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zhetenyi1973
Posts: 18
Joined: Thu Apr 04, 2019 7:08 pm

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:17 pm

What I don't understand why there is no MCAS trim down action for a considerable time. Shouldn't we see MCAS activation during this time without the trim movement?
It happened once why did it not happen after that? Also, why did the crew not trim back to 5 units? Why did they stop at 2.3 before cutout? Can it be they thought 2.3 was 5?
 
Jetty
Posts: 1286
Joined: Wed Nov 11, 2015 12:27 pm

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:17 pm

morrisond wrote:
No they did not have proper control of the aircraft. That is basic aviation 101. They had a system (Electric Trim) that wasn't acting as they expected it too - they had no idea why it wasn't acting as it should but the first reaction should have been to turn it off - just like any system that wasn't acting properly.

If the Autopilot was turning you 90 degrees in the wrong direction would you keep using it turning yourself back on course 22 times or turn it off?

If you did not have the comfort to turn it off you shouldn't be in the cockpit. It should not be an unrealistic expectation that a commercial airplane pilot can fly the plane manually with no electronic helpers - that is why we have pilots to take over when the systems fail - through bad design or outright failure just because sometimes things break - which can and will happen no matter how well a system is designed or made fault tolerant.

Yes the MAX has a systems problem that doesn't appear to be fault tolerant enough - however MCAS was basically designed to help pilots with poor piloting skills from entering a stall.

Both MAX's crashed due to inadequate basic training - they were both perfectly capable of flying in Manual mode. Even if you didn't know about MCAS (understandable on Lionair -inexcusable on the ET flight) - any reasonably competent Pilot should have been able to realize that a system wasn't doing what it was supposed to and turn it off.

Have we really entered the realm of it's always the planes fault and never the Pilot's?

:o Seems you were as wrong as could be. We have entered the realm of you consistently finding excuses for the badly designed MAX and never taking responsibility for the spreading of misinformation, even after you've been proven wrong.
 
kalvado
Posts: 2853
Joined: Wed Mar 01, 2006 4:29 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:17 pm

fabian9 wrote:
morrisond wrote:
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.


I can’t find the part of the report that says the electronic trim was switched back on. Could you point me at it?

PS: I posted this question earlier, but I think it got deleted.

If you look at reply 4114 by patplan (or the graph itself: https://ibb.co/yQ0KbRN ), there are FDR graphs - and around 05.43.20 there is an automatic trim down command with actual pitch trim occuring. THis is possible only if switches were re-engaged. Earlier trim commands at 05.40.40 did not produce any trim action, e.g. switches were likely off.
You don't really need to read the report to see that.
 
Morvious
Posts: 657
Joined: Sat Feb 19, 2005 8:36 pm

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:23 pm

hivue wrote:
2175301 wrote:
They did not have sufficient surplus altitude AGL to sacrifice.


This.

Combined with a plane trimming itself towards the ground every few seconds that last thing on earth you think of is sacrificing altitude.

They never had much of a chance.
have a good day,

HereThen
 
hivue
Posts: 2078
Joined: Tue Feb 26, 2013 2:26 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:28 pm

fabian9 wrote:
I can’t find the part of the report that says the electronic trim was switched back on. Could you point me at it?


No. There is no such part. You have to read between the lines.
"You're sitting. In a chair. In the SKY!!" ~ Louis C.K.
 
dragon6172
Posts: 1128
Joined: Sat Jul 14, 2007 9:56 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:29 pm

hivue wrote:
litz wrote:
And that's the saddest thing of all right there ... both of these crashes would never have happened had the crew simply re-extended the flaps,and returned for an emergency landing.


The ET crew could not have deployed flaps at the kinds of airspeeds they were traveling. As I said in a post up-thread, it looks like they were caught in an awful trap. How much of that was due to MCAS and how much to crew actions is yet to be determined.

Stick shaker was active with diverging airspeeds and altitudes between the two sides for at least a minute before the flaps were raised. Probably in the future would be best to leave the flaps out in that scenario to keep MCAS out of the loop.

mzlin wrote:
What's doubly odd is there was no callout by either pilot asking or confirming reactivation of electrical trim power. There was also no callout or confirmation of the use of manual electrical trim. So it makes me wonder if one pilot reactivated electrical trim without notifying the other, and if the same pilot also did not realize that they would then have to counter MCAS with manual electrical trim. This may then be very much like the Lion Air situation where the caption countered MCAS with manual electrical trim to keep neutral trim 20 times, then passed control over to the FO, who then only countered MCAS with single manual inputs which were insufficient to keep trim at neutral, allowing MCAS to push trim to the fully down position.

The report doesn't say there was a callout for turning the trim back on, that does not mean there wasn't one. And I don't mean that in a way that implies the authorities are trying to hide it.

Planetalk wrote:
So to sum up the key action of the pilots as compared to the checklist.

- They did trim up to counter the MCAS movement before hitting the trim cutout switch.
- They did try to use manual trim as the procedure states when they still couldn't control the aircraft.
- Manual trim didn't work.

What exactly could they have done except reengage electric trim at this point? Note the checklist has now ended. The same checklist various posters insisted the pilots obviously hadn't followed.

