hull loss" into "equipment failure induced hull loss", then at least you stay on topic on this thread.

Yeah, but I did the math and can show that 1/9 hull loss rate of early A320s, and so I can just project that as a thing.
Wake up to find out that you are the eyes of the world
The heart has its beaches, its homeland and thoughts of its own
Wake now, discover that you are the song that the morning brings
The heart has its seasons, its evenings and songs of its own
 
User avatar
Revelation
Posts: 21741
Joined: Wed Feb 09, 2005 9:37 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 1:44 am

mjoelnir wrote:
So in regards to the cockpit alerting system, Boeing has not even moved the 737 to their own 1980s standard, introduced with the 757/767. Not with the advent of the NG nor with the coming of the 737MAX. Solidly stuck in the 1960s. To be able to do that, Boeing uses grandfathering and needs the FAA to relax its rules.

Excuse me for working your side of the street a bit but I'm bored, and suggest you should take it one more step like Ray did:

XRAYretired wrote:
Peter Lemme has re-tweeted a conversation that confirms that the P-8 is fitted with EICAS system (by Boeing Defense, post Renton as B737-800) that probably correctly concludes the issue with fitting EICAS system to MAX is only related to it being no longer certifiable as a 737 derivative and would require significant training. the quoted $10billion cost is likely mostly projected loss of profits on sales since certification of an available military EICAS for a 737 airframe would surely not cost a massive amount as part of an existing design and certification project.

So if true it's even worse than you suggest, there was a workable version of EICAS for the 737 largely ready to go, but it didn't make it onto the airplane, presumably for the reasons being suggested, avoiding retraining costs for airlines, in turn making 737 easier for Boeing to sell to said airlines.

I looked for the tweet/retweet being referenced but could not find it.

ST says the $10B includes the cost of complying with the exempted regulations along with the cost of retraining all future MAX pilots for the differences due to such compliance.

I guess there really is a lot of story fatigue with regard to MAX, since this stuff along with the whistleblower articles really aren't attracting much attention.
Wake up to find out that you are the eyes of the world
The heart has its beaches, its homeland and thoughts of its own
Wake now, discover that you are the song that the morning brings
The heart has its seasons, its evenings and songs of its own
 
XRAYretired
Posts: 674
Joined: Fri Mar 15, 2019 11:21 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 6:59 am

Revelation wrote:
mjoelnir wrote:
So in regards to the cockpit alerting system, Boeing has not even moved the 737 to their own 1980s standard, introduced with the 757/767. Not with the advent of the NG nor with the coming of the 737MAX. Solidly stuck in the 1960s. To be able to do that, Boeing uses grandfathering and needs the FAA to relax its rules.

Excuse me for working your side of the street a bit but I'm bored, and suggest you should take it one more step like Ray did:

XRAYretired wrote:
Peter Lemme has re-tweeted a conversation that confirms that the P-8 is fitted with EICAS system (by Boeing Defense, post Renton as B737-800) that probably correctly concludes the issue with fitting EICAS system to MAX is only related to it being no longer certifiable as a 737 derivative and would require significant training. the quoted $10billion cost is likely mostly projected loss of profits on sales since certification of an available military EICAS for a 737 airframe would surely not cost a massive amount as part of an existing design and certification project.

So if true it's even worse than you suggest, there was a workable version of EICAS for the 737 largely ready to go, but it didn't make it onto the airplane, presumably for the reasons being suggested, avoiding retraining costs for airlines, in turn making 737 easier for Boeing to sell to said airlines.

I looked for the tweet/retweet being referenced but could not find it.

ST says the $10B includes the cost of complying with the exempted regulations along with the cost of retraining all future MAX pilots for the differences due to such compliance.

I guess there really is a lot of story fatigue with regard to MAX, since this stuff along with the whistleblower articles really aren't attracting much attention.

https://twitter.com/cambuntu/status/117 ... dancy.html

Try this.

Ray
 
sgrow787
Posts: 312
Joined: Fri May 16, 2014 8:12 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 8:09 am

planecane wrote:
The 767 had a completely different FCC architecture to start with. I would guess that on the 767 (I do not know this for a fact) the two AoA sensors were already checked against each other for their other functions.

It wasn't that difficult to implement the dual sensor solution on the 737 as evidenced that they had it done within a few months. The last several months of the grounding have been created by the bit flip issue causing a major architecture change in the software. The bit flip issue wouldn't have come up if they had gone 2 sensors from the beginning.


I wasn't alluding to the much different 767.

We don't know if Boeing ever formally submitted anything to the FAA to date. Just because they went out to the Boeing facility and sat down for a test drive doesn't mean a formal submittal for certification.

Major architectural change? All the software engineers on this board will tell you that means a year at least, not a few months. The likely scenario is Boeing is tweaking the cycle processing resources to accommodate the AOA data comparison and hysteresis, at the expense of decreasing the refresh of lower priority data. Expect the worse case: spaghetti code + engineers that don't have the experience or knowledge, or perhaps even any real incentive to do the job right. The longer this goes on the more it becomes time to admit defeat and start over.
Just one sensor,
Oh just one se-en-sor,
Just one sensor,
Ooh ooh oo-ooh
Oo-oo-ooh.
 
jollo
Posts: 383
Joined: Mon Aug 08, 2011 7:24 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 8:35 am

prebennorholm wrote:
I don't agree with that. Two redundant sensors is a vast improvement. When one fails, the system will know that there is a failure and automatically deactivate MCAS.

Instead of a string of confusing failure messages plus conversion into kamikaze mode, the crew will be told that there is an AoA sensor failure, so please don't do any high AoA work.

Triple sensors with voting is better than dual sensor redundancy. But if the 737 MAX ends up being re-certified with dual redundancy only, then it makes the plane safety wise on par with the industry norm, even if it theoretically may not be the world record holder as the very safest plane in the sky.
[...]
If MCAS 2.0 failure means a flight crew annoyance once every 150 million years. Instead of a kamikaze dive once every 4 months and 2 weeks. A dive which only North American pilots are good enough to control [/sarcasm]. Then I can live with MCAS 2.0. And I would assume that so can FAA, EASA, etc.


:checkmark: Well said.

A MAX with an inoperative MCAS v2 - because of a single AoA sensor failure, detected in flight through comparison with the other sensor - will NOT fall out of the sky: pilots will have to know the limits of the “MCAS-inop” safe flight envelope (no wind-up turns with an AoA disagree flag) and divert to alternate.

On the ground, a MAX with a failed AoA sensor will just stay on the ground.

Will that require new/revised NNCs and sim training?
Yes. Will that hurt despatch rate? Yes. Will that cost 10 billion $ to the industry? No.
 
uta999
Posts: 753
Joined: Mon Jun 14, 2010 11:10 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 8:36 am

Does anybody have any suggestions for Boeing for a Plan B? Something needs to be done by March 2020, otherwise the nuclear option will be upon them. Conversion back to NG and losing 50% of their order book. EIS is really no nearer than it was in March.
Your computer just got better
 
User avatar
PixelFlight
Posts: 740
Joined: Thu Nov 08, 2018 11:09 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 10:00 am

morrisond wrote:
PixelFlight wrote:
glideslope wrote:
Disconnecting your AT is always a good starting point in a recovery.

