OldAeroGuy
Posts: 3870
Joined: Sun Dec 05, 2004 6:50 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 20, 2019 11:29 pm

SheikhDjibouti wrote:
OldAeroGuy wrote:
The point is: Why were the Flaps retracted with an active stick shaker, contrary to the "STALL RECOVERY" NNC ?

Because they looked out of the window and could see they were clearly not in a stall situation?


How does looking out the window tell you that you aren't near stall? That sounds like the US Congress testimony that says looking out the window will tell you the AoA.

SheikhDjibouti wrote:
Morrisond assures us that the numerous clues on approach to stall are so blindingly obvious that they cannot be missed. He has stalled a Cessna dozens of times. :yes:
Apart from the stick shaker, what indications of an approaching stall did they have?


In many situations, stick shaker will be the primary indication you're near stall. A 737 is not a Cessna.

Besides, even a false stick shaker tells you something is wrong with the airplane. The crew cannot continue to operate the airplane as if all is normal.

SheikhDjibouti wrote:
Hindsight is a such a beautiful thing.


No hindsight needed, just applying the appropriate NNC's for the cues the airplane is giving you.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
OldAeroGuy
Posts: 3870
Joined: Sun Dec 05, 2004 6:50 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 20, 2019 11:36 pm

RickNRoll wrote:
OldAeroGuy wrote:
PixelFlight wrote:
ET302 _DID_NOT_STALL_ !!!!! How hard is that to understand, really ? :banghead:

There no point to do a NCC that do not correspond to the situation.


I understand perfectly well that ET 302 did not stall.

But the sticker shaker was active through out the ET 302 flight.

With an active stick shaker, why were the Flaps retracted?

Please do not say to avoid the Flaps 5 placard. The ET crew had complete control pitch and power at Flaps 5.

Speed was controllable below the Flaps 5 placard by referencing either Left or Right Airspeed indicators.

It was the perfect set up to conduct the "Airspeed Unreliable" NNC.


The Boeing EAD didn't think so.


The FAA EAD is written for erroneous MCAS operation. If Flaps are down, no erroneous MCAS operation so run the "STALL RECOVERY" NNC that the stick shaker is prompting you do do.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
RickNRoll
Posts: 1723
Joined: Fri Jan 06, 2012 9:30 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Mon May 20, 2019 11:39 pm

OldAeroGuy wrote:
RickNRoll wrote:
OldAeroGuy wrote:

I understand perfectly well that ET 302 did not stall.

But the sticker shaker was active through out the ET 302 flight.

With an active stick shaker, why were the Flaps retracted?

Please do not say to avoid the Flaps 5 placard. The ET crew had complete control pitch and power at Flaps 5.

Speed was controllable below the Flaps 5 placard by referencing either Left or Right Airspeed indicators.

It was the perfect set up to conduct the "Airspeed Unreliable" NNC.


The Boeing EAD didn't think so.


The FAA EAD is written for erroneous MCAS operation. If Flaps are down, no erroneous MCAS operation so run the "STALL RECOVERY" NNC that the stick shaker is prompting you do do.
Yet Boeing knew that. Transparency. Openness. It goes a long way and could have saved lives. MCAS is just about to go berserk and could kill you, but we won't mention that
 
morrisond
Posts: 1178
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 12:00 am

SheikhDjibouti wrote:
OldAeroGuy wrote:
The point is: Why were the Flaps retracted with an active stick shaker, contrary to the "STALL RECOVERY" NNC ?

Because they looked out of the window and could see they were clearly not in a stall situation?
Morrisond assures us that the numerous clues on approach to stall are so blindingly obvious that they cannot be missed. He has stalled a Cessna dozens of times. :yes:
Apart from the stick shaker, what indications of an approaching stall did they have?

No Flap retraction -> No MCAS and need to run the "STAB RUNAWAY" NNC.

Yeah, I get that.
Hindsight is a such a beautiful thing.



Nice personal attack BTW.

That being said I'll bet you I practised it more (stalls) than either of the ET pilots plus full spins which I doubt they did.

If you think I'm inexperienced just remember both ET pilots had marginally more hours and they were put into the cockpit of a 737. So if you think I'm inexperienced WTH are they doing in the cockpit of a 737.

And just for the record - on a 737 there is the stick shaker - loud audio alarms and voice warnings and the frame also buffets as you approach stall - if you miss those blindingly obvious clues then you really don't belong in the cockpit.
 
mjoelnir
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 12:02 am

Kirkland consultant questioned for six hours in criminal probe of Boeing 737 MAX crashes

https://www.seattletimes.com/business/b ... 7-crashes/

It seems quite clear now that there is a criminal investigation in regards to the two accidents and the design and certification off the 737MAX.
 
SEU
Posts: 146
Joined: Wed Mar 13, 2019 7:21 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 12:08 am

morrisond wrote:
SheikhDjibouti wrote:
OldAeroGuy wrote:
The point is: Why were the Flaps retracted with an active stick shaker, contrary to the "STALL RECOVERY" NNC ?

Because they looked out of the window and could see they were clearly not in a stall situation?
Morrisond assures us that the numerous clues on approach to stall are so blindingly obvious that they cannot be missed. He has stalled a Cessna dozens of times. :yes:
Apart from the stick shaker, what indications of an approaching stall did they have?

No Flap retraction -> No MCAS and need to run the "STAB RUNAWAY" NNC.

Yeah, I get that.
Hindsight is a such a beautiful thing.



Nice personal attack BTW.

That being said I'll bet you I practised it more (stalls) than either of the ET pilots plus full spins which I doubt they did.

If you think I'm inexperienced just remember both ET pilots had marginally more hours and they were put into the cockpit of a 737. So if you think I'm inexperienced WTH are they doing in the cockpit of a 737.

And just for the record - on a 737 there is the stick shaker - loud audio alarms and voice warnings and the frame also buffets as you approach stall - if you miss those blindingly obvious clues then you really don't belong in the cockpit.


You are making blind assumptions, both those pilots had in total 10k hours of flying time between them (over a year in the air). What experience do you have ?

Boeing is to blame. Give up.
 
OldAeroGuy
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 12:16 am

RickNRoll wrote:
OldAeroGuy wrote:
RickNRoll wrote:

The Boeing EAD didn't think so.


The FAA EAD is written for erroneous MCAS operation. If Flaps are down, no erroneous MCAS operation so run the "STALL RECOVERY" NNC that the stick shaker is prompting you do do.
Yet Boeing knew that. Transparency. Openness. It goes a long way and could have saved lives. MCAS is just about to go berserk and could kill you, but we won't mention that


Here is a section of text from EAD 2018-23-51:

Runaway Stabilizer
In the event of an uncommanded horizontal stabilizer trim movement,
combined with any of the following potential effects or indications
resulting from an erroneous Angle of Attack (AOA) input, the flight crew
must comply with the Runaway Stabilizer procedure in the Operating
Procedures chapter of this manual:
• Continuous or intermittent stick shaker on the affected side only.
• Minimum speed bar (red and black) on the affected side only.
• Increasing nose down control forces.
• IAS DISAGREE alert.
• ALT DISAGREE alert.
• AOA DISAGREE alert (if the option is installed).
• FEEL DIFF PRESS light.
• Autopilot may disengage.
• Inability to engage autopilot.