They didn't trim to counter MCAS before using the cutout switch. At least not equally.
-MCAS trimmed down 4.6 to 2.1 units
-Pilot trimmed up 2.1 to 2.4 units
-MCAS trimmed down 2.4 to 0.4 units
-Pilot trimmed up 0.4 to 2.3 units
-Switches moved to cutout
As you see... still 2.3 units short of where they started, requiring excessive control forces to maintain level flight. Probably have to be spelled out even more clearly to use electric trim to return the aircraft to an "in trim" state before using cutout switches.
Phrogs Phorever
 
mzlin
Posts: 128
Joined: Sat Mar 31, 2012 6:32 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:34 pm

patplan wrote:
ET-AVJ Preliminary Accident Report, pp26-27

..
Image
..
..
Image


This is consistent with what I suggested earlier. At 05:43:00, the flight was doing okay, the the pilots apparently have saved the flight from the initial MCAS malfunction. They then turned electrical trim power back on and made a small upward manual electrical trim input at 05:43:15, but then failed to counteract the erroneous MCAS nose-down commands after 5:43:20. If they had either (1) not turned electrical trim back on sometime right before 05:43:15, or (2) continued to use manual electrical trim inputs to counteract the erroneous MCAS nose-down commands after 05:43:20, the flight could have eventually been controlled (after reducing airspeed) and brought back to the airport.

The pilots did things correctly until 05:43:00 but then they made the mistake of not counteracting MCAS after 05:43:20. And as stated above, I suspect one pilot acted alone to turn on electrical trim because there was no verbal discussion or callout or confirmation. (This would then be a CRM issue.) And whoever switched it on may not have realized that MCAS would come back. And finally neither pilot noticed the trim moving back down.
 
morrisond
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Joined: Thu Jan 07, 2010 12:22 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:34 pm

Eyad89 wrote:
2175301 wrote:
Condolences to the families of all involved: Here is my understanding of what happened.

1) The pilots correctly cut out electric trim controls; at which point they could manually fly the aircraft in a somewhat stable configuration, and apparently were doing so with difficulties.

2) Key difficulty is that they were already over the speed envelope of the aircraft - which made manual trim control very difficult (if not impossible).

A likely - although unnatural solution would have been to reduce thrust and slow the aircraft down - and sacrifice altitude in the process to regain usability of the manual trim. Given they were at about 14,000 ft already that would be a scary thought; not to mention all the other distractions in the cockpit at the time. Unless you trained repeatedly in how to slow an aircraft down that was above flight envelope speed this would not likely occur to the pilots.

3) The evidence strongly suggest that they re-powered the electric trim in an attempt to regain control as they then imputed manual electric trim commands that worked... and an automatic MCAS trim down command also worked - which put the aircraft into a final dive.

The full report may identify other things and will likely identify other factors. While some may claim that the aircraft was saveable with manual flying (it likely was with the right person who innately understood some things); I would not expect an average pilot to have figured out to slow the aircraft down and sacrifice altitude to allow manual trim wheels to work again; especially in the time allowed.

Keep in mind that Sully was a very experienced glider pilot and was used to non-powered landings. He innately did some things that most pilots would not.

Have a great day,


+1


This explanation is my understanding as well however I will differ on the interpretation of #2.

I would not want to be in any Aircraft that was piloted by a Pilot that was not capable of pulling the power back to reduce speed below the max limits - they way above above stall speed at 94% Power ( at least 100 knots). You do not need 94% power to maintain level flight at 14,000. According to the 737 Memory list (which pilots are required to memorize - and remember there are two of them - one should have remembered) - if faced with unreliable airspeed set power to 75% - they practice this in the simulator (or are supposed to).

The unnatural thing would to keep the thrust levers where they were.

They initially saved it (Hats off to them) however they then allowed a perfectly controllable aircraft with Manual controls get outside the flight envelope - in this case excess speed.

Do I feel bad about the Pilots and the loss of life - Yes

However I am lot more angry at the fact that professional pilot standards are this low.
 
XRAYretired
Posts: 870
Joined: Fri Mar 15, 2019 11:21 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:35 pm

Jetty wrote:
PixelFlight wrote:
At 05:38:44, shortly after liftoff, the left and right recorded AOA values deviated. Left AOA
decreased to 11.1° then increased to 35.7° while value of right AOA indicated 14.94°. Then after, the
left AOA value reached 74.5° in 3⁄4 seconds while the right AOA reached a maximum value of 15.3°.

Which shows that the plane didn't even need to compare the 2 AoA sensors to establish a malfunction. Such quick changes are impossible and should never be relied upon to automatically adjust the trim in any decently designed plane even with only 1 sensor present. And if one AoA sensor provides logical outputs and the other does not it should have been plain obvious to rely on the sensor that makes sense, no need to disable MCAS in that scenario as Boeing is planning to do with the software update.

I would argue that the described MCAS fix is competent and accounts for this failure condition and all the other failure conditions you have not considered here.

Ray
 
kalvado
Posts: 2853
Joined: Wed Mar 01, 2006 4:29 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:35 pm

dragon6172 wrote:
As you see... still 2.3 units short of where they started, requiring excessive control forces to maintain level flight. Probably have to be spelled out even more clearly to use electric trim to return the aircraft to an "in trim" state before using cutout switches.

Which basically means runaway trim procedure is irrelevant, MCAS is NOT a runaway trim, and that escalates all the way to new type rating. Tough choices.
 
Etheereal
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:37 pm

PixelFlight wrote:
At 05:43:20, approximately five seconds after the last manual electric trim input, an AND automatic
trim command occurred and the stabilizer moved in the AND direction from 2.3 to 1.0 unit in
approximately 5 seconds. The aircraft began pitching nose down. Additional simultaneous aft
column force was applied, but the nose down pitch continues, eventually reaching 40° nose down.
The stabilizer position varied between 1.1 and 0.8 units for the remainder of the recording.


So the pilots re-enabled the switches, trimmed manually to get their desired pitch, and then forgot to disconnect them again after MCAS trimmed down again?

Also, that recording shows they used Column which has been stated at some point here that has insufficient authority compared to nose trim wheel.
 
rideforever
Posts: 23
Joined: Mon Mar 11, 2019 1:06 pm

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:40 pm

One AoA vane look like it is stuck and no longer varies.
It's a pretty simply type of error that they system could not cope with.
Isn't there supposed to be some superior "processing" to detect AoA problems ?
 
tphuang
Posts: 5209
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:40 pm

I love all the armchair QB dissecting all of the pilots possible mistakes from the comfort of their home computer without impending death facing them.
 
