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benbeny
Posts: 240
Joined: Thu Nov 03, 2016 1:44 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 8:12 am

mmo wrote:
enzo011 wrote:

On the second bolded part, do you not think it is a little simple to identify a runaway trim stabilizer when it is not continuously moving AND while you are dealing with two other disagreements with the instruments and a stick shaker at the same time? I think what is apparent with this flight and AF447 is at the end there was too much information for the crews to process and while the solution was simple in either case with hindsight, it is too easy to be smart after the fact.



Personally, I think it's very easy. If you are hand flying the aircraft and the trim wheel moves without you activating it by the trim switches, you have a problem. Very simple. The instrument and the stick shaker are basic airmanship. In the QRH, you have a pitch power chart for unreliable airspeed. if you have climb thrust set and have the correct pitch you are good, the aircraft is climbing and you can concentrate on the highest priority problem. Part of the "airmanship" issue is understanding what you are being told by the aircraft. It is up to the crew to prioritize their actions to ensure they can remain safe. It's the old adage, "Aviate, navigate and communicate", in that order. The accident report cited the distraction by ATC. That is easily remedied by saying, "stand by". ATC can wait, but flying the aircraft can't.


I thought that the report talked about the noise of stick shaker and asked about the noise masking the sound of trim wheel, right? I forgot what's their conclusion, but I think considering the overwhelmed captain then it might be possible.
 
kalvado
Posts: 2932
Joined: Wed Mar 01, 2006 4:29 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 8:16 am

mmo wrote:

Personally, I think it's very easy. If you are hand flying the aircraft and the trim wheel moves without you activating it by the trim switches, you have a problem.

Maybe a different one, though. Trim may be operated by the STS as designed, and the problem is a wrong person in a wrong cockpit.
 
User avatar
flyingphil
Posts: 313
Joined: Wed May 16, 2007 2:56 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 8:59 am

So.. any suggestions for questions that Congress may like to ask DM?

Still no answers on:
#Lack of redundancy of the rudder cables
#Too high surface temperature allowed in the fuel tank
#Insufficient fireproofing around the APU in the tail
#Using high-power wiring to connect a switch inside the fuel tank

and the (MAD)MAX10 . . has it passed its evacuation test yet?
Have you tested the new extendable main landing gear? Is it going to fly soon?

How are your share options?
Will you still be in a job at Christmas?

Anymore suggestions?
 
asdf
Posts: 705
Joined: Tue Mar 18, 2014 12:03 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 9:19 am

SheikhDjibouti wrote:
Are these "problems" identified by Dominic Gates new to the MAX, or grandfathered down from the NG?


if a plane has stable, neutral flight attudides, you never ever need a manual trim wheel at all
the NG is a old concept, but it has neutral attitudes and the STS is kinda primitiv but it is doing what it is supposed to
so moving of the manual trim wheel never ever was a thing what a NG crew desides to do
simply not nesssesary
they even dont do it in the SIM

the MAX is not stable
there is electronic, sensors and aktuators nessesary to cover (augment) that

you need the manual trim wheel if something goes wrong up there with the augmentation and you get out of trim
but out of trim the trim wheel dont work any more

so:
the non functional trim wheel @ the NG is maybe against certification rules, but it doesent really matter
a non functional trim wheel @ the MAX is not aceptable because the chance that the crew need it is pretty high
 
FluidFlow
Posts: 738
Joined: Wed Apr 10, 2019 6:39 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 9:53 am

As the AoA disagree light has not worked up to now, but I hope it will be a standard feature in the future how exactly will an AoA disagree be handled from no going forward. As the AoA sensors are only reliable from a certain speed and chances are high the AoA disagree will only show up close to V1 or above, the crew will get the warning of AoA disagree shortly after or during take off. What procedure will need to be done at that point? I only see two options:

1. Immediate return to the airport, or
2. Fly on with MCAS off which in my opinion will likely need sim training (training how to fly a MAX without MCAS)

Option 1 could have massive implications on the MAX economy, because next to the delay for the passengers you also just burned a ton of fuel for nothing. It is not possible to detect an AoA disagree on the ground just by the way AoA sensors work. Dispatch reliability will be reduced to the reliability of the sensors and as it will need both sensors if one fails it is enough for a return to the airport. For Option 2: That would mean a lot of additional costs for Boeing due to contractual penalties and even airlines that do not have that contractual penalty might be able to sue Boeing for compensation as it was advertised that no additional training was needed.
 
morrisond
Posts: 2862
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 10:07 am

asdf wrote:
SheikhDjibouti wrote:
Are these "problems" identified by Dominic Gates new to the MAX, or grandfathered down from the NG?


if a plane has stable, neutral flight attudides, you never ever need a manual trim wheel at all
the NG is a old concept, but it has neutral attitudes and the STS is kinda primitiv but it is doing what it is supposed to
so moving of the manual trim wheel never ever was a thing what a NG crew desides to do
simply not nesssesary
they even dont do it in the SIM

the MAX is not stable
there is electronic, sensors and aktuators nessesary to cover (augment) that

you need the manual trim wheel if something goes wrong up there with the augmentation and you get out of trim
but out of trim the trim wheel dont work any more

so:
the non functional trim wheel @ the NG is maybe against certification rules, but it doesent really matter
a non functional trim wheel @ the MAX is not aceptable because the chance that the crew need it is pretty high


The manual trim wheels are there in case Electric Trim fails and to give you a visual clue on what the trim is actually doing.

Sometimes a Video is worth a thousand words. Video of the trim wheels in an A320 https://www.youtube.com/watch?v=_4aoSBtOJv4

That is used as a back up in the A320 as well if the electric trim fails.

Good luck with an A320 flying without electronics, sensors and actuators.

Please provide evidence the MAX is unstable - all you can say is that it might be unstable in certain parts of the flight regime and even that claim is highly nebulous and most likely about to be proved wrong. The proof will be when EASA approves the MAX for return to service.

The MAX will not pitch up or down (assuming MCAS is not acting up) or roll side to side unless you do something to its controls.

It is aerodynamically stable and does not require computers to make it fly straight and level like an Fighter.

If they are not practising using the manual trim wheel in the sims that is on the training organization and the pilots - it is a control that can affect the planes flight path and pilots need to be proficient with it.
 
mjoelnir
Posts: 9411
Joined: Sun Feb 03, 2013 11:06 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 10:20 am

mmo wrote:
enzo011 wrote:

On the second bolded part, do you not think it is a little simple to identify a runaway trim stabilizer when it is not continuously moving AND while you are dealing with two other disagreements with the instruments and a stick shaker at the same time? I think what is apparent with this flight and AF447 is at the end there was too much information for the crews to process and while the solution was simple in either case with hindsight, it is too easy to be smart after the fact.



Personally, I think it's very easy. If you are hand flying the aircraft and the trim wheel moves without you activating it by the trim switches, you have a problem. Very simple. The instrument and the stick shaker are basic airmanship. In the QRH, you have a pitch power chart for unreliable airspeed. if you have climb thrust set and have the correct pitch you are good, the aircraft is climbing and you can concentrate on the highest priority problem. Part of the "airmanship" issue is understanding what you are being told by the aircraft. It is up to the crew to prioritize their actions to ensure they can remain safe. It's the old adage, "Aviate, navigate and communicate", in that order. The accident report cited the distraction by ATC. That is easily remedied by saying, "stand by". ATC can wait, but flying the aircraft can't.


STS moves the trim all the time. So you first have to realize that it is not STS doing its normal work. For simple design MCAS was added on top of STS and column cutout removed.

So you should keep your big words like airmanship away from defending a terrible design. And the men machine interface on the 737 is an aged design flooding the pilots with alarms at the same time. That interface is not compliant with current FARs and depends on exemptions from the rules.
 
morrisond
Posts: 2862
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 1:03 pm

mjoelnir wrote:
mmo wrote:
enzo011 wrote:

On the second bolded part, do you not think it is a little simple to identify a runaway trim stabilizer when it is not continuously moving AND while you are dealing with two other disagreements with the instruments and a stick shaker at the same time? I think what is apparent with this flight and AF447 is at the end there was too much information for the crews to process and while the solution was simple in either case with hindsight, it is too easy to be smart after the fact.