At Flaps 5 with an erroneous AoA, Items 1, 4, 5, 7, and 8 were certainly present on ET302. The airplane systems were warning that an MCAS malfunction was likely. If the ET 302 had the text of the EAD, it should have been clear that a Runaway Stabilizer was possible.

How much more Transparent and Open did Boeing and the FAA need to be?
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
GalaxyFlyer
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Joined: Fri Jan 01, 2016 4:44 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 12:54 am

speedbored wrote:
GalaxyFlyer wrote:
speedbored wrote:
No, it does not. If the pilots could adequately control "airplane pitch" with just the control column, there would be no need to even touch the electric trim, if following what the NNC actually says. The wording "as needed" is negligently vague.

Also, the note at the bottom of the AD says:


The use of "may" and "can" clearly makes all of this optional. If the pilots had what they perceived to be adequate control just using the control column, then there is no reason for them to use electric trim. And why would they if MCAS keeps adding nose-down? The urgency would be on stopping that happening. They would then be able to remove any adverse trim afterwards using the manual trim wheel - the AD clearly says that they will be able to do so ("can"), though this is also negligently incorrect in some circumstances, it seems.


You clearly don’t understand how pitch is controlled—apply stick forces to achieve the desired pitch and airspeed, then use the trim to neutralize the stick force.

Oh but I do understand. I qualified as a commercial pilot many years ago and have flown 737s (classics). I had to give it up on medical grounds after a car crash.

Unlike you, apparently, I also understand human factors, especially those involved in high stress situations such as these.
GalaxyFlyer wrote:
One never holds the control force and not trim.

Agreed. But how do you know that that is not what the pilots tried to do? There is no reason why it has to be immediate unless the control column forces are excessive.

Have you even entertained the possibility that they might just have decided to prioritise disabling MCAS over correcting the trim? After all, Boeing explicitly told them in the AD that they WOULD be able to correct adverse trim using the manual trim wheel. IMO, the fact that they later tried re-enabling electric trim suggests that this is actually what happened.

planecane wrote:
Thank you for posting this. It is frustrating trying to have a discussion and people posting authoritative sounding posts when they don't have an understanding of how an aircraft is actually flown.

Just because people disagree with your assumptions about what happened does not mean that they do not understand what they are talking about. Until the final report comes out, you are only guessing, like everyone else. Some of us, however, are doing so without bias.


If the yoke is being progressively snatched out of hands, the ONLY tool left is using the thumb switches. I flew the 727, same system, same responses, pull back and trim out the forces. This really is Flight 1 at any school. Yes, under high stress one reverts to trained, even subconscious, actions. Trimming, I would submit, is or should one.

I was in a mid-air, nothing left of my plane, I tried to use the stick, it wasn’t connected to anything, time to eject; but I made that a conscious decision. Pilots must be trained to eliminate reactions and to think under pressure.

GF
Last edited by GalaxyFlyer on Tue May 21, 2019 12:56 am, edited 1 time in total.
 
User avatar
7BOEING7
Posts: 3038
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 12:56 am

mjoelnir wrote:
Kirkland consultant questioned for six hours in criminal probe of Boeing 737 MAX crashes

https://www.seattletimes.com/business/b ... 7-crashes/

It seems quite clear now that there is a criminal investigation in regards to the two accidents and the design and certification off the 737MAX.



There is an investigation but they're just fishing so far -- a key quote from the Times article below:

"Although Lemme has no direct personal knowledge of the airplane’s development or certification,.."

They're just looking to see if Boeing's processes were all correct -- IMHO it will come to nothing.
 
mjoelnir
Posts: 8363
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 12:56 am

OldAeroGuy wrote:
RickNRoll wrote:
OldAeroGuy wrote:

The FAA EAD is written for erroneous MCAS operation. If Flaps are down, no erroneous MCAS operation so run the "STALL RECOVERY" NNC that the stick shaker is prompting you do do.
Yet Boeing knew that. Transparency. Openness. It goes a long way and could have saved lives. MCAS is just about to go berserk and could kill you, but we won't mention that


Here is a section of text from EAD 2018-23-51:

Runaway Stabilizer
In the event of an uncommanded horizontal stabilizer trim movement,
combined with any of the following potential effects or indications
resulting from an erroneous Angle of Attack (AOA) input, the flight crew
must comply with the Runaway Stabilizer procedure in the Operating
Procedures chapter of this manual:
• Continuous or intermittent stick shaker on the affected side only.
• Minimum speed bar (red and black) on the affected side only.
• Increasing nose down control forces.
• IAS DISAGREE alert.
• ALT DISAGREE alert.
• AOA DISAGREE alert (if the option is installed).
• FEEL DIFF PRESS light.
• Autopilot may disengage.
• Inability to engage autopilot.

At Flaps 5 with an erroneous AoA, Items 1, 4, 5, 7, and 8 were certainly present on ET302. The airplane systems were warning that an MCAS malfunction was likely. If the ET 302 had the text of the EAD, it should have been clear that a Runaway Stabilizer was possible.

How much more Transparent and Open did Boeing and the FAA need to be?


How about naming MCAS and explaining exactly what it does.
How about explaining that AoA disagree does not work, even so it is not optional and mentioned in the manuals.
How about mentioning that retracting flaps will lead to repeated aggressive stabilizer trim down commands by the flight control in those conditions.

Just to start.off
 
User avatar
SheikhDjibouti
Posts: 1717
Joined: Sat Sep 30, 2017 4:59 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 12:59 am

morrisond wrote:
SheikhDjibouti wrote:
Because they looked out of the window and could see they were clearly not in a stall situation?
Morrisond assures us that the numerous clues on approach to stall are so blindingly obvious that they cannot be missed. He has stalled a Cessna dozens of times. :yes:
Apart from the stick shaker, what indications of an approaching stall did they have?

Nice personal attack BTW.

That being said I'll bet you I practised it more (stalls) than either of the ET pilots plus full spins which I doubt they did.

If you think I'm inexperienced just remember both ET pilots had marginally more hours and they were put into the cockpit of a 737. So if you think I'm inexperienced WTH are they doing in the cockpit of a 737.

And just for the record - on a 737 there is the stick shaker - loud audio alarms and voice warnings and the frame also buffets as you approach stall - if you miss those blindingly obvious clues then you really don't belong in the cockpit.

How is that a personal attack?
Some weeks ago, too far back to recover actual quotes from you, we argued over how the 737 stalls, and I was forced to acknowledge you must have more expertise in this area than myself.
You were (and still are) quite adamant that you know enough about stalling (& spinning) aircraft, and the specific stall characteristics of the 737 MAX.

I stated this, and you have subsequently posted a 100% confirmation that the comments I attributed to you were correct.

How is that a personal attack? I would call it an invitation for you to join the conversation - and it worked, so what's not to like? :bigthumbsup:
Nothing to see here; move along please.
 