Leung
Posts: 1
Joined: Thu Apr 04, 2019 6:46 pm

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:41 pm

Hi, Long term lurker posting for the first time.
Horrible reading the preliminary report, looks like the pilot's tried their best and applied the correct process but to no avail.

Couple of comments/questions on the report.
Looks like at 5:40:12 the pilots trimmed to level flight WHILST holding control column back. (trim pos 2.3). Then they cut out the stab trim.

Should they have actually kept commanding manual electric trim ANU and gradually released control column back to neutral? so that trim position would have been roughly 5?

If they had control column back from 5:40:42 to 5:43:11 would that have put enough force on the stabiliser to gradually mechanically move the pitch position down from 2.3 to 2.1?

Also asking a stupid question, Is it possible to stall the stabiliser without stalling the wing?
Maybe stall the airflow over the section that has the elevators?
An AND stabiliser movement with a localised stall over the elevator would suddenly give a big nose over command?
 
mzlin
Posts: 128
Joined: Sat Mar 31, 2012 6:32 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:43 pm

Etheereal wrote:
PixelFlight wrote:
At 05:43:20, approximately five seconds after the last manual electric trim input, an AND automatic
trim command occurred and the stabilizer moved in the AND direction from 2.3 to 1.0 unit in
approximately 5 seconds. The aircraft began pitching nose down. Additional simultaneous aft
column force was applied, but the nose down pitch continues, eventually reaching 40° nose down.
The stabilizer position varied between 1.1 and 0.8 units for the remainder of the recording.


So the pilots re-enabled the switches, trimmed manually to get their desired pitch, and then forgot to disconnect them again after MCAS trimmed down again?

Also, that recording shows they used Column which has been stated at some point here that has insufficient authority compared to nose trim wheel.


Yes but as I explain above I think it wasn't "the pilots" who re-enabled the switches. I think it was "a pilot", because there was no callout and no verbal confirmation, so I think one pilot acted alone. After that, he could have continued to use the manual electric trim to counteract MCAS, but didn't. And I wonder if the other pilot didn't even know electric trim was back on. Would be interesting to know which column (left or right) put in the manual commands at 05:43:15.
Last edited by mzlin on Thu Apr 04, 2019 8:08 pm, edited 1 time in total.
 
mzlin
Posts: 128
Joined: Sat Mar 31, 2012 6:32 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:44 pm

tphuang wrote:
I love all the armchair QB dissecting all of the pilots possible mistakes from the comfort of their home computer without impending death facing them.


Actually we do like to do that, because we are interested in learning more about civil aviation, including understanding the risks involved when getting on an airplane, and that is why we are on this site.
Last edited by mzlin on Thu Apr 04, 2019 7:45 pm, edited 1 time in total.
 
mazdaman007
Posts: 1
Joined: Sun Jul 08, 2018 11:16 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:45 pm

tphuang wrote:
I love all the armchair QB dissecting all of the pilots possible mistakes from the comfort of their home computer without impending death facing them.


It truly is disgusting.
 
hivue
Posts: 2078
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:45 pm

mzlin wrote:
This is consistent with what I suggested earlier. At 05:43:00, the flight was doing okay, the the pilots apparently have saved the flight from the initial MCAS malfunction. They then turned electrical trim power back on and made a small upward manual electrical trim input at 05:43:15,


I don't think they would have touched the stab trim switches again unless they were getting desperate.
"You're sitting. In a chair. In the SKY!!" ~ Louis C.K.
 
fabian9
Posts: 64
Joined: Thu Mar 29, 2007 5:27 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:47 pm

zuckie13 wrote:
1) Why did they not reduce thrust?


Would a reduction in thrust not initially result in a further pitch down moment on the aircraft as this is effectively a rear wards change in thrust below the centre of lift?

Kind of in the opposite sense of direction of increasing thrust last when performing a stall recovery manoeuvre so as to not induce a positive pitch up moment?
 
mzlin
Posts: 128
Joined: Sat Mar 31, 2012 6:32 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:48 pm

hivue wrote:
mzlin wrote:
This is consistent with what I suggested earlier. At 05:43:00, the flight was doing okay, the the pilots apparently have saved the flight from the initial MCAS malfunction. They then turned electrical trim power back on and made a small upward manual electrical trim input at 05:43:15,


I don't think they would have touched the stab trim switches again unless they were getting desperate.


I think it may not have been desperation. They were already at 13000 feet, their selected attitude. They probably felt safe. A clue comes from the transcript; the captain asks if manual trim is working, and the FO replies no. Afterwards, sometime before 05:43:15, someone flips on the electrical power to the trim, but without any verbalization. A reasonable explanation would be that person wanted to get control over the trim, but didn't realize the MCAS problem would come back.
Last edited by mzlin on Thu Apr 04, 2019 7:50 pm, edited 3 times in total.
 
morrisond
Posts: 2731
Joined: Thu Jan 07, 2010 12:22 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:48 pm

Jetty wrote:
morrisond wrote:
No they did not have proper control of the aircraft. That is basic aviation 101. They had a system (Electric Trim) that wasn't acting as they expected it too - they had no idea why it wasn't acting as it should but the first reaction should have been to turn it off - just like any system that wasn't acting properly.

If the Autopilot was turning you 90 degrees in the wrong direction would you keep using it turning yourself back on course 22 times or turn it off?

If you did not have the comfort to turn it off you shouldn't be in the cockpit. It should not be an unrealistic expectation that a commercial airplane pilot can fly the plane manually with no electronic helpers - that is why we have pilots to take over when the systems fail - through bad design or outright failure just because sometimes things break - which can and will happen no matter how well a system is designed or made fault tolerant.

