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speedbored
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 3:53 pm

morrisond wrote:
Even though I don't think it has been released yet - I found it on another forum
http://www.ecaa.gov.et/documents/20435/ ... af1ee17f3e

Thanks for the link.

morrisond wrote:
We can believe accident reports that show actual evidence like FDR traces to back them up.

So I guess that we can believe this report now then?
 
Interested
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:01 pm

jimp9106 wrote:
The preliminary report of Aircraft Accident Investigation Bureau on #ET302 can be downloaded here http://www.ecaa.gov.et/documents/20435/ ... af1ee17f3e


Not nice to read

They gave it a good go

Poor guys
 
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scbriml
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:02 pm

spinotter wrote:
But Boeing seems to be denying that they have received the report as of today, is that true?


Do you have a source for that? I can't find anything.
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:02 pm

speedbored wrote:
morrisond wrote:
Even though I don't think it has been released yet - I found it on another forum
http://www.ecaa.gov.et/documents/20435/ ... af1ee17f3e

Thanks for the link.

morrisond wrote:
We can believe accident reports that show actual evidence like FDR traces to back them up.

So I guess that we can believe this report now then?


How come flicking the switch didn't work then?

I thought this was basic stuff for any decent pilot to deal with?
 
morrisond
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:07 pm

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.
 
PlaneInsomniac
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:10 pm

morrisond wrote:
scbriml wrote:
morrisond wrote:
And again they are saying they followed all procedures but the ABC report is saying otherwise.


Two anonymous sources are claiming that. The same sources that claim the AOA sensor was damaged by FOD.

"We did not find any information regarding the FOD (foreign object damage) on the aircraft," Amdye Andualem, chairman of the Ethiopian Accident Investigation Bureau told reporters at Thursday's press conference. "The data provided by the FDR (flight data recorder) doesn't indicate that there is an FOD."

Doesn't make those sources sound very reliable, does it?


No - no one will know anything unless the FDR traces are released. You can't treat the Ethiopian report as Gospel.


The preliminary offical investigation report is far and away the best source we have at the moment.

All you have OTOH is wishful thinking. You should really stop trying to impose arbitrary standards of proof on others because the facts keep disagreeing with your world view. It's getting embarrassing to watch.
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morrisond
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:10 pm

Interested wrote:
I've seen it mentioned more than once that although the Ethiopiain Pilots did follow the Boeing procedures to save the plane - they didn't follow all of them

Yet for the past two weeks I've also read that all they needed to do was flick a switch and the plane would be safe

I'm confused?

The way it was described sounded so simple and easy

What have I missed?


It appears from the accident report they flicked the switch back on.

The only other explanation is that somehow the Electric Trim system got power from somewhere else that the TRIM CUTOUT switches didn't block.
 
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:11 pm

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.

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 don't get it still

Why when they first flicked the switch wasn't everything ok?

Like everyone said it would be.

I thought this was a simple problem that could be dealt with by one flick of a switch?

I thought all they had to do was flick a switch and just fly the plane

Why did the stick keep shaking and why did the plane keep struggling so much after they flicked the switch

It reads to me like they knew what to do but nothing was working for them?
Last edited by Interested on Thu Apr 04, 2019 4:15 pm, edited 1 time in total.
 
morrisond
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:13 pm

PlaneInsomniac wrote:
morrisond wrote:
scbriml wrote:

Two anonymous sources are claiming that. The same sources that claim the AOA sensor was damaged by FOD.

"We did not find any information regarding the FOD (foreign object damage) on the aircraft," Amdye Andualem, chairman of the Ethiopian Accident Investigation Bureau told reporters at Thursday's press conference. "The data provided by the FDR (flight data recorder) doesn't indicate that there is an FOD."

Doesn't make those sources sound very reliable, does it?


No - no one will know anything unless the FDR traces are released. You can't treat the Ethiopian report as Gospel.


The preliminary offical investigation report is far and away the best source we have at the moment.

All you have OTOH is wishful thinking. You should really stop trying to impose arbitrary standards of proof on others because the facts keep disagreeing with your world view. It's getting embarrassing to watch.