RickNRoll
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 1:13 am

OldAeroGuy wrote:
RickNRoll wrote:
OldAeroGuy wrote:

I understand perfectly well that ET 302 did not stall.

But the sticker shaker was active through out the ET 302 flight.

With an active stick shaker, why were the Flaps retracted?

Please do not say to avoid the Flaps 5 placard. The ET crew had complete control pitch and power at Flaps 5.

Speed was controllable below the Flaps 5 placard by referencing either Left or Right Airspeed indicators.

It was the perfect set up to conduct the "Airspeed Unreliable" NNC.


The Boeing EAD didn't think so.


The FAA EAD is written for erroneous MCAS operation. If Flaps are down, no erroneous MCAS operation so run the "STALL RECOVERY" NNC that the stick shaker is prompting you do do.


But if you read the EAD.

Additionally, pilots are reminded that an erroneous AOA can cause some or all of the following indications and effects:

- Continuous or intermittent stick shaker on the affected side only.
- Minimum speed bar (red and black) on the affected side only.
- Increasing nose down control forces.
- Inability to engage autopilot.
- Automatic disengagement of autopilot.
- IAS DISAGREE alert.
- ALT DISAGREE alert.
- AOA DISAGREE alert (if the AOA indicator option is installed)
- FEEL DIFF PRESS light.

In the event an uncommanded nose down stabilizer trim is experienced on the 737 - 8 / - 9, in conjunction with one or more of the above indications or effects, do the Runaway Stabilizer NNC ensuring that the STAB TRIM CUTOUT switches are set to CUTOUT and stay in the CUTOUT position for the remainder of the flight.


Stick shaker once side only. There it is. Follow "Runaway Stabilizer NNC".

Nothng about follow "Airspeed Unreliable" NNC. Nothing about if you don't raise the flaps the runaway can't happen.
 
User avatar
SheikhDjibouti
Posts: 1717
Joined: Sat Sep 30, 2017 4:59 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 1:20 am

OldAeroGuy wrote:
SheikhDjibouti wrote:
OldAeroGuy wrote:
The point is: Why were the Flaps retracted with an active stick shaker, contrary to the "STALL RECOVERY" NNC ?

Because they looked out of the window and could see they were clearly not in a stall situation?

How does looking out the window tell you that you aren't near stall? That sounds like the US Congress testimony that says looking out the window will tell you the AoA.
It might sound like that, but maybe you have forgotten that the stick shaker was active immediately following take-off. Looking out of the window whilst so close to the runway would give you some idea of your progress. Whereas when flying along at 4,000' AGL or higher, I agree you will have fewer clues.

SheikhDjibouti wrote:
Apart from the stick shaker, what indications of an approaching stall did they have?

In many situations, stick shaker will be the primary indication you're near stall. A 737 is not a Cessna.
Just the stick shaker? However did pilots manage before it's invention (1963) and widespread use (1980's?) Fortunately Morrisond is here now to discuss the finer points of how the 737 stalls. I'm hungry; buffet anyone?

Besides, even a false stick shaker tells you something is wrong with the airplane. The crew cannot continue to operate the airplane as if all is normal.
Great analysis! But which of the many many checklists do you apply. I'm not aware of one called "False stick shaker".
On the other hand, I can visualize plenty of crews who would continue their flight "as if all is normal" whilst troubleshooting minor problems. Isn't that why they have hotlines to their maintenance departments? Prior to these crashes, a false stick shaker was probably defined as a minor problem. I suspect that is going to change from now on.

SheikhDjibouti wrote:
Hindsight is a such a beautiful thing.

No hindsight needed, just applying the appropriate NNC's for the cues the airplane is giving you.
No need to be so vague - just state exactly what the stall recovery NNC says. You came up with an imgur link but for some reason I like to see the actual words here on a.net

But if that's a problem. allow me to "initiate the recovery";
Boeing 737 FCOM Stall Recovery MAN.1.1 wrote:
1) Smoothly apply nose down elevator to reduce AoA until buffet or stick shaker stops.

There are further instructions as part of this procedure, but before considering them, I've got to ask; what is the procedure if the stick shaker doesn't stop?
I'm guessing you don't keep "smoothly applying the elevator" until the brown stuff meets the windscreen?

The problem seems to be that the NNC is treating it as if it was a stall situation, in which case it would be cured. Except it isn't.
Unfortunately nothing else on the list comes close to dealing with a stubbornly continuous stick shaker, and neither does this NNC specify which NNC to try next.

Presumably, without resorting to hindsight whatsoever, you have the answer to this too.
Is it by any chance execute a 180 and land a.s.a.p. to allow maint to sort the unknown problem?
You are the professional; I'm just here to learn. :)
Nothing to see here; move along please.
 
PixelPilot
Posts: 252
Joined: Tue Jan 16, 2018 1:19 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 1:27 am

How far will people go to hide deficiencies in training is beyond me.
Instead of pushing both the manufacturer and the regulators to create better systems AND training all I see here is a boeing hate.
Seems a lot of you have personal agendas instead of common sense/will to create the safest possible outcome/environment for the travelers.
Beat the drum... dum dum dum.

For now you always need two to tango and I would like to know that both factors are prepared to the highest standards.
 
OldAeroGuy
Posts: 3870
Joined: Sun Dec 05, 2004 6:50 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 1:33 am

mjoelnir wrote:
How about naming MCAS and explaining exactly what it does.

Wouldn't have prevented the ET 302 crash. Complying with the EAD and properly executing the "Runaway Stabilizer" NNC would have avoided the crash.

mjoelnir wrote:
How about explaining that AoA disagree does not work, even so it is not optional and mentioned in the manuals.

Wouldn't have prevented the ET 302 crash. All cues associated with "AoA Disagree" (one side stick shaker, "IAS Disagree" & "ALT Disagree") were present and not acted upon. Complying with the EAD and properly executing the "Runaway Stabilizer" NNC would have avoided the crash.

mjoelnir wrote:
How about mentioning that retracting flaps will lead to repeated aggressive stabilizer trim down commands by the flight control in those conditions.

Might have prevented the ET 302 crash. Cues such as stick shaker, "IAS Disagree" & "ALT Disagree" were present and not acted upon, leading to inappropriate Flap retraction. Following "Airspeed Unreliable" NNC prior to Flap retraction may have avoided the crash. Complying with the EAD and properly executing the "Runaway Stabilizer" NNC after Flap retraction would have avoided the crash.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
OldAeroGuy
Posts: 3870
Joined: Sun Dec 05, 2004 6:50 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 1:53 am

RickNRoll wrote:
Stick shaker once side only. There it is. Follow "Runaway Stabilizer NNC".

Strictly only applicable if there is uncommanded stabilizer activity.

However, if the "Runaway Stabilizer" NNC had been performed correctly at Flaps 5, the ET 302 crash would not have happened.

RickNRoll wrote:
Nothing about follow "Airspeed Unreliable" NNC. Nothing about if you don't raise the flaps the runaway can't happen.


Nothing except for:

"IAS Disagree" Alert prompts the "Airspeed Unreliable" NNC

Stick shaker prompts the Stall Recovery NNC which says don't retract Flaps.