Why is that relevant ? In both crashes the AT disconnected itself due to the airspeed disagree caused by the left AoA failure. The stupidity of the MCAS is that it put the aircraft toward the ground precisely because of the same left AoA failure _AND_ because the AT disconnected (because of the same left AoA failure) !!! :crazy:
Strangely, at that point of the flight it was safer to stay with AT enabled to prevent MCAS action...


You are confusing Autothrottle (AT) with Autopilot (AP).

AP disconnected but AT in ET302 stayed engaged for basically the entire flight at Full Thrust - even when it was pointed down. Not a good thing.

Oups, you are right. My post is coherent about the Auto Pilot. The ET302 preliminary report did not have any reference to Auto Throttle, so my confusion.

But the ET302 preliminary report did contain this:

"At 05:39:42, Level Change mode was engaged. The selected altitude was 32000 ft. Shortly after the mode change, the selected airspeed was set to 238 kt"

So the pilots did correctly set the speed at a good value. This is precisely because of the left AoA failure that the throttles was still at the setting it was when the Auto Pilot disconnected because of the Speed Disagree, because of the left AoA failure.

I know it's a bit complex to understand, but the way the 737-8/9 MAX was designed produced a lots of safety consequences just from the single left AoA failure alone, and those consequences promptly puts the pilots in a situation where the established trained procedures are not enough to safely save the flight. Not that it was impossible to save the flight, but that it was not possible at the expected safety level with the established trained procedures.

1) Left AoA failure with high value -> Speed Disagree indication -> Speed Disagree procedure.

2) Left AoA failure with high value -> Speed Disagree indication -> Auto Pilot disconnect -> Throttles stay at the setting to keep 238 kt while climbing. Aircraft still climbing at that time so nothing to do.

3) Left AoA failure with high value -> Speed Disagree indication -> Auto Pilot disconnect -> Enable MCAS operation.

4) Left AoA failure with high value -> MCAS generate repetitive horizontal stabilizer fast rate trim nose down commands -> Ground Proximity Warning System “DON’T SINK” alerts. -> Stab runaway procedure.

5) Left AoA failure with high value[/b] -> MCAS generate repetitive horizontal stabilizer fast rate trim nose down commands -> attitude change from climb to descent -> speed increase with Throttles stay at the setting to keep 238 kt while climbing. -> Manual stab trim wheels unusable for the above still ongoing procedure -> crash.

My concern is that the officially published EAD did only present the analysis that contains the point 3 and part of the point 4 in the list (point 1 and 2 are not explicitly listed as a concern), while a proper analysis at that time must have see all the points in the list. Especially the point 5 that combined with the previous point create a very unusual situation far away from any trained procedure that all the contributors in this forum was able to show. Remember that it take days after the second crash before some experts did raise the possibility that the speed did play a major role in the crashes. This understanding was not available to the ET302 pilots.

The risk assessment of a left AoA failure with high value was incredibly negligent, not only at the design time, but at the certification time, and even more incredibly at the analysis that motivated the EAD.
 
XRAYretired
Posts: 674
Joined: Fri Mar 15, 2019 11:21 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 10:04 am

jollo wrote:
prebennorholm wrote:
I don't agree with that. Two redundant sensors is a vast improvement. When one fails, the system will know that there is a failure and automatically deactivate MCAS.

Instead of a string of confusing failure messages plus conversion into kamikaze mode, the crew will be told that there is an AoA sensor failure, so please don't do any high AoA work.

Triple sensors with voting is better than dual sensor redundancy. But if the 737 MAX ends up being re-certified with dual redundancy only, then it makes the plane safety wise on par with the industry norm, even if it theoretically may not be the world record holder as the very safest plane in the sky.
[...]
If MCAS 2.0 failure means a flight crew annoyance once every 150 million years. Instead of a kamikaze dive once every 4 months and 2 weeks. A dive which only North American pilots are good enough to control [/sarcasm]. Then I can live with MCAS 2.0. And I would assume that so can FAA, EASA, etc.


:checkmark: Well said.

A MAX with an inoperative MCAS v2 - because of a single AoA sensor failure, detected in flight through comparison with the other sensor - will NOT fall out of the sky: pilots will have to know the limits of the “MCAS-inop” safe flight envelope (no wind-up turns with an AoA disagree flag) and divert to alternate.

On the ground, a MAX with a failed AoA sensor will just stay on the ground.

Will that require new/revised NNCs and sim training?
Yes. Will that hurt despatch rate? Yes. Will that cost 10 billion $ to the industry? No.

Not to dampen the enthusiasm for V2.0, just a cautinary note.

The published functionality of V2.0 does not preclude or prevent the other accompanying alerts and warnings associated with AoA failed high such as single side stick shaker, Airspeed Disagree etc. So, unless there are some other, as yet, undisclosed changes, these will still occur but without the MCAS dive!

Similarly, the MAX MMEL did not allow single AoA despatch from the start, so providing the AoA failed during the previous flight leg a fault code was recorded (and MX read the fault codes in OMS) and/or the pilot notes (I assume it will still be) AOA DISAGREE in the pilots report it should be identified and fixed prior to the next flight leg. So, unless there is some other undisclosed change, this is 'as is' and AoA failed high occurring post MX action or by bird strike, will still only be detected above 400ft.

Ray
 
planecane
Posts: 1231
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 10:10 am

XRAYretired wrote:
jollo wrote:
prebennorholm wrote:
I don't agree with that. Two redundant sensors is a vast improvement. When one fails, the system will know that there is a failure and automatically deactivate MCAS.

Instead of a string of confusing failure messages plus conversion into kamikaze mode, the crew will be told that there is an AoA sensor failure, so please don't do any high AoA work.

Triple sensors with voting is better than dual sensor redundancy. But if the 737 MAX ends up being re-certified with dual redundancy only, then it makes the plane safety wise on par with the industry norm, even if it theoretically may not be the world record holder as the very safest plane in the sky.
[...]
If MCAS 2.0 failure means a flight crew annoyance once every 150 million years. Instead of a kamikaze dive once every 4 months and 2 weeks. A dive which only North American pilots are good enough to control [/sarcasm]. Then I can live with MCAS 2.0. And I would assume that so can FAA, EASA, etc.


:checkmark: Well said.

A MAX with an inoperative MCAS v2 - because of a single AoA sensor failure, detected in flight through comparison with the other sensor - will NOT fall out of the sky: pilots will have to know the limits of the “MCAS-inop” safe flight envelope (no wind-up turns with an AoA disagree flag) and divert to alternate.

On the ground, a MAX with a failed AoA sensor will just stay on the ground.

Will that require new/revised NNCs and sim training?
Yes. Will that hurt despatch rate? Yes. Will that cost 10 billion $ to the industry? No.

Not to dampen the enthusiasm for V2.0, just a cautinary note.

