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MAX’s Return Delayed by FAA Reevaluation of 737 Safety Procedures

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MAX’s Return Delayed by FAA Reevaluation of 737 Safety Procedures

Old 30th Oct 2019, 03:18
  #3561 (permalink)  
 
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Originally Posted by Australopithecus View Post


we were discussing the stall warning on take-off Hans, not the opposite AF447 case which was a different scenario that was always going to result in a stall. I am sorry that you dislike my tone, and I am sorry to have employed understatement by writing “useful” when yes, it should have been mandatory to have three independent alpha sources.

Stall recovery has evolved over the years from trying to power out of it while loosing minimum altitude to the current positive and deliberate reduction in pitch (and hence, it is assumed, alpha). The stall warning on take-off case isn’t currently addressed, and a tiny AoA disagree message, if fitted, surely wouldn’t be the key to detecting a nuisance warning.
Thanks.
Yes, definitely agree that B idea of crew alerting needs work. Cannot switch off the Stick shaker even after positively identifying the problem, tiny little AOA disagree in the corner of the display. It might have been okay in 1967, but it is not today, and when they put the big screens in the NG it should have been required to change the overhead as well, and install some sort of EICAS. Every other B product of that era is vastly superior as far as cockpit design is concerned. They put out the new B757/767/777 around the same time. The biggest one: the B747-400. Same type rating as the -300 and look at the cockpit:
https://www.quora.com/What-is-the-di...Boeing-747-400 (look at the overhead panel!!). There is no justification, and when "designing" the MAX the FAA should have stepped in and said no.
Having said that, and having read the Lion Air report, there is plenty of butter to pass around. It took the FO 4 minutes to find the MEMORY ITEMS IN THE QRH (!!!), while talking to ATC about headings and altitudes. Training & checking (because I don't believe it is just a training issue) needs to improve big time.
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Old 30th Oct 2019, 03:21
  #3562 (permalink)  
 
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Originally Posted by hans brinker View Post
Thanks.
Yes, definitely agree that B idea of crew alerting needs work. Cannot switch off the Stick shaker even after positively identifying the problem, tiny little AOA disagree in the corner of the display. It might have been okay in 1967, but it is not today, and when they put the big screens in the NG it should have been required to change the overhead as well, and install some sort of EICAS. Every other B product of that era is vastly superior as far as cockpit design is concerned. They put out the new B757/767/777 around the same time. The biggest one: the B747-400. Same type rating as the -300 and look at the cockpit:
https://www.quora.com/What-is-the-di...Boeing-747-400 (look at the overhead panel!!). There is no justification, and when "designing" the MAX the FAA should have stepped in and said no.
Having said that, and having read the Lion Air report, there is plenty of butter to pass around. It took the FO 4 minutes to find the MEMORY ITEMS IN THE QRH (!!!), while talking to ATC about headings and altitudes. Training & checking (because I don't believe it is just a training issue) needs to improve big time.
Daar ben ik het volledig mee eens

or: I agree wholeheartedly.
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Old 30th Oct 2019, 03:28
  #3563 (permalink)  
 
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I can confidently say I have read every single MAX post on these (and a few other) forums, and I think it is time to repeat a question that has not been answered by Boeing.
If you have a real runaway trim B expects you to take action in 3 seconds, and save the day. When they designed the MAX, they found the stick force to light in certain regions of the envelope, so they introduced a 10 second runaway trim. If the pilot responds the way B expects they will cut-off the trim so the solution to the stick force problem doesn't work. How was this ever certified?????
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Old 30th Oct 2019, 05:29
  #3564 (permalink)  
 
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I watched the hearings after Indonesian and at the time it was all about blaming the foreign-trained pilots and telling the foreign victims relatives “too bad”., with the unions confirming their entire confidence in the plane.

It’s worth looking that up on Cspan.
I told my friends another 737 Max would go down, it did.

All these guys on the dais are superb actors, but they make their living as lice on the industry.
Edmund

Originally Posted by Zeffy View Post
Live Senate hearings:
https://www.commerce.senate.gov/2019...1-957d0e82f168
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Old 30th Oct 2019, 05:35
  #3565 (permalink)  
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When this is over, I reckon the Board will can Muilenberg. But he'll be allowed to retire with a suitable golden sofa.
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Old 30th Oct 2019, 05:37
  #3566 (permalink)  
 
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Emails:Capt. Mike Forkner, ex 737 Chief Technical Pilot,NYT today..