So, if the Flaps had been left at Flaps 5, the crew had applied the Runaway Stabilizer" NNC correctly and the "Airspeed Unreliable" NNC had been conducted, would ET 302 have crashed?
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
RickNRoll
Posts: 1723
Joined: Fri Jan 06, 2012 9:30 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 2:20 am

OldAeroGuy wrote:
RickNRoll wrote:
Stick shaker once side only. There it is. Follow "Runaway Stabilizer NNC".

Strictly only applicable if there is uncommanded stabilizer activity.

However, if the "Runaway Stabilizer" NNC had been performed correctly at Flaps 5, the ET 302 crash would not have happened.

RickNRoll wrote:
Nothing about follow "Airspeed Unreliable" NNC. Nothing about if you don't raise the flaps the runaway can't happen.


Nothing except for:

"IAS Disagree" Alert prompts the "Airspeed Unreliable" NNC

Stick shaker prompts the Stall Recovery NNC which says don't retract Flaps.

So, if the Flaps had been left at Flaps 5, the crew had applied the Runaway Stabilizer" NNC correctly and the "Airspeed Unreliable" NNC had been conducted, would ET 302 have crashed?


Maybe you should have written the EAD? It is supposed to be informing pilots about an error in the MCAS design that had already brought down one plane. Why not say just that?
Last edited by RickNRoll on Tue May 21, 2019 2:30 am, edited 1 time in total.
 
morrisond
Posts: 1178
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 2:21 am

SheikhDjibouti wrote:
morrisond wrote:
SheikhDjibouti wrote:
Because they looked out of the window and could see they were clearly not in a stall situation?
Morrisond assures us that the numerous clues on approach to stall are so blindingly obvious that they cannot be missed. He has stalled a Cessna dozens of times. :yes:
Apart from the stick shaker, what indications of an approaching stall did they have?

Nice personal attack BTW.

That being said I'll bet you I practised it more (stalls) than either of the ET pilots plus full spins which I doubt they did.

If you think I'm inexperienced just remember both ET pilots had marginally more hours and they were put into the cockpit of a 737. So if you think I'm inexperienced WTH are they doing in the cockpit of a 737.

And just for the record - on a 737 there is the stick shaker - loud audio alarms and voice warnings and the frame also buffets as you approach stall - if you miss those blindingly obvious clues then you really don't belong in the cockpit.

How is that a personal attack?
Some weeks ago, too far back to recover actual quotes from you, we argued over how the 737 stalls, and I was forced to acknowledge you must have more expertise in this area than myself.
You were (and still are) quite adamant that you know enough about stalling (& spinning) aircraft, and the specific stall characteristics of the 737 MAX.

I stated this, and you have subsequently posted a 100% confirmation that the comments I attributed to you were correct.

How is that a personal attack? I would call it an invitation for you to join the conversation - and it worked, so what's not to like? :bigthumbsup:


Here is a good video on stalls in the 737 NG. It's pretty evident if you are doing something wrong - you have tons of time to not get into an actual stall.

https://www.youtube.com/watch?v=zCJco59tqoQ

The FAA would not have certified the MAX if it had weird stall behaviour as it is not allowed by the FAR's. They did over 300 test flights - they might have missed MCAS but they wouldn't have missed if the MAX had some weird stall behaviour that is different from the NG.
 
planecane
Posts: 1031
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 2:27 am

RickNRoll wrote:
OldAeroGuy wrote:
RickNRoll wrote:

The Boeing EAD didn't think so.


The FAA EAD is written for erroneous MCAS operation. If Flaps are down, no erroneous MCAS operation so run the "STALL RECOVERY" NNC that the stick shaker is prompting you do do.


But if you read the EAD.

Additionally, pilots are reminded that an erroneous AOA can cause some or all of the following indications and effects:

- Continuous or intermittent stick shaker on the affected side only.
- Minimum speed bar (red and black) on the affected side only.
- Increasing nose down control forces.
- Inability to engage autopilot.
- Automatic disengagement of autopilot.
- IAS DISAGREE alert.
- ALT DISAGREE alert.
- AOA DISAGREE alert (if the AOA indicator option is installed)
- FEEL DIFF PRESS light.

In the event an uncommanded nose down stabilizer trim is experienced on the 737 - 8 / - 9, in conjunction with one or more of the above indications or effects, do the Runaway Stabilizer NNC ensuring that the STAB TRIM CUTOUT switches are set to CUTOUT and stay in the CUTOUT position for the remainder of the flight.


Stick shaker once side only. There it is. Follow "Runaway Stabilizer NNC".

Nothng about follow "Airspeed Unreliable" NNC. Nothing about if you don't raise the flaps the runaway can't happen.

If the airspeed is unreliable, you run the airspeed unreliable NNC. The fact that one NNC is called for does not mean to not address anything else.
 
RickNRoll
Posts: 1723
Joined: Fri Jan 06, 2012 9:30 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 2:36 am

planecane wrote:
RickNRoll wrote:
OldAeroGuy wrote:

The FAA EAD is written for erroneous MCAS operation. If Flaps are down, no erroneous MCAS operation so run the "STALL RECOVERY" NNC that the stick shaker is prompting you do do.


But if you read the EAD.

Additionally, pilots are reminded that an erroneous AOA can cause some or all of the following indications and effects:

- Continuous or intermittent stick shaker on the affected side only.
- Minimum speed bar (red and black) on the affected side only.
- Increasing nose down control forces.
- Inability to engage autopilot.
- Automatic disengagement of autopilot.
- IAS DISAGREE alert.
- ALT DISAGREE alert.
- AOA DISAGREE alert (if the AOA indicator option is installed)
- FEEL DIFF PRESS light.

In the event an uncommanded nose down stabilizer trim is experienced on the 737 - 8 / - 9, in conjunction with one or more of the above indications or effects, do the Runaway Stabilizer NNC ensuring that the STAB TRIM CUTOUT switches are set to CUTOUT and stay in the CUTOUT position for the remainder of the flight.


Stick shaker once side only. There it is. Follow "Runaway Stabilizer NNC".

Nothng about follow "Airspeed Unreliable" NNC. Nothing about if you don't raise the flaps the runaway can't happen.

If the airspeed is unreliable, you run the airspeed unreliable NNC. The fact that one NNC is called for does not mean to not address anything else.


I am talking about the EAD. It refers to only one NNC when it should have referred to two. Just in the interestes of trying to save peoples lives would it have hurt Boeing to be a little more expansive? They already knew exactly what was going on and why.
 
kayik
Posts: 34
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 2:39 am

OldAeroGuy wrote:
mjoelnir wrote:
How about naming MCAS and explaining exactly what it does.

Wouldn't have prevented the ET 302 crash. Complying with the EAD and properly executing the "Runaway Stabilizer" NNC would have avoided the crash.

mjoelnir wrote:
How about explaining that AoA disagree does not work, even so it is not optional and mentioned in the manuals.

Wouldn't have prevented the ET 302 crash. All cues associated with "AoA Disagree" (one side stick shaker, "IAS Disagree" & "ALT Disagree") were present and not acted upon. Complying with the EAD and properly executing the "Runaway Stabilizer" NNC would have avoided the crash.

mjoelnir wrote:
How about mentioning that retracting flaps will lead to repeated aggressive stabilizer trim down commands by the flight control in those conditions.