The published functionality of V2.0 does not preclude or prevent the other accompanying alerts and warnings associated with AoA failed high such as single side stick shaker, Airspeed Disagree etc. So, unless there are some other, as yet, undisclosed changes, these will still occur but without the MCAS dive!

Similarly, the MAX MMEL did not allow single AoA despatch from the start, so providing the AoA failed during the previous flight leg a fault code was recorded (and MX read the fault codes in OMS) and/or the pilot notes (I assume it will still be) AOA DISAGREE in the pilots report it should be identified and fixed prior to the next flight leg. So, unless there is some other undisclosed change, this is 'as is' and AoA failed high occurring post MX action or by bird strike, will still only be detected above 400ft.

Ray


Don't all of the other failures due to a single failed AoA sensor exist on every other 737 starting with the -100? Since, based on the MAX, the failure rate of an AoA sensor is relatively high, it seems that pilots must be able to deal with all the associated failures easily.
 
XRAYretired
Posts: 674
Joined: Fri Mar 15, 2019 11:21 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 10:53 am

planecane wrote:
XRAYretired wrote:
jollo wrote:

:checkmark: Well said.

A MAX with an inoperative MCAS v2 - because of a single AoA sensor failure, detected in flight through comparison with the other sensor - will NOT fall out of the sky: pilots will have to know the limits of the “MCAS-inop” safe flight envelope (no wind-up turns with an AoA disagree flag) and divert to alternate.

On the ground, a MAX with a failed AoA sensor will just stay on the ground.

Will that require new/revised NNCs and sim training?
Yes. Will that hurt despatch rate? Yes. Will that cost 10 billion $ to the industry? No.

Not to dampen the enthusiasm for V2.0, just a cautinary note.

The published functionality of V2.0 does not preclude or prevent the other accompanying alerts and warnings associated with AoA failed high such as single side stick shaker, Airspeed Disagree etc. So, unless there are some other, as yet, undisclosed changes, these will still occur but without the MCAS dive!

Similarly, the MAX MMEL did not allow single AoA despatch from the start, so providing the AoA failed during the previous flight leg a fault code was recorded (and MX read the fault codes in OMS) and/or the pilot notes (I assume it will still be) AOA DISAGREE in the pilots report it should be identified and fixed prior to the next flight leg. So, unless there is some other undisclosed change, this is 'as is' and AoA failed high occurring post MX action or by bird strike, will still only be detected above 400ft.

Ray


Don't all of the other failures due to a single failed AoA sensor exist on every other 737 starting with the -100? Since, based on the MAX, the failure rate of an AoA sensor is relatively high, it seems that pilots must be able to deal with all the associated failures easily.

Didn't say otherwise. Status quo is what I illustrated. 'Easily' is another question. There are question marks in these threads including for a few events.

NTSB have recommended a review for any other potentially hazardous/catastrophic failure modes requiring 'immediate' pilot action, when accompanied by other alerts/warnings, to be reconsidered.

Ray
 
mjoelnir
Posts: 8760
Joined: Sun Feb 03, 2013 11:06 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 10:59 am

uta999 wrote:
Does anybody have any suggestions for Boeing for a Plan B? Something needs to be done by March 2020, otherwise the nuclear option will be upon them. Conversion back to NG and losing 50% of their order book. EIS is really no nearer than it was in March.


My plan B for Boeing would be:

- Try to get the 737MAX flying with the minimum changes that FAA, EASA and so on would except as a short term solution.
- Make an agreement to rework the MAX in regards to all complaints by the FAA, EASA and so on. (I would absolutely include redoing the Manual trim, include EICAS)
- Bring the MAX 2.0.
- Bring successive all current MAX to the 2.0 standard.
- Accept, that the MAX will be different from the NG and pilots need serious training for moving from NG to MAX.
 
morrisond
Posts: 1650
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 11:09 am

PixelFlight wrote:
morrisond wrote:
PixelFlight wrote:
Why is that relevant ? In both crashes the AT disconnected itself due to the airspeed disagree caused by the left AoA failure. The stupidity of the MCAS is that it put the aircraft toward the ground precisely because of the same left AoA failure _AND_ because the AT disconnected (because of the same left AoA failure) !!! :crazy:
Strangely, at that point of the flight it was safer to stay with AT enabled to prevent MCAS action...


You are confusing Autothrottle (AT) with Autopilot (AP).

AP disconnected but AT in ET302 stayed engaged for basically the entire flight at Full Thrust - even when it was pointed down. Not a good thing.

Oups, you are right. My post is coherent about the Auto Pilot. The ET302 preliminary report did not have any reference to Auto Throttle, so my confusion.

But the ET302 preliminary report did contain this:

"At 05:39:42, Level Change mode was engaged. The selected altitude was 32000 ft. Shortly after the mode change, the selected airspeed was set to 238 kt"

So the pilots did correctly set the speed at a good value. This is precisely because of the left AoA failure that the throttles was still at the setting it was when the Auto Pilot disconnected because of the Speed Disagree, because of the left AoA failure.

I know it's a bit complex to understand, but the way the 737-8/9 MAX was designed produced a lots of safety consequences just from the single left AoA failure alone, and those consequences promptly puts the pilots in a situation where the established trained procedures are not enough to safely save the flight. Not that it was impossible to save the flight, but that it was not possible at the expected safety level with the established trained procedures.

1) Left AoA failure with high value -> Speed Disagree indication -> Speed Disagree procedure.

2) Left AoA failure with high value -> Speed Disagree indication -> Auto Pilot disconnect -> Throttles stay at the setting to keep 238 kt while climbing. Aircraft still climbing at that time so nothing to do.

3) Left AoA failure with high value -> Speed Disagree indication -> Auto Pilot disconnect -> Enable MCAS operation.

4) Left AoA failure with high value -> MCAS generate repetitive horizontal stabilizer fast rate trim nose down commands -> Ground Proximity Warning System “DON’T SINK” alerts. -> Stab runaway procedure.

5) Left AoA failure with high value[/b] -> MCAS generate repetitive horizontal stabilizer fast rate trim nose down commands -> attitude change from climb to descent -> speed increase with Throttles stay at the setting to keep 238 kt while climbing. -> Manual stab trim wheels unusable for the above still ongoing procedure -> crash.

My concern is that the officially published EAD did only present the analysis that contains the point 3 and part of the point 4 in the list (point 1 and 2 are not explicitly listed as a concern), while a proper analysis at that time must have see all the points in the list. Especially the point 5 that combined with the previous point create a very unusual situation far away from any trained procedure that all the contributors in this forum was able to show. Remember that it take days after the second crash before some experts did raise the possibility that the speed did play a major role in the crashes. This understanding was not available to the ET302 pilots.

The risk assessment of a left AoA failure with high value was incredibly negligent, not only at the design time, but at the certification time, and even more incredibly at the analysis that motivated the EAD.


Try writing a procedure for what you just wrote that can be memorized or understood in less than 10 seconds vs. just turning everything off and flying manually. Sometimes it's better just to dumb things down.