Can someone please help me understand the following;

1.
"I'm doing a bunch of travelling though the next few months; simulator validations, jedi-mind tricking regulators into accepting the training that I got accepted by the FAA" .

What exactly is "jedi mind tricking" and why was Forkner so busy travelling the world "tricking"?

2.
Why was Boeing's 737 Chief Technical Pilot so busy selling product and not wholly focused on the technical development of a new aeroplane?

Thanks..
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Old 30th Oct 2019, 08:27
  #3567 (permalink)  
 
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DP Davies on stability towards the stall; the FAA

Or - There is nothing new under the sun.

In the following interviews with D.P. Davies, Chief Test Pilot for the CAA and author of Handling the Big Jets, he comments on points of apparent relevance to the 737 Max debacle. I have included a few notes I made in case anyone is interested in easily finding sections of the audio that I think may be relevant. I have included a link to the first interview for completeness - I suspect I have not listened to it.

D.P. Davies interviews

My understanding is that D.P. Davies was the Chief Test Pilot for the Air Registration Board which was later incorporated into the UK CAA. He was for many years in this post effectively the final decision maker on whether to award a UK Certificate of Airworthiness or otherwise. It appears he had a few run-ins with the FAA (indirectly - via US manufacturers who came to him waving an FAA Certificate).

Quotes below were transcribed from the audio for my purposes and may not be accurate. Please refer to the original audio for clarification. I make no comment on the content of these audio recordings and I post the notes here in case anyone is interested in listening to the recordings for themselves and for no other purpose.

1.
Description -
https://www.aerosociety.com/news/aud...ing-the-1940s/
Interview 1992

Audio -

2.
Description -
https://www.aerosociety.com/news/aud...nnia-brabazon/
1992

Audio -

At 3:48 - 4.05
"Elevators overbalanced on the way to the stall."
former CAA Chief Test Pilot D. P. Davies
(1951)

At 1:28:00 - 1:38:00
"707-336 - leading edge devices
Pitch up at stall
Equivalent level or safety
No aeroplane should be allowed to pitch up into the stall
Compromising a fundamental principle of stability in the requirements"
NOT a continuous quote

3.
Description -
https://www.aerosociety.com/news/aud...he-boeing-727/
1992

Audio -

11:15 -- really should listen from start or recording
first 20mins

747-400 Speed Trim

pre 36min - "stick pusher and stick pusher reliability requirements (low because not needed often)" - looks like my paraphrase.

51:30 "Absolute ... FAA" - A comment on integrity of FAA
727

4.
Description -
https://www.aerosociety.com/news/aud...the-v-bombers/
1992

Audio -

At 37:00
"The FAA lacks courage, political clout, all the American constructors can dominate the FAA for political and economic gain and they do."

Edited to add links to the Audio - The RAeS don't seem to make it that easy and I had forgotten that my RAeS links were not to the audio. I feel that there might be more use made of these amazing recordings if they were easier to access. There are I think hundreds of them.

Last edited by jimjim1; 30th Oct 2019 at 09:06. Reason: small adjustments for clarity
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Old 30th Oct 2019, 08:36
  #3568 (permalink)  
 
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Originally Posted by hans brinker View Post
The biggest one: the B747-400. Same type rating as the -300 and look at the cockpit:
Is that true ?
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Old 30th Oct 2019, 08:55
  #3569 (permalink)  
 
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Originally Posted by hans brinker View Post
The way you wrote that I think I am on Mikes side, and your snide reply doesn't help. AF447 was climbing very well while they got closer and closer to stalling, so apparently not that obvious in 5 seconds. It would not have been "useful", it should have been required to have two inputs for MCAS.

The fact that you can't cancel all the erroneous warnings alone is already enough reason the NG should not been certified.
Hi, it seem you are confusing af 447 with some other event.
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Old 30th Oct 2019, 08:57
  #3570 (permalink)  
 
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Quoted post to automagically make links work

Originally Posted by jimjim1 View Post
Or - There is nothing new under the sun.

In the following interviews with D.P. Davies, Chief Test Pilot for the CAA and author of Handling the Big Jets, he comments on points of apparent relevance to the 737 Max debacle. I have included a few notes I made in case anyone is interested in easily finding sections of the audio that I think may be relevant. I have included a link to the first interview for completeness - I suspect I have not listened to it.