Might have prevented the ET 302 crash. Cues such as stick shaker, "IAS Disagree" & "ALT Disagree" were present and not acted upon, leading to inappropriate Flap retraction. Following "Airspeed Unreliable" NNC prior to Flap retraction may have avoided the crash. Complying with the EAD and properly executing the "Runaway Stabilizer" NNC after Flap retraction would have avoided the crash.


I think he raised these three points as examples to "How much more Transparent and Open did Boeing and the FAA need to be?" Not for you to answer.
 
planecane
Posts: 1031
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 2:39 am

RickNRoll wrote:
OldAeroGuy wrote:
RickNRoll wrote:
Stick shaker once side only. There it is. Follow "Runaway Stabilizer NNC".

Strictly only applicable if there is uncommanded stabilizer activity.

However, if the "Runaway Stabilizer" NNC had been performed correctly at Flaps 5, the ET 302 crash would not have happened.

RickNRoll wrote:
Nothing about follow "Airspeed Unreliable" NNC. Nothing about if you don't raise the flaps the runaway can't happen.


Nothing except for:

"IAS Disagree" Alert prompts the "Airspeed Unreliable" NNC

Stick shaker prompts the Stall Recovery NNC which says don't retract Flaps.

So, if the Flaps had been left at Flaps 5, the crew had applied the Runaway Stabilizer" NNC correctly and the "Airspeed Unreliable" NNC had been conducted, would ET 302 have crashed?


Maybe you should have written the EAD? It is supposed to be informing pilots about an error in the MCAS design that had already brought down one plane. Why not say just that?


Maybe you should understand that the EAD is not the document that the pilots are trained on. The EAD directed updates be made to the FCOM and QRH. It is those updated documents that are relevant. For the runaway stabilizer NNC the "trigger" is uncommanded stabilizer movement. Nothing about airspeed unreliable needs to be in the EAD because no changes were needed for that failure mode or associated NNC. It stands on its own completely separate from runaway stabilizer.
 
planecane
Posts: 1031
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 2:45 am

PixelPilot wrote:
How far will people go to hide deficiencies in training is beyond me.
Instead of pushing both the manufacturer and the regulators to create better systems AND training all I see here is a boeing hate.
Seems a lot of you have personal agendas instead of common sense/will to create the safest possible outcome/environment for the travelers.
Beat the drum... dum dum dum.

For now you always need two to tango and I would like to know that both factors are prepared to the highest standards.

THANK YOU! Nobody is making a case that MCAS was implemented properly. However, many posters are legitimately criticizing the actions of the crew as well. It was the combination of bad MCAS design and imperfect reaction by the crews that causes the crashes. Boeing put the ball on the tee and the crews hit it.

However, there are several posters who keep posting nonsense to try and get everyone to agree that these crashes were 100% Boeing's fault because they are greedy and evil and nothing either crew could have done would have saved the plane (ignoring the fact that Lion Air 043 dealt with the same failure and recovered easily).
 
smartplane
Posts: 1024
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 3:18 am

OldAeroGuy wrote:
RickNRoll wrote:

The EAD says MCAS "could" experience a stick shaker event but makes no mention at all of not lowering the flaps as a means of avoiding nose diving into the dirt. The only option it gives is the Trim Runaway.


The point is: Why were the Flaps retracted with an active stick shaker, contrary to the "STALL RECOVERY" NNC ?

https://imgur.com/JyM0nKQ

No Flap retraction -> No MCAS and need to run the "STAB RUNAWAY" NNC.

But is it accepted practice of 737 pilots, to disregard a stick shaker if occurring only on one side, especially if there are other issues with the aircraft? Perhaps a stick shaker on one side in the NG and MAX is more common than it should be, so pilots have learned to ignore or work around.
 
AABusDrvr
Posts: 36
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 3:24 am

smartplane wrote:
OldAeroGuy wrote:
RickNRoll wrote:

The EAD says MCAS "could" experience a stick shaker event but makes no mention at all of not lowering the flaps as a means of avoiding nose diving into the dirt. The only option it gives is the Trim Runaway.


The point is: Why were the Flaps retracted with an active stick shaker, contrary to the "STALL RECOVERY" NNC ?

https://imgur.com/JyM0nKQ

No Flap retraction -> No MCAS and need to run the "STAB RUNAWAY" NNC.

But is it accepted practice of 737 pilots, to disregard a stick shaker if occurring only on one side, especially if there are other issues with the aircraft? Perhaps a stick shaker on one side in the NG and MAX is more common than it should be, so pilots have learned to ignore or work around.


Accepted practice where? You wouldn't know it was only on one side, unless both pilots were hands on the controls, and talking about exactly that.
 
OldAeroGuy
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 3:39 am

smartplane wrote:
But is it accepted practice of 737 pilots, to disregard a stick shaker if occurring only on one side, especially if there are other issues with the aircraft? Perhaps a stick shaker on one side in the NG and MAX is more common than it should be, so pilots have learned to ignore or work around.


Do you have any information to support your supposition?

On the 737 NG and MAX, stick shaker on one side only will cause "IAS Disagree" and "Alt Disagree" Alerts.

Are you suggesting that 737 crews are ignoring these Alert messages?

And, are they completing their missions with a stick shaker active? There is no approved procedure for disabling a stick shaker in flight.

If crews are flying missions with active stick shakers, they are operating airplanes that are not in compliance with their certification basis.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
OldAeroGuy
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 4:14 am

SEU wrote:
You are making blind assumptions, both those pilots had in total 10k hours of flying time between them (over a year in the air). What experience do you have ?


About 90K hours of Part 25 airplane design & performance, safety and certification experience.

While I agree that Boeing had a major role in the JT610 and ET302 crashes, both crews made fundamental errors as well.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
kayik
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 4:20 am

planecane wrote:
PixelPilot wrote:
How far will people go to hide deficiencies in training is beyond me.
Instead of pushing both the manufacturer and the regulators to create better systems AND training all I see here is a boeing hate.
Seems a lot of you have personal agendas instead of common sense/will to create the safest possible outcome/environment for the travelers.
Beat the drum... dum dum dum.

For now you always need two to tango and I would like to know that both factors are prepared to the highest standards.

THANK YOU! Nobody is making a case that MCAS was implemented properly. However, many posters are legitimately criticizing the actions of the crew as well. It was the combination of bad MCAS design and imperfect reaction by the crews that causes the crashes. Boeing put the ball on the tee and the crews hit it.

However, there are several posters who keep posting nonsense to try and get everyone to agree that these crashes were 100% Boeing's fault because they are greedy and evil and nothing either crew could have done would have saved the plane (ignoring the fact that Lion Air 043 dealt with the same failure and recovered easily).