Personally, I think it's very easy. If you are hand flying the aircraft and the trim wheel moves without you activating it by the trim switches, you have a problem. Very simple. The instrument and the stick shaker are basic airmanship. In the QRH, you have a pitch power chart for unreliable airspeed. if you have climb thrust set and have the correct pitch you are good, the aircraft is climbing and you can concentrate on the highest priority problem. Part of the "airmanship" issue is understanding what you are being told by the aircraft. It is up to the crew to prioritize their actions to ensure they can remain safe. It's the old adage, "Aviate, navigate and communicate", in that order. The accident report cited the distraction by ATC. That is easily remedied by saying, "stand by". ATC can wait, but flying the aircraft can't.


STS moves the trim all the time. So you first have to realize that it is not STS doing its normal work. For simple design MCAS was added on top of STS and column cutout removed.

So you should keep your big words like airmanship away from defending a terrible design. And the men machine interface on the 737 is an aged design flooding the pilots with alarms at the same time. That interface is not compliant with current FARs and depends on exemptions from the rules.


Do you want to ground the A330 as well?

From the NTSB report

"Multiple alerts and indications in the cockpit can increase pilots’ workload and can also
make it more difficult to identify which procedure the pilots should conduct. The NTSB notes that
the Lion Air and Ethiopian Airlines accident pilots’ responses to multiple alerts and indications are
similar to the circumstances of a 2009 accident involving Air France flight 447, an Airbus A330,
which was traveling from Rio de Janeiro to Paris when it crashed in the Atlantic Ocean.19 In its
accident report, the Bureau d’Enquêtes et d’Analyses Pour la Sécurité de L’aviation Civile (BEA)
concluded that failure messages successively displayed on the electronic centralized aircraft
monitoring system did not allow the crew to rapidly and effectively diagnose the issue (the
blockage of the pitot probes) or make the connection between the messages that appeared and the
procedure to use. Accordingly, the BEA recommended that EASA “study the relevance of having
a dedicated warning provided to the crew when specific monitoring is triggered, in order to
facilitate comprehension of the situation.”
 
morrisond
Posts: 2862
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 1:26 pm

If anyone wants to get out the pitchforks - Muilengurg is about to testify - it will be live on CNBC.

In the press scrum beforehand - he is using his usual platitues " It will be be one of the safest planes"

Asked directly if he will remain CEO - basically says he won't resign but up to the board.

Rightly so - sounding pretty humble.
Last edited by morrisond on Tue Oct 29, 2019 1:32 pm, edited 1 time in total.
 
shmerik
Posts: 68
Joined: Sun May 05, 2019 2:28 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 1:28 pm

shmerik wrote:
Hopefully this isn't considered off topic in this thread, not sure if I should ask in the old ET302 crash thread instead but anyways...

I was looking over the Ethiopian preliminary report again now that we have the final from Indonesia just to go over similarities/differences between the two and noticed something that I hadn't really thought too much of before. It's where the pilot asks the FO to communicate that they're experiencing flight control problems, but this is 3 seconds before the first MCAS AND activation:

At 05:39:57, the Captain advised again the First-Officer to request to maintain runway heading and that they are having flight control problems.


Was this just due to the errors that were going off from the busted AOA vane saying that something is wrong with their instruments or was he already having trouble with flying the plane the way he intended? To people who have looked at more FDR charts than I have think that the outputs from before 05:40:00 look like a standard takeoff? Not suggesting anything is out of place I just don't have a background that would let me figure that out.

It looks like the climb flattens out several seconds before MCAS kicks in for the first time.

Also is this part just writing out explicitly the normal variations experienced while in flight or is there a reason they put it in the report?

Six seconds after the autopilot engagement, there were small amplitude roll oscillations accompanied by lateral acceleration, rudder oscillations and slight heading changes. These oscillations continued also after the autopilot was disengaged.


Thanks


Anyone have an insight into this?
 
FluidFlow
Posts: 738
Joined: Wed Apr 10, 2019 6:39 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 1:58 pm

morrisond wrote:
mjoelnir wrote:
mmo wrote:

Personally, I think it's very easy. If you are hand flying the aircraft and the trim wheel moves without you activating it by the trim switches, you have a problem. Very simple. The instrument and the stick shaker are basic airmanship. In the QRH, you have a pitch power chart for unreliable airspeed. if you have climb thrust set and have the correct pitch you are good, the aircraft is climbing and you can concentrate on the highest priority problem. Part of the "airmanship" issue is understanding what you are being told by the aircraft. It is up to the crew to prioritize their actions to ensure they can remain safe. It's the old adage, "Aviate, navigate and communicate", in that order. The accident report cited the distraction by ATC. That is easily remedied by saying, "stand by". ATC can wait, but flying the aircraft can't.


STS moves the trim all the time. So you first have to realize that it is not STS doing its normal work. For simple design MCAS was added on top of STS and column cutout removed.

So you should keep your big words like airmanship away from defending a terrible design. And the men machine interface on the 737 is an aged design flooding the pilots with alarms at the same time. That interface is not compliant with current FARs and depends on exemptions from the rules.


Do you want to ground the A330 as well?

From the NTSB report

"Multiple alerts and indications in the cockpit can increase pilots’ workload and can also
make it more difficult to identify which procedure the pilots should conduct. The NTSB notes that
the Lion Air and Ethiopian Airlines accident pilots’ responses to multiple alerts and indications are
similar to the circumstances of a 2009 accident involving Air France flight 447, an Airbus A330,
which was traveling from Rio de Janeiro to Paris when it crashed in the Atlantic Ocean.19 In its
accident report, the Bureau d’Enquêtes et d’Analyses Pour la Sécurité de L’aviation Civile (BEA)
concluded that failure messages successively displayed on the electronic centralized aircraft
monitoring system did not allow the crew to rapidly and effectively diagnose the issue (the
blockage of the pitot probes) or make the connection between the messages that appeared and the
procedure to use. Accordingly, the BEA recommended that EASA “study the relevance of having
a dedicated warning provided to the crew when specific monitoring is triggered, in order to
facilitate comprehension of the situation.”


Just to put an end to this endless AF447 thing. Here is the final report, it includes the changes that were implemented by all the different parties:

https://web.archive.org/web/20130608070534/http://www.bea.aero/fr/enquetes/vol.af.447/rapport.final.fr.php

All can be found under Section 5 (at the very end of the report):

It includes changes to hardware (pitot tube), CRM, sim training etc.

For example:

Flight simulator training
Additional unreliable airspeed session:
- Summer 2009 (A320, A330/A340).
- Session booklet and briefing: technical reminders, human factors and Threat and
Error Management (TEM) aspects.
- Revision of the emergency manoeuvre, on take-off and in cruise phase.
- High altitude flight in alternate law.
- Approach to stall with triggering of STALL warning.
- Landing without airspeed indications.
- Related briefings (all flight crew):
Weather radar
Ice crystals.
- Alternate Training & Qualification Programme (ATQP) (preliminary version)
operational on Airbus A320 since March 2012.
Note: These elements were incorporated into the type ratings


So actually the lessons out of this crash were definitely learned.

Lets hope advanced sim training will now also be included for the MAX so there will be no pilot overload.
 
User avatar
aerolimani
Posts: 1323
Joined: Tue Jun 18, 2013 5:46 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 2:04 pm

morrisond wrote:
The manual trim wheels are there in case Electric Trim fails and to give you a visual clue on what the trim is actually doing.

Sometimes a Video is worth a thousand words. Video of the trim wheels in an A320 https://www.youtube.com/watch?v=_4aoSBtOJv4

That is used as a back up in the A320 as well if the electric trim fails.

Good luck with an A320 flying without electronics, sensors and actuators.