Yes the MAX has a systems problem that doesn't appear to be fault tolerant enough - however MCAS was basically designed to help pilots with poor piloting skills from entering a stall.

Both MAX's crashed due to inadequate basic training - they were both perfectly capable of flying in Manual mode. Even if you didn't know about MCAS (understandable on Lionair -inexcusable on the ET flight) - any reasonably competent Pilot should have been able to realize that a system wasn't doing what it was supposed to and turn it off.

Have we really entered the realm of it's always the planes fault and never the Pilot's?

:o Seems you were as wrong as could be. We have entered the realm of you consistently finding excuses for the badly designed MAX and never taking responsibility for the spreading of misinformation, even after you've been proven wrong.


Where do you get that from? Where was I wrong? How was ET302 not controllable in Manual Mode assuming the pilots stayed within the flight envelope?

It appears as though ET302 crashed due to excessive airspeed where manual trim was not usable and turning Electric trim back on. The first a failure in basic training - the second should been imprinted on there brains from the November bulletin - don't turn the Electric Trim back on. If they hadn't turned it back on they might have finally thought of reducing airspeed (they had several minutes to think of this and the overspeed warning combined with monitoring the backup instrument should have given them a clue - and if that wasn't working the memory procedure was to set power to 75% N1 when airspeed was unreliable anyways) where the manual trim wheel would have become usable again.

All a chain of very unfortunate events - a very bad design for a system that wasn't really needed (MCAS - unintended consequences of possible Over regulation ), followed by failure to keep the airplane within the flight envelope once they had reestablished basic control which led to them trying what they could (turning the electric trim back on).

If they had reduced thrust to 0 and pulled the column all the way back and the plane fell out of the sky would that be the planes fault?
 
kalvado
Posts: 2853
Joined: Wed Mar 01, 2006 4:29 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:49 pm

mzlin wrote:
tphuang wrote:
I love all the armchair QB dissecting all of the pilots possible mistakes from the comfort of their home computer without impending death facing them.


Actually we do like to do that, because we are interested in learning more about civil aviation, including understanding the risks involved when getting on an airplane, and that is why we are on this site.

There is a difference between looking at what was done, what could be done, and understanding why things went wrong; and plainly blaming pilots for "doing stupid things"
It is OK - actually its a must - to learn on other's mistakes. Blaming people for mistakes in critical situation - especially if they have no chance to respond - is stupid at best.
 
morrisond
Posts: 2731
Joined: Thu Jan 07, 2010 12:22 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:50 pm

fabian9 wrote:
zuckie13 wrote:
1) Why did they not reduce thrust?


Would a reduction in thrust not initially result in a further pitch down moment on the aircraft as this is effectively a rear wards change in thrust below the centre of lift?

Kind of in the opposite sense of direction of increasing thrust last when performing a stall recovery manoeuvre so as to not induce a positive pitch up moment?


According to 737 pilots on another forum - this effect would be very-very minor - plus you would unload the stabilizer making easier to pull back to offset the slight nose down.
 
mzlin
Posts: 128
Joined: Sat Mar 31, 2012 6:32 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:53 pm

kalvado wrote:
mzlin wrote:
tphuang wrote:
I love all the armchair QB dissecting all of the pilots possible mistakes from the comfort of their home computer without impending death facing them.


Actually we do like to do that, because we are interested in learning more about civil aviation, including understanding the risks involved when getting on an airplane, and that is why we are on this site.

There is a difference between looking at what was done, what could be done, and understanding why things went wrong; and plainly blaming pilots for "doing stupid things"
It is OK - actually its a must - to learn on other's mistakes. Blaming people for mistakes in critical situation - especially if they have no chance to respond - is stupid at best.


Agreed, which is why I and others posting about facts and mechanisms haven't used the words stupid or blame. In fact I did a search and couldn't find the word "stupid" until your post, so that appears to be a bit of a straw man. Whereas some people seem to find posting of facts and reasoning offensive and have used words like disgusting or made judgements like armchair quarterbacking.

Can we get back to trying to figure out how to improve machine and training without some people attacking rational analysis please?
 
Etika
Posts: 31
Joined: Wed Mar 13, 2019 8:14 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:58 pm

morrisond wrote:
Eyad89 wrote:
2175301 wrote:
Condolences to the families of all involved: Here is my understanding of what happened.

1) The pilots correctly cut out electric trim controls; at which point they could manually fly the aircraft in a somewhat stable configuration, and apparently were doing so with difficulties.

2) Key difficulty is that they were already over the speed envelope of the aircraft - which made manual trim control very difficult (if not impossible).

A likely - although unnatural solution would have been to reduce thrust and slow the aircraft down - and sacrifice altitude in the process to regain usability of the manual trim. Given they were at about 14,000 ft already that would be a scary thought; not to mention all the other distractions in the cockpit at the time. Unless you trained repeatedly in how to slow an aircraft down that was above flight envelope speed this would not likely occur to the pilots.

3) The evidence strongly suggest that they re-powered the electric trim in an attempt to regain control as they then imputed manual electric trim commands that worked... and an automatic MCAS trim down command also worked - which put the aircraft into a final dive.

The full report may identify other things and will likely identify other factors. While some may claim that the aircraft was saveable with manual flying (it likely was with the right person who innately understood some things); I would not expect an average pilot to have figured out to slow the aircraft down and sacrifice altitude to allow manual trim wheels to work again; especially in the time allowed.

Keep in mind that Sully was a very experienced glider pilot and was used to non-powered landings. He innately did some things that most pilots would not.

Have a great day,


+1


This explanation is my understanding as well however I will differ on the interpretation of #2.

I would not want to be in any Aircraft that was piloted by a Pilot that was not capable of pulling the power back to reduce speed below the max limits - they way above above stall speed at 94% Power ( at least 100 knots). You do not need 94% power to maintain level flight at 14,000. According to the 737 Memory list (which pilots are required to memorize - and remember there are two of them - one should have remembered) - if faced with unreliable airspeed set power to 75% - they practice this in the simulator (or are supposed to).