Lion Air 043 had a third hand thinking of something else when pilots were busy. If he was not there we probably would still have 2 crashes. However, he saved the plane, but the next crew on the same plane could not. The same scenario can be applied to ET. One crew succeed, next crew may not, because the equipment is not right. Naturally, the blame goes to the manufacturer. That's why MAX is grounded, and as news keep coming in, the shit gets deeper and deeper.
 
rheinwaldner
Posts: 1709
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 4:32 am

OldAeroGuy wrote:
rheinwaldner wrote:
OldAeroGuy wrote:

If you're going to quote me, please do so in the proper context.

The claim was made in this thread that ET, other than ET 302, had not had a loss of control crash in the last 15 years.

Then that claim was off topic too.


The claim was being made to illustrate the efficacy of ET pilot training. As pilot training levels have been discussed extensively in this thread, it was relevant to the general topic.

Maybe we can stop discussing pilots because it is off topic in this thread? The ET crash thread would be the right one. Try to discuss the grounding there. By very rigid forum police you will get reminded immediately to come here. There is a trend to flood all MAX threads with pilots topics. Guess whose agenda that would be?

OldAeroGuy wrote:
The point is: Why were the Flaps retracted with an active stick shaker, contrary to the "STALL RECOVERY" NNC?

These pilots are "grounded" forever and wont tell you anymore. This thread is about the grounded MAX. Ask the question in the thread about the ET crash.
Many things are difficult, all things are possible!
 
OldAeroGuy
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 5:01 am

SheikhDjibouti wrote:
It might sound like that, but maybe you have forgotten that the stick shaker was active immediately following take-off. Looking out of the window whilst so close to the runway would give you some idea of your progress. Whereas when flying along at 4,000' AGL or higher, I agree you will have fewer clues.

The problem is that you don't know why the stick shaker is active. If the cause is a leading edge issue, the window picture and speed may be close to what you'd consider normal but you may be near to stall due to leading edge damage. Best to heed your warnings near the ground.

SheikhDjibouti wrote:
Just the stick shaker? However did pilots manage before it's invention (1963) and widespread use (1980's?)


In his comprehensive book, "Handling the Big Jets", D. P. Davies dates the stick shaker invention to the mid-50's, Stick shakers were in wide spread use on Part 25 airplanes by the 1960's.

You may be thinking of the BAC 1-11 stick shaker/stick pusher combination that was fitted in 1963 after the test flight crash.

SheikhDjibouti wrote:
Great analysis! But which of the many many checklists do you apply. I'm not aware of one called "False stick shaker".
On the other hand, I can visualize plenty of crews who would continue their flight "as if all is normal" whilst troubleshooting minor problems. Isn't that why they have hotlines to their maintenance departments? Prior to these crashes, a false stick shaker was defined a "minor" issue.


Because of its cascading impact on other airplane systems, an active stick shaker is never considered "minor".

SheikhDjibouti wrote:

There are further instructions as part of this procedure, but before considering them, I've got to ask; what is the procedure if the stick shaker doesn't stop?
I'm guessing you don't keep "smoothly applying the elevator" until the brown stuff meets the windscreen?

The problem seems to be that the NNC is treating it as if it was a stall situation, in which case it would be cured. Except it isn't.
Unfortunately nothing else on the list comes close to dealing with a stubbornly continuous stick shaker, and neither does this NNC specify which NNC to try next.


The GPWS saying "Don't Sink" will be a great cue telling you not to push over anymore. The "IAS Disagree" Alert gives you a great intro as what NNC ("Unreliable Airspeed" to apply next.

SheikhDjibouti wrote:
Presumably, without resorting to hindsight whatsoever, you have the answer to this too.
Is it by any chance execute a 180 and land a.s.a.p. to allow maint to sort the unknown problem?
You are the professional; I'm just here to learn. :)


Yes, this would be my advice to any crew with a continuous stick shaker.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
OldAeroGuy
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 5:12 am

rheinwaldner wrote:
OldAeroGuy wrote:
rheinwaldner wrote:
Then that claim was off topic too.


The claim was being made to illustrate the efficacy of ET pilot training. As pilot training levels have been discussed extensively in this thread, it was relevant to the general topic.

Maybe we can stop discussing pilots because it is off topic in this thread? The ET crash thread would be the right one. Try to discuss the grounding there. By very rigid forum police you will get reminded immediately to come here. There is a trend to flood all MAX threads with pilots topics. Guess whose agenda that would be?

OldAeroGuy wrote:
The point is: Why were the Flaps retracted with an active stick shaker, contrary to the "STALL RECOVERY" NNC?

These pilots are "grounded" forever and wont tell you anymore. This thread is about the grounded MAX. Ask the question in the thread about the ET crash.


Interesting interpretation. The MAX is grounded due to two crashes. The crashes were caused by mistakes by Boeing and the flight crews. It would seem that both topics are open for discussion in this thread.

Have you suggested to the Anet Mods that replies discussing pilot performance on this thread be deleted?
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
zoom321
Posts: 38
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 5:30 am

planecane wrote:
PixelPilot wrote:
How far will people go to hide deficiencies in training is beyond me.
Instead of pushing both the manufacturer and the regulators to create better systems AND training all I see here is a boeing hate.
Seems a lot of you have personal agendas instead of common sense/will to create the safest possible outcome/environment for the travelers.
Beat the drum... dum dum dum.

For now you always need two to tango and I would like to know that both factors are prepared to the highest standards.

THANK YOU! Nobody is making a case that MCAS was implemented properly. However, many posters are legitimately criticizing the actions of the crew as well. It was the combination of bad MCAS design and imperfect reaction by the crews that causes the crashes. Boeing put the ball on the tee and the crews hit it.

However, there are several posters who keep posting nonsense to try and get everyone to agree that these crashes were 100% Boeing's fault because they are greedy and evil and nothing either crew could have done would have saved the plane (ignoring the fact that Lion Air 043 dealt with the same failure and recovered easily).

Which in many ways show why B behavior post Lion crash was worse. In their haste to portray the solution as simple and existing, instead of giving the full picture, they led the ET pilots to electric trim cut off too soon.
If you can't say something right, it's better not to say anything at all.
The Lion pilots stayed in the air longer without B 'solution'.
 
zoom321
Posts: 38
Joined: Sat Mar 09, 2019 3:05 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 5:41 am

https://www.bloomberg.com/news/articles ... emium-asia

Despite what many fan boys may say, the world will put safety first.
 
AirwayBill
Posts: 135
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 6:23 am

double post please remove
Last edited by AirwayBill on Tue May 21, 2019 6:33 am, edited 1 time in total.
 
PStechPaul
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 6:27 am

It seems to me that it might be a good idea to implement a software solution for the abnormal conditions checklist, where the flight computer could present the appropriate checklist items on-screen, or perhaps on a connected tablet, rather than (or in addition to) printed paper. The pilots could also enter their own observations to the "digital assistant", to correct for known malfunctions of sensors. Such a system would also allow almost immediate updates, much faster than printing them and handing them out.
 
XRAYretired
Posts: 488
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 6:30 am

OldAeroGuy wrote:
RickNRoll wrote:

The EAD says MCAS "could" experience a stick shaker event but makes no mention at all of not lowering the flaps as a means of avoiding nose diving into the dirt. The only option it gives is the Trim Runaway.