Speed was set to 238 knots in the climb to 32,000' - which if you look at the traces is = to TOGA(Full Thrust) - when AP disengaged Full thrust kept going.

I am not an expert by far - but I think I was able to point out within a few minutes of the ET302 pre-lim being published that they were going too fast.

My quote from about 30 minutes after the preliminary report was issued (or when I posted the link on these forums).

"My take on reading the accident report is that the flight was saveable until they turned the Electric Trim back on which reactivated MCAS which due to the high speed they were travelling at they were not able to recover from as the airspeed was excessive.

On Page 33 of the Accident report the Boeing Nov 6, 2018 Flight bulletin clearly says to not reengage the Electric Trim system for the remainder of the flight."

I'm sorry but if a Pilot doesn't understand that going above Vmo is a really bad thing they shouldn't be a pilot. It's almost as bad as not having enough speed/thrust.

If the thrust levers were somehow at Zero when the event started would that be Boeing's fault for not telling them to ensure that you have sufficient thrust to maintain desired speed/altitude?
 
planecane
Posts: 1231
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 11:49 am

mjoelnir wrote:
uta999 wrote:
Does anybody have any suggestions for Boeing for a Plan B? Something needs to be done by March 2020, otherwise the nuclear option will be upon them. Conversion back to NG and losing 50% of their order book. EIS is really no nearer than it was in March.


My plan B for Boeing would be:

- Try to get the 737MAX flying with the minimum changes that FAA, EASA and so on would except as a short term solution.
- Make an agreement to rework the MAX in regards to all complaints by the FAA, EASA and so on. (I would absolutely include redoing the Manual trim, include EICAS)
- Bring the MAX 2.0.
- Bring successive all current MAX to the 2.0 standard.
- Accept, that the MAX will be different from the NG and pilots need serious training for moving from NG to MAX.


Your first step is surely happening. I think the only potential "MAX 2.0" modifications that you will see (which would then be retrofitted to existing examples) would be maybe adding a 3rd AoA vane and re-wiring the cutoff switches to allow for cutting off automatic electric trim while maintaining manual electric trim.
 
User avatar
Dutchy
Posts: 10183
Joined: Sat Nov 03, 2007 1:25 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 11:56 am

With Iceland Air moving its MAX-fleet to Toulouse and Silk Air moving theirs to Australia, does this signal that these airlines don't expect them to return to service before mid-2020?
Many happy landings, greetings from The Netherlands!
 
mjoelnir
Posts: 8760
Joined: Sun Feb 03, 2013 11:06 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 11:58 am

morrisond wrote:
PixelFlight wrote:
morrisond wrote:

You are confusing Autothrottle (AT) with Autopilot (AP).

AP disconnected but AT in ET302 stayed engaged for basically the entire flight at Full Thrust - even when it was pointed down. Not a good thing.

Oups, you are right. My post is coherent about the Auto Pilot. The ET302 preliminary report did not have any reference to Auto Throttle, so my confusion.

But the ET302 preliminary report did contain this:

"At 05:39:42, Level Change mode was engaged. The selected altitude was 32000 ft. Shortly after the mode change, the selected airspeed was set to 238 kt"

So the pilots did correctly set the speed at a good value. This is precisely because of the left AoA failure that the throttles was still at the setting it was when the Auto Pilot disconnected because of the Speed Disagree, because of the left AoA failure.

I know it's a bit complex to understand, but the way the 737-8/9 MAX was designed produced a lots of safety consequences just from the single left AoA failure alone, and those consequences promptly puts the pilots in a situation where the established trained procedures are not enough to safely save the flight. Not that it was impossible to save the flight, but that it was not possible at the expected safety level with the established trained procedures.

1) Left AoA failure with high value -> Speed Disagree indication -> Speed Disagree procedure.

2) Left AoA failure with high value -> Speed Disagree indication -> Auto Pilot disconnect -> Throttles stay at the setting to keep 238 kt while climbing. Aircraft still climbing at that time so nothing to do.

3) Left AoA failure with high value -> Speed Disagree indication -> Auto Pilot disconnect -> Enable MCAS operation.

4) Left AoA failure with high value -> MCAS generate repetitive horizontal stabilizer fast rate trim nose down commands -> Ground Proximity Warning System “DON’T SINK” alerts. -> Stab runaway procedure.

5) Left AoA failure with high value[/b] -> MCAS generate repetitive horizontal stabilizer fast rate trim nose down commands -> attitude change from climb to descent -> speed increase with Throttles stay at the setting to keep 238 kt while climbing. -> Manual stab trim wheels unusable for the above still ongoing procedure -> crash.

My concern is that the officially published EAD did only present the analysis that contains the point 3 and part of the point 4 in the list (point 1 and 2 are not explicitly listed as a concern), while a proper analysis at that time must have see all the points in the list. Especially the point 5 that combined with the previous point create a very unusual situation far away from any trained procedure that all the contributors in this forum was able to show. Remember that it take days after the second crash before some experts did raise the possibility that the speed did play a major role in the crashes. This understanding was not available to the ET302 pilots.

The risk assessment of a left AoA failure with high value was incredibly negligent, not only at the design time, but at the certification time, and even more incredibly at the analysis that motivated the EAD.


Try writing a procedure for what you just wrote that can be memorized or understood in less than 10 seconds vs. just turning everything off and flying manually. Sometimes it's better just to dumb things down.

Speed was set to 238 knots in the climb to 32,000' - which if you look at the traces is = to TOGA(Full Thrust) - when AP disengaged Full thrust kept going.

I am not an expert by far - but I think I was able to point out within a few minutes of the ET302 pre-lim being published that they were going too fast.

My quote from about 30 minutes after the preliminary report was issued (or when I posted the link on these forums).

"My take on reading the accident report is that the flight was saveable until they turned the Electric Trim back on which reactivated MCAS which due to the high speed they were travelling at they were not able to recover from as the airspeed was excessive.

On Page 33 of the Accident report the Boeing Nov 6, 2018 Flight bulletin clearly says to not reengage the Electric Trim system for the remainder of the flight."

I'm sorry but if a Pilot doesn't understand that going above Vmo is a really bad thing they shouldn't be a pilot. It's almost as bad as not having enough speed/thrust.

If the thrust levers were somehow at Zero when the event started would that be Boeing's fault for not telling them to ensure that you have sufficient thrust to maintain desired speed/altitude?


Boeing was talking about, that MCAS trim was possible to be fully compensated by pulling on the yoke, it was just supposed to be a heavy pull. So you should be able to start fighting by simply pulling on the yoke and than adjusting trim. So according to Boeing, pulling back on the yoke should have enabled the crew to keep climbing.
It is just, that Boeing was not clear about how much authority the elevator gives compared to the trim on the horizontal stabiliser, the same way as Boeing was not clear about how much authority the manual trim wheel offers.
There is again the ghost of grandfathering. Boeing was able to grandfather the controls on the 737, while in reality changing it. The authority of the manual trim wheel was reduced from the original and size of the vertical stabiliser was increased, without increasing the size of the elevator and the power to move it.