That is a misunderstanding of the A320 trim system. Those wheels are not connected by cables, or by any physical means, to the horizontal stabilizer. If the electric trim fails, which is extremely unlikely due to its many system redundancies, those wheels are absolutely useless. They are a visual reference. They are not a backup system.
 
sharpley
Posts: 25
Joined: Mon Jul 29, 2019 10:28 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 2:04 pm

Muilenburg's taken his seat for the hearing. Being streamed live on CNBC YouTube channel now. There are a few people in the audience with photos of the victims as well
 
mmo
Posts: 2059
Joined: Thu Apr 18, 2013 3:04 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 2:15 pm

mjoelnir wrote:

STS moves the trim all the time. So you first have to realize that it is not STS doing its normal work. For simple design MCAS was added on top of STS and column cutout removed.

So you should keep your big words like airmanship away from defending a terrible design. And the men machine interface on the 737 is an aged design flooding the pilots with alarms at the same time. That interface is not compliant with current FARs and depends on exemptions from the rules.


I disagree. Have you read the entire Lion Air accident report? If not, read it then come back and make your comments. If you have read it, I would suggest you missed a lot. The FO was raked over the controls by the accident report. The accident report even criticized the FO for not running the runaway stab trim checklist, which they agree would have solved the problem.

Go back to my original post and I made a very deliberate disclaimer about not defending the MCAS design. So, rather than picking out parts of a post and trying to say I am "defending a terrible design", I would take that time to read the accident report.

Airmanship is knowing when STS is doing what it should or something else is going on. My reading of the FO in the accident report stated he had trouble going through training, failed his last OPC for speed control on an ILS and other things. Have you asked yourself if he should have even been in the seat? After years as a TRE one thing, I always tried to do was keep things in perspective. In a checkride, there are tolerances for everything airspeed, heading, altitude and so on. I defy anyone to not have an excursion out of the acceptable (written tolerances) during a checkride. My bottom line was would I put my family on an aircraft the person I am evaluating was flying. If I am comfortable with their performance then they pass. If not they get to have another shot at it.

If you don't think that is Airmanship, then what is it?
If we weren't all crazy we'd all go insane!
 
AABusDrvr
Posts: 158
Joined: Sat Dec 03, 2016 6:48 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 2:29 pm

aerolimani wrote:
morrisond wrote:
The manual trim wheels are there in case Electric Trim fails and to give you a visual clue on what the trim is actually doing.

Sometimes a Video is worth a thousand words. Video of the trim wheels in an A320 https://www.youtube.com/watch?v=_4aoSBtOJv4

That is used as a back up in the A320 as well if the electric trim fails.

Good luck with an A320 flying without electronics, sensors and actuators.

That is a misunderstanding of the A320 trim system. Those wheels are not connected by cables, or by any physical means, to the horizontal stabilizer. If the electric trim fails, which is extremely unlikely due to its many system redundancies, those wheels are absolutely useless. They are a visual reference. They are not a backup system.


That is not correct, on the A320 series at least. The trim wheels are mechanically connected to the stabilizer actuators. As long as you have hydraulic power, you can control the THS with the trim wheels.

It's been a few years since I last flew the Airbus, but I still have the books. From the systems manual.

"Mechanical Control.
Mechanical control of the THS is available from the pitch trim wheel at any time, if either the green or yellow hydraulic system is functioning.
Mechanical control from the pitch trim wheel has priority over electrical control."
 
kalvado
Posts: 2932
Joined: Wed Mar 01, 2006 4:29 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 2:34 pm

AABusDrvr wrote:
aerolimani wrote:
morrisond wrote:
The manual trim wheels are there in case Electric Trim fails and to give you a visual clue on what the trim is actually doing.

Sometimes a Video is worth a thousand words. Video of the trim wheels in an A320 https://www.youtube.com/watch?v=_4aoSBtOJv4

That is used as a back up in the A320 as well if the electric trim fails.

Good luck with an A320 flying without electronics, sensors and actuators.

That is a misunderstanding of the A320 trim system. Those wheels are not connected by cables, or by any physical means, to the horizontal stabilizer. If the electric trim fails, which is extremely unlikely due to its many system redundancies, those wheels are absolutely useless. They are a visual reference. They are not a backup system.


That is not correct, on the A320 series at least. The trim wheels are mechanically connected to the stabilizer actuators. As long as you have hydraulic power, you can control the THS with the trim wheels.

It's been a few years since I last flew the Airbus, but I still have the books. From the systems manual.

"Mechanical Control.
Mechanical control of the THS is available from the pitch trim wheel at any time, if either the green or yellow hydraulic system is functioning.
Mechanical control from the pitch trim wheel has priority over electrical control."

If I understand correctly, Airbus trim wheels are the very last fallback mechanism in case of total FBW failure, so they should bypass as much control as possible. Manual control of actuator valves sounds about right...
 
BravoOne
Posts: 4094
Joined: Fri Apr 12, 2013 2:27 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 2:38 pm

FluidFlow wrote:
As the AoA disagree light has not worked up to now, but I hope it will be a standard feature in the future how exactly will an AoA disagree be handled from no going forward. As the AoA sensors are only reliable from a certain speed and chances are high the AoA disagree will only show up close to V1 or above, the crew will get the warning of AoA disagree shortly after or during take off. What procedure will need to be done at that point? I only see two options:

1. Immediate return to the airport, or
2. Fly on with MCAS off which in my opinion will likely need sim training (training how to fly a MAX without MCAS)

Option 1 could have massive implications on the MAX economy, because next to the delay for the passengers you also just burned a ton of fuel for nothing. It is not possible to detect an AoA disagree on the ground just by the way AoA sensors work. Dispatch reliability will be reduced to the reliability of the sensors and as it will need both sensors if one fails it is enough for a return to the airport. For Option 2: That would mean a lot of additional costs for Boeing due to contractual penalties and even airlines that do not have that contractual penalty might be able to sue Boeing for compensation as it was advertised that no additional training was needed.



Where do you come up with the statement "as it was advertised that no additional training was needed". These are usually contractural inclusions in purchase agreements, not advertisements and other than SWA, I'm not sure we know what was said, if anything.
 
morrisond
Posts: 2862
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 2:39 pm

FluidFlow wrote:
morrisond wrote:
mjoelnir wrote:

STS moves the trim all the time. So you first have to realize that it is not STS doing its normal work. For simple design MCAS was added on top of STS and column cutout removed.

So you should keep your big words like airmanship away from defending a terrible design. And the men machine interface on the 737 is an aged design flooding the pilots with alarms at the same time. That interface is not compliant with current FARs and depends on exemptions from the rules.


Do you want to ground the A330 as well?

From the NTSB report

"Multiple alerts and indications in the cockpit can increase pilots’ workload and can also
make it more difficult to identify which procedure the pilots should conduct. The NTSB notes that
the Lion Air and Ethiopian Airlines accident pilots’ responses to multiple alerts and indications are
similar to the circumstances of a 2009 accident involving Air France flight 447, an Airbus A330,
which was traveling from Rio de Janeiro to Paris when it crashed in the Atlantic Ocean.19 In its
accident report, the Bureau d’Enquêtes et d’Analyses Pour la Sécurité de L’aviation Civile (BEA)
concluded that failure messages successively displayed on the electronic centralized aircraft
monitoring system did not allow the crew to rapidly and effectively diagnose the issue (the
blockage of the pitot probes) or make the connection between the messages that appeared and the
procedure to use. Accordingly, the BEA recommended that EASA “study the relevance of having
a dedicated warning provided to the crew when specific monitoring is triggered, in order to
facilitate comprehension of the situation.”


Just to put an end to this endless AF447 thing. Here is the final report, it includes the changes that were implemented by all the different parties:

https://web.archive.org/web/20130608070534/http://www.bea.aero/fr/enquetes/vol.af.447/rapport.final.fr.php

All can be found under Section 5 (at the very end of the report):

It includes changes to hardware (pitot tube), CRM, sim training etc.