D.P. Davies interviews

My understanding is that D.P. Davies was the Chief Test Pilot for the Air Registration Board which was later incorporated into the UK CAA. He was for many years in this post effectively the final decision maker on whether to award a UK Certificate of Airworthiness or otherwise. It appears he had a few run-ins with the FAA (indirectly - via US manufacturers who came to him waving an FAA Certificate).

Quotes below were transcribed from the audio for my purposes and may not be accurate. Please refer to the original audio for clarification. I make no comment on the content of these audio recordings and I post the notes here in case anyone is interested in listening to the recordings for themselves and for no other purpose.

1.
Description -
https://www.aerosociety.com/news/aud...ing-the-1940s/
Interview 1992

Audio -
https://soundcloud.com/aerosociety-p...-fleet-air-arm

2.
Description -
https://www.aerosociety.com/news/aud...nnia-brabazon/
1992

Audio -
https://soundcloud.com/aerosociety-p...terview-comets

At 3:48 - 4.05
"Elevators overbalanced on the way to the stall."
former CAA Chief Test Pilot D. P. Davies
(1951)

At 1:28:00 - 1:38:00
"707-336 - leading edge devices
Pitch up at stall
Equivalent level or safety
No aeroplane should be allowed to pitch up into the stall
Compromising a fundamental principle of stability in the requirements"
NOT a continuous quote

3.
Description -
https://www.aerosociety.com/news/aud...he-boeing-727/
1992

Audio -
https://soundcloud.com/aerosociety-p...iew-boeing-747

11:15 -- really should listen from start or recording
first 20mins

747-400 Speed Trim

pre 36min - "stick pusher and stick pusher reliability requirements (low because not needed often)" - looks like my paraphrase.

51:30 "Absolute ... FAA" - A comment on integrity of FAA
727

4.
Description -
https://www.aerosociety.com/news/aud...the-v-bombers/
1992

Audio -
https://soundcloud.com/aerosociety-p...-the-v-bombers

At 37:00
"The FAA lacks courage, political clout, all the American constructors can dominate the FAA for political and economic gain and they do."

Edited to add links to the Audio - The RAeS don't seem to make it that easy and I had forgotten that my RAeS links were not to the audio. I feel that there might be more use made of these amazing recordings if they were easier to access. There are I think hundreds of them.
I am leaving the original post in the forum so that I can point the support team to the non functioning links.
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Old 30th Oct 2019, 09:03
  #3571 (permalink)  
 
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jimjim1,

He is even more damning about the lateral control and Vcmg and Vcma on the original 707. He required Boeing to modify the rudder. Start at 1.14. 31 into this one:-
https://www.aerosociety.com/news/aud...nnia-brabazon/
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Old 30th Oct 2019, 09:06
  #3572 (permalink)  
 
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In the press today

The chairman of the House Transportation and Infrastructure Committee is quoted by the LA Times as writing:
We now know of at least one case where a Boeing manager implored the then-vice president and general manager of the 737 program to shut down the 737 Max production line because of safety concerns, several months before the Lion Air crash in October 2018,
What is that based on? In particular, what was the safety concern?
____________

Independently: USA Today has an article titled:
FAA admin. on Boeing 737 Max: We're still deciding 'when, whether' plane will fly again
What's the original statement and context?

While I am uncertain that the "whether" is more than rhetorical, as an (insufficiently informed) engineer, I see it as a legitimate question, given in particular uncertainties about
- the physical feasibility of manual trimming as part of a backup procedure, which remains part of the current certification reasoning/charade
- aerodynamic stability in degraded modes with the revised MCAS inop (which is more likely due to the fixes, since one of two redundant sensors fail more often than one sensor).
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Old 30th Oct 2019, 09:26
  #3573 (permalink)  
 
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Things are really going pear-shaped for Boeing when statements like this can be made in a Senate Committee:

Senator Jon Testor:
...told the boss of Boeing: “I would walk before I would get on a 737 Max.
Testor Quotes

IG
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Old 30th Oct 2019, 09:49
  #3574 (permalink)  
 
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Just a stray thought, we know about MCAS and manual trim wheel problems, what else might lurk there? Did the greed produce any other questionable solutions to grandmother problems?
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Old 30th Oct 2019, 10:05
  #3575 (permalink)  
 