You keep full tilt blaming the pilots, to minimize the part Boeing plays in this accidents.

From my view Boeing is 100 % responsible for both accidents by designing an airplane with a dangerous automatic function.

Yes, the pilots could have done better, if they would have been better trained for this failure mode on the MAX. But there again all the responsibility lies 100% with Boeing, who were hiding MCAS from customers and pilots and were selling to the airlines the promise, that only minimal training would be necessary for pilots moving from the NG to the MAX.
Last edited by mjoelnir on Fri Oct 04, 2019 12:12 pm, edited 1 time in total.
 
jollo
Posts: 383
Joined: Mon Aug 08, 2011 7:24 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 11:59 am

planecane wrote:
Don't all of the other failures due to a single failed AoA sensor exist on every other 737 starting with the -100? Since, based on the MAX, the failure rate of an AoA sensor is relatively high, it seems that pilots must be able to deal with all the associated failures easily.


Yes, but all the “other” failures (the ones NG and ancestors are vulnerable to) do not involve aggressive uncommanded control inputs, pointing the a/c to the ground just after t/o. It’s not a case of a straw that broke the camel’s back, but rather a log ...
 
User avatar
PixelFlight
Posts: 740
Joined: Thu Nov 08, 2018 11:09 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 12:00 pm

morrisond wrote:
PixelFlight wrote:
morrisond wrote:

You are confusing Autothrottle (AT) with Autopilot (AP).

AP disconnected but AT in ET302 stayed engaged for basically the entire flight at Full Thrust - even when it was pointed down. Not a good thing.

Oups, you are right. My post is coherent about the Auto Pilot. The ET302 preliminary report did not have any reference to Auto Throttle, so my confusion.

But the ET302 preliminary report did contain this:

"At 05:39:42, Level Change mode was engaged. The selected altitude was 32000 ft. Shortly after the mode change, the selected airspeed was set to 238 kt"

So the pilots did correctly set the speed at a good value. This is precisely because of the left AoA failure that the throttles was still at the setting it was when the Auto Pilot disconnected because of the Speed Disagree, because of the left AoA failure.

I know it's a bit complex to understand, but the way the 737-8/9 MAX was designed produced a lots of safety consequences just from the single left AoA failure alone, and those consequences promptly puts the pilots in a situation where the established trained procedures are not enough to safely save the flight. Not that it was impossible to save the flight, but that it was not possible at the expected safety level with the established trained procedures.

1) Left AoA failure with high value -> Speed Disagree indication -> Speed Disagree procedure.

2) Left AoA failure with high value -> Speed Disagree indication -> Auto Pilot disconnect -> Throttles stay at the setting to keep 238 kt while climbing. Aircraft still climbing at that time so nothing to do.

3) Left AoA failure with high value -> Speed Disagree indication -> Auto Pilot disconnect -> Enable MCAS operation.

4) Left AoA failure with high value -> MCAS generate repetitive horizontal stabilizer fast rate trim nose down commands -> Ground Proximity Warning System “DON’T SINK” alerts. -> Stab runaway procedure.

5) Left AoA failure with high value[/b] -> MCAS generate repetitive horizontal stabilizer fast rate trim nose down commands -> attitude change from climb to descent -> speed increase with Throttles stay at the setting to keep 238 kt while climbing. -> Manual stab trim wheels unusable for the above still ongoing procedure -> crash.

My concern is that the officially published EAD did only present the analysis that contains the point 3 and part of the point 4 in the list (point 1 and 2 are not explicitly listed as a concern), while a proper analysis at that time must have see all the points in the list. Especially the point 5 that combined with the previous point create a very unusual situation far away from any trained procedure that all the contributors in this forum was able to show. Remember that it take days after the second crash before some experts did raise the possibility that the speed did play a major role in the crashes. This understanding was not available to the ET302 pilots.

The risk assessment of a left AoA failure with high value was incredibly negligent, not only at the design time, but at the certification time, and even more incredibly at the analysis that motivated the EAD.


Try writing a procedure for what you just wrote that can be memorized or understood in less than 10 seconds vs. just turning everything off and flying manually. Sometimes it's better just to dumb things down.

Speed was set to 238 knots in the climb to 32,000' - which if you look at the traces is = to TOGA(Full Thrust) - when AP disengaged Full thrust kept going.

I am not an expert by far - but I think I was able to point out within a few minutes of the ET302 pre-lim being published that they were going too fast.

My quote from about 30 minutes after the preliminary report was issued (or when I posted the link on these forums).

"My take on reading the accident report is that the flight was saveable until they turned the Electric Trim back on which reactivated MCAS which due to the high speed they were travelling at they were not able to recover from as the airspeed was excessive.

On Page 33 of the Accident report the Boeing Nov 6, 2018 Flight bulletin clearly says to not reengage the Electric Trim system for the remainder of the flight."

I'm sorry but if a Pilot doesn't understand that going above Vmo is a really bad thing they shouldn't be a pilot. It's almost as bad as not having enough speed/thrust.

If the thrust levers were somehow at Zero when the event started would that be Boeing's fault for not telling them to ensure that you have sufficient thrust to maintain desired speed/altitude?

You even confess that you are not an expert, and what you write at that time did not explain that an excessive speed prevented the manual trim wheels to function as expected by the established procedure. My guess is that you mentioned the speed at that time only because there was an overspeed alert, and that you try, as you demonstrate since many months, to blame the pilots are every occasions with every possible arguments. You made a good guess, but without understanding why.

Now you have to understand that 'you making a good guess without understanding why' is really not an argument, nor to blame the pilots, nor to improve flight safety. There is a hug difference between "it was possible to save that flight" and "all future flights that will face that situation will remain safe". That difference include in particular the risk assessment and it's now very clear that many correctives actions was recently implemented at that level to reach the safety certification level that the 737-8/9 MAX should have from day one of commercial operation.
 
Alfons
Posts: 271
Joined: Sun Feb 03, 2013 1:17 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 12:10 pm

It's very dangerous to blame your customers. You can create a 2nd "MAX" with that behaviour, from which you will never recover from. People think here that trying to play advocate for their favorite company will help that company, but don't realize that they do exactly the opposite. Even if another culprit is responsible for 10% of a failure, you won't put 100% of your efforts on that one, as if you do that, you will fail in front of the judge.

Keep single human beings (pilots) out of the equation, if you want to help an organization to fix itself. Eveything else is short-minded.
 
planecane
Posts: 1231
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 12:13 pm

jollo wrote:
planecane wrote:
Don't all of the other failures due to a single failed AoA sensor exist on every other 737 starting with the -100? Since, based on the MAX, the failure rate of an AoA sensor is relatively high, it seems that pilots must be able to deal with all the associated failures easily.


Yes, but all the “other” failures (the ones NG and ancestors are vulnerable to) do not involve aggressive uncommanded control inputs, pointing the a/c to the ground just after t/o. It’s not a case of a straw that broke the camel’s back, but rather a log ...