For example:

Flight simulator training
Additional unreliable airspeed session:
- Summer 2009 (A320, A330/A340).
- Session booklet and briefing: technical reminders, human factors and Threat and
Error Management (TEM) aspects.
- Revision of the emergency manoeuvre, on take-off and in cruise phase.
- High altitude flight in alternate law.
- Approach to stall with triggering of STALL warning.
- Landing without airspeed indications.
- Related briefings (all flight crew):
Weather radar
Ice crystals.
- Alternate Training & Qualification Programme (ATQP) (preliminary version)
operational on Airbus A320 since March 2012.
Note: These elements were incorporated into the type ratings


So actually the lessons out of this crash were definitely learned.

Lets hope advanced sim training will now also be included for the MAX so there will be no pilot overload.


Did they make any changes in the crew alerting system? It had the wholly grail EICAS system that some are saying the MAX should have before it flies again.
 
AABusDrvr
Posts: 158
Joined: Sat Dec 03, 2016 6:48 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 2:41 pm

kalvado wrote:
AABusDrvr wrote:
aerolimani wrote:
That is a misunderstanding of the A320 trim system. Those wheels are not connected by cables, or by any physical means, to the horizontal stabilizer. If the electric trim fails, which is extremely unlikely due to its many system redundancies, those wheels are absolutely useless. They are a visual reference. They are not a backup system.


That is not correct, on the A320 series at least. The trim wheels are mechanically connected to the stabilizer actuators. As long as you have hydraulic power, you can control the THS with the trim wheels.

It's been a few years since I last flew the Airbus, but I still have the books. From the systems manual.

"Mechanical Control.
Mechanical control of the THS is available from the pitch trim wheel at any time, if either the green or yellow hydraulic system is functioning.
Mechanical control from the pitch trim wheel has priority over electrical control."

If I understand correctly, Airbus trim wheels are the very last fallback mechanism in case of total FBW failure, so they should bypass as much control as possible. Manual control of actuator valves sounds about right...


That is correct. The lowest of the flight control laws on the bus is "Mechanical Backup". This is the book description:

Mechanical Back-Up.

Pitch.
Mechanical backup enables the pilot to control the aircraft during a temporary complete loss of electrical power. He does this in pitch by manually applying trim to the THS. The PFDs display “MAN PITCH TRIM ONLY” in red.

Lateral.
The pilot uses the rudder pedals as the mechanical backup to laterally control the aircraft .

It's intended to give you limited aircraft control, while you attempt to reestablish a higher control law.
 
morrisond
Posts: 2862
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 2:42 pm

aerolimani wrote:
morrisond wrote:
The manual trim wheels are there in case Electric Trim fails and to give you a visual clue on what the trim is actually doing.

Sometimes a Video is worth a thousand words. Video of the trim wheels in an A320 https://www.youtube.com/watch?v=_4aoSBtOJv4

That is used as a back up in the A320 as well if the electric trim fails.

Good luck with an A320 flying without electronics, sensors and actuators.

That is a misunderstanding of the A320 trim system. Those wheels are not connected by cables, or by any physical means, to the horizontal stabilizer. If the electric trim fails, which is extremely unlikely due to its many system redundancies, those wheels are absolutely useless. They are a visual reference. They are not a backup system.


ASDF was saying that a trim wheel had no use in an cockpit. The visual reference part is very much a useful safety device.
 
IADFCO
Posts: 201
Joined: Sun May 22, 2016 4:20 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 2:49 pm

If anybody would like to listen to the US Senate hearings in prograss, download the free "CSPAN Radio" app, and go to CSPAN-3
 
FluidFlow
Posts: 738
Joined: Wed Apr 10, 2019 6:39 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 3:01 pm

morrisond wrote:
FluidFlow wrote:
morrisond wrote:

Do you want to ground the A330 as well?

From the NTSB report

"Multiple alerts and indications in the cockpit can increase pilots’ workload and can also
make it more difficult to identify which procedure the pilots should conduct. The NTSB notes that
the Lion Air and Ethiopian Airlines accident pilots’ responses to multiple alerts and indications are
similar to the circumstances of a 2009 accident involving Air France flight 447, an Airbus A330,
which was traveling from Rio de Janeiro to Paris when it crashed in the Atlantic Ocean.19 In its
accident report, the Bureau d’Enquêtes et d’Analyses Pour la Sécurité de L’aviation Civile (BEA)
concluded that failure messages successively displayed on the electronic centralized aircraft
monitoring system did not allow the crew to rapidly and effectively diagnose the issue (the
blockage of the pitot probes) or make the connection between the messages that appeared and the
procedure to use. Accordingly, the BEA recommended that EASA “study the relevance of having
a dedicated warning provided to the crew when specific monitoring is triggered, in order to
facilitate comprehension of the situation.”


Just to put an end to this endless AF447 thing. Here is the final report, it includes the changes that were implemented by all the different parties:

https://web.archive.org/web/20130608070534/http://www.bea.aero/fr/enquetes/vol.af.447/rapport.final.fr.php

All can be found under Section 5 (at the very end of the report):

It includes changes to hardware (pitot tube), CRM, sim training etc.

For example:

Flight simulator training
Additional unreliable airspeed session:
- Summer 2009 (A320, A330/A340).
- Session booklet and briefing: technical reminders, human factors and Threat and
Error Management (TEM) aspects.
- Revision of the emergency manoeuvre, on take-off and in cruise phase.
- High altitude flight in alternate law.
- Approach to stall with triggering of STALL warning.
- Landing without airspeed indications.
- Related briefings (all flight crew):
Weather radar
Ice crystals.
- Alternate Training & Qualification Programme (ATQP) (preliminary version)
operational on Airbus A320 since March 2012.
Note: These elements were incorporated into the type ratings


So actually the lessons out of this crash were definitely learned.

Lets hope advanced sim training will now also be included for the MAX so there will be no pilot overload.


Did they make any changes in the crew alerting system? It had the wholly grail EICAS system that some are saying the MAX should have before it flies again.


They did, one for example was: Recommendation FRAN-2012-050

It was then included in:

Stall Warning is a combination of aural warning and Master Warning Light, when parameters are valid.
In order to reinforce crew awareness in case of stall situation, it will be displayed STALL STALL on Primary Flight Display (PFD) when Stall Warning (SW) is triggered.
Modifications of forthcoming display standards for A320 family, A330/A340 family, A380, A350 and
A400M aircraft are on-going. Retrofit policy is under discussion.
On the A300/A310/A300-600 family program, as the stick shaker provides an additional warning to the
flight crew it is considered sufficient.


Source: https://www.easa.europa.eu/sites/default/files/dfu/206004_EASA_ANNUAL_SAFETY_RECOMMENDATION_REVIEW.pdf

Now this was the first one I researched, so feel free to research the rest of them but to answer your question: Yes it was changed for aircraft built after this release and not only on the A330 but on all Airbus aircraft except the A300/A310/A300-600 which were not built anymore at that time. So I am too lazy to see if they also retrofitted the upgrade but they might have.
 
morrisond
Posts: 2862
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 3:19 pm

FluidFlow wrote:
morrisond wrote:
FluidFlow wrote:

Just to put an end to this endless AF447 thing. Here is the final report, it includes the changes that were implemented by all the different parties:

https://web.archive.org/web/20130608070534/http://www.bea.aero/fr/enquetes/vol.af.447/rapport.final.fr.php

All can be found under Section 5 (at the very end of the report):

It includes changes to hardware (pitot tube), CRM, sim training etc.

For example:



So actually the lessons out of this crash were definitely learned.

Lets hope advanced sim training will now also be included for the MAX so there will be no pilot overload.


Did they make any changes in the crew alerting system? It had the wholly grail EICAS system that some are saying the MAX should have before it flies again.


They did, one for example was: Recommendation FRAN-2012-050

It was then included in:

Stall Warning is a combination of aural warning and Master Warning Light, when parameters are valid.
In order to reinforce crew awareness in case of stall situation, it will be displayed STALL STALL on Primary Flight Display (PFD) when Stall Warning (SW) is triggered.
Modifications of forthcoming display standards for A320 family, A330/A340 family, A380, A350 and
A400M aircraft are on-going. Retrofit policy is under discussion.
On the A300/A310/A300-600 family program, as the stick shaker provides an additional warning to the
flight crew it is considered sufficient.