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Originally Posted by hans brinker View Post
I can confidently say I have read every single MAX post on these (and a few other) forums, and I think it is time to repeat a question that has not been answered by Boeing.
If you have a real runaway trim B expects you to take action in 3 seconds, and save the day. When they designed the MAX, they found the stick force to light in certain regions of the envelope, so they introduced a 10 second runaway trim. If the pilot responds the way B expects they will cut-off the trim so the solution to the stick force problem doesn't work. How was this ever certified?????
I too was vexed by this but after reading the excellent analysis linked to in post 3536 (the one at Satcom Guru; sorry no permission to link), I think I understand the reasoning.

The expectation was that, faced with sudden pitch changes due to runaway trim, pilots would quickly (the 3-4 seconds) react by correcting with elevator (I can buy that). At that point, the column trim switches that prevent electrical trim in the opposite direction would activate. Thing is, these are precisely the ones that MCAS bypasses to operate against pilot elevator command.

So the next step in my interpretation is that B counted on pilots not reacting to the non-continuous trim inputs of MCAS, which not only are time-limited, but have a 5-second "grace" period between activations. Unlike regular runaways. Hence relying on the runaway trim checklist to downgrade MCAS risk (if that happened) is questionable.

So I'm still thinking that the rationale for simultaneous MCAS operation and safety is a case of having the cake and eating it too.

BTW, the article in Satcom has lots of juicy bits that I guess aren't entering the radar of this thread due to its length.
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Old 30th Oct 2019, 10:11
  #3576 (permalink)  
 
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Originally Posted by robocoder View Post
I too was vexed by this but after reading the excellent analysis linked to in post 3536 (the one at Satcom Guru; sorry no permission to link), I think I understand the reasoning.

The expectation was that, faced with sudden pitch changes due to runaway trim, pilots would quickly (the 3-4 seconds) react by correcting with elevator (I can buy that). At that point, the column trim switches that prevent electrical trim in the opposite direction would activate. Thing is, these are precisely the ones that MCAS bypasses to operate against pilot elevator command.

So the next step in my interpretation is that B counted on pilots not reacting to the non-continuous trim inputs of MCAS, which not only are time-limited, but have a 5-second "grace" period between activations. Unlike regular runaways. Hence relying on the runaway trim checklist to downgrade MCAS risk (if that happened) is questionable.

So I'm still thinking that the rationale for simultaneous MCAS operation and safety is a case of having the cake and eating it too.

BTW, the article in Satcom has lots of juicy bits that I guess aren't entering the radar of this thread due to its length.
One of the highlights, but barely noticed points in the testimony, was when Senator Duckworth asked that Peter Lemme's article be read into the record, and this was accepted with no comments!? This article: https://www.satcom.guru/2019/10/flaw...-disaster.html
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Old 30th Oct 2019, 11:35
  #3577 (permalink)  
 
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When and IF the Max ever flies again, how will this all affect the MAX 10 which is longer and a different beast altogether.
any thoughts out there. ?
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Old 30th Oct 2019, 11:40
  #3578 (permalink)  
 
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No MCAS needed on the -10.
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Old 30th Oct 2019, 12:32
  #3579 (permalink)  
 
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Originally Posted by hans brinker View Post
I can confidently say I have read every single MAX post on these (and a few other) forums, and I think it is time to repeat a question that has not been answered by Boeing.
If you have a real runaway trim B expects you to take action in 3 seconds, and save the day. When they designed the MAX, they found the stick force to light in certain regions of the envelope, so they introduced a 10 second runaway trim. If the pilot responds the way B expects they will cut-off the trim so the solution to the stick force problem doesn't work. How was this ever certified?????
Agree entirely but I'll take it a step further. Who, in their right mind, uses movement of the horizontal stab to correct for stick force non-linearity?
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Old 30th Oct 2019, 12:37
  #3580 (permalink)  
 
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Originally Posted by ktcanuck View Post
Agree entirely but I'll take it a step further. Who, in their right mind, uses movement of the horizontal stab to correct for stick force non-linearity?
Agreed. I remember asking this question months ago...
Maybe, as the STS was there, they thought it convenient to just add a few code lines ?
The declaration of Muilenburg yesterday seems to support the idea : "the MCAS was just an add-on to the STS..."
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