I understand that. However, MCAS 2.0 removes the straw that broke the camel's back.
 
cledaybuck
Posts: 1559
Joined: Thu Aug 18, 2016 6:07 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 12:22 pm

uta999 wrote:
Does anybody have any suggestions for Boeing for a Plan B? Something needs to be done by March 2020, otherwise the nuclear option will be upon them. Conversion back to NG and losing 50% of their order book. EIS is really no nearer than it was in March.
No. There is no plan B. The only plan is to fix the MAX and get it back in the air safely ASAP.
As we celebrate mediocrity, all the boys upstairs want to see, how much you'll pay for what you used to get for free.
 
jollo
Posts: 383
Joined: Mon Aug 08, 2011 7:24 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 12:22 pm

I think the only potential "MAX 2.0" modifications that you will see (which would then be retrofitted to existing examples) would be maybe adding a 3rd AoA vane

I bet the MAX will end its service life without a 3rd AoA sensor, but I also bet it will prove safe enough with a sane control logic using both already available sensors.

and re-wiring the cutoff switches to allow for cutting off automatic electric trim while maintaining manual electric trim.

That would be an excellent move: simple (just bring back the NG’s cutout switches), cheap and probably effective. But I would make Boeing explain why they changed the stab trim a/p cut out switch function in the first place (nobody ever even suggested a possible explanation for that).
 
morrisond
Posts: 1650
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 12:50 pm

PixelFlight wrote:
morrisond wrote:
PixelFlight wrote:
Oups, you are right. My post is coherent about the Auto Pilot. The ET302 preliminary report did not have any reference to Auto Throttle, so my confusion.

But the ET302 preliminary report did contain this:


So the pilots did correctly set the speed at a good value. This is precisely because of the left AoA failure that the throttles was still at the setting it was when the Auto Pilot disconnected because of the Speed Disagree, because of the left AoA failure.

I know it's a bit complex to understand, but the way the 737-8/9 MAX was designed produced a lots of safety consequences just from the single left AoA failure alone, and those consequences promptly puts the pilots in a situation where the established trained procedures are not enough to safely save the flight. Not that it was impossible to save the flight, but that it was not possible at the expected safety level with the established trained procedures.

1) Left AoA failure with high value -> Speed Disagree indication -> Speed Disagree procedure.

2) Left AoA failure with high value -> Speed Disagree indication -> Auto Pilot disconnect -> Throttles stay at the setting to keep 238 kt while climbing. Aircraft still climbing at that time so nothing to do.

3) Left AoA failure with high value -> Speed Disagree indication -> Auto Pilot disconnect -> Enable MCAS operation.

4) Left AoA failure with high value -> MCAS generate repetitive horizontal stabilizer fast rate trim nose down commands -> Ground Proximity Warning System “DON’T SINK” alerts. -> Stab runaway procedure.

5) Left AoA failure with high value[/b] -> MCAS generate repetitive horizontal stabilizer fast rate trim nose down commands -> attitude change from climb to descent -> speed increase with Throttles stay at the setting to keep 238 kt while climbing. -> Manual stab trim wheels unusable for the above still ongoing procedure -> crash.

My concern is that the officially published EAD did only present the analysis that contains the point 3 and part of the point 4 in the list (point 1 and 2 are not explicitly listed as a concern), while a proper analysis at that time must have see all the points in the list. Especially the point 5 that combined with the previous point create a very unusual situation far away from any trained procedure that all the contributors in this forum was able to show. Remember that it take days after the second crash before some experts did raise the possibility that the speed did play a major role in the crashes. This understanding was not available to the ET302 pilots.

The risk assessment of a left AoA failure with high value was incredibly negligent, not only at the design time, but at the certification time, and even more incredibly at the analysis that motivated the EAD.


Try writing a procedure for what you just wrote that can be memorized or understood in less than 10 seconds vs. just turning everything off and flying manually. Sometimes it's better just to dumb things down.

Speed was set to 238 knots in the climb to 32,000' - which if you look at the traces is = to TOGA(Full Thrust) - when AP disengaged Full thrust kept going.

I am not an expert by far - but I think I was able to point out within a few minutes of the ET302 pre-lim being published that they were going too fast.

My quote from about 30 minutes after the preliminary report was issued (or when I posted the link on these forums).

"My take on reading the accident report is that the flight was saveable until they turned the Electric Trim back on which reactivated MCAS which due to the high speed they were travelling at they were not able to recover from as the airspeed was excessive.

On Page 33 of the Accident report the Boeing Nov 6, 2018 Flight bulletin clearly says to not reengage the Electric Trim system for the remainder of the flight."

I'm sorry but if a Pilot doesn't understand that going above Vmo is a really bad thing they shouldn't be a pilot. It's almost as bad as not having enough speed/thrust.

If the thrust levers were somehow at Zero when the event started would that be Boeing's fault for not telling them to ensure that you have sufficient thrust to maintain desired speed/altitude?

You even confess that you are not an expert, and what you write at that time did not explain that an excessive speed prevented the manual trim wheels to function as expected by the established procedure. My guess is that you mentioned the speed at that time only because there was an overspeed alert, and that you try, as you demonstrate since many months, to blame the pilots are every occasions with every possible arguments. You made a good guess, but without understanding why.

Now you have to understand that 'you making a good guess without understanding why' is really not an argument, nor to blame the pilots, nor to improve flight safety. There is a hug difference between "it was possible to save that flight" and "all future flights that will face that situation will remain safe". That difference include in particular the risk assessment and it's now very clear that many correctives actions was recently implemented at that level to reach the safety certification level that the 737-8/9 MAX should have from day one of commercial operation.



Sorry - talking about Manual trim possibly not being effective came three minutes later that day after writing that post. See post 4072 in viewtopic.php?f=3&t=1417519&p=21250347#p21250347

"The flight was okay after turning it off for several minutes - but it appears as though they flicked the switch again and turned it on (Electric Trim) which the Boeing bulletin says specifically not to do.

They probably turned on the electric system again as they couldn't trim the plane correctly as they were travelling too fast."

Sorry for the three minute delay that day to clarify what I wrote.
 
morrisond
Posts: 1650
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 12:58 pm

jollo wrote:
I think the only potential "MAX 2.0" modifications that you will see (which would then be retrofitted to existing examples) would be maybe adding a 3rd AoA vane

I bet the MAX will end its service life without a 3rd AoA sensor, but I also bet it will prove safe enough with a sane control logic using both already available sensors.

and re-wiring the cutoff switches to allow for cutting off automatic electric trim while maintaining manual electric trim.

That would be an excellent move: simple (just bring back the NG’s cutout switches), cheap and probably effective. But I would make Boeing explain why they changed the stab trim a/p cut out switch function in the first place (nobody ever even suggested a possible explanation for that).


Yes - going back to NG wiring would be a good thing.

You will have to dig for it but there was a long discussion in a previous thread on why Boeing had to wire the MAX this way. As I recall it didn't make Boeing look that good.
 