Source: https://www.easa.europa.eu/sites/default/files/dfu/206004_EASA_ANNUAL_SAFETY_RECOMMENDATION_REVIEW.pdf

Now this was the first one I researched, so feel free to research the rest of them but to answer your question: Yes it was changed for aircraft built after this release and not only on the A330 but on all Airbus aircraft except the A300/A310/A300-600 which were not built anymore at that time. So I am too lazy to see if they also retrofitted the upgrade but they might have.


Thanks - that seems like a good resource - but no whole scale redesign to lower the number of warnings/confusion?
 
morrisond
Posts: 2862
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 3:24 pm

Muilenberg just said the FAA did know about the extension of MCAS to the low speed regime and the new faster speed/greater range.
 
FluidFlow
Posts: 738
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Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 3:27 pm

morrisond wrote:
FluidFlow wrote:
morrisond wrote:

Did they make any changes in the crew alerting system? It had the wholly grail EICAS system that some are saying the MAX should have before it flies again.


They did, one for example was: Recommendation FRAN-2012-050

It was then included in:

Stall Warning is a combination of aural warning and Master Warning Light, when parameters are valid.
In order to reinforce crew awareness in case of stall situation, it will be displayed STALL STALL on Primary Flight Display (PFD) when Stall Warning (SW) is triggered.
Modifications of forthcoming display standards for A320 family, A330/A340 family, A380, A350 and
A400M aircraft are on-going. Retrofit policy is under discussion.
On the A300/A310/A300-600 family program, as the stick shaker provides an additional warning to the
flight crew it is considered sufficient.


Source: https://www.easa.europa.eu/sites/default/files/dfu/206004_EASA_ANNUAL_SAFETY_RECOMMENDATION_REVIEW.pdf

Now this was the first one I researched, so feel free to research the rest of them but to answer your question: Yes it was changed for aircraft built after this release and not only on the A330 but on all Airbus aircraft except the A300/A310/A300-600 which were not built anymore at that time. So I am too lazy to see if they also retrofitted the upgrade but they might have.


Thanks - that seems like a good resource - but no whole scale redesign to lower the number of warnings/confusion?


A lot got actually changed so the work load will be reduced to the important stuff, the document is a good read (the relevant part for the A330 starts at page 58):

Safety Recommendation FRAN-2012-048 (BEA)
The BEA recommends that EASA require a review of the functional or display logic of the flight director so that
it disappears or presents appropriate orders when the stall warning is triggered.
Reply
EASA has launched a review of flight director re-display and reconnection logic.
As a result, A320 and A330/340 will be modified. Flight Director (FD) will be disconnected in case of stall warning.
Retrofit policy is under discussion.
Status: Open – Category:
Safety Recommendation FRAN-2012-049 (BEA)
The BEA recommends that EASA study the relevance of having a dedicated warning provided to the crew when
specific monitoring is triggered, in order to facilitate comprehension of the situation.
Reply
The adequacy of the general crew alerting system is addressed by certification requirements in particular Certification Specifications CS25.1302, CS.1309 and CS25.1322.
In some circumstances, on all Airbus Fly By Wire (FBW) programs, except A350XWB, airspeed can be
detected erroneous by the flight control system, while it is still displayed on the Primary Flight Display
(PFD).
Studies are on-going to evaluate the relevance of flagging the speed in the cockpit when a system monitoring is triggered on Airbus Flight-by-Wire aircraft except on A350XWB where in case of detection of
erroneous airspeed, the switching to the adequate displayed airspeed is automatically realised.
 
asdf
Posts: 705
Joined: Tue Mar 18, 2014 12:03 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 3:39 pm

morrisond wrote:
Muilenberg just said the FAA did know about the extension of MCAS to the low speed regime and the new faster speed/greater range.


does this indicate that the FAA is taking the complete blame and that boeing is taking over selfcertification in the future .... ?
 
kalvado
Posts: 2932
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Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 3:39 pm

mmo wrote:
Airmanship is knowing when STS is doing what it should or something else is going on.

Do you have a full description of STS functionality - what exactly it is doing - actuation at what speed, how fast, how far, etc?
My impression so far that STS is communicated to pilots under same "need to know" approach s MCAS after the first crash - it is there, good luck.
 
SkyGrunt
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Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 3:40 pm

Oh my, Ms Duckworth is destroying Muilenberg
 
mjoelnir
Posts: 9411
Joined: Sun Feb 03, 2013 11:06 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 3:41 pm

morrisond wrote:
FluidFlow wrote:
morrisond wrote:

Did they make any changes in the crew alerting system? It had the wholly grail EICAS system that some are saying the MAX should have before it flies again.


They did, one for example was: Recommendation FRAN-2012-050

It was then included in:

Stall Warning is a combination of aural warning and Master Warning Light, when parameters are valid.
In order to reinforce crew awareness in case of stall situation, it will be displayed STALL STALL on Primary Flight Display (PFD) when Stall Warning (SW) is triggered.
Modifications of forthcoming display standards for A320 family, A330/A340 family, A380, A350 and
A400M aircraft are on-going. Retrofit policy is under discussion.
On the A300/A310/A300-600 family program, as the stick shaker provides an additional warning to the
flight crew it is considered sufficient.


Source: https://www.easa.europa.eu/sites/default/files/dfu/206004_EASA_ANNUAL_SAFETY_RECOMMENDATION_REVIEW.pdf

Now this was the first one I researched, so feel free to research the rest of them but to answer your question: Yes it was changed for aircraft built after this release and not only on the A330 but on all Airbus aircraft except the A300/A310/A300-600 which were not built anymore at that time. So I am too lazy to see if they also retrofitted the upgrade but they might have.


Thanks - that seems like a good resource - but no whole scale redesign to lower the number of warnings/confusion?


There were only two serious points to the confusion about stall on AF447.

The confusion in regards to the stall warning stopping to sound, when the speed goes under 60 kn.

and

the confusion with the pilot flying, who could not remember, that when you hear stall stall stall, you push the joystick forward instead of pulling it back.
Even when the stopping of the stall warning did confuse him, he had already pulled the frame up into stall ignoring the stall warning completely reaching below 60 kn in speed.

Yes there were a heap of other warnings in the cockpit, but it should have been possible to work through them, when he would not have pulled the frame up into stall. Now pilots will get an stall indication on the screen together with the aureal alarm, so they will do something about the stall first, before looking at other things.

The main problem was perhaps, that the case of freezing pilot tubes, producing unreliable airspeed indication, with than dropping out of autopilot and dropping from normal law into alternate law, with than the need to handfly the frame and loosing stall protection, was not trained at Air France, but once in the beginning of training.

If the guy simple had kept the frame level, nothing would have happened.
Last edited by mjoelnir on Tue Oct 29, 2019 4:08 pm, edited 3 times in total.
 
MSPNWA
Posts: 3698
Joined: Thu Apr 23, 2009 2:48 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 3:42 pm

SkyGrunt wrote:
Oh my, Ms Duckworth is destroying Muilenberg


If she wasn't so misinformed she would have a good point. Now Cruz is making the same mistake.

I haven't tuned in long, but this hearing shows how misinformed Congress is.
 
asdf
Posts: 705
Joined: Tue Mar 18, 2014 12:03 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 3:45 pm

MSPNWA wrote:
SkyGrunt wrote:
Oh my, Ms Duckworth is destroying Muilenberg


If she wasn't so misinformed she would have a good point. Now Cruz is making the same mistake.

I haven't tuned in long, but this hearing shows how misinformed Congress is.


maybe they should read anet like the media ..
 
XRAYretired
Posts: 870
Joined: Fri Mar 15, 2019 11:21 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 3:52 pm

mmo wrote:
mjoelnir wrote:

STS moves the trim all the time. So you first have to realize that it is not STS doing its normal work. For simple design MCAS was added on top of STS and column cutout removed.

So you should keep your big words like airmanship away from defending a terrible design. And the men machine interface on the 737 is an aged design flooding the pilots with alarms at the same time. That interface is not compliant with current FARs and depends on exemptions from the rules.


I disagree. Have you read the entire Lion Air accident report? If not, read it then come back and make your comments. If you have read it, I would suggest you missed a lot. The FO was raked over the controls by the accident report. The accident report even criticized the FO for not running the runaway stab trim checklist, which they agree would have solved the problem.

Go back to my original post and I made a very deliberate disclaimer about not defending the MCAS design. So, rather than picking out parts of a post and trying to say I am "defending a terrible design", I would take that time to read the accident report.

Airmanship is knowing when STS is doing what it should or something else is going on. My reading of the FO in the accident report stated he had trouble going through training, failed his last OPC for speed control on an ILS and other things. Have you asked yourself if he should have even been in the seat? After years as a TRE one thing, I always tried to do was keep things in perspective. In a checkride, there are tolerances for everything airspeed, heading, altitude and so on. I defy anyone to not have an excursion out of the acceptable (written tolerances) during a checkride. My bottom line was would I put my family on an aircraft the person I am evaluating was flying. If I am comfortable with their performance then they pass. If not they get to have another shot at it.

If you don't think that is Airmanship, then what is it?

Apologies for interceding, but I thought I ought to mention that if you have read the report then you would not need to make some assumption of what the JT043 pilot reported or veiled castigation of the Lion Air procedures (as you did in your first post #1780) since both are fully detailed in sections 1.17.1.1, 1.1.18.1 and 2.1.3 in particular.

Additionally, at no point in the report is the FO 'even criticized .... for not running the runaway stab trim checklist'. As close as the criticisms get, is non completion of the AIRSPEED UNRELIABLE NNC viz:

(2.3.1) '................ Despite the flight crew’s attempt to execute of the NNC, due to increase workload, and distractions from the ATC communication, the NNC was unable to be completed in that situation. The unfinished NNC made it difficult for the flight crew of LNI610 to understand the aircraft problem and how to mitigate the problem..........'

(2.3.3) '.................. In LNI610 flight, while the multiple problems occurred, the activation of stick shaker and MCAS activated repeatedly, the flight crew attempted to complete the NNC, as they are trained to refer to QRH in abnormal condition. The NNC should be performed to identify and mitigate the problem. However, the NNC was unable to be completed in that situation. Therefore, until the end of the flight, the flight crew was unable to complete the NNC and identify the problem. This made the flight crew did not understand the aircraft problem and how to mitigate.........'

As an observation, it has not been unusual for pilots in these threads to - on the one hand decry failure to follow SOPs/NNCs to the letter, and on the other spout airmanship as a reason for not doing so when they do so feel like it. I felt particularly sorry for the padawan belittled for questioning why his training Captain was instructing him to operate in contradiction of his company SOPs. I'm not sure this contributes to safety at all.

On the final note, the prime source of miss-information are sites like this, which fortunately, will be completely ignored by anyone in authority with any sense.

Ray
 
majano
Posts: 280
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Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 3:55 pm

SkyGrunt wrote:
Oh my, Ms Duckworth is destroying Muilenberg

Is there a Mr or Ms Lewis in this hearing? If yes, this hearing will soon turn into :P a statistics masterclass!!
 
frmrCapCadet
Posts: 4416
Joined: Thu May 29, 2008 8:24 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 4:00 pm

Politicians are not the best investigators, and there really is no reason they should be. But their aides are often the best, and those interviews are off camera, and often not directly made available. One would hope that the aides have carefully explained what questions need to be asked, and know how to reject answers that are not answers. It requires skills.
Buffet: the airline business...has eaten up capital...like..no other (business)
 
Agrajag
Posts: 128
Joined: Wed Mar 27, 2019 8:23 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 4:07 pm

:yes:
majano wrote:
SkyGrunt wrote:
Oh my, Ms Duckworth is destroying Muilenberg

Is there a Mr or Ms Lewis in this hearing? If yes, this hearing will soon turn into :P a statistics masterclass!!


Bravo...

However, i fear our American cousins will not understand this.
The plural of anecdote is anecdotes, not data.
Slartibartfast had a point
 
User avatar
aerolimani
Posts: 1323
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Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 4:26 pm

AABusDrvr wrote:
kalvado wrote:
AABusDrvr wrote:

That is not correct, on the A320 series at least. The trim wheels are mechanically connected to the stabilizer actuators. As long as you have hydraulic power, you can control the THS with the trim wheels.

It's been a few years since I last flew the Airbus, but I still have the books. From the systems manual.

"Mechanical Control.
Mechanical control of the THS is available from the pitch trim wheel at any time, if either the green or yellow hydraulic system is functioning.
Mechanical control from the pitch trim wheel has priority over electrical control."

If I understand correctly, Airbus trim wheels are the very last fallback mechanism in case of total FBW failure, so they should bypass as much control as possible. Manual control of actuator valves sounds about right...


That is correct. The lowest of the flight control laws on the bus is "Mechanical Backup". This is the book description:

Mechanical Back-Up.

Pitch.
Mechanical backup enables the pilot to control the aircraft during a temporary complete loss of electrical power. He does this in pitch by manually applying trim to the THS. The PFDs display “MAN PITCH TRIM ONLY” in red.

Lateral.
The pilot uses the rudder pedals as the mechanical backup to laterally control the aircraft .

It's intended to give you limited aircraft control, while you attempt to reestablish a higher control law.

I stand to be corrected! I adjust my understanding of the A320 trim wheels accordingly. I always thought the wheels were just another version of an electronic switch. Still, their independent movement is not a direct mechanical reflection of the stab’s movement. That’s the computer instructing a motor to turn the wheels, isn’t it?

Nonetheless, there is still not the direct mechanical connection, like the cable in the 737. A hydraulic actuator is still a switch controlling a system that does the actual operation.

May the gods help you though, if your FBW plane is in such dire straits that your electrical system is down. Only rudder and stabilizer trim to fly a plane!!! Fortunately, Airbus mechanical law doesn’t seem to be frequently needed. Hopefully, the revised MAX will get back to a situation where its manual trim wheels are as near to unnecessary.
 
XRAYretired
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Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 4:29 pm

Agrajag wrote:
:yes:
majano wrote:
SkyGrunt wrote:
Oh my, Ms Duckworth is destroying Muilenberg

Is there a Mr or Ms Lewis in this hearing? If yes, this hearing will soon turn into :P a statistics masterclass!!


Bravo...

However, i fear our American cousins will not understand this.

Had me stumped for a while. Excellent!

Ray
 
kalvado
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Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 4:38 pm

aerolimani wrote:
Nonetheless, there is still not the direct mechanical connection, like the cable in the 737. A hydraulic actuator is still a switch controlling a system that does the actual operation.

I doubt any sort of direct mechanical actuation would be good enough for effective control of a widebody. As we see, it is barely adequate even for a large narrowbody. If you think about it, there is a force acting on control elements which affects entire plane, and control input needs to overcome that force. Basically shifting a plane by hand can be either very hard or very slow if you use high lever ratio..
If I remember correctly, some planes - I believe IL-62 was mentioned - used tiered control system, whew defection of a trim tab deflected control surface which deflected the plane. I have some doubts that I remember things correctly, though. Could work, but again wouldn't be very fast control.
One of the reasons to switching to all-electronic control mode: heavy plane, variety of control conditions (speed, pressure) - consistency would be hard to achieve.
 
Agrajag
Posts: 128
Joined: Wed Mar 27, 2019 8:23 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 4:45 pm

XRAYretired wrote:
Agrajag wrote:
:yes:
majano wrote:
Is there a Mr or Ms Lewis in this hearing? If yes, this hearing will soon turn into :P a statistics masterclass!!


Bravo...

However, i fear our American cousins will not understand this.

Had me stumped for a while. Excellent!

Ray



Muilenberg may be on a bit of a sticky wicket!
The plural of anecdote is anecdotes, not data.
Slartibartfast had a point
 
oschkosch
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Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 4:52 pm

So Dennis said "safety is not a part of our business"? That is shocking!

And one Senator who flys 4 legs a week clearly said he would currently prefer tonwalk than fly one a max.

Gesendet von meinem SM-G950F mit Tapatalk
:stirthepot: :airplane: "This airplane is designed by clowns, who in turn are supervised by monkeys" :airplane: :stirthepot:
 
mjoelnir
Posts: 9411
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Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 5:15 pm

aerolimani wrote:
AABusDrvr wrote:
kalvado wrote:
If I understand correctly, Airbus trim wheels are the very last fallback mechanism in case of total FBW failure, so they should bypass as much control as possible. Manual control of actuator valves sounds about right...


That is correct. The lowest of the flight control laws on the bus is "Mechanical Backup". This is the book description:

Mechanical Back-Up.

Pitch.
Mechanical backup enables the pilot to control the aircraft during a temporary complete loss of electrical power. He does this in pitch by manually applying trim to the THS. The PFDs display “MAN PITCH TRIM ONLY” in red.

Lateral.
The pilot uses the rudder pedals as the mechanical backup to laterally control the aircraft .

It's intended to give you limited aircraft control, while you attempt to reestablish a higher control law.

I stand to be corrected! I adjust my understanding of the A320 trim wheels accordingly. I always thought the wheels were just another version of an electronic switch. Still, their independent movement is not a direct mechanical reflection of the stab’s movement. That’s the computer instructing a motor to turn the wheels, isn’t it?

Nonetheless, there is still not the direct mechanical connection, like the cable in the 737. A hydraulic actuator is still a switch controlling a system that does the actual operation.

May the gods help you though, if your FBW plane is in such dire straits that your electrical system is down. Only rudder and stabilizer trim to fly a plane!!! Fortunately, Airbus mechanical law doesn’t seem to be frequently needed. Hopefully, the revised MAX will get back to a situation where its manual trim wheels are as near to unnecessary.


It depends on how you build a hydraulic linkage. There is for example on tractors, when you miss hydraulic power, the steering wheel is connected to a pump that pumps oil into the steering cylinder. Highly geared but works completely without actuators. So you can have a hydraulic linkage that is not less direct than a rod or a wire.

In regards to the trim wheel, we have now seen what happens, when something touted as the last line of defense, is in reality not working when needed. It is not enough that you hardly ever need it.

That is like wearing a parachute that will not open when you need it being OK, because it is hardly ever used.
 
planecane
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Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 5:34 pm

mjoelnir wrote:
aerolimani wrote:
AABusDrvr wrote:

That is correct. The lowest of the flight control laws on the bus is "Mechanical Backup". This is the book description:

Mechanical Back-Up.

Pitch.
Mechanical backup enables the pilot to control the aircraft during a temporary complete loss of electrical power. He does this in pitch by manually applying trim to the THS. The PFDs display “MAN PITCH TRIM ONLY” in red.

Lateral.
The pilot uses the rudder pedals as the mechanical backup to laterally control the aircraft .

It's intended to give you limited aircraft control, while you attempt to reestablish a higher control law.

I stand to be corrected! I adjust my understanding of the A320 trim wheels accordingly. I always thought the wheels were just another version of an electronic switch. Still, their independent movement is not a direct mechanical reflection of the stab’s movement. That’s the computer instructing a motor to turn the wheels, isn’t it?

Nonetheless, there is still not the direct mechanical connection, like the cable in the 737. A hydraulic actuator is still a switch controlling a system that does the actual operation.

May the gods help you though, if your FBW plane is in such dire straits that your electrical system is down. Only rudder and stabilizer trim to fly a plane!!! Fortunately, Airbus mechanical law doesn’t seem to be frequently needed. Hopefully, the revised MAX will get back to a situation where its manual trim wheels are as near to unnecessary.


It depends on how you build a hydraulic linkage. There is for example on tractors, when you miss hydraulic power, the steering wheel is connected to a pump that pumps oil into the steering cylinder. Highly geared but works completely without actuators. So you can have a hydraulic linkage that is not less direct than a rod or a wire.

In regards to the trim wheel, we have now seen what happens, when something touted as the last line of defense, is in reality not working when needed. It is not enough that you hardly ever need it.

That is like wearing a parachute that will not open when you need it being OK, because it is hardly ever used.


We haven't seen what happens because we still don't know if the ET crew actually tried the manual wheel. We know from simulations that in extreme out of trim conditions it is difficult to move (and always has been). We don't know (at least I don't) if, prior to MCAS 1.0 a 737 crew has ever needed to use the manual wheel in an extreme out of trim situation.
 
ShamrockBoi330
Posts: 357
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Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 5:39 pm

MSPNWA wrote:
SkyGrunt wrote:
Oh my, Ms Duckworth is destroying Muilenberg


If she wasn't so misinformed she would have a good point. Now Cruz is making the same mistake.

I haven't tuned in long, but this hearing shows how misinformed Congress is.


Please enlighten those of us who aren't watching, what have the 2 Senators stated that is so misinformed? And if so I assume Muilenburg has corrected them?
 
MrBretz
Posts: 560
Joined: Tue Jun 14, 2016 9:13 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 6:04 pm

I saw bits and pieces. He certainly didn't get a pass from the senators. He tried to be very polite and humble. Yes, I too think he was grilled quite well. Cruz put up the text string from the test pilot, maybe simulator test pilot. Cruz expressed shock that the CEO didn't bring the pilot in to discuss this and only found out about the comments recently. Muilenburg didn't say much and looked sadden. I don't think much will come of all this. I do expect Muilenburg to be toast sometime in the near future.
 
AABusDrvr
Posts: 158
Joined: Sat Dec 03, 2016 6:48 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 6:23 pm

kalvado wrote:
aerolimani wrote:
Nonetheless, there is still not the direct mechanical connection, like the cable in the 737. A hydraulic actuator is still a switch controlling a system that does the actual operation.

I doubt any sort of direct mechanical actuation would be good enough for effective control of a widebody. As we see, it is barely adequate even for a large narrowbody. If you think about it, there is a force acting on control elements which affects entire plane, and control input needs to overcome that force. Basically shifting a plane by hand can be either very hard or very slow if you use high lever ratio..
If I remember correctly, some planes - I believe IL-62 was mentioned - used tiered control system, whew defection of a trim tab deflected control surface which deflected the plane. I have some doubts that I remember things correctly, though. Could work, but again wouldn't be very fast control.
One of the reasons to switching to all-electronic control mode: heavy plane, variety of control conditions (speed, pressure) - consistency would be hard to achieve.



If both hydraulic systems fail on the 737, you can fly it in a manual reversion mode. They do assume the standby hydraulic system will still power the rudder, but the ailerons and elevator are 100% manually controlled. I've done it in the sim, it's a lot of work, but it can be done.

The DC-9/MD-80 has all manual controls, except for the rudder, in normal operation. The yoke isn't connected to the actual flight controls, at all. When you deflect the yoke, you move a control tab, on the control surface. That tab moves opposite to the desired direction of movement of the control surface, and "fly's" the surface to the desired position. Perhaps the IL-62 uses a similar system.
 
asdf
Posts: 705
Joined: Tue Mar 18, 2014 12:03 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 6:25 pm

planecane wrote:
We haven't seen what happens because we still don't know if the ET crew actually tried the manual wheel. ....



hmmmmm
no

i pretty well remember the first ET report where there was mentioned a conversation between the pilots kinda
instruction: "try the trim!"
answer: "it dont work!"

you can now deside what you want to believe
- was it the electric trim, than it was maybe a overload of the flightcomputer
- was it the manual trimwheel, then it was probably a aerodynamical overload because of the high forces at the flight surface

both alternatives are not really sexy ...
 
asdf
Posts: 705
Joined: Tue Mar 18, 2014 12:03 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 6:29 pm

AABusDrvr wrote:
If both hydraulic systems fail on the 737, you can fly it in a manual reversion mode. They do assume the standby hydraulic system will still power the rudder, but the ailerons and elevator are 100% manually controlled. I've done it in the sim, it's a lot of work, but it can be done.


are you shure?
as far as i know the 737-800 SIMs out there even can not simulate a AoA failure (!) on takeoff, regardless of the importance of that sensor we learned in this year

and you think manual reversion of hydraulic powder is realistic simulated in those SIMs?
 