The point is: Why were the Flaps retracted with an active stick shaker, contrary to the "STALL RECOVERY" NNC ?

https://imgur.com/JyM0nKQ

No Flap retraction -> No MCAS and need to run the "STAB RUNAWAY" NNC.


Perhaps because all 4 crews we can identify had single side stick shaker had correctly identified it was erroneous and did not need to run stall recovery NNC.

Ray
 
AirwayBill
Posts: 135
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 6:32 am

zoom321 wrote:
https://www.bloomberg.com/news/articles/2019-05-21/boeing-max-could-stay-grounded-beyond-this-year-indonesia-says?srnd=premium-asia

Despite what many fan boys may say, the world will put safety first.


It is getting pretty obvious that we will not see the 737 MAX back into the air in 2019 at all. In fact, a full year grounding is very much realistic at this stage.

And by the time it is allowed to fly again, the grounding will probably have costed Boeing much more than the originally forecasted USD 1bn, probably more in the dozens of bn, with all compensations claims incoming (which are only one part of the overall costs).

There's a long road ahead, but some people would still rather dig their heads into the sand instead of admitting that this is full scale disaster that is not ready to end anytime soon.
 
XRAYretired
Posts: 488
Joined: Fri Mar 15, 2019 11:21 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 6:39 am

RickNRoll wrote:
kalvado wrote:
XRAYretired wrote:

Gentlemen, perhaps it is a little simpler. Perhaps either a FAR waiver/noncompliance or a dual sensor MCAS (competent design) would push MAX toward a new type approval that would contrary to the commercial imperative.

Ray

One thing I don't understand: 737 already has artificially applied elevator feel force, and even has separate set of Pitot tubes for that.
Why on earth tweaking that part, or a stick pusher, was not sufficient for force emulation, why aerodynamic solution?
"Just a little lighter controls" is not really an answer for that, there should be much more behind MCAS approach.


Why go for the 500lb gorilla option of 2.5 degrees horizontal stabiliser to tweak the control column feel? It is a bizarre concept.If a tweak was all that was needed why was the proposed 0.6 degree max movement quadrupled to 2.5 degree? Not my definition of a tweak.


Whatever the primary reason for going for MCAS, please remember its about rate of change not the maximum change in a 9.26sec cycle. The design always allowed for inhibiting stabiliser movement once the AOA dropped 0.5deg below the set value when not in fault condition. I would suspect this may be purely a function of the available speed settings of the Trim Motor itself.

Ray
 
XRAYretired
Posts: 488
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 6:55 am

OldAeroGuy wrote:
RickNRoll wrote:
OldAeroGuy wrote:

The FAA EAD is written for erroneous MCAS operation. If Flaps are down, no erroneous MCAS operation so run the "STALL RECOVERY" NNC that the stick shaker is prompting you do do.
Yet Boeing knew that. Transparency. Openness. It goes a long way and could have saved lives. MCAS is just about to go berserk and could kill you, but we won't mention that


Here is a section of text from EAD 2018-23-51:

Runaway Stabilizer
In the event of an uncommanded horizontal stabilizer trim movement,
combined with any of the following potential effects or indications
resulting from an erroneous Angle of Attack (AOA) input, the flight crew
must comply with the Runaway Stabilizer procedure in the Operating
Procedures chapter of this manual:
• Continuous or intermittent stick shaker on the affected side only.
• Minimum speed bar (red and black) on the affected side only.
• Increasing nose down control forces.
• IAS DISAGREE alert.
• ALT DISAGREE alert.
• AOA DISAGREE alert (if the option is installed).
• FEEL DIFF PRESS light.
• Autopilot may disengage.
• Inability to engage autopilot.

At Flaps 5 with an erroneous AoA, Items 1, 4, 5, 7, and 8 were certainly present on ET302. The airplane systems were warning that an MCAS malfunction was likely. If the ET 302 had the text of the EAD, it should have been clear that a Runaway Stabilizer was possible.

How much more Transparent and Open did Boeing and the FAA need to be?



So. you require the crew to follow procedure with precision. Which one, since you now offer two again?

Stall recovery- when there is no stall?
or
Runaway Stabiliser - when there is no runaway?

Perhaps they should run Airspeed Unreliable, since Airspeed unreliable is present, and in climb since they are at low altitude in climb. Seems this likely what they did. Quelle surprise.

Ray
 
XRAYretired
Posts: 488
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 7:27 am

OldAeroGuy wrote:
smartplane wrote:
But is it accepted practice of 737 pilots, to disregard a stick shaker if occurring only on one side, especially if there are other issues with the aircraft? Perhaps a stick shaker on one side in the NG and MAX is more common than it should be, so pilots have learned to ignore or work around.


Do you have any information to support your supposition?

On the 737 NG and MAX, stick shaker on one side only will cause "IAS Disagree" and "Alt Disagree" Alerts.

Are you suggesting that 737 crews are ignoring these Alert messages?

And, are they completing their missions with a stick shaker active? There is no approved procedure for disabling a stick shaker in flight.

If crews are flying missions with active stick shakers, they are operating airplanes that are not in compliance with their certification basis.


Lion Air Preliminary Report relating to JT043-
"The PIC performed three Non-Normal Checklists and none contained the instruction “Plan to land at the nearest suitable airport”.

JT043 followed your much vaunted NNCs to the letter. surely you support this?

Ironically, JT043 was the one of three that elected to continue the flight and landed successfully. It is quite possible that if JT043 had elected to return any time in the first ~6mins of flight, prior to Stab Trim Cut-Off, it would have been JT043 that crashed rather than JT610.

Ray
 
mjoelnir
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 8:52 am

OldAeroGuy wrote:
mjoelnir wrote:
How about naming MCAS and explaining exactly what it does.

Wouldn't have prevented the ET 302 crash. Complying with the EAD and properly executing the "Runaway Stabilizer" NNC would have avoided the crash.

mjoelnir wrote:
How about explaining that AoA disagree does not work, even so it is not optional and mentioned in the manuals.

Wouldn't have prevented the ET 302 crash. All cues associated with "AoA Disagree" (one side stick shaker, "IAS Disagree" & "ALT Disagree") were present and not acted upon. Complying with the EAD and properly executing the "Runaway Stabilizer" NNC would have avoided the crash.

mjoelnir wrote:
How about mentioning that retracting flaps will lead to repeated aggressive stabilizer trim down commands by the flight control in those conditions.

Might have prevented the ET 302 crash. Cues such as stick shaker, "IAS Disagree" & "ALT Disagree" were present and not acted upon, leading to inappropriate Flap retraction. Following "Airspeed Unreliable" NNC prior to Flap retraction may have avoided the crash. Complying with the EAD and properly executing the "Runaway Stabilizer" NNC after Flap retraction would have avoided the crash.


I thought we were talking about transparency?

So you want really insist on Boeing telling everybody about MCAS and allowing training for that new dangerous situation, would not have prevented the crashes? Really?
 
planecane
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 10:14 am

zoom321 wrote:
https://www.bloomberg.com/news/articles/2019-05-21/boeing-max-could-stay-grounded-beyond-this-year-indonesia-says?srnd=premium-asia

Despite what many fan boys may say, the world will put safety first.