User avatar
JetBuddy
Posts: 2246
Joined: Wed Dec 25, 2013 1:04 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 1:22 pm

Revelation wrote:
mjoelnir wrote:
So in regards to the cockpit alerting system, Boeing has not even moved the 737 to their own 1980s standard, introduced with the 757/767. Not with the advent of the NG nor with the coming of the 737MAX. Solidly stuck in the 1960s. To be able to do that, Boeing uses grandfathering and needs the FAA to relax its rules.

Excuse me for working your side of the street a bit but I'm bored, and suggest you should take it one more step like Ray did:

XRAYretired wrote:
Peter Lemme has re-tweeted a conversation that confirms that the P-8 is fitted with EICAS system (by Boeing Defense, post Renton as B737-800) that probably correctly concludes the issue with fitting EICAS system to MAX is only related to it being no longer certifiable as a 737 derivative and would require significant training. the quoted $10billion cost is likely mostly projected loss of profits on sales since certification of an available military EICAS for a 737 airframe would surely not cost a massive amount as part of an existing design and certification project.

So if true it's even worse than you suggest, there was a workable version of EICAS for the 737 largely ready to go, but it didn't make it onto the airplane, presumably for the reasons being suggested, avoiding retraining costs for airlines, in turn making 737 easier for Boeing to sell to said airlines.

I looked for the tweet/retweet being referenced but could not find it.

ST says the $10B includes the cost of complying with the exempted regulations along with the cost of retraining all future MAX pilots for the differences due to such compliance.

I guess there really is a lot of story fatigue with regard to MAX, since this stuff along with the whistleblower articles really aren't attracting much attention.


This is one of the important elements of this story.

If EICAS was already developed for the P-8 (737-800) - although not FAA certified - it means implementing the original MCAS from the 767 tankers would likely have been much easier and straight forward. The $10 billion figure sounds incredibly high, even when training is included. The R&D was basically done already.

EICAS equipped 737 MAX would likely require differences training only. A 3 day course with half a day in the simulator.

Part of the $10 billion cost would have to be swallowed by the customer. I wonder if part of the cost is a calculation of how many sales would be lost due to customers choosing another type.

Another aspect of this is that Boeing could have modernized the entire flight deck further if implementing EICAS. All the grandfathered weird quirks and details in the overhead panel would no longer be necessary. The manual trim wheels might not have been necessary either.

But Boeing chose to cut corners to save costs. Southwest would likely have bought the plane regardless. American Airlines, maybe not.
 
mjoelnir
Posts: 8760
Joined: Sun Feb 03, 2013 11:06 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 1:34 pm

morrisond wrote:
PixelFlight wrote:
morrisond wrote:

Try writing a procedure for what you just wrote that can be memorized or understood in less than 10 seconds vs. just turning everything off and flying manually. Sometimes it's better just to dumb things down.

Speed was set to 238 knots in the climb to 32,000' - which if you look at the traces is = to TOGA(Full Thrust) - when AP disengaged Full thrust kept going.

I am not an expert by far - but I think I was able to point out within a few minutes of the ET302 pre-lim being published that they were going too fast.

My quote from about 30 minutes after the preliminary report was issued (or when I posted the link on these forums).

"My take on reading the accident report is that the flight was saveable until they turned the Electric Trim back on which reactivated MCAS which due to the high speed they were travelling at they were not able to recover from as the airspeed was excessive.

On Page 33 of the Accident report the Boeing Nov 6, 2018 Flight bulletin clearly says to not reengage the Electric Trim system for the remainder of the flight."

I'm sorry but if a Pilot doesn't understand that going above Vmo is a really bad thing they shouldn't be a pilot. It's almost as bad as not having enough speed/thrust.

If the thrust levers were somehow at Zero when the event started would that be Boeing's fault for not telling them to ensure that you have sufficient thrust to maintain desired speed/altitude?

You even confess that you are not an expert, and what you write at that time did not explain that an excessive speed prevented the manual trim wheels to function as expected by the established procedure. My guess is that you mentioned the speed at that time only because there was an overspeed alert, and that you try, as you demonstrate since many months, to blame the pilots are every occasions with every possible arguments. You made a good guess, but without understanding why.

Now you have to understand that 'you making a good guess without understanding why' is really not an argument, nor to blame the pilots, nor to improve flight safety. There is a hug difference between "it was possible to save that flight" and "all future flights that will face that situation will remain safe". That difference include in particular the risk assessment and it's now very clear that many correctives actions was recently implemented at that level to reach the safety certification level that the 737-8/9 MAX should have from day one of commercial operation.



Sorry - talking about Manual trim possibly not being effective came three minutes later that day after writing that post. See post 4072 in viewtopic.php?f=3&t=1417519&p=21250347#p21250347

"The flight was okay after turning it off for several minutes - but it appears as though they flicked the switch again and turned it on (Electric Trim) which the Boeing bulletin says specifically not to do.

They probably turned on the electric system again as they couldn't trim the plane correctly as they were travelling too fast."

Sorry for the three minute delay that day to clarify what I wrote.


That manual trim is not effective, has been talked about hundreds of times in this threads. There must have been an effort to not to read about it, if one followed this threads.
Again a Boeing information problem. The part about difficult manual trim, accompanied by description of the roller coaster mode, seems to have departed the manuals with the NG, when at that time Boeing made using the trim wheel still more difficult by reducing its size.
 
User avatar
PixelFlight
Posts: 740
Joined: Thu Nov 08, 2018 11:09 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 1:37 pm

morrisond wrote:
PixelFlight wrote:
morrisond wrote:

Try writing a procedure for what you just wrote that can be memorized or understood in less than 10 seconds vs. just turning everything off and flying manually. Sometimes it's better just to dumb things down.

Speed was set to 238 knots in the climb to 32,000' - which if you look at the traces is = to TOGA(Full Thrust) - when AP disengaged Full thrust kept going.

I am not an expert by far - but I think I was able to point out within a few minutes of the ET302 pre-lim being published that they were going too fast.

My quote from about 30 minutes after the preliminary report was issued (or when I posted the link on these forums).

"My take on reading the accident report is that the flight was saveable until they turned the Electric Trim back on which reactivated MCAS which due to the high speed they were travelling at they were not able to recover from as the airspeed was excessive.

On Page 33 of the Accident report the Boeing Nov 6, 2018 Flight bulletin clearly says to not reengage the Electric Trim system for the remainder of the flight."

I'm sorry but if a Pilot doesn't understand that going above Vmo is a really bad thing they shouldn't be a pilot. It's almost as bad as not having enough speed/thrust.

If the thrust levers were somehow at Zero when the event started would that be Boeing's fault for not telling them to ensure that you have sufficient thrust to maintain desired speed/altitude?

You even confess that you are not an expert, and what you write at that time did not explain that an excessive speed prevented the manual trim wheels to function as expected by the established procedure. My guess is that you mentioned the speed at that time only because there was an overspeed alert, and that you try, as you demonstrate since many months, to blame the pilots are every occasions with every possible arguments. You made a good guess, but without understanding why.