MSPNWA
Posts: 3698
Joined: Thu Apr 23, 2009 2:48 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 6:30 pm

ShamrockBoi330 wrote:
Please enlighten those of us who aren't watching, what have the 2 Senators stated that is so misinformed? And if so I assume Muilenburg has corrected them?


Among her hits and misses, in round one Duckworth was making a claim to the effect MCAS could not be stopped by a pilot. In her second round, in trying to contrast the MAX versus the NG, she made the claim to the effect that in the NG simply hauling back on control stick will stop a runaway trim. One can make the assumption she was being fed information about the airplanes, and it wasn't very accurate. Her time wasn't meant to be in questions that Muilenburg could respond to. It was meant to be a rambling grilling, facts be damned.

Cruz couldn't get off the Forkner message chain, something that only Forkner can make a conclusion on. Sounded like Cruz was wanting it to be the smoking gun, but of course it isn't at this point because we don't even know if it's relevant. Frankly I thought Muilenburg could have pushed back strongly, but for some reason he didn't.

There were plenty of other moments. I don't remember who, but one senator was essentially trying to blame Boeing for not being a global regulator, not sounding the global alarm that Brazil decided their pilots needed to know more about MCAS than the U.S. regulators. Another general theme was the impossible standard of "you don't know every detail about your company, or you haven't read every document?" There is much more knowledge displayed on this site everyday than was present at the hearing. It was expected, but it never fails to sadden.
Last edited by MSPNWA on Tue Oct 29, 2019 6:32 pm, edited 1 time in total.
 
morrisond
Posts: 2862
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 6:30 pm

MrBretz wrote:
I saw bits and pieces. He certainly didn't get a pass from the senators. He tried to be very polite and humble. Yes, I too think he was grilled quite well. Cruz put up the text string from the test pilot, maybe simulator test pilot. Cruz expressed shock that the CEO didn't bring the pilot in to discuss this and only found out about the comments recently. Muilenburg didn't say much and looked sadden. I don't think much will come of all this. I do expect Muilenburg to be toast sometime in the near future.


I think he looked really weak in the Cruz exchange - just sat there taking it when Cruz was making some big whoppers of wrong assertions.

If I was the Board I would want someone with who can project more Confidence to come in and project strength and assure everyone that they will fix what is wrong.

Maybe they need to bring in someone from the Old days at Boeing - I'm not that personally familiar with the perception of Alan Mulally's work at Boeing but he was head of commercial and led the design of the 767 Cockpit.

From Wiki "Mulally led the design team of the first all-digital flight deck in a commercial aircraft, as seen here in the cockpit of the Boeing 767."

At 74 he might be too old - but he could be the one to come in for 2-3 years and right the ship and get it back on track. His experience seems perfect

"Mulally was hired by Boeing immediately out of college in 1969 as an engineer. He held a number of engineering and program management positions, making contributions to the Boeing 727, 737, 747, 757, 767 and Boeing 777 projects. He led the cockpit design team on the 757/767 project. Its revolutionary design featured the first all-digital flight deck in a commercial aircraft, the second two-man crew for long range aircraft after the Airbus A300, and a common type rating for pilots on two different aircraft. He worked on the 777 program first as director of engineering and, from September 1992, as vice-president and general manager.[14]

He was later named as Vice President of Engineering for the commercial airplane group. He is known and recognized for elevating Phil Condit's "Working Together" philosophy through and beyond the 777 program. In 1994, Mulally was promoted to senior vice president of Airplane Development and was in charge of all airplane development activities, flight test operations, certification, and government technical liaison. In 1997, Mulally became the president of the Boeing Information, Space & Defense Systems and senior vice president.[15] He held this position until 1998 when he was made president of Boeing Commercial Airplanes, Chief Executive Officer duties were added in 2001."

He seems like he was intimately involved in some great Boeing programs.

He is also perceived as the savior of Ford - he would probably be a popular choice.
 
mjoelnir
Posts: 9411
Joined: Sun Feb 03, 2013 11:06 pm

Re: Boeing 737MAX Grounded Worldwide Q4 2019

Tue Oct 29, 2019 6:31 pm

morrisond wrote:
mjoelnir wrote:
mmo wrote:

Personally, I think it's very easy. If you are hand flying the aircraft and the trim wheel moves without you activating it by the trim switches, you have a problem. Very simple. The instrument and the stick shaker are basic airmanship. In the QRH, you have a pitch power chart for unreliable airspeed. if you have climb thrust set and have the correct pitch you are good, the aircraft is climbing and you can concentrate on the highest priority problem. Part of the "airmanship" issue is understanding what you are being told by the aircraft. It is up to the crew to prioritize their actions to ensure they can remain safe. It's the old adage, "Aviate, navigate and communicate", in that order. The accident report cited the distraction by ATC. That is easily remedied by saying, "stand by". ATC can wait, but flying the aircraft can't.


STS moves the trim all the time. So you first have to realize that it is not STS doing its normal work. For simple design MCAS was added on top of STS and column cutout removed.

So you should keep your big words like airmanship away from defending a terrible design. And the men machine interface on the 737 is an aged design flooding the pilots with alarms at the same time. That interface is not compliant with current FARs and depends on exemptions from the rules.


Do you want to ground the A330 as well?

From the NTSB report

"Multiple alerts and indications in the cockpit can increase pilots’ workload and can also
make it more difficult to identify which procedure the pilots should conduct. The NTSB notes that
the Lion Air and Ethiopian Airlines accident pilots’ responses to multiple alerts and indications are
similar to the circumstances of a 2009 accident involving Air France flight 447, an Airbus A330,
which was traveling from Rio de Janeiro to Paris when it crashed in the Atlantic Ocean.19 In its
accident report, the Bureau d’Enquêtes et d’Analyses Pour la Sécurité de L’aviation Civile (BEA)
concluded that failure messages successively displayed on the electronic centralized aircraft
monitoring system did not allow the crew to rapidly and effectively diagnose the issue (the
blockage of the pitot probes) or make the connection between the messages that appeared and the
procedure to use. Accordingly, the BEA recommended that EASA “study the relevance of having
a dedicated warning provided to the crew when specific monitoring is triggered, in order to
facilitate comprehension of the situation.”


Let us now see, flood of error message in the 737MAX has little to do with MCAS. MCAS does not produce one error message. Perhaps it would be better if it would. Regarding the man machine interface the 737 uses very old technology, that can only be used with getting exceptions from the rules,
That 737 man machine interface is from before the advent of the 757/767 development. The 757/767 introduced EICAS, that have been used in all Boeing developments since than, but in the commercial 737. Boeing did not take the opportunity with the NG to introduce EICAS, neither with the MAX. The US Air Force was not prepared to live with that ancient man machine interface, so the P-8 got EICAS.

Now you try to compare this non compliant 737 interface, based on exceptions to the rules, with the situation on the A330. First, the A330 interface is compliant to the rules written down in the applicable FARs. And yes one can find most of the times something to do better.

But here come the some differences.
There was one A330 accident in this form, not a frame diving into the ground every few month.
The accident trigger in the chain in the A330 is a standard well know situation pilots should have been trained for, the primary cause for that accident was pilot action.
Nothing about the behavior of this frame in this situation had been hidden by Airbus from pilots.
The technical solution for the pilot tubes was already in place, but not yet installed on the frame, because airlines usually get a time frame for when the change out has to occur.

The absolute main difference is, that in the 737MAX, MCAS and it´s failure mode, has been identified as the primary cause, not the pilots.
MCAS was hidden from pilots, so it was not possible to train for its actions and Boeing cut a main feature for the MCAS action, the column cutout switch that in all other currently build Boeing frame cuts any and every automated trim action, but not MCAS in the 737MAX. Pilots were not supposed to have an easy way to cut of MCAS.

I know you are getting desperate in your defense of Boeing, but this is getting ridiculous.

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