The report actually looks quite comprehensive however it conveniently doesn't talk about the last few minutes of the flight when DOWN electric trim was recorded.
 
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:15 pm

morrisond wrote:
Interested wrote:
I've seen it mentioned more than once that although the Ethiopiain Pilots did follow the Boeing procedures to save the plane - they didn't follow all of them

Yet for the past two weeks I've also read that all they needed to do was flick a switch and the plane would be safe

I'm confused?

The way it was described sounded so simple and easy

What have I missed?


It appears from the accident report they flicked the switch back on.

The only other explanation is that somehow the Electric Trim system got power from somewhere else that the TRIM CUTOUT switches didn't block.

No, it does not appear from the accident report that they flicked the switch back on. It is your own confirmation bias kicking in. The accident report which you yourself supplied has noting on that.
 
VV
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:16 pm

Is flipping the switch back on part of the procedure?

I am confused.
 
PlaneInsomniac
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:17 pm

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.

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.


Well, evidently they found the plane uncontrollable with manual trim. So what were they supposed to do?
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Interested
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:17 pm

morrisond wrote:
PlaneInsomniac wrote:
morrisond wrote:

No - no one will know anything unless the FDR traces are released. You can't treat the Ethiopian report as Gospel.


The preliminary offical investigation report is far and away the best source we have at the moment.

All you have OTOH is wishful thinking. You should really stop trying to impose arbitrary standards of proof on others because the facts keep disagreeing with your world view. It's getting embarrassing to watch.



The report actually looks quite comprehensive however it conveniently doesn't talk about the last few minutes of the flight when DOWN electric trim was recorded.


Morrison

Now you've read the report do you have any sympathy for those pilots?

Do you feel sorry for them in any way?

And what they had to try to deal with?

Would you have liked to get that job that day?
Last edited by Interested on Thu Apr 04, 2019 4:21 pm, edited 2 times in total.
 
Interested
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:19 pm

majano wrote:
morrisond wrote:
Interested wrote:
I've seen it mentioned more than once that although the Ethiopiain Pilots did follow the Boeing procedures to save the plane - they didn't follow all of them

Yet for the past two weeks I've also read that all they needed to do was flick a switch and the plane would be safe

I'm confused?

The way it was described sounded so simple and easy

What have I missed?


It appears from the accident report they flicked the switch back on.

The only other explanation is that somehow the Electric Trim system got power from somewhere else that the TRIM CUTOUT switches didn't block.

No, it does not appear from the accident report that they flicked the switch back on. It is your own confirmation bias kicking in. The accident report which you yourself supplied has noting on that.


Now I'm even more confused??

If they didn't flick the switch back on who else can we blame for the crash?
 
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:20 pm

morrisond wrote:
PlaneInsomniac wrote:
morrisond wrote:

No - no one will know anything unless the FDR traces are released. You can't treat the Ethiopian report as Gospel.


The preliminary offical investigation report is far and away the best source we have at the moment.

All you have OTOH is wishful thinking. You should really stop trying to impose arbitrary standards of proof on others because the facts keep disagreeing with your world view. It's getting embarrassing to watch.



The report actually looks quite comprehensive however it conveniently doesn't talk about the last few minutes of the flight when DOWN electric trim was recorded.


So all you have is a "convenient" conspiracy theory? And that gives you the right to question all the published facts?
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speedbored
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:20 pm

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.

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.

Not convinced about this. According to the flight history, it looks like they lost ~600ft despite both pilots pulling to pitch the aircraft up. Having failed to be able to correct the adverse nose down trim using the manual wheel, it looks like they gave up on the checklist and decided to try electric trim again. To no avail.

Can't imagine how helpless they must have felt.

One interesting observation from the FDR data is that the two AoA sensors didn't remain a consistent distance out of sync in the way the Lionair sensors did. So it looks like it could be a different sensor fault.
 
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:21 pm

Here is Boeing's statement on the investigation preliminary report

http://www.boeing.com/commercial/737max ... /statement
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:24 pm

morrisond wrote:
The report actually looks quite comprehensive however it conveniently doesn't talk about the last few minutes of the flight when DOWN electric trim was recorded.