Now you have to understand that 'you making a good guess without understanding why' is really not an argument, nor to blame the pilots, nor to improve flight safety. There is a hug difference between "it was possible to save that flight" and "all future flights that will face that situation will remain safe". That difference include in particular the risk assessment and it's now very clear that many correctives actions was recently implemented at that level to reach the safety certification level that the 737-8/9 MAX should have from day one of commercial operation.



Sorry - talking about Manual trim possibly not being effective came three minutes later that day after writing that post. See post 4072 in viewtopic.php?f=3&t=1417519&p=21250347#p21250347

"The flight was okay after turning it off for several minutes - but it appears as though they flicked the switch again and turned it on (Electric Trim) which the Boeing bulletin says specifically not to do.

They probably turned on the electric system again as they couldn't trim the plane correctly as they were travelling too fast."

Sorry for the three minute delay that day to clarify what I wrote.


What I wrote is:
Remember that it take days after the second crash before some experts did raise the possibility that the speed did play a major role in the crashes. This understanding was not available to the ET302 pilots.

Your post is only after the ET302 preliminary report that was published the 04 April 2019 not after the ET302 crash the 10 March 2019. You are just more than one full month too late to save the plane !!!
 
User avatar
PW100
Posts: 3887
Joined: Mon Jan 28, 2002 9:17 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 1:40 pm

AABusDrvr wrote:
I don't understand why the Lion air crew watched the airplane trim AND 22 times, correcting with manual stab trim after every time, and then not doing the only appropriate QRH procedure. If nothing else, they should have known that if the automation keeps doing something you don't want it to do, you disconnect, or disable that system. What kind of transfer of control did they do, when the ca gave the airplane to the fo? It obviously wasn't good enough, because the fo lost control of the airplane, shortly after the ca gave it to him, after the ca did a respectable job of flying the airplane for several minutes.


They were having control problems. They knew that electric trimming was working for them. Shutting down the automation also meant taking away that one thing that was apparently working for them: manual electric trimming.

It would have been nice if they would have a shut off switch shutting down the automation, WITHOUT taking away manual electric trimming. But such option was not available to them.



AABusDrvr wrote:
MHO the ET crew wasn't flying the airplane, it was flying them. The absolutely wrong thing to do was leave the auto throttles engaged, and try and engage the autopilot. Calling "stab trim cutout" twice, and then switching off the trim cutouts isn't "preforming the NNC", it's a panic response. Unless the CVR shows a proper challenge/response, and completion of the entire procedure, then I'll gladly retract that statement.

Doesn’t such “proper challenge/response, and completion of the entire procedure” goes against the three second assumption of cutting out electric trimming/MCAS/Runaway trim NNC?
Then every memory item could be described as “panic response” (which may, ironically, very well be the correct description in stopping run-away-MCAS).



AABusDrvr wrote:
When you push out very low time pilots, with more simulator time, than actual aircraft flight time, you end up with good systems operators, that never really learned how to fly airplanes. And even the airbus can end up in a situation where it flies like every other non FBW airplane. The crowd will argue that 1500 hours in a Cessna doesn't mean anything, yes it does, it teaches you how to actually fly, not just manage automation. Both are important skills, some will argue automation management is more important in the modern airline pilot. It may be, right up to the point that the automation quits doing it's job properly, then you had better have some actual flying skills.

The very low time pilot was the one calling out for trim cut out. Which would suggest that he was rather on top of things, despite his low milage.
I have yet to see any evidence that his low time was in any way related to the accident. I’m sure though that the final report will have a chapter going into pilot performance and CRM.
Immigration officer: "What's the purpose of your visit to the USA?" Spotter: "Shooting airliners with my Canon!"
 
Alfons
Posts: 271
Joined: Sun Feb 03, 2013 1:17 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 1:44 pm

My last post has been deleted from someone. Just want to put it back down here, rewriting it a bit differently.

Sticking on the pilots as being in fault, while connecting them to a bad training, must make us have to look at the big picture.

The pilot skills are created by the airlines training qualities, which at the end are basing their training process on what the manufacturer is offering them as knowledge and toolings on their product. Or, in the case of MAX, didn't wanted to offer them.

So, going after the little fish, the pilot, just makes no sense at all, and makes us grab the snake by the wrong end. What the manufacturer offered to the airlines, is what creates the negative training quality plea. It didn't started with the airline, and for sure not the pilots.
 
User avatar
Revelation
Posts: 21741
Joined: Wed Feb 09, 2005 9:37 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 1:48 pm

JetBuddy wrote:
This is one of the important elements of this story.

If EICAS was already developed for the P-8 (737-800) - although not FAA certified - it means implementing the original MCAS from the 767 tankers would likely have been much easier and straight forward. The $10 billion figure sounds incredibly high, even when training is included. The R&D was basically done already.

EICAS equipped 737 MAX would likely require differences training only. A 3 day course with half a day in the simulator.

Part of the $10 billion cost would have to be swallowed by the customer. I wonder if part of the cost is a calculation of how many sales would be lost due to customers choosing another type.

Another aspect of this is that Boeing could have modernized the entire flight deck further if implementing EICAS. All the grandfathered weird quirks and details in the overhead panel would no longer be necessary. The manual trim wheels might not have been necessary either.

But Boeing chose to cut corners to save costs. Southwest would likely have bought the plane regardless. American Airlines, maybe not.

I don't think there is much overlap between MCAS and EICAS.

MCAS is a function of FCC (flight control computer) whereas EICAS ( https://en.wikipedia.org/wiki/Engine-in ... ing_system ) is more of a FMS (flight management system) function.

Yet there aren't many details of these black boxes in the public arena.

EICAS certainly could be used to announce the AoA Disagree quite clearly and presumably guide pilots through an electronic checklist, but would not do anything to fix the dreadful MCAS 1.0 FCC implementation.

Of course a wholesale redo of the 737 cockpit and sensors would do wonders but that's not been on the cards, because then you really do move away from the N days differences training.
Wake up to find out that you are the eyes of the world
The heart has its beaches, its homeland and thoughts of its own
Wake now, discover that you are the song that the morning brings
The heart has its seasons, its evenings and songs of its own
 
User avatar
Erebus
Posts: 1061
Joined: Tue Oct 20, 2015 2:40 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Fri Oct 04, 2019 2:02 pm

Waterbomber2 wrote:
This is taking the proportions of a scandal, akin to VW's dieselgate.

If I were Muellenberg, I would order to stop producing MAXes and start producing B738NG's again. The B738NG may not be as competitive but at least it is a well proven design and many airlines will accept to switch back to it at the right price.


Funny, you had to bring up the VW scandal. Nobody died as a result of an emissions cheating device but the US courts still took it upon themselves to dish out a $2.8 billion fine and criminally charge their (ex) CEO.

What kind of criminal consequences do you think Boeing will face for a scandal involving serious safety regulatory lapses and 346 dead? With the amount of power and influence Boeing has, I'd say it will walk away with none - "change my mind".
  • 1
  • 3
  • 4
  • 5
  • 6
  • 7
  • 59

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos