planecane
Posts: 759
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Fri May 17, 2019 11:59 pm

PixelFlight wrote:
planecane wrote:
Virtual737 wrote:
Do you see the subtle but important difference? The first suggests that you only manually trim if you had to disconnect the A/P. The second states that you do it regardless. More than one poster has argued that these checklists should be followed to the letter, no exceptions, no excuses. It would help if the checklists were accurate.

I guess I can see what you are saying. The way I read it, it is part of step 2. I think it is just treated kind of like common sense basically saying "fly the airplane."

The common sens will not guess that the pilot have only maximum 5 seconds to go from the second indented (could be misinterpreted as only if AP engaged) point 2 to the first indented (could be misinterpreted due to MCAS discontinue action) point 5, and that all the next points can't be done at high speed. Under stress and without appropriate specific training, this procedure as redacted could easily be error prone.


Don't focus on MCAS in this case. If the training isn't adequate for runaway stabilizer then it is an issue for ALL causes of runaway stabilizer. If they (specifically the ET crew) didn't run the NNC properly for an MCAS induced runaway stabilizer, they wouldn't have run it properly for runaway stabilizer caused by something else.
 
PixelPilot
Posts: 245
Joined: Tue Jan 16, 2018 1:19 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 12:11 am

morrisond wrote:
AABusDrvr wrote:
GalaxyFlyer wrote:

If we need a checklist step instructing pilots to control pitch with the column and manual electric trim; training is far, FAR worse than I imagined.

GF


That’s a massive understatement.


Apparently monitoring airspeed and controlling thrust with the Throttles to keep it from over or underspend should be on the checklist as well.

Maybe also they should add "Check Engines are on"


I have a weird feeling somebody is already thinking where to add that memo.
It's scary.
 
RickNRoll
Posts: 1620
Joined: Fri Jan 06, 2012 9:30 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 12:31 am

planecane wrote:
PixelFlight wrote:
planecane wrote:
I guess I can see what you are saying. The way I read it, it is part of step 2. I think it is just treated kind of like common sense basically saying "fly the airplane."

The common sens will not guess that the pilot have only maximum 5 seconds to go from the second indented (could be misinterpreted as only if AP engaged) point 2 to the first indented (could be misinterpreted due to MCAS discontinue action) point 5, and that all the next points can't be done at high speed. Under stress and without appropriate specific training, this procedure as redacted could easily be error prone.


Don't focus on MCAS in this case. If the training isn't adequate for runaway stabilizer then it is an issue for ALL causes of runaway stabilizer. If they (specifically the ET crew) didn't run the NNC properly for an MCAS induced runaway stabilizer, they wouldn't have run it properly for runaway stabilizer caused by something else.


The reality of the situation versus the dry, low key tone of the EDA and NNC don't let pilots in on the reality of experiencing MCAS failure.

https://news.ycombinator.com/item?id=19902068

The U.S. crew tested this by setting up a 737-Next Generation simulator at 10,000 ft., 250 kt. and 2 deg. nose up stabilizer trim. This is slightly higher altitude but otherwise similar to what the ET302 crew faced as it de-powered the trim motors 3 min. into the 6 min. flight, and about 1 min. after the first uncommanded MCAS input. Leading up to the scenario, the Ethiopian crew used column-mounted manual electric trim to counter some of the MCAS inputs, but did not get the aircraft back to level trim, as the 737 manual instructs before de-powering the stabilizer trim motor. The crew also did not reduce their unusually high speed.

What the U.S. crew found was eye-opening. Keeping the aircraft level required significant aft-column pressure by the captain, and aerodynamic forces prevented the first officer from moving the trim wheel a full turn. They resorted to a little-known procedure to regain control.

The crew repeatedly executed a three-step process known as the roller coaster. First, let the aircraft’s nose drop, removing elevator nose-down force. Second, crank the trim wheel, inputting nose-up stabilizer, as the aircraft descends. Third, pull back on the yokes to raise the nose and slow the descent. The excessive descent rates during the first two steps meant the crew got as low as 2,000 ft. during the recovery.

The Ethiopian Ministry of Transport preliminary report on the Mar. 10 ET302 accident suggests the crew attempted to use manual trim after de-powering the stabilizer motors, but determined it “was not working,” the report said. A constant trust setting at 94% N1 meant ET302’s airspeed increased to the 737 MAX’s maximum (Vmo), 340 kt., soon after the stabilizer trim motors were cut off, and did not drop below that level for the remainder of the flight. The pilots, struggling to keep the aircraft from descending, also maintained steady to strong aft control-column inputs from the time MCAS first fired through the end of the flight.

The U.S. crew’s session and a video posted recently by YouTube’s Mentour Pilot that shows a similar scenario inside a simulator suggest that the resulting forces on ET302’s stabilizer would have made it nearly impossible to move by hand.

Neither the current 737 flight manual nor any MCAS-related guidance issued by Boeing in the wake of the October 2018 crash of Lion Air Flight 610 (JT610), when MCAS first came to light for most pilots, discuss the roller-coaster procedure for recovering from severe out-of-trim conditions. The 737 manual explains that “effort required to manually rotate the stabilizer trim wheels may be higher under certain flight conditions,” but does not provide details.


The bland and dry EAD is not going to prepare pilots for the shock of the reality. Overload from alerts and the shock of the plane diving down when you have barely left the ground. Then the manual trim control is impossible to move. Then you only have a few minutes to get it right.
 
morrisond
Posts: 1108
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 12:49 am

RickNRoll wrote:
planecane wrote:
PixelFlight wrote:
The common sens will not guess that the pilot have only maximum 5 seconds to go from the second indented (could be misinterpreted as only if AP engaged) point 2 to the first indented (could be misinterpreted due to MCAS discontinue action) point 5, and that all the next points can't be done at high speed. Under stress and without appropriate specific training, this procedure as redacted could easily be error prone.


Don't focus on MCAS in this case. If the training isn't adequate for runaway stabilizer then it is an issue for ALL causes of runaway stabilizer. If they (specifically the ET crew) didn't run the NNC properly for an MCAS induced runaway stabilizer, they wouldn't have run it properly for runaway stabilizer caused by something else.


The reality of the situation versus the dry, low key tone of the EDA and NNC don't let pilots in on the reality of experiencing MCAS failure.

https://news.ycombinator.com/item?id=19902068

The U.S. crew tested this by setting up a 737-Next Generation simulator at 10,000 ft., 250 kt. and 2 deg. nose up stabilizer trim. This is slightly higher altitude but otherwise similar to what the ET302 crew faced as it de-powered the trim motors 3 min. into the 6 min. flight, and about 1 min. after the first uncommanded MCAS input. Leading up to the scenario, the Ethiopian crew used column-mounted manual electric trim to counter some of the MCAS inputs, but did not get the aircraft back to level trim, as the 737 manual instructs before de-powering the stabilizer trim motor. The crew also did not reduce their unusually high speed.

What the U.S. crew found was eye-opening. Keeping the aircraft level required significant aft-column pressure by the captain, and aerodynamic forces prevented the first officer from moving the trim wheel a full turn. They resorted to a little-known procedure to regain control.

The crew repeatedly executed a three-step process known as the roller coaster. First, let the aircraft’s nose drop, removing elevator nose-down force. Second, crank the trim wheel, inputting nose-up stabilizer, as the aircraft descends. Third, pull back on the yokes to raise the nose and slow the descent. The excessive descent rates during the first two steps meant the crew got as low as 2,000 ft. during the recovery.

The Ethiopian Ministry of Transport preliminary report on the Mar. 10 ET302 accident suggests the crew attempted to use manual trim after de-powering the stabilizer motors, but determined it “was not working,” the report said. A constant trust setting at 94% N1 meant ET302’s airspeed increased to the 737 MAX’s maximum (Vmo), 340 kt., soon after the stabilizer trim motors were cut off, and did not drop below that level for the remainder of the flight. The pilots, struggling to keep the aircraft from descending, also maintained steady to strong aft control-column inputs from the time MCAS first fired through the end of the flight.

The U.S. crew’s session and a video posted recently by YouTube’s Mentour Pilot that shows a similar scenario inside a simulator suggest that the resulting forces on ET302’s stabilizer would have made it nearly impossible to move by hand.

Neither the current 737 flight manual nor any MCAS-related guidance issued by Boeing in the wake of the October 2018 crash of Lion Air Flight 610 (JT610), when MCAS first came to light for most pilots, discuss the roller-coaster procedure for recovering from severe out-of-trim conditions. The 737 manual explains that “effort required to manually rotate the stabilizer trim wheels may be higher under certain flight conditions,” but does not provide details.


The bland and dry EAD is not going to prepare pilots for the shock of the reality. Overload from alerts and the shock of the plane diving down when you have barely left the ground. Then the manual trim control is impossible to move. Then you only have a few minutes to get it right.


Yet - the U.S. crew screwed up the procedure as well by not using Electric trim to return the plane to in-trim before hitting the cut-offs.
 
MrBretz
Posts: 306
Joined: Tue Jun 14, 2016 9:13 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 1:23 am

Some more bad news: 737 MAX simulators don't properly simulate all the force needed to turn the trim wheels....

https://www.nytimes.com/2019/05/17/busi ... ators.html
 
MSPNWA
Posts: 3203
Joined: Thu Apr 23, 2009 2:48 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 1:36 am

MrBretz wrote:
Some more bad news: 737 MAX simulators don't properly simulate all the force needed to turn the trim wheels....

https://www.nytimes.com/2019/05/17/busi ... ators.html


For the media, yes. Would help the credibility of the article if it didn't claim that the ET pilots "struggled to turn the wheel". There is no public confirmation that it occurred.

With such basic errors, we can't trust the words or motives of that article.
 
mysfit
Posts: 15
Joined: Tue Dec 27, 2016 7:16 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 1:43 am

I thought the CVR indicated the FO stated he couldn't turn the wheel.
 
MSPNWA
Posts: 3203
Joined: Thu Apr 23, 2009 2:48 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 2:14 am

mysfit wrote:
I thought the CVR indicated the FO stated he couldn't turn the wheel.


No, the FO didn't say anything specifically about the trim wheel. It can't be confirmed that either attempted the maneuver. It may have occurred, but the information made public doesn't confirm it. Instead it raises doubts that it was attempted.
 
planecane
Posts: 759
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 2:30 am

morrisond wrote:
RickNRoll wrote:
planecane wrote:

Don't focus on MCAS in this case. If the training isn't adequate for runaway stabilizer then it is an issue for ALL causes of runaway stabilizer. If they (specifically the ET crew) didn't run the NNC properly for an MCAS induced runaway stabilizer, they wouldn't have run it properly for runaway stabilizer caused by something else.


The reality of the situation versus the dry, low key tone of the EDA and NNC don't let pilots in on the reality of experiencing MCAS failure.

https://news.ycombinator.com/item?id=19902068

The U.S. crew tested this by setting up a 737-Next Generation simulator at 10,000 ft., 250 kt. and 2 deg. nose up stabilizer trim. This is slightly higher altitude but otherwise similar to what the ET302 crew faced as it de-powered the trim motors 3 min. into the 6 min. flight, and about 1 min. after the first uncommanded MCAS input. Leading up to the scenario, the Ethiopian crew used column-mounted manual electric trim to counter some of the MCAS inputs, but did not get the aircraft back to level trim, as the 737 manual instructs before de-powering the stabilizer trim motor. The crew also did not reduce their unusually high speed.

What the U.S. crew found was eye-opening. Keeping the aircraft level required significant aft-column pressure by the captain, and aerodynamic forces prevented the first officer from moving the trim wheel a full turn. They resorted to a little-known procedure to regain control.

The crew repeatedly executed a three-step process known as the roller coaster. First, let the aircraft’s nose drop, removing elevator nose-down force. Second, crank the trim wheel, inputting nose-up stabilizer, as the aircraft descends. Third, pull back on the yokes to raise the nose and slow the descent. The excessive descent rates during the first two steps meant the crew got as low as 2,000 ft. during the recovery.

The Ethiopian Ministry of Transport preliminary report on the Mar. 10 ET302 accident suggests the crew attempted to use manual trim after de-powering the stabilizer motors, but determined it “was not working,” the report said. A constant trust setting at 94% N1 meant ET302’s airspeed increased to the 737 MAX’s maximum (Vmo), 340 kt., soon after the stabilizer trim motors were cut off, and did not drop below that level for the remainder of the flight. The pilots, struggling to keep the aircraft from descending, also maintained steady to strong aft control-column inputs from the time MCAS first fired through the end of the flight.

The U.S. crew’s session and a video posted recently by YouTube’s Mentour Pilot that shows a similar scenario inside a simulator suggest that the resulting forces on ET302’s stabilizer would have made it nearly impossible to move by hand.

Neither the current 737 flight manual nor any MCAS-related guidance issued by Boeing in the wake of the October 2018 crash of Lion Air Flight 610 (JT610), when MCAS first came to light for most pilots, discuss the roller-coaster procedure for recovering from severe out-of-trim conditions. The 737 manual explains that “effort required to manually rotate the stabilizer trim wheels may be higher under certain flight conditions,” but does not provide details.


The bland and dry EAD is not going to prepare pilots for the shock of the reality. Overload from alerts and the shock of the plane diving down when you have barely left the ground. Then the manual trim control is impossible to move. Then you only have a few minutes to get it right.


Yet - the U.S. crew screwed up the procedure as well by not using Electric trim to return the plane to in-trim before hitting the cut-offs.


This was on purpose it seems which is why that simulation made no sense. They simulated what would happen AFTER electric trim was already cut and called it a critical part of the ET flight. They should have simulated recovering from the initial failure when flaps were retracted.
 
Aviation737
Posts: 45
Joined: Sun Nov 25, 2018 1:53 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 2:46 am

Update from Silkair on their MAX orders.
https://www.channelnewsasia.com/news/si ... s-11542090
They are still committed to the aircraft.
 
prebennorholm
Posts: 6911
Joined: Tue Mar 21, 2000 6:25 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 3:47 am

LH452 wrote:
In the updated software, what is the max travel of the stab?

As I undertand it, it will neither be the original 0.6 deg, nor the implemented 2.5 deg. Or some fixed value in between.

Instead the new software will use available data to calculate a max stab travel to be whatever value which still allows minimum +1.5 g with full up-elevator on the yoke.

So three major MCAS changes:
- "intelligent limit" (as above)
- only one activation per AoA event
- disabled in case of AoA disagree
Always keep your number of landings equal to your number of take-offs
 
Virtual737
Posts: 526
Joined: Tue Jul 19, 2016 6:16 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 5:24 am

Moose135 wrote:
Maybe I'm missing something but wouldn't you be controlling the pitch manually with column and trim whenever the A/P isn't engaged, regardless of how you got to that state? Why should it be a separate step on the checklist? The way it is written, it sounds like a reminder of standard pilot procedure.


Boeing put it on the checklist. If its there, it should be clear.

GalaxyFlyer wrote:

If we need a checklist step instructing pilots to control pitch with the column and manual electric trim; training is far, FAR worse than I imagined.

GF


...yet Boeing clearly thought it should be on the checklist, as they put it there.

AABusDrvr wrote:
GalaxyFlyer wrote:
If we need a checklist step instructing pilots to control pitch with the column and manual electric trim; training is far, FAR worse than I imagined.

GF


That’s a massive understatement.


Again, why is it there then?

morrisond wrote:
Apparently monitoring airspeed and controlling thrust with the Throttles to keep it from over or underspend should be on the checklist as well.

Maybe also they should add "Check Engines are on"


...but only for exported 737s, right?
 
AABusDrvr
Posts: 33
Joined: Sat Dec 03, 2016 6:48 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 6:39 am

Virtual737 wrote:
Moose135 wrote:
Maybe I'm missing something but wouldn't you be controlling the pitch manually with column and trim whenever the A/P isn't engaged, regardless of how you got to that state? Why should it be a separate step on the checklist? The way it is written, it sounds like a reminder of standard pilot procedure.


Boeing put it on the checklist. If its there, it should be clear.

GalaxyFlyer wrote:

If we need a checklist step instructing pilots to control pitch with the column and manual electric trim; training is far, FAR worse than I imagined.

GF


...yet Boeing clearly thought it should be on the checklist, as they put it there.

AABusDrvr wrote:
GalaxyFlyer wrote:
If we need a checklist step instructing pilots to control pitch with the column and manual electric trim; training is far, FAR worse than I imagined.

GF


That’s a massive understatement.


Again, why is it there then?

morrisond wrote:
Apparently monitoring airspeed and controlling thrust with the Throttles to keep it from over or underspend should be on the checklist as well.

Maybe also they should add "Check Engines are on"


...but only for exported 737s, right?


Why is it there? Attorneys.

Any "pilot" who requires a checklist note to remind him or herself to control the airplane via the primary flight controls, has no business at all sitting in a jumpseat, let alone a pilot seat. On any airplane, anywhere in the world.
 
XRAYretired
Posts: 368
Joined: Fri Mar 15, 2019 11:21 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 7:20 am

planecane wrote:
morrisond wrote:
RickNRoll wrote:

The reality of the situation versus the dry, low key tone of the EDA and NNC don't let pilots in on the reality of experiencing MCAS failure.

https://news.ycombinator.com/item?id=19902068



The bland and dry EAD is not going to prepare pilots for the shock of the reality. Overload from alerts and the shock of the plane diving down when you have barely left the ground. Then the manual trim control is impossible to move. Then you only have a few minutes to get it right.


Yet - the U.S. crew screwed up the procedure as well by not using Electric trim to return the plane to in-trim before hitting the cut-offs.


This was on purpose it seems which is why that simulation made no sense. They simulated what would happen AFTER electric trim was already cut and called it a critical part of the ET flight. They should have simulated recovering from the initial failure when flaps were retracted.

They simulated exactly what they intended to simulate which was recovery (or virtual impossibility of recovery) once trim cut-out was selected. No screw up at all.

Ray
 
User avatar
hilram
Posts: 726
Joined: Wed Aug 20, 2014 11:12 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 7:27 am

Revelation wrote:
Yet that's not how things work for any aircraft currently in service.

It's clear the A320 is much more automated than the 737 is, yet even it is "certified with the system and pilot working together" and Airbus does not take on the burden of determining if the pilots are trained to the point where they can perform all the procedures they need to perform when the automation fails or sensors deliver inaccurate information. They document the procedures, then they let the regulators certify the documents, and expect the national authorities to verify the pilots are trained to the level they need to be trained to for safe operation of the aircraft.

(...)

(My emphasis in Bold)

Yet in this particular case, Boeing
a) Did not initially document the procedure - as the entire system was kept unknown to airlines and pilots, resulting in Lion Air crash.
b) Did eventually document a procedure - issuing the MCAS Bulletin - but writing it in such an ambivalent way - not putting emphasis on using electric trim until stab level before cutoff - so that ET pilots were unable to use manual trim to save their flight

Two crashes because of lack of transparency, a requirement to shoehorn a system in without extra Pilot training, badly implemented design, lack of proper documentation, and poor quality control when documentation finally came out.

I wish I were a fly on the wall in the discussions leading up to the decisions of
a) Making MCAS one-sensor only
b) Keeping it hidden from airlines and pilots

I guess whenever somebody in the room tried to be the Devil's advocate, considering worst case scenario, someone senior in the room must have repeatedly circled back to best case scenario, just like in the NASA meetings before the Columbia accident, after video footage revealed the spaceship had been struck by debris at launch.. :ill:
Flown on: A319, 320, 321, 332, 333, 343 | B732, 734, 735, 736, 73G, 738, 743, 744, 772, 77W | BAe-146 | DHC-6, 7, 8 | F50 | E195 | MD DC-9 41, MD-82, MD-87
 
XRAYretired
Posts: 368
Joined: Fri Mar 15, 2019 11:21 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 8:21 am

MSPNWA wrote:
mysfit wrote:
I thought the CVR indicated the FO stated he couldn't turn the wheel.


No, the FO didn't say anything specifically about the trim wheel. It can't be confirmed that either attempted the maneuver. It may have occurred, but the information made public doesn't confirm it. Instead it raises doubts that it was attempted.


There are only two options available: MANUAL electric TRIM and MANUAL TRIM wheel.

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 the First-Officer replied that it is not working.

I think it is unlikely that the F/O would use two different terms for the same function in the same sentence and would not be asking the Capt. to confirm trying the same function for a second time using two terms. But two terms are used. The only satisfactory conclusion is that the F/O is referring to both functions. The question is which term refers to which function.

My suggestion is that, remembering that it was FO that offered STAB TRIM CUT-OUT ~1 min. before hand and the Capt. seemed unsure in his response, that the Capt. was asking for confirmation that manual electric TRIM was not available, that the FO confirmed not working, because it was in cut-out, and then suggested to try MANUAL trim wheel -also not working.

Ray
 
bcg
Posts: 2
Joined: Sat Apr 27, 2019 9:35 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 8:25 am

in the MCAS v1, are the pilots able to override the MCAS with manual electric trim after MCAS kicks in for 10s of 0.25/s?

say 5s of MCAS and then pilot intervenes with manual electric trim in the opposite direction?
 
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PixelFlight
Posts: 432
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 9:47 am

bcg wrote:
in the MCAS v1, are the pilots able to override the MCAS with manual electric trim after MCAS kicks in for 10s of 0.25/s?

Yes. The MCAS stop as soon as a pilot use the manual electric stab trim. This is observable for example in the FDR trace of the JT610 preliminary report.
One of the main issue of the MCAS v1 is that it reset itself after 5 seconds and generate a new command again and again as long as a single AoA value is high.
The fixed MCAS v2 will only generate a single command for a high AoA value cycle. Applied to the JT043, JT610 and ET302, this fix alone would have stabilized the situation after the first manual electric stab trim correction that each crews have done, without the need to used the cutoff switch. There are two others fixes publicly know to be in the MCAS v2: two AoA sensors comparison, and extreme out of trim protection to grant the stab elevator authority.
 
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SomebodyInTLS
Posts: 1633
Joined: Wed Jun 15, 2016 12:31 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 10:20 am

MrBretz wrote:
Some more bad news: 737 MAX simulators don't properly simulate all the force needed to turn the trim wheels....

https://www.nytimes.com/2019/05/17/busi ... ators.html


This is not a surprise, of course... Simulators are designed to reproduce expected behaviour, not unplanned behaviour.
"As with most things related to aircraft design, it's all about the trade-offs and much more nuanced than A.net likes to make out."
 
kalvado
Posts: 1743
Joined: Wed Mar 01, 2006 4:29 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 11:14 am

SomebodyInTLS wrote:
MrBretz wrote:
Some more bad news: 737 MAX simulators don't properly simulate all the force needed to turn the trim wheels....

https://www.nytimes.com/2019/05/17/busi ... ators.html


This is not a surprise, of course... Simulators are designed to reproduce expected behaviour, not unplanned behaviour.

Which brings the question how accurate are published sim videos, e.g. mentourpilot one;and if limitations of trim wheel were understood previously but that knowledge dissipated. Mere fact that trim wheel forces can be simulated at all in the sim and drivers are powerful enough to exercise high force indicates it was a concern at some point.
 
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hilram
Posts: 726
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 11:15 am

Does anyone have a current estimate of how much the grounding has cost Boeing so far?

I would like to compare those numbers to how much it would have cost Boeing in penalties, had they designed MCAS v2 from the Get-Go, plus included AOA disagree for every plane with no extra 100K fee for this "feature".

As we know, this could/would have led to difference training requirements / Simulator time. Which would mean a million dollar fine per plane delivered to Southwest. (Also American Airlines?)


So to calculate:
280 planes for Southwest = 280 Million Dollars "fine"
100 planes for American Airlines = 100 Million Dollars "fine"

Plus 100k in lost revenue for the AOA disagree "option" for roughly 20% of the order total of ~5000 planes = another 100 million
Altogether 480 Million Dollars - my early "guesstimate" of what it would have cost to "Always put Safety First".

Is it safe to say that this mess has cost Boeing over 1 BN dollars so far? In addition to the horror of lives lost, public scrutiny, a tarnished reputation etc.?

Shareholders should be demanding somebody's head on a platter!
Flown on: A319, 320, 321, 332, 333, 343 | B732, 734, 735, 736, 73G, 738, 743, 744, 772, 77W | BAe-146 | DHC-6, 7, 8 | F50 | E195 | MD DC-9 41, MD-82, MD-87
 
planecane
Posts: 759
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 11:31 am

XRAYretired wrote:
planecane wrote:
morrisond wrote:

Yet - the U.S. crew screwed up the procedure as well by not using Electric trim to return the plane to in-trim before hitting the cut-offs.


This was on purpose it seems which is why that simulation made no sense. They simulated what would happen AFTER electric trim was already cut and called it a critical part of the ET flight. They should have simulated recovering from the initial failure when flaps were retracted.

They simulated exactly what they intended to simulate which was recovery (or virtual impossibility of recovery) once trim cut-out was selected. No screw up at all.

Ray

Well it was disingenuous. A laymen isn't going to make the distinction and then a bunch of media referenced the simulation saying that an American crew struggled to recover from a "critical" part of the ET flight and needed more altitude than ET had. This "Cliff's notes" version paints the picture that the incident was unrecoverable by an American crew.
 
planecane
Posts: 759
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 11:33 am

hilram wrote:
Does anyone have a current estimate of how much the grounding has cost Boeing so far?

I would like to compare those numbers to how much it would have cost Boeing in penalties, had they designed MCAS v2 from the Get-Go, plus included AOA disagree for every plane with no extra 100K fee for this "feature".

As we know, this could/would have led to difference training requirements / Simulator time. Which would mean a million dollar fine per plane delivered to Southwest. (Also American Airlines?)


So to calculate:
280 planes for Southwest = 280 Million Dollars "fine"
100 planes for American Airlines = 100 Million Dollars "fine"

Plus 100k in lost revenue for the AOA disagree "option" for roughly 20% of the order total of ~5000 planes = another 100 million
Altogether 480 Million Dollars - my early "guesstimate" of what it would have cost to "Always put Safety First".

Is it safe to say that this mess has cost Boeing over 1 BN dollars so far? In addition to the horror of lives lost, public scrutiny, a tarnished reputation etc.?

Shareholders should be demanding somebody's head on a platter!


AoA disagree was not intended to be an option. The option was for a display of the AoA. That was an error that it wasn't included. Also, it wouldn't have changed anything with respect to these incidents.
 
User avatar
PixelFlight
Posts: 432
Joined: Thu Nov 08, 2018 11:09 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 12:22 pm

planecane wrote:
PixelFlight wrote:
planecane wrote:
I guess I can see what you are saying. The way I read it, it is part of step 2. I think it is just treated kind of like common sense basically saying "fly the airplane."

The common sens will not guess that the pilot have only maximum 5 seconds to go from the second indented (could be misinterpreted as only if AP engaged) point 2 to the first indented (could be misinterpreted due to MCAS discontinue action) point 5, and that all the next points can't be done at high speed. Under stress and without appropriate specific training, this procedure as redacted could easily be error prone.


Don't focus on MCAS in this case. If the training isn't adequate for runaway stabilizer then it is an issue for ALL causes of runaway stabilizer. If they (specifically the ET crew) didn't run the NNC properly for an MCAS induced runaway stabilizer, they wouldn't have run it properly for runaway stabilizer caused by something else.

I would like to know exactly the training that pilots of airlines operating the 747-8/9 MAX have followed about runaway stabilizer. As the 737-8/9 MAX was designed to minimize difference with the 737-800/900 NG, it's likely that there simply have the exact same runaway stabilizer training as of the 737-800/900 NG pilots, and likely this is not so different than for the pilots trained for the previous 737 models.

Maybe some 737 pilots out there can describes how a runaway stabilizer training simulator session look like on his airline, so we can understand what the pilots are prepared to handle.
 
mjoelnir
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 12:23 pm

planecane wrote:
hilram wrote:
Does anyone have a current estimate of how much the grounding has cost Boeing so far?

I would like to compare those numbers to how much it would have cost Boeing in penalties, had they designed MCAS v2 from the Get-Go, plus included AOA disagree for every plane with no extra 100K fee for this "feature".

As we know, this could/would have led to difference training requirements / Simulator time. Which would mean a million dollar fine per plane delivered to Southwest. (Also American Airlines?)


So to calculate:
280 planes for Southwest = 280 Million Dollars "fine"
100 planes for American Airlines = 100 Million Dollars "fine"

Plus 100k in lost revenue for the AOA disagree "option" for roughly 20% of the order total of ~5000 planes = another 100 million
Altogether 480 Million Dollars - my early "guesstimate" of what it would have cost to "Always put Safety First".

Is it safe to say that this mess has cost Boeing over 1 BN dollars so far? In addition to the horror of lives lost, public scrutiny, a tarnished reputation etc.?

Shareholders should be demanding somebody's head on a platter!


AoA disagree was not intended to be an option. The option was for a display of the AoA. That was an error that it wasn't included. Also, it wouldn't have changed anything with respect to these incidents.


A very nice and very lame excuse.

AoA disagree warning was a standard feature not an option when the MAX was sold. Explained in the manuals. It took Boeing 13 month after realizing that it did not work, to inform customers and the FAA that that standard feature was not working.
And could you explain exactly, how a warning about the fault, that initiated both deadly accidents, would not have helped the pilots to better understand what was happening?
 
Ertro
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 12:27 pm

planecane wrote:
AoA disagree was not intended to be an option. The option was for a display of the AoA. That was an error that it wasn't included. Also, it wouldn't have changed anything with respect to these incidents.


Maybe they wouldn't or maybe they could have changed something on these specific flights but what about possible warnings on other flights?

What about a theory that the lack of observed warnings seen on a display device that pilots thought was present could send a false negative indication convincing people that there are no problems with the AoA related systems.

If there would have been such a display it could have blinked warnings on previous flights and on other airlines other planes making everybody more alert and maybe start ball rolling to fix things before even the first Lion Air crash.

And if pilots would have known that there does not exists such a display that would also have been better situation since such completely missing device cannot send false negative indications.
 
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hilram
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 12:43 pm

Ertro wrote:
What about a theory that the lack of observed warnings seen on a display device that pilots thought was present could send a false negative indication convincing people that there are no problems with the AoA related systems.

:checkmark:

Food for thought. And lawyers.
Flown on: A319, 320, 321, 332, 333, 343 | B732, 734, 735, 736, 73G, 738, 743, 744, 772, 77W | BAe-146 | DHC-6, 7, 8 | F50 | E195 | MD DC-9 41, MD-82, MD-87
 
MrBretz
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 2:46 pm

kalvado wrote:
SomebodyInTLS wrote:
MrBretz wrote:
Some more bad news: 737 MAX simulators don't properly simulate all the force needed to turn the trim wheels....

https://www.nytimes.com/2019/05/17/busi ... ators.html


This is not a surprise, of course... Simulators are designed to reproduce expected behaviour, not unplanned behaviour.

Which brings the question how accurate are published sim videos, e.g. mentourpilot one;and if limitations of trim wheel were understood previously but that knowledge dissipated. Mere fact that trim wheel forces can be simulated at all in the sim and drivers are powerful enough to exercise high force indicates it was a concern at some point.


I seem to recall the pulled Mentour pilot video showed the trim wheels were all but impossible to turn under similar conditions. They were done in a 737, not MAX, simulator weren’t they?
 
GalaxyFlyer
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 3:02 pm

Agrajag wrote:
I am very interested to know what the Boeing defenders on these pages honestly think about Boeing's assertion that there were "no technical gaps or slips" with regards to MCAS implementation. Be honest now.


Completely disagree with Boeing’s assertion, their sales and contracts groups should never have agreed to the penalty in the event Level D was ultimately required by the certification authorities. They should never have released the system dependent on a single sensor. That contract started a lot of this nonsense. That said, any pilot in an airliner should not have any difficulty hand flying it. The required action to trim opposite the MCAS input should be as automatic as anything in flying.

I believe complacency has overcome sound judgement in many areas of aviation. Complacency in design, in training and in line operations. Too many assumptions that it’ll all work out because it has. Aircraft reliability has covered for a lot of sins. 10,000 hours now means 200 hours of flying and 9,800 hours of watching an autopilot fly.

GF
 
GalaxyFlyer
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 3:04 pm

MrBretz wrote:
kalvado wrote:
SomebodyInTLS wrote:

This is not a surprise, of course... Simulators are designed to reproduce expected behaviour, not unplanned behaviour.

Which brings the question how accurate are published sim videos, e.g. mentourpilot one;and if limitations of trim wheel were understood previously but that knowledge dissipated. Mere fact that trim wheel forces can be simulated at all in the sim and drivers are powerful enough to exercise high force indicates it was a concern at some point.


I seem to recall the pulled Mentour pilot video showed the trim wheels were all but impossible to turn under similar conditions. They were done in a 737, not MAX, simulator weren’t they?


If you let the plane get out of trim and speed gets away from you, it will be impossible to move the man trim. Been that way since the Dash 80.

GF
 
bgm
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 4:00 pm

GalaxyFlyer wrote:
Agrajag wrote:
I am very interested to know what the Boeing defenders on these pages honestly think about Boeing's assertion that there were "no technical gaps or slips" with regards to MCAS implementation. Be honest now.


Completely disagree with Boeing’s assertion, their sales and contracts groups should never have agreed to the penalty in the event Level D was ultimately required by the certification authorities. They should never have released the system dependent on a single sensor. That contract started a lot of this nonsense. That said, any pilot in an airliner should not have any difficulty hand flying it. The required action to trim opposite the MCAS input should be as automatic as anything in flying.

I believe complacency has overcome sound judgement in many areas of aviation. Complacency in design, in training and in line operations. Too many assumptions that it’ll all work out because it has. Aircraft reliability has covered for a lot of sins. 10,000 hours now means 200 hours of flying and 9,800 hours of watching an autopilot fly.

GF


And yet flying is much safer now than it was back in the 'good old days' you reminisce about when there was more hand flying and less automation. The single biggest cause of aircraft accidents has been, is, and always will be, pilot error.

This is why the MAX crashes are so unusual. It's Boeing that screwed up, and they cut corners to save money and put a ticking time bomb in every frame.
The Boeing 737 MAX: aviation's most notorious lawn dart.
 
Vladex
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 4:20 pm

par13del wrote:
Venatt wrote:
Some people in Boeing should be behind bars.

We could explore that, where do you suggest we start, engineers who coded, supervisors who approved, FAA inspectors who certified, Boeing CEO because the buck stops there?


In is probably the shareholders/investors and probably something like Southwest and American airlines who nudged the B. into the course of action. The former ones wanted something and whatever immediate and the latter ones wanted something cheaper. I don't see any internal conspiracy. There was probably some unwitting collusion from within with outsiders . B. is also a victim of outside interference which is one of the downfalls of being a public company. The problem is that they can't do anything about it right now as any public company is beholden to investors and the biggest customers. This is the reason why there is so much confusion and misdirection about the whole issue
 
GalaxyFlyer
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 5:06 pm

bgm wrote:
GalaxyFlyer wrote:
Agrajag wrote:
I am very interested to know what the Boeing defenders on these pages honestly think about Boeing's assertion that there were "no technical gaps or slips" with regards to MCAS implementation. Be honest now.


Completely disagree with Boeing’s assertion, their sales and contracts groups should never have agreed to the penalty in the event Level D was ultimately required by the certification authorities. They should never have released the system dependent on a single sensor. That contract started a lot of this nonsense. That said, any pilot in an airliner should not have any difficulty hand flying it. The required action to trim opposite the MCAS input should be as automatic as anything in flying.

I believe complacency has overcome sound judgement in many areas of aviation. Complacency in design, in training and in line operations. Too many assumptions that it’ll all work out because it has. Aircraft reliability has covered for a lot of sins. 10,000 hours now means 200 hours of flying and 9,800 hours of watching an autopilot fly.

GF



And yet flying is much safer now than it was back in the 'good old days' you reminisce about when there was more hand flying and less automation. The single biggest cause of aircraft accidents has been, is, and always will be, pilot error.

This is why the MAX crashes are so unusual. It's Boeing that screwed up, and they cut corners to save money and put a ticking time bomb in every frame.


Well, yes and no. Two upgrades did the majority of the reduction in risk—EGPWS with terrain displayed and Nav Displays eliminated CFIT and TCAS eliminated mid-airs. When I went from steam sugars to a glass cockpit, I was stunned my the difference in situational awareness. Having flown into mountainous airports in the “good old days”, accurately drawing a mental picture of the how the terrain was in relation to the routing was a tough skill to acquire and a minor error was an accident. Pretty difficult error to make know with the map display and EGPWS as a back-up. Put those upgrades into a 707 and the comparison would be more accurate. It’s apples and oranges. Then, CRM eliminated Skygod stupidity. But, the good pilots in the old days were naturals at CRM. I flew with several pilots from the ‘50s and 60s who were great at CRM and morons that were terrible. Still true at some operations.

It’s safer due to equipment reliability and better information to the pilots; not because the old guys were bozos and the new guys are Luke Skywalkers. I’m not reminiscing about the good old days, I certainly wouldn’t want to fly that equipment into places like Aspen or Yerevan again.
 
art
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 5:28 pm

Know what? Before the MAX crashes I had a great respect for Boeing. Their management by their subsequent deceit and lack of real interest in protecting people flying in the MAX have managed to seriously tarnish the company's image for me. I won't be happy to fly on the aircraft until non-FAA agencies - without any pressure or obfuscation from Boeing or FAA - have had a thorough look at the certification of the aircraft and at MCAS 2.

And I hope this all costs Boeing tens of billions so that they won't ever dare compromising passenger safety again as they did with this design update.
 
kalvado
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 5:51 pm

GalaxyFlyer wrote:
MrBretz wrote:
kalvado wrote:
Which brings the question how accurate are published sim videos, e.g. mentourpilot one;and if limitations of trim wheel were understood previously but that knowledge dissipated. Mere fact that trim wheel forces can be simulated at all in the sim and drivers are powerful enough to exercise high force indicates it was a concern at some point.


I seem to recall the pulled Mentour pilot video showed the trim wheels were all but impossible to turn under similar conditions. They were done in a 737, not MAX, simulator weren’t they?


If you let the plane get out of trim and speed gets away from you, it will be impossible to move the man trim. Been that way since the Dash 80.

GF

My point is that someone bothered to design that wheel force emulator for the sim, at least for NG one - and probably thought it is important to have that emulation.
There are quite a few messages here that trim wheel is easy to operate (when it is close to the proper position, apparently).
Now NYT reports that "The simulators did not reflect the immense force that it would take for pilots to regain control of the aircraft once the system activated on a plane traveling at a high speed."
At least one popular video - one by MentourPilot - showed high forces on both yoke and trim wheel, and that sounds as an accurate simulation of actual flight. But things don't quite add up for me with NYT statement.
Were those forces lower than in actual airplane? Or MAX sims had those force feedback servos removed/downgraded? NYT reporting wrong? SOmething else?
 
planecane
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 6:03 pm

mjoelnir wrote:
planecane wrote:
hilram wrote:
Does anyone have a current estimate of how much the grounding has cost Boeing so far?

I would like to compare those numbers to how much it would have cost Boeing in penalties, had they designed MCAS v2 from the Get-Go, plus included AOA disagree for every plane with no extra 100K fee for this "feature".

As we know, this could/would have led to difference training requirements / Simulator time. Which would mean a million dollar fine per plane delivered to Southwest. (Also American Airlines?)


So to calculate:
280 planes for Southwest = 280 Million Dollars "fine"
100 planes for American Airlines = 100 Million Dollars "fine"

Plus 100k in lost revenue for the AOA disagree "option" for roughly 20% of the order total of ~5000 planes = another 100 million
Altogether 480 Million Dollars - my early "guesstimate" of what it would have cost to "Always put Safety First".

Is it safe to say that this mess has cost Boeing over 1 BN dollars so far? In addition to the horror of lives lost, public scrutiny, a tarnished reputation etc.?

Shareholders should be demanding somebody's head on a platter!


AoA disagree was not intended to be an option. The option was for a display of the AoA. That was an error that it wasn't included. Also, it wouldn't have changed anything with respect to these incidents.


A very nice and very lame excuse.

AoA disagree warning was a standard feature not an option when the MAX was sold. Explained in the manuals. It took Boeing 13 month after realizing that it did not work, to inform customers and the FAA that that standard feature was not working.
And could you explain exactly, how a warning about the fault, that initiated both deadly accidents, would not have helped the pilots to better understand what was happening?

"Excuse?" I was pointing out that Boeing didn't intend to charge $100k for the AoA disagree warning.

To answer your question, there were other obvious indications of what was going on like stick shaker on one side only. Also, the Lion Air crew would have had absolutely no clue that an AoA disagree would have anything to do with a runaway stabilizer since MCAS was not disclosed at that time. The ET crew did recognize what they were dealing with, they just didn't respond in exactly the manner needed. In neither case would the AoA disagree alert have helped the crew to understand the situation. Would the ET crew have finished trimming out the MCAS nose down trim before they hit the cutout switches if a warning on the PFD said AoA disagree? There is no logical argument to say they would have.
 
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aerolimani
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 7:05 pm

kalvado wrote:
GalaxyFlyer wrote:
MrBretz wrote:

I seem to recall the pulled Mentour pilot video showed the trim wheels were all but impossible to turn under similar conditions. They were done in a 737, not MAX, simulator weren’t they?


If you let the plane get out of trim and speed gets away from you, it will be impossible to move the man trim. Been that way since the Dash 80.

GF

My point is that someone bothered to design that wheel force emulator for the sim, at least for NG one - and probably thought it is important to have that emulation.
There are quite a few messages here that trim wheel is easy to operate (when it is close to the proper position, apparently).
Now NYT reports that "The simulators did not reflect the immense force that it would take for pilots to regain control of the aircraft once the system activated on a plane traveling at a high speed."
At least one popular video - one by MentourPilot - showed high forces on both yoke and trim wheel, and that sounds as an accurate simulation of actual flight. But things don't quite add up for me with NYT statement.
Were those forces lower than in actual airplane? Or MAX sims had those force feedback servos removed/downgraded? NYT reporting wrong? SOmething else?

I'll make a lot of assumptions here, but I think they're fairly safe assumptions.
1) A MAX's manual trim wheel probably behaves very similarly to a Classic or NG. There's no reason to think it would have changed much.
2) The forces were probably being underrepresented in the MAX simulator. The NG simulator (as we saw in the MentourPilot video) shows that in certain flight regimes, very high force is needed to turn the wheel. The NG sims have been around a long time, and surely by now, we would know if they were inaccurate. What are the chances that the MAX sims were overdoing it in regards to force necessary? #
3) The MAX sims most likely have the requisite force feedback mechanisms.
From https://www.reuters.com/article/us-ethi ... SKCN1SO01T:
The spokesman, Gordon Johndroe, said the changes will ensure that the simulator experience is representative across different flight conditions and will improve the simulation of force loads on the manual trim wheel that helps control the airplane.

It takes a little reading between the lines, but it sounds like the ability to simulate the loads exists in the MAX simulators (as we know it does in NG simulators). Rather, Boeing's original simulator software did not specify correctly the behaviour of the manual trim wheels.

In the end, the sim builders can only rely on Boeing to accurately portray the performance of the aircraft.
 
XRAYretired
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 8:41 pm

planecane wrote:
mjoelnir wrote:
planecane wrote:

AoA disagree was not intended to be an option. The option was for a display of the AoA. That was an error that it wasn't included. Also, it wouldn't have changed anything with respect to these incidents.


A very nice and very lame excuse.

AoA disagree warning was a standard feature not an option when the MAX was sold. Explained in the manuals. It took Boeing 13 month after realizing that it did not work, to inform customers and the FAA that that standard feature was not working.
And could you explain exactly, how a warning about the fault, that initiated both deadly accidents, would not have helped the pilots to better understand what was happening?

"Excuse?" I was pointing out that Boeing didn't intend to charge $100k for the AoA disagree warning.

To answer your question, there were other obvious indications of what was going on like stick shaker on one side only. Also, the Lion Air crew would have had absolutely no clue that an AoA disagree would have anything to do with a runaway stabilizer since MCAS was not disclosed at that time. The ET crew did recognize what they were dealing with, they just didn't respond in exactly the manner needed. In neither case would the AoA disagree alert have helped the crew to understand the situation. Would the ET crew have finished trimming out the MCAS nose down trim before they hit the cutout switches if a warning on the PFD said AoA disagree? There is no logical argument to say they would have.


It is possible had AOA DISAGREE been displayed on JT043, the pilot would have recorded it, as well as IAS and Altitude, such that MX would have to address it prior to JT610 getting into the air and may well have resulted in MX taking the correct action. If AOA DISAGREE had been displayed in ET302, it might have coloured their appreciation of the situation and what subsequent actions they took.

Ray
 
kayik
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 9:14 pm

This is from Air Transat's web site

"Following Canada’s Minister of Transports’ announcements concerning the Boeing 737 MAX, we have received a volume of questions about our fleet and our flights’ status. We want to reassure our passengers: Our flights are not affected by this announcement since we do not operate B737 MAX."

...and when you google the airline this comes in the "people also ask" section: Does Air Transat have 737 MAX 8 planes?
 
mjoelnir
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 9:20 pm

planecane wrote:
mjoelnir wrote:
planecane wrote:

AoA disagree was not intended to be an option. The option was for a display of the AoA. That was an error that it wasn't included. Also, it wouldn't have changed anything with respect to these incidents.


A very nice and very lame excuse.

AoA disagree warning was a standard feature not an option when the MAX was sold. Explained in the manuals. It took Boeing 13 month after realizing that it did not work, to inform customers and the FAA that that standard feature was not working.
And could you explain exactly, how a warning about the fault, that initiated both deadly accidents, would not have helped the pilots to better understand what was happening?

"Excuse?" I was pointing out that Boeing didn't intend to charge $100k for the AoA disagree warning.

To answer your question, there were other obvious indications of what was going on like stick shaker on one side only. Also, the Lion Air crew would have had absolutely no clue that an AoA disagree would have anything to do with a runaway stabilizer since MCAS was not disclosed at that time. The ET crew did recognize what they were dealing with, they just didn't respond in exactly the manner needed. In neither case would the AoA disagree alert have helped the crew to understand the situation. Would the ET crew have finished trimming out the MCAS nose down trim before they hit the cutout switches if a warning on the PFD said AoA disagree? There is no logical argument to say they would have.


Trying to babble yourself out of a concrete question. You are just making unsubstantiated statements. The AoA disagree warning would have come on straight after rotation before MCAS ambushed the frame and pilots. First harbinger of trouble. You can not know if it would have made a difference.

If Boeing would not have sabotaged the possibility of training for the MAX, pilots would have known that AoA failure and retracting the flaps would instantly lead to MCAS ambushing the safety of the airplane.
 
WIederling
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 9:40 pm

prebennorholm wrote:
LH452 wrote:
In the updated software, what is the max travel of the stab?

As I undertand it, it will neither be the original 0.6 deg, nor the implemented 2.5 deg. Or some fixed value in between.

Instead the new software will use available data to calculate a max stab travel to be whatever value which still allows minimum +1.5 g with full up-elevator on the yoke.

So three major MCAS changes:
- "intelligent limit" (as above)
- only one activation per AoA event
- disabled in case of AoA disagree


heuristics that will fail unpleasantly on another unrelated data input fault ?
( like for example an intermittend error on one AoA that could masage #2 into action :-)
Murphy is an optimist
 
planecane
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 9:47 pm

mjoelnir wrote:
planecane wrote:
mjoelnir wrote:

A very nice and very lame excuse.

AoA disagree warning was a standard feature not an option when the MAX was sold. Explained in the manuals. It took Boeing 13 month after realizing that it did not work, to inform customers and the FAA that that standard feature was not working.
And could you explain exactly, how a warning about the fault, that initiated both deadly accidents, would not have helped the pilots to better understand what was happening?

"Excuse?" I was pointing out that Boeing didn't intend to charge $100k for the AoA disagree warning.

To answer your question, there were other obvious indications of what was going on like stick shaker on one side only. Also, the Lion Air crew would have had absolutely no clue that an AoA disagree would have anything to do with a runaway stabilizer since MCAS was not disclosed at that time. The ET crew did recognize what they were dealing with, they just didn't respond in exactly the manner needed. In neither case would the AoA disagree alert have helped the crew to understand the situation. Would the ET crew have finished trimming out the MCAS nose down trim before they hit the cutout switches if a warning on the PFD said AoA disagree? There is no logical argument to say they would have.


Trying to babble yourself out of a concrete question. You are just making unsubstantiated statements. The AoA disagree warning would have come on straight after rotation before MCAS ambushed the frame and pilots. First harbinger of trouble. You can not know if it would have made a difference.

If Boeing would not have sabotaged the possibility of training for the MAX, pilots would have known that AoA failure and retracting the flaps would instantly lead to MCAS ambushing the safety of the airplane.

My reply is based on the reality that Boeing didn't disclose anything about MCAS so therefore, especially for Lion Air, an AoA disagree alert wouldn't have made any difference. The entire primary PFD could have said "MCAS FAILURE" and it still would have meant nothing to them.

The ET crew knew they were dealing with an MCAS runaway situation. Adding an AoA disagree alert wouldn't have made them more aware.
 
planecane
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 9:48 pm

XRAYretired wrote:
planecane wrote:
mjoelnir wrote:

A very nice and very lame excuse.

AoA disagree warning was a standard feature not an option when the MAX was sold. Explained in the manuals. It took Boeing 13 month after realizing that it did not work, to inform customers and the FAA that that standard feature was not working.
And could you explain exactly, how a warning about the fault, that initiated both deadly accidents, would not have helped the pilots to better understand what was happening?

"Excuse?" I was pointing out that Boeing didn't intend to charge $100k for the AoA disagree warning.

To answer your question, there were other obvious indications of what was going on like stick shaker on one side only. Also, the Lion Air crew would have had absolutely no clue that an AoA disagree would have anything to do with a runaway stabilizer since MCAS was not disclosed at that time. The ET crew did recognize what they were dealing with, they just didn't respond in exactly the manner needed. In neither case would the AoA disagree alert have helped the crew to understand the situation. Would the ET crew have finished trimming out the MCAS nose down trim before they hit the cutout switches if a warning on the PFD said AoA disagree? There is no logical argument to say they would have.


It is possible had AOA DISAGREE been displayed on JT043, the pilot would have recorded it, as well as IAS and Altitude, such that MX would have to address it prior to JT610 getting into the air and may well have resulted in MX taking the correct action. If AOA DISAGREE had been displayed in ET302, it might have coloured their appreciation of the situation and what subsequent actions they took.

Ray


MX replaced the AoA sensor so they knew there was a disagreement and they replaced the bad one.
 
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PixelFlight
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 11:24 pm

planecane wrote:
XRAYretired wrote:
possible had AOA DISAGREE been displayed on JT043, the pilot would have recorded it, as well as IAS and Altitude, such that MX would have to address it prior to JT610 getting into the air and may well have resulted in MX taking the correct action. If AOA DISAGREE had been displayed in ET302, it might have coloured their appreciation of the situation and what subsequent actions they took.

Ray


MX replaced the AoA sensor so they knew there was a disagreement and they replaced the bad one.

Where did you get the information that MX replaced the bad AoA sensor on JT610 ?
 
mjoelnir
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 11:42 pm

planecane wrote:
mjoelnir wrote:
planecane wrote:
"Excuse?" I was pointing out that Boeing didn't intend to charge $100k for the AoA disagree warning.

To answer your question, there were other obvious indications of what was going on like stick shaker on one side only. Also, the Lion Air crew would have had absolutely no clue that an AoA disagree would have anything to do with a runaway stabilizer since MCAS was not disclosed at that time. The ET crew did recognize what they were dealing with, they just didn't respond in exactly the manner needed. In neither case would the AoA disagree alert have helped the crew to understand the situation. Would the ET crew have finished trimming out the MCAS nose down trim before they hit the cutout switches if a warning on the PFD said AoA disagree? There is no logical argument to say they would have.


Trying to babble yourself out of a concrete question. You are just making unsubstantiated statements. The AoA disagree warning would have come on straight after rotation before MCAS ambushed the frame and pilots. First harbinger of trouble. You can not know if it would have made a difference.

If Boeing would not have sabotaged the possibility of training for the MAX, pilots would have known that AoA failure and retracting the flaps would instantly lead to MCAS ambushing the safety of the airplane.

My reply is based on the reality that Boeing didn't disclose anything about MCAS so therefore, especially for Lion Air, an AoA disagree alert wouldn't have made any difference. The entire primary PFD could have said "MCAS FAILURE" and it still would have meant nothing to them.

The ET crew knew they were dealing with an MCAS runaway situation. Adding an AoA disagree alert wouldn't have made them more aware.


An AoA disagree could have made them more aware before MCAS ambushed them. At least for the Ethiopian pilots. Furthermore AoA disagree would have directly indicated to the pilots, why they were getting wrong stall warning and stick shaker.
 
beechnut
Posts: 732
Joined: Wed Apr 21, 2004 12:27 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sat May 18, 2019 11:54 pm

MSPNWA wrote:
mysfit wrote:
I thought the CVR indicated the FO stated he couldn't turn the wheel.


No, the FO didn't say anything specifically about the trim wheel. It can't be confirmed that either attempted the maneuver. It may have occurred, but the information made public doesn't confirm it. Instead it raises doubts that it was attempted.


From the preliminary report:

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.


Beech
 
RickNRoll
Posts: 1620
Joined: Fri Jan 06, 2012 9:30 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 12:04 am

mjoelnir wrote:
planecane wrote:
mjoelnir wrote:

A very nice and very lame excuse.

AoA disagree warning was a standard feature not an option when the MAX was sold. Explained in the manuals. It took Boeing 13 month after realizing that it did not work, to inform customers and the FAA that that standard feature was not working.
And could you explain exactly, how a warning about the fault, that initiated both deadly accidents, would not have helped the pilots to better understand what was happening?

"Excuse?" I was pointing out that Boeing didn't intend to charge $100k for the AoA disagree warning.

To answer your question, there were other obvious indications of what was going on like stick shaker on one side only. Also, the Lion Air crew would have had absolutely no clue that an AoA disagree would have anything to do with a runaway stabilizer since MCAS was not disclosed at that time. The ET crew did recognize what they were dealing with, they just didn't respond in exactly the manner needed. In neither case would the AoA disagree alert have helped the crew to understand the situation. Would the ET crew have finished trimming out the MCAS nose down trim before they hit the cutout switches if a warning on the PFD said AoA disagree? There is no logical argument to say they would have.


Trying to babble yourself out of a concrete question. You are just making unsubstantiated statements. The AoA disagree warning would have come on straight after rotation before MCAS ambushed the frame and pilots. First harbinger of trouble. You can not know if it would have made a difference.

If Boeing would not have sabotaged the possibility of training for the MAX, pilots would have known that AoA failure and retracting the flaps would instantly lead to MCAS ambushing the safety of the airplane.


Exactly. Boeing gambled and chose to play dumb in the hope that the Lion Air accident was a once off. A full explanation of the MCAS failure mode would have made a difference.
 
Agrajag
Posts: 44
Joined: Wed Mar 27, 2019 8:23 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 12:06 am

MSPNWA, it is my suspicion that you are paid by Boeing to be on these pages.

It is also clear that they are not getting value for money.
The plural of anecdote is anecdotes, not data.
Slartibartfast had a point
 
PixelPilot
Posts: 245
Joined: Tue Jan 16, 2018 1:19 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 12:45 am

Agrajag wrote:
MSPNWA, it is my suspicion that you are paid by Boeing to be on these pages.

It is also clear that they are not getting value for money.


New acc, joined last month.
Does that make you airbus employee?

LOL. Children.
 
User avatar
7BOEING7
Posts: 2994
Joined: Fri Oct 12, 2012 5:28 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Sun May 19, 2019 1:23 am

mjoelnir wrote:

An AoA disagree could have made them more aware before MCAS ambushed them. At least for the Ethiopian pilots. Furthermore AoA disagree would have directly indicated to the pilots, why they were getting wrong stall warning and stick shaker.


The don't need that information they just need to do the checklist(s) -- which it appears they weren't up to doing.

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