But that is automatic down trim. And it is mentioned in the report.
 
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:26 pm

Interested wrote:
speedbored wrote:
morrisond wrote:
Even though I don't think it has been released yet - I found it on another forum
http://www.ecaa.gov.et/documents/20435/ ... af1ee17f3e

Thanks for the link.

morrisond wrote:
We can believe accident reports that show actual evidence like FDR traces to back them up.

So I guess that we can believe this report now then?


How come flicking the switch didn't work then?

I thought this was basic stuff for any decent pilot to deal with?


Perhaps because manual trim does not work like it is supposed to do?
 
zuckie13
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:28 pm

The two questions I'm left with are:

1) Why did they not reduce thrust?
2) After cutting out the electric trim, did they really try to move the trim manually (as in spinning the wheel), or did they try to "manually" move it with the switches on the control column? From my look at the data, I'm not convinced they moved the wheel (but cant' tell if because they didn't' try, or literally couldn't.

Would decelerating make manual pitch control easier?
 
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:29 pm

morrisond wrote:
mjoelnir wrote:
morrisond wrote:

Can you point me to a link - I've searched and all that comes up is the Ethiopian Airlines Press release.

No - I'm not astonished by the one year final report - but has any actual evidence been released? Hopefully someone leaks the FDR traces like was done on Lionair.

Thanks


Nowhere is talked about a Ethiopian airlines press release. The information release started with the Ethiopian transport minister Dagmawit Moges.

https://edition.cnn.com/africa/live-new ... index.html

of course very difficult to find.

I think the onus is on you to show that today was a press conference by Ethiopian Airlines.


I was referring to the fact that they haven't release the written report yet.

The only written report/press release has come from Ethiopian airlines.

If you have a link to the copy of the written report please post it.

From your link



Investigators yet to publish report
While Ethiopian investigators announced in a press conference the findings of the preliminary report, they haven't actually published the report.

CNN anchor and aviation expert Richard Quest said this was "unusual."

"We are slightly taking their word for what they are saying is in the report," he said.

and


CNN's Oren Liebermann says a 'tremendous amount of information is still missing'
From CNN's Oren Liebermann

"A preliminary report should have information about the flight crew's experience, the weather conditions, any maintenance issues with previous flights, relevant airworthiness directives, a detailed timeline of the flight, information about the cockpit voice recorder, instrument readings and system activations from the flight data recorder, etc," says CNN's Oren Lieberman.

"In other words, there is a tremendous amount of information that we're still looking for about Ethiopian Airlines flight 302."

Dont know what report Lieberman is referring to, but the Preliminary Report on the ECAA web site contains all the relevant information.

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

Thu Apr 04, 2019 4:31 pm

Interested 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.

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 don't get it still

Why when they first flicked the switch wasn't everything ok?

Like everyone said it would be.

I thought this was a simple problem that could be dealt with by one flick of a switch?

I thought all they had to do was flick a switch and just fly the plane

Why did the stick keep shaking and why did the plane keep struggling so much after they flicked the switch

It reads to me like they knew what to do but nothing was working for them?


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.
 
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:33 pm

qf789 wrote:
Here is Boeing's statement on the investigation preliminary report

http://www.boeing.com/commercial/737max ... /statement


"The preliminary report contains flight data recorder information indicating the airplane had an erroneous angle of attack sensor input that activated the Maneuvering Characteristics Augmentation System (MCAS) function during the flight, as it had during the Lion Air 610 flight."

That lays to rest any lingering doubts that MCAS was involved in both accidents and that the grounding wasn't justified.
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:34 pm

zuckie13 wrote:
The two questions I'm left with are:

1) Why did they not reduce thrust?
2) After cutting out the electric trim, did they really try to move the trim manually (as in spinning the wheel), or did they try to "manually" move it with the switches on the control column? From my look at the data, I'm not convinced they moved the wheel (but cant' tell if because they didn't' try, or literally couldn't.

Would decelerating make manual pitch control easier?


That is the Question - why did they not reduce thrust. They were getting abnormal readings on there Instruments but the back-up should have given them a reliable source.

Decelerating to within the Flight Envelope should have made the plane controllable with Manual Trim (just as the flight was controllable on the Lionair Flight previous to the crash flight).
 
MSPNWA
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:35 pm

We have a long ways to go before I'm making any judgements, but my initial view of the report is that there seems to be crucial information missing, in particular the events after they first used the cut-off switches. A plane doesn't just trim down on its own without a cause.
 
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:36 pm

speedbored wrote:
morrisond wrote:
The report actually looks quite comprehensive however it conveniently doesn't talk about the last few minutes of the flight when DOWN electric trim was recorded.

But that is automatic down trim. And it is mentioned in the report.


Which could only have been activated if they had turned the Electric Trim back on - which the Boeing Bulletin specifically says not to do.
 
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:39 pm

MSPNWA wrote:
We have a long ways to go before I'm making any judgements, but my initial view of the report is that there seems to be crucial information missing, in particular the events after they first used the cut-off switches. A plane doesn't just trim down on its own without a cause.



What do you think happened then?
 
morrisond
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:39 pm

speedbored 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.

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.

Not convinced about this. According to the flight history, it looks like they lost ~600ft despite both pilots pulling to pitch the aircraft up. Having failed to be able to correct the adverse nose down trim using the manual wheel, it looks like they gave up on the checklist and decided to try electric trim again. To no avail.

Can't imagine how helpless they must have felt.

One interesting observation from the FDR data is that the two AoA sensors didn't remain a consistent distance out of sync in the way the Lionair sensors did. So it looks like it could be a different sensor fault.


They were also travelling at an excessive speed which would have made it very difficult to control Vmo is 230 knots on the MAX I believe - they were well above that for a lot of the flight.
 
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:40 pm

MSPNWA wrote:
We have a long ways to go before I'm making any judgements, but my initial view of the report is that there seems to be crucial information missing, in particular the events after they first used the cut-off switches. A plane doesn't just trim down on its own without a cause.


The FDR data is clear that the electric trim was used to manually trim up, very close to the dive. The crucial missing information is whether or not they turned the trim back on. If they did, then all the headlines stating that the pilots followed the procedure, are suspect.
Last edited by ContnlEliteCMH on Thu Apr 04, 2019 4:41 pm, edited 1 time in total.
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Interested
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:40 pm

morrisond wrote:
speedbored wrote:
morrisond wrote:
The report actually looks quite comprehensive however it conveniently doesn't talk about the last few minutes of the flight when DOWN electric trim was recorded.

But that is automatic down trim. And it is mentioned in the report.


Which could only have been activated if they had turned the Electric Trim back on - which the Boeing Bulletin specifically says not to do.


So it was the pilots who turned the trim back on?
 
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:44 pm

MSPNWA wrote:
We have a long ways to go before I'm making any judgements, but my initial view of the report is that there seems to be crucial information missing, in particular the events after they first used the cut-off switches. A plane doesn't just trim down on its own without a cause.


At least you know lots more about what happened

Now you know a lot more

What percentage of pilots would save that plane in your opinion

Seems to have been a much harder job than people suggested it should have been?

What's the normal procedure when both pilots try to pull the plane up together and nothing happens?

I assumed flying these planes was much easier than it looks in that report?
 
VV
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:44 pm

Reading the comments above I became confused.

Were the switches flipped off or were they on?

Is flipping the switch back on part of the procedure?
 
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PixelFlight
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:46 pm

morrisond wrote:
Even though I don't think it has been released yet - I found it on another forum

http://www.ecaa.gov.et/documents/20435/ ... af1ee17f3e

Many thanks for this finding :-)

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°.

At 05:40:35, the First-Officer called out “stab trim cut-out” two times. Captain agreed and First-
Officer confirmed stab trim cut-out.

At 05:41:46, the Captain asked the First-Officer if the trim is functional. The First-Officer has replied
that the trim was not working and asked if he could try it manually. The Captain told him to try. At
05:41:54, the First-Officer replied that it is not working.

At 05:42:54, both pilots called out “left alpha vane”.

At 05:43:11, about 32 seconds before the end of the recording, at approximately 13,400 2 ft, two
momentary manual electric trim inputs are recorded in the ANU direction. The stabilizer moved in
the ANU direction from 2.1 units to 2.3 units.

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.

And this is just the key points. The details fully confirm the "scary place" scenario that many here have speculated. Sorry Boeing, this is really not just two switches to hit in quiet cockpit.
Finally this:
The STAB TRIM PRI cutout switch and the STAB TRIM B/U cutout switch are located on the control
stand. If either switch is positioned to CUTOUT, both the autopilot and main electric trim inputs are
disconnected from the stabilizer trim motor.
Last edited by PixelFlight on Thu Apr 04, 2019 4:50 pm, edited 2 times in total.
:stirthepot: 737-8 MAX: "For all speeds higher than 220 Kts and trim set at a value of 2.5 units, the difficulity level of turning the manual trim wheel was level A (trim wheel not movable)." :stirthepot:
 
ContnlEliteCMH
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:47 pm

VV wrote:
Reading the comments above I became confused.

Were the switches flipped off or were they on?

Is flipping the switch back on part of the procedure?


The report does not state the position of the trim cutout switches. Per the checklist, the system should not be reenabled.
Christianity. Islam. Hinduism. Anthropogenic Global Warming. All are matters of faith!
 
morrisond
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:47 pm

VV wrote:
Reading the comments above I became confused.

Were the switches flipped off or were they on?

Is flipping the switch back on part of the procedure?



It appears as though they initially flipped them off but then several minutes later they turned them back on.
 
Interested
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:48 pm

VV wrote:
Reading the comments above I became confused.

Were the switches flipped off or were they on?

Is flipping the switch back on part of the procedure?


Me too

I've been told for two or three weeks all they needed to do was flick a switch and fly the plane with normal stick and rudder control like all the US pilots would do

I've read the report. But after they flicked the switch it reads like they still had no control on the plane?
 
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:50 pm

PixelFlight wrote:
morrisond wrote:
Even though I don't think it has been released yet - I found it on another forum

http://www.ecaa.gov.et/documents/20435/ ... af1ee17f3e

Many thanks for this finding :-)

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°.

At 05:40:35, the First-Officer called out “stab trim cut-out” two times. Captain agreed and First-
Officer confirmed stab trim cut-out.

At 05:41:46, the Captain asked the First-Officer if the trim is functional. The First-Officer has replied
that the trim was not working and asked if he could try it manually. The Captain told him to try. At
05:41:54, the First-Officer replied that it is not working.

At 05:42:54, both pilots called out “left alpha vane”.

At 05:43:11, about 32 seconds before the end of the recording, at approximately 13,400 2 ft, two
momentary manual electric trim inputs are recorded in the ANU direction. The stabilizer moved in
the ANU direction from 2.1 units to 2.3 units.

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.

And this is just the key points. The details fully confirm the "scary place" scenario that many here have speculated. Sorry Boeing, this is really not just two switches to hit in quiet cockpit.



So flicking the switch made no difference?

It didn't work?
 
XRAYretired
Posts: 870
Joined: Fri Mar 15, 2019 11:21 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:51 pm

morrisond wrote:
PlaneInsomniac wrote:
morrisond wrote:

No - no one will know anything unless the FDR traces are released. You can't treat the Ethiopian report as Gospel.


The preliminary offical investigation report is far and away the best source we have at the moment.

All you have OTOH is wishful thinking. You should really stop trying to impose arbitrary standards of proof on others because the facts keep disagreeing with your world view. It's getting embarrassing to watch.



The report actually looks quite comprehensive however it conveniently doesn't talk about the last few minutes of the flight when DOWN electric trim was recorded.

15 seconds, as you're well aware fella.
 
Interested
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:52 pm

qf789 wrote:
Here is Boeing's statement on the investigation preliminary report

http://www.boeing.com/commercial/737max ... /statement


Basically they are going to try to make an unsafe plane safer
Last edited by Interested on Thu Apr 04, 2019 4:54 pm, edited 1 time in total.
 
Interested
Posts: 890
Joined: Thu May 19, 2016 12:19 pm

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:53 pm

XRAYretired wrote:
morrisond wrote:
PlaneInsomniac wrote:

The preliminary offical investigation report is far and away the best source we have at the moment.

All you have OTOH is wishful thinking. You should really stop trying to impose arbitrary standards of proof on others because the facts keep disagreeing with your world view. It's getting embarrassing to watch.



The report actually looks quite comprehensive however it conveniently doesn't talk about the last few minutes of the flight when DOWN electric trim was recorded.

15 seconds, as you're well aware fella.


That's the bit when they started to pray

I think we can allow them that can't we?
 
hivue
Posts: 2098
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:54 pm

morrisond wrote:
It appears as though they initially flipped them off but then several minutes later they turned them back on.


The preliminary report doesn't state any straight, direct evidence that they switched off the stab trim cutouts. It's inferred that they actually did because of a subsequent AND command to the electrical trim which wasn't answered by actual stab movement. Later, there was a ANU command to the electrical trim (which would not come from MCAS but only from the crew) which was answered by stab movement.
"You're sitting. In a chair. In the SKY!!" ~ Louis C.K.
 
Dreamflight767
Posts: 497
Joined: Sun Dec 28, 2008 10:43 pm

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:55 pm

mjoelnir wrote:
Interested wrote:
ELBOB wrote:

Boeing culture and management changed with the merger in 1997, this is well known.

But the company itself has a long history of gotchas and indifference. For over a decade after entering service the 737-200 had a reputation for unpredictable, vicious pitch-up and roll-off on take-off when icing formed symmetrically on the leading edges. Boeing's advice was to go easy on the rotation... Thankfully eventually the NTSB issued a series of recommendations and ADs to address the issue.


The failings of FAA are also clear to see. But it's half understandable. You would just assume that with all the skills and money and talent at Boeing - they surely aren't going to design a plane that's not at least as safe as the one it replaces.

So you wouldn't feel like you need to oversee every decision they make.

As most have said Boeing staff wouldn't deliberately make a plane to kill people

You wouldn't feel you need to watch every step they take when designing this plane


The battery problem in the 787 should have been a wake up call for the FAA. It seems they went to sleeping straight away again.


I don't understand why people are always shocked/surprised by the FAA's incompetence, inability to regulate, and/or provide oversight. Are people actually naive enough to think the FAA did (does) it's own independent studies and testing of the batteries and MCAS - or any other new aviation related technology? No, they simply "review" what is submitted and draw a little picture of a frown or smiley face. The FAA is a very much a wait-and-see/react AFTER social media outcry or loss-of-life. And that's only because they are scared of lawsuits.
 
Interested
Posts: 890
Joined: Thu May 19, 2016 12:19 pm

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 4:56 pm

hivue wrote:
morrisond wrote:
It appears as though they initially flipped them off but then several minutes later they turned them back on.


The preliminary report doesn't state any straight, direct evidence that they switched off the stab trim cutouts. It's inferred that they actually did because of a subsequent AND command to the electrical trim which wasn't answered by actual stab movement. Later, there was a ANU command to the electrical trim (which would not come from MCAS but only from the crew) which was answered by stab movement.


Please please don't give him a chance to say they forgot to flick the switch!!

No wonder they crashed
 
hivue
Posts: 2098
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 5:03 pm

Interested wrote:
Please please don't give him a chance to say they forgot to flick the switch!!


It's obvious they did "flick the switch." But that has to be inferred from the information in the preliminary report (as does the fact that they obviously flicked it back on later). There's nothing direct that says that -- only what the FO said and the behavior of the stab.
"You're sitting. In a chair. In the SKY!!" ~ Louis C.K.
 
Dreamflight767
Posts: 497
Joined: Sun Dec 28, 2008 10:43 pm

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 5:03 pm

Interested wrote:
qf789 wrote:
Here is Boeing's statement on the investigation preliminary report

http://www.boeing.com/commercial/737max ... /statement


Basically they are going to try to make an unsafe plane safer


Absolutely agree! If ANY system requires this many amendments/tweaks/changes/revisions or whatever, the system was broken to start with and should have never been implemented/released.

Secondly, now you have flight crews who are going to have to relearn/retrain. Forgetting old procedures can be difficult, especially during time of urgency.
 
User avatar
PixelFlight
Posts: 1026
Joined: Thu Nov 08, 2018 11:09 pm

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 5:07 pm

planecane wrote:
Is Airbus management too business based to do the NEO instead of a clean sheet replacement?

The A320 is already a clean sheet design compared to the B737. Changing the engines was more easy for the NEO than for the MAX.
:stirthepot: 737-8 MAX: "For all speeds higher than 220 Kts and trim set at a value of 2.5 units, the difficulity level of turning the manual trim wheel was level A (trim wheel not movable)." :stirthepot:
 
fabian9
Posts: 66
Joined: Thu Mar 29, 2007 5:27 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 5:09 pm

morrisond wrote:
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.


After reading the report, I did not get the impression that the electric trim was switched back on.

Would you mind referencing the section of the report that discusses this?
 
User avatar
BaconButty
Posts: 831
Joined: Tue Aug 06, 2013 3:42 pm

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 5:21 pm

ContnlEliteCMH wrote:
The FDR data is clear that the electric trim was used to manually trim up, very close to the dive. The crucial missing information is whether or not they turned the trim back on. If they did, then all the headlines stating that the pilots followed the procedure, are suspect.


They followed the procedure and it didn't work. The stabiliser trim was cutout by 5:40:41. It was reactivated (possibly) by 5:43:20. In the 2m39s in between they have attempted to combine their strength pulling back the sticks ("Not enough") and tried the manual trim ("not working") .

At this point the altitude has levelled out, they've been unable to make an impression on their pitch trim, they're both pulling back to keep the plane level, and they've somehow got to get the aircraft down. If the electric trim can't help, and the manual trim can't help, they only hope is to gamble and pray the STS kicks in and helps them out - flick the switches?

Pretty horrible.
Last edited by BaconButty on Thu Apr 04, 2019 5:24 pm, edited 1 time in total.
Down with that sort of thing!
 
Interested
Posts: 890
Joined: Thu May 19, 2016 12:19 pm

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 5:24 pm

BaconButty wrote:
ContnlEliteCMH wrote:
The FDR data is clear that the electric trim was used to manually trim up, very close to the dive. The crucial missing information is whether or not they turned the trim back on. If they did, then all the headlines stating that the pilots followed the procedure, are suspect.


They followed the procedure and it didn't work. The stabiliser trim was cutout by 5:40:41. It was reactivated (possibly) by 5:43:20. In the 2m39s in between they have attempted to combine their strength pulling back the sticks, tried the manual trim ("not working") and pulling back both together ("Not enough").

At this point the altitude has levelled out, they've been unable to make an impression on their pitch trim, and they've somehow got to get the aircraft down. If the electric trim can't help, and the manual trim can't help, they only hope is to gamble and pray the STS kicks in and helps them out - flick the switches?

Pretty horrible.


What does the procedure say that they should do when having combined their strength to pull back on the sticks nothing happens

What would all the pilots and armchair pilots on here do next at that stage?
 
XRAYretired
Posts: 870
Joined: Fri Mar 15, 2019 11:21 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Thu Apr 04, 2019 5:25 pm

hivue wrote:
morrisond wrote:
It appears as though they initially flipped them off but then several minutes later they turned them back on.


The preliminary report doesn't state any straight, direct evidence that they switched off the stab trim cutouts. It's inferred that they actually did because of a subsequent AND command to the electrical trim which wasn't answered by actual stab movement. Later, there was a ANU command to the electrical trim (which would not come from MCAS but only from the crew) which was answered by stab movement.

"At 05:40:35, the First-Officer called out “stab trim cut-out” two times. Captain agreed and FirstOfficer confirmed stab trim cut-out. "

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