The unnatural thing would to keep the thrust levers where they were.

They initially saved it (Hats off to them) however they then allowed a perfectly controllable aircraft with Manual controls get outside the flight envelope - in this case excess speed.

Do I feel bad about the Pilots and the loss of life - Yes

However I am lot more angry at the fact that professional pilot standards are this low.


You are considering one malfunction at time, not the complete picture. And that makes you ignore important threats that the pilots had to evaluate and avoid.

Namely, at that point when reduction of power could be considered the PF is already pulling back on the stick with near full force to keep the plane on level flight. Reducing the power at that point would cause additional nose-down momentum. Thus, there is a very real risk that reducing the thrust at that pint would have caused the total nose-down momentum to exceed the ability of the pilots to counteract it by pulling back on the stick. At the very least, that is a threat that would be in their mind.

Thus, to the pilots it might well be impossible to reduce the thrust before they somehow get the trim back up enough to restore adequate margin to be able to counteract the nose-down momentum that reducing the thrust would cause.

Regardless of the real amount of nose-down momentum caused, they were near the limit of what they could pull via stick, so even a slight nose-down momentum might be enough to overwhelm their control. At the very least, they would have been unable to know for sure if that would be the case.
Last edited by Etika on Thu Apr 04, 2019 8:01 pm, edited 1 time in total.
 
Interested
Posts: 887
Joined: Thu May 19, 2016 12:19 pm

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 7:58 pm

morrisond wrote:
Eyad89 wrote:
2175301 wrote:
Condolences to the families of all involved: Here is my understanding of what happened.

1) The pilots correctly cut out electric trim controls; at which point they could manually fly the aircraft in a somewhat stable configuration, and apparently were doing so with difficulties.

2) Key difficulty is that they were already over the speed envelope of the aircraft - which made manual trim control very difficult (if not impossible).

A likely - although unnatural solution would have been to reduce thrust and slow the aircraft down - and sacrifice altitude in the process to regain usability of the manual trim. Given they were at about 14,000 ft already that would be a scary thought; not to mention all the other distractions in the cockpit at the time. Unless you trained repeatedly in how to slow an aircraft down that was above flight envelope speed this would not likely occur to the pilots.

3) The evidence strongly suggest that they re-powered the electric trim in an attempt to regain control as they then imputed manual electric trim commands that worked... and an automatic MCAS trim down command also worked - which put the aircraft into a final dive.

The full report may identify other things and will likely identify other factors. While some may claim that the aircraft was saveable with manual flying (it likely was with the right person who innately understood some things); I would not expect an average pilot to have figured out to slow the aircraft down and sacrifice altitude to allow manual trim wheels to work again; especially in the time allowed.

Keep in mind that Sully was a very experienced glider pilot and was used to non-powered landings. He innately did some things that most pilots would not.

Have a great day,


+1


This explanation is my understanding as well however I will differ on the interpretation of #2.

I would not want to be in any Aircraft that was piloted by a Pilot that was not capable of pulling the power back to reduce speed below the max limits - they way above above stall speed at 94% Power ( at least 100 knots). You do not need 94% power to maintain level flight at 14,000. According to the 737 Memory list (which pilots are required to memorize - and remember there are two of them - one should have remembered) - if faced with unreliable airspeed set power to 75% - they practice this in the simulator (or are supposed to).

The unnatural thing would to keep the thrust levers where they were.

They initially saved it (Hats off to them) however they then allowed a perfectly controllable aircraft with Manual controls get outside the flight envelope - in this case excess speed.

Do I feel bad about the Pilots and the loss of life - Yes

However I am lot more angry at the fact that professional pilot standards are this low.


You are starting to embarrass yourself now
 
Etheereal
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 8:00 pm

WorldFlier wrote:
hivue wrote:
litz wrote:
And that's the saddest thing of all right there ... both of these crashes would never have happened had the crew simply re-extended the flaps,and returned for an emergency landing.


The ET crew could not have deployed flaps at the kinds of airspeeds they were traveling. As I said in a post up-thread, it looks like they were caught in an awful trap. How much of that was due to MCAS and how much to crew actions is yet to be determined.


What is the maximum airspeed for which you can deploy minimum flaps?

The 738 has around 250 kts for 1° to 5° Flaps. It should work the same on the Max 8, and at climbing speeds the plane should be arond that same speed.
 
UALWN
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 8:00 pm

mzlin wrote:
hivue wrote:
mzlin wrote:
This is consistent with what I suggested earlier. At 05:43:00, the flight was doing okay, the the pilots apparently have saved the flight from the initial MCAS malfunction. They then turned electrical trim power back on and made a small upward manual electrical trim input at 05:43:15,


I don't think they would have touched the stab trim switches again unless they were getting desperate.


I think it may not have been desperation. They were already at 13000 feet, their selected attitude. They probably felt safe. A clue comes from the transcript; the captain asks if manual trim is working, and the FO replies no. Afterwards, sometime before 05:43:15, someone flips on the electrical power to the trim, but without any verbalization. A reasonable explanation would be that person wanted to get control over the trim, but didn't realize the MCAS problem would come back.


I don't think so. This is from just before the switch was re-engaged: "At 05:43:04, the Captain asked the First Officer to pitch up together and said that pitch is not enough." They were desperate.
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mzlin
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 8:04 pm

UALWN wrote:
mzlin wrote:
hivue wrote:

I don't think they would have touched the stab trim switches again unless they were getting desperate.


I think it may not have been desperation. They were already at 13000 feet, their selected attitude. They probably felt safe. A clue comes from the transcript; the captain asks if manual trim is working, and the FO replies no. Afterwards, sometime before 05:43:15, someone flips on the electrical power to the trim, but without any verbalization. A reasonable explanation would be that person wanted to get control over the trim, but didn't realize the MCAS problem would come back.


I don't think so. This is from just before the switch was re-engaged: "At 05:43:04, the Captain asked the First Officer to pitch up together and said that pitch is not enough." They were desperate.


That is a bit odd; they asked to go to 13000 feet and they were just reaching 13000 feet with positive rate of climb level at 05:43:04, so why would the captain say the pitch was not enough?
Last edited by mzlin on Thu Apr 04, 2019 8:06 pm, edited 2 times in total.
 
Planetalk
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 8:05 pm

hivue wrote:
2175301 wrote:
Given they were at about 14,000 ft already that would be a scary thought; not to mention all the other distractions in the cockpit at the time.


That's MSL, not AGL.

2175301 wrote:
I would not expect an average pilot to have figured out to slow the aircraft down and sacrifice altitude to allow manual trim wheels to work again; especially in the time allowed.


They did not have sufficient surplus altitude AGL to sacrifice.


Indeed, from the FDR traces the final dive only looks about 5000 ft, and happened in 15 seconds. Reducing thrust 5000 feet above ground level with unreliable airspeed and stickshaker? Also bear in mind that reducing thrust will initially pitch the nose down which is exactly what they were trying to fight.

I can only repeat that it is a catastrophic failure of design that MCAS activation seems to be an almost inevitable consequence of AoA disagree, which isn't a fun situation at low level but manageable, but now on top of that you have to deal with the plane trying to fly itself into the ground too and prevent you flying pitch and power. I can only assume no-one at Boeing was actually aware of this consequence, because if they were that is criminal, and frankly if they weren't it shows unbelievable negligence in the design and testing of this.
 
hivue
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 8:07 pm

mzlin wrote:
I think it may not have been desperation. They were already at 13000 feet, their selected attitude. They probably felt safe. A clue comes from the transcript; the captain asks if manual trim is working, and the FO replies no. Afterwards, sometime before 05:43:15, someone flips on the electrical power to the trim, but without any verbalization. A reasonable explanation would be that person wanted to get control over the trim, but didn't realize the MCAS problem would come back.


Maybe desperation is too strong a term. But I agree that they very much needed to re-trim the airplane and resorting to the trim wheel wasn't doing the job. So they took a gamble and turned stab trim back on.
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Planetalk
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 8:08 pm

fabian9 wrote:
zuckie13 wrote:
1) Why did they not reduce thrust?


Would a reduction in thrust not initially result in a further pitch down moment on the aircraft as this is effectively a rear wards change in thrust below the centre of lift?

Kind of in the opposite sense of direction of increasing thrust last when performing a stall recovery manoeuvre so as to not induce a positive pitch up moment?


yes it would...
 
XRAYretired
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 8:10 pm

zhetenyi1973 wrote:
What I don't understand why there is no MCAS trim down action for a considerable time. Shouldn't we see MCAS activation during this time without the trim movement?
It happened once why did it not happen after that? Also, why did the crew not trim back to 5 units? Why did they stop at 2.3 before cutout? Can it be they thought 2.3 was 5?


MCAS active can only be inferred by autrotrim down (FLAPS UP, AP OFF). This ship did not have AOA angle indicator, so a trim can only be set by feel and other visual references.

Ray
 
Interested
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 8:10 pm

hivue wrote:
mzlin wrote:
I think it may not have been desperation. They were already at 13000 feet, their selected attitude. They probably felt safe. A clue comes from the transcript; the captain asks if manual trim is working, and the FO replies no. Afterwards, sometime before 05:43:15, someone flips on the electrical power to the trim, but without any verbalization. A reasonable explanation would be that person wanted to get control over the trim, but didn't realize the MCAS problem would come back.


Maybe desperation is too strong a term. But I agree that they very much needed to re-trim the airplane and resorting to the trim wheel wasn't doing the job. So they took a gamble and turned stab trim back on.


I've asked a few times now

Once the trim wheel wasn't working and once they together pulled back on the sticks with no success what would the next options be to try ?

What would be the next procedure to follow?
 
MSPNWA
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 8:13 pm

Interested wrote:
What other gambles could they try at that stage?


It's not a gamble to properly manage your speed and manually trim the airplane when it is at a pitch up attitude.

It appears they put themselves into a box they couldn't get out of. Very sad.
 
Planetalk
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 8:15 pm

mzlin wrote:
hivue wrote:
mzlin wrote:
This is consistent with what I suggested earlier. At 05:43:00, the flight was doing okay, the the pilots apparently have saved the flight from the initial MCAS malfunction. They then turned electrical trim power back on and made a small upward manual electrical trim input at 05:43:15,


I don't think they would have touched the stab trim switches again unless they were getting desperate.


I think it may not have been desperation. They were already at 13000 feet, their selected attitude. They probably felt safe. A clue comes from the transcript; the captain asks if manual trim is working, and the FO replies no. Afterwards, sometime before 05:43:15, someone flips on the electrical power to the trim, but without any verbalization. A reasonable explanation would be that person wanted to get control over the trim, but didn't realize the MCAS problem would come back.


I very much doubt they felt safe. Bear in mind that was only about 5000 ft AGL and they were still hauling back on the control column to stay level.
 
Interested
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 8:16 pm

MSPNWA wrote:
Interested wrote:
What other gambles could they try at that stage?


It's not a gamble to properly manage your speed and manually trim the airplane when it is at a pitch up attitude.

It appears they put themselves into a box they couldn't get out of. Very sad.


So they've tried to sort the trim and it's not worked

They've tried together to pull the sticks up and it's not worked

Was that still on procedure?

And if do what would be the next procedure to follow ?

By now shouldn't they have expected some positive results from following procedure?
Last edited by Interested on Thu Apr 04, 2019 8:17 pm, edited 1 time in total.
 
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hilram
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 8:16 pm

morrisond wrote:
fabian9 wrote:
zuckie13 wrote:
1) Why did they not reduce thrust?


Would a reduction in thrust not initially result in a further pitch down moment on the aircraft as this is effectively a rear wards change in thrust below the centre of lift?

Kind of in the opposite sense of direction of increasing thrust last when performing a stall recovery manoeuvre so as to not induce a positive pitch up moment?


According to 737 pilots on another forum - this effect would be very-very minor - plus you would unload the stabilizer making easier to pull back to offset the slight nose down.


This was the situation:
The pilots correctly identified MCAS misbehavior.
They followed the checklist and turned electric trim off to disable MCAS.
Then they couldn’t recover the plane using manual trim like the checklist said.
Imagine that:
Two pilots cranking the manual trim wheels as hard as they can, at low altitude, fighting for their lives, ultimately giving up and in desperation resort to turning electric trim back on. Then MCAS killed them. And everyone on board.

Your comments in this thread make it sound like easy-Peasy to get out of a situation like this. And you say you’re “frustrated” over the low quality of pilots...

How dare you. Your kind disgust me.
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mzlin
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 8:16 pm

Interested wrote:
hivue wrote:
mzlin wrote:
I think it may not have been desperation. They were already at 13000 feet, their selected attitude. They probably felt safe. A clue comes from the transcript; the captain asks if manual trim is working, and the FO replies no. Afterwards, sometime before 05:43:15, someone flips on the electrical power to the trim, but without any verbalization. A reasonable explanation would be that person wanted to get control over the trim, but didn't realize the MCAS problem would come back.


Maybe desperation is too strong a term. But I agree that they very much needed to re-trim the airplane and resorting to the trim wheel wasn't doing the job. So they took a gamble and turned stab trim back on.


I've asked a few times now

Once the trim wheel wasn't working and once they together pulled back on the sticks with no success what would the next options be to try ?

What would be the next procedure to follow?


And you've been answered a few times, but you may not have noticed, as you would have to read a lot of posts, so:

05:43:00 they are in stable flight with overspeed. Ideally, they would reduce thrust to reduce airspeed and regain control using the trim wheels. Once airspeed is reduced, flaps can be extended for more lift if necessary. It would not be advised to turn back electrical trim power, but if they did (and they did), then they can use the manual electrical trim inputs (thumb tabs on the column) to get upward trim. Indeed one pilot did do this but then didn't counter MCAS when it kicked in again (5 seconds later).

Not saying MCAS isn't badly designed or isn't primarily to blame. It is badly designed and it is primarily to blame. However, you asked (and you seem genuinely curious) what could have been done to save the plane. The above are some steps that could have been used to save the plane. I hope that is helpful.
Last edited by mzlin on Thu Apr 04, 2019 8:24 pm, edited 3 times in total.
 
Planetalk
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 8:18 pm

Worth bearing in mind that this is by no means the full CVR transcript and there ay be parts that answer some of the questions asked, that for whatever reason aren't in this report. And I am not suggesting there is anything malicious about that. that is perfectly normal for a preliminary report, and this one contains more detail than many do.

So don't assume because something isn't in there, it was never said. By now I would hope people have learned not to make assumptions given how many times they have been wrong since the start of this thread.

Similarly, this shows how cautious to be using FR24 data to infer what happened, as it drew some very different conclusions to what actually transpired, up to a discussion that kept returning of whether they rotated at 90 knots.
Last edited by Planetalk on Thu Apr 04, 2019 8:19 pm, edited 1 time in total.
 
pugman211
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 8:18 pm

Before anyone says the pilots should of done this and that. Factor in 2 VERY serious things in your 'assessment ' of what you would of done in that cockpit, in that scenario.

1. Sheer panic would set in. Disorientation, mental workload as you fight to keep yourself and passengers safe.

2. Lactic acid would be building up very quickly in your muscles, and eventually muscle fatigue will kick in despite your best efforts to pull back as much as you can. Your gripping the column so hard that you probably feel like you can't move your thumb to that trim switch.

In hindsight, it is easy to say do this or that.but you add the 2 above factors in and your mental thoughts process will probably be different. Also, who knew that the stabilizer could become over pressured and unable to move in manual conditions, probably not a lot of people.
 
Interested
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 8:19 pm

mzlin wrote:
Interested wrote:
hivue wrote:

Maybe desperation is too strong a term. But I agree that they very much needed to re-trim the airplane and resorting to the trim wheel wasn't doing the job. So they took a gamble and turned stab trim back on.


I've asked a few times now

Once the trim wheel wasn't working and once they together pulled back on the sticks with no success what would the next options be to try ?

What would be the next procedure to follow?


And you've been answered a few times, but you may not have noticed, as you would have to read a lot of posts, so:

05:43:00 they are in stable flight with overspeed. Ideally, they would reduce thrust and regain control using the trim wheels. It would not be advised to turn back electrical power, but if they did (and they did), then they can use the manual electrical trim inputs (thumb tabs on the column) to get upward trim. Indeed one pilot did do this but then didn't counter MCAS when it kicked in again (5 seconds later).


Ideally they would reduce thrust you say

So that's the procedure is it after trim has failed and pulling the sticks has failed the correct procedure is to reduce thrust?

What does "ideally" mean?

Is "ideally" just another gamble or is it the procedure they should have been following

We can't have it both ways

What is the next procedure to follow in their situation. Do the procedures go that far?
Last edited by Interested on Thu Apr 04, 2019 8:21 pm, edited 2 times in total.
 
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scbriml
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 8:20 pm

mzlin wrote:
I think it may not have been desperation. They were already at 13000 feet, their selected attitude. They probably felt safe.


Except that's MSL, not AGL. In reality, they were something like 5,000ft AGL. Not that comfortable with a struggling plane.
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Interested
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 8:23 pm

scbriml wrote:
mzlin wrote:
I think it may not have been desperation. They were already at 13000 feet, their selected attitude. They probably felt safe.


Except that's MSL, not AGL. In reality, they were something like 5,000ft AGL. Not that comfortable with a struggling plane.


Another devastating answer to an armchair poster trying to suggest this situation was easy to deal with?

Whats the next thing to throw at these pilots?
Last edited by Interested on Thu Apr 04, 2019 8:24 pm, edited 1 time in total.
 
Chemist
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 8:23 pm

2175301 wrote:
Condolences to the families of all involved: Here is my understanding of what happened.

1) The pilots correctly cut out electric trim controls; at which point they could manually fly the aircraft in a somewhat stable configuration, and apparently were doing so with difficulties.

2) Key difficulty is that they were already over the speed envelope of the aircraft - which made manual trim control very difficult (if not impossible).

A likely - although unnatural solution would have been to reduce thrust and slow the aircraft down - and sacrifice altitude in the process to regain usability of the manual trim. Given they were at about 14,000 ft already that would be a scary thought; not to mention all the other distractions in the cockpit at the time. Unless you trained repeatedly in how to slow an aircraft down that was above flight envelope speed this would not likely occur to the pilots.

3) The evidence strongly suggest that they re-powered the electric trim in an attempt to regain control as they then imputed manual electric trim commands that worked... and an automatic MCAS trim down command also worked - which put the aircraft into a final dive.

The full report may identify other things and will likely identify other factors. While some may claim that the aircraft was saveable with manual flying (it likely was with the right person who innately understood some things); I would not expect an average pilot to have figured out to slow the aircraft down and sacrifice altitude to allow manual trim wheels to work again; especially in the time allowed.

Keep in mind that Sully was a very experienced glider pilot and was used to non-powered landings. He innately did some things that most pilots would not.

Have a great day,


You wouldn't have to slow down and lose altitude if you are already overspeed.
While I agree that MCAS design is a disaster and they were in a very tough situation, isn't there a backup airspeed indicator? And aren't they trained for erroneous airspeed indications to set certain power and attitude? I would expect that manually trimming would be possible if their airspeed were in the normal range. But I agree it's hard to know all of this in a tense situation. So while they might have made some suboptimal decisions, it still was a tough situation for them given Boeing's screwups.
 
MSPNWA
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 8:24 pm

Interested wrote:
So they've tried to sort the trim and it's not worked

They've tried together to pull the sticks up and it's not worked

Was that still on procedure?

And if do what would be the next procedure to follow ?

By now shouldn't they have expected some positive results from following procedure?


You're making assumptions that aren't in the report. We don't know if the manual trim truly didn't work, or if didn't they know enough about it/didn't execute it properly. If it's the former, then we have decades of design at question going back to the original 737. If it's the latter, which is very plausible looking at the report, we have a training/CRM issue.
Last edited by MSPNWA on Thu Apr 04, 2019 8:25 pm, edited 2 times in total.
 
Interested
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 8:27 pm

Shall we just all agree no pilots should have had to figure out how to deal with all of this?

Would any of you volunteer to go on a test flight with the above conditions with any confidence?

And that's even with the test pilots knowing what to expect

The test pilots would be training like hell for weeks in advance
 
Interested
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 8:30 pm

MSPNWA wrote:
Interested wrote:
So they've tried to sort the trim and it's not worked

They've tried together to pull the sticks up and it's not worked

Was that still on procedure?

And if do what would be the next procedure to follow ?

By now shouldn't they have expected some positive results from following procedure?


You're making assumptions that aren't in the report. We don't know if the manual trim truly didn't work, or if didn't they know enough about it/didn't execute it properly. If it's the former, then we have decades of design at question going back to the original 737. If it's the latter, which is very plausible looking at the report, we have a training/CRM issue.


You've not answered my question at all

We KNOW the pilots didn't believe the manual trim was working

We KNOW they both tried together to pull the sticks and that didn't work for them

What would be the next procedure to follow? If you are the pilots and it appears to you the trim isn't working and you can't make any impact on the sticks?

Stick to what we know about their actions and procedure. Several have said turning the switch back on isn't procedure

So what would be the next procedure for them to follow?

Is there one?
Last edited by Interested on Thu Apr 04, 2019 8:32 pm, edited 1 time in total.
 
Chemist
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 8:31 pm

MSPNWA wrote:
Interested wrote:
So they've tried to sort the trim and it's not worked

They've tried together to pull the sticks up and it's not worked

Was that still on procedure?

And if do what would be the next procedure to follow ?

By now shouldn't they have expected some positive results from following procedure?


You're making assumptions that aren't in the report. We don't know if the manual trim truly didn't work, or if didn't they know enough about it/didn't execute it properly. If it's the former, then we have decades of design at question going back to the original 737. If it's the latter, which is very plausible looking at the report, we have a training/CRM issue.


My guess would be that they allowed themselves to severely overspeed which made manual trim difficult to impossible. Just a bit of throttle down might have made the difference (and that's assuming they still didn't manually/electrically trim to neutral, which it seems they never did).
 
Planetalk
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 8:31 pm

Interested wrote:
Shall we just all agree no pilots should have had to figure out how to deal with all of this?

Would any of you volunteer to go on a test flight with the above conditions with any confidence?

And that's even with the test pilots knowing what to expect

The test pilots would be training like hell for weeks in advance


Indeed. The design has taken two separate failures, AoA disagree and trim malfunction, and inextricably linked them so they become a perhaps inevitable far bigger and far harder to manage failure, AoA failure should not as a direct consequence require you to shut off your trim control. I'm still struggling to believe someone actually designed that. And it got certified.

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