It is snarky comments and attitudes like this that have ruined this thread. What "fan boys" have been saying not to put safety first? Discussing and criticizing crew actions IN ADDITION TO Boeing's design error doesn't mean not putting safety first.

Indonesians are offended because Boeing essentially blamed the crew following the Lion Air crash. Therefore, Indonesian authorities are speaking out more strongly against Boeing. Boeing should not have reacted that way when they realized that MCAS-induced runaway stabilizer led to the crash. Even though I am of the opinion that the same crew, with the same other alerts/issues going on would not have responded properly to a runaway stabilizer caused by something else as described in the FCOM/QRH, the fact that the failure mode was slightly different and undocumented means that Boeing should not have publicly blamed the crew.

With the post-Lion Air EAD and documentation of MCAS, I am also of the opinion that any crew should have been able to recognize and recover from an MCAS-induced runaway stabilizer. The fact that the ET crew didn't indicates either a training or an understanding of training and documentation issue that needs to be addressed because it might not only apply to MCAS-induced runaway stabilizer.

With all that said, I think that the grounding was the correct course of action and Boeing must demonstrate that with the fixes MCAS-induced runaway stabilizer events will happen at a rate as low or lower than other causes of runaway stabilizer. Crews should be able to handle emergencies but that doesn't mean I would want emergencies happening at a high rate to be dealt with.

They must also demonstrate that, if it does happen, crews will have the training to properly recognize it and recover from it without difficulty. Finally, they also must disclose ALL changes made from the NG to the MAX so that worldwide authorities can analyze the changes and ensure nothing else was missed during certification.

If they do all of this and a country refuses to lift the grounding, then they are doing it for reasons other than putting safety first.

I'd like to request that the anti-Boeing and/or anti-American posters please stop using the MCAS related MAX crashes to "get" Boeing or "put the U.S.A. in its place." I'd suggest the moderators lock this thread and start a news/facts only thread on the grounding. The only reason that I keep responding to things that I view as wrong is that I'm sure there is non-aviation media that reads this site for background information on MAX stories and I don't want them taking opinions or incorrect statements as facts and presenting them to the "average Joe" audience.
 
User avatar
PixelFlight
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 10:29 am

morrisond wrote:
That being said I'll bet you I practised it more (stalls) than either of the ET pilots plus full spins which I doubt they did.
[...]
About 90K hours of Part 25 airplane design & performance, safety and certification experience.

Fine, I will believe you only when you will be able to describe in detail how is done a 737 NG/MAX runaway stabilizer training session on a simulator.
 
art
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 10:41 am

OldAeroGuy wrote:
RickNRoll wrote:

The EAD says MCAS "could" experience a stick shaker event but makes no mention at all of not lowering the flaps as a means of avoiding nose diving into the dirt. The only option it gives is the Trim Runaway.


The point is: Why were the Flaps retracted with an active stick shaker, contrary to the "STALL RECOVERY" NNC ?

https://imgur.com/JyM0nKQ

No Flap retraction -> No MCAS and need to run the "STAB RUNAWAY" NNC.


Flaps retracted because airspeed exceeded the max allowed for the flap setting?

Do you know which is dominant and which recessive where there is a conflict between what the NNC demands and what the operating manual demands eg manual gives max speed allowed for 5, 10, 15 flaps but NNC specifies keeping flaps setting at airspeed exceeding allowed airspeed for those settings?
 
User avatar
PixelFlight
Posts: 507
Joined: Thu Nov 08, 2018 11:09 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 11:17 am

planecane wrote:
I'd like to request that the anti-Boeing and/or anti-American posters please stop using the MCAS related MAX crashes to "get" Boeing or "put the U.S.A. in its place." I'd suggest the moderators lock this thread and start a news/facts only thread on the grounding. The only reason that I keep responding to things that I view as wrong is that I'm sure there is non-aviation media that reads this site for background information on MAX stories and I don't want them taking opinions or incorrect statements as facts and presenting them to the "average Joe" audience.

THIS is the thread for the 737-8/9 MAX grounding. A few posters hijacked it to make is a "dead pilots errors" and now one of them reclaims a new grounding thread... :crazy:

From my point of view, the primary reason why this "dead pilots errors" discussion did not evolve constructively is because some posters assume pilots do act like automates executing procedures and refuse to take in account the human factor that introduce errors. I like to quote a part of the (generally praised) US1549 final report that describes well that factor. The chapter was about the divergence the captain have between his perception of "maintained a speed “safely above V LS" and the fact that the "FDR data indicated that the airplane was below green dot speed and at V LS or slightly less for most of the descent, and about 15 to 19 knots below V LS during the last 200 feet":

[emphasis mine]
During emergency situations, such as the accident event, pilots experience high levels of
stress resulting from high workload, time pressure, and noise. Stress can distract pilots from
cockpit duties and result in pilot errors or performance degradation
. 133 For example, stress can
lead to a phenomenon known as “tunnel vision,” or the narrowing of attention in which simple
things can be overlooked
(for example, airspeed and descent rate) and an individual focuses on a
narrow piece of information perceived to be most threatening or salient
(for example,
surrounding terrain and a suitable landing location). 134 During the emergency, the flight crew
was faced with a series of GPWS and TCAS aural alerts and many ATC communications, which
can also present distractions during an emergency. Further, during postaccident interviews, the
captain stated that, during the emergency situation, time was very compressed and that, because
he was intensely focused on maintaining a successful flightpath, his attention was narrowed
.
[...]
The NTSB concludes the captain’s difficulty maintaining his intended airspeed during the
final approach resulted, in part, from high workload, stress, and task saturation.


JT043, JT610 and ET302 did not perceived that there could act in an other way that there did (an extra guy saved JT043). The constructive attitude is now to understand why and to propose improvement where it will be effective. What have been proposed so far ?
1) Multiple MCAS fixes, there are so official that nobody can ignore them.
2) Safety assessment activity and certification improvement, this point is subject of various legal probes, difficult to ignore.
3) Documentations, procedures, references, checklists improvement. A minimum was done post JT610, but there are strong signals that more will be required, to date no big statement on this from Boeing.
4) Training. The most debated point. Maybe runaway stabilizer are so rare that there are not trained enough, especially when repetitive, coupled with others problems and at low altitude. To date Boeing still publicly keep his goal to not require additional training for the 737-8/9 MAX.

The human factor need to be addressed in the "safety assessment activity and certification" point. Boeing and FAA jobs.
 
Ertro
Posts: 37
Joined: Thu Apr 04, 2019 9:28 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 11:29 am

planecane wrote:
Discussing and criticizing crew actions IN ADDITION TO Boeing's design error doesn't mean not putting safety first.


How much criticizing crew is enough and appropriate? I am not going to count but my gut feeling is that there are about 1000 messages about crew and we all are pretty much unanimous in saying that pilots could have done better and they have some blame on the outcome. I have not read one single new comment about crew actions for a long time that brings anything new to the table. Would 100 more comments rehashing same old stuff everybody has heard a 1000 times make a difference?

On the other hand there are almost daily new developments on other issues that are new and would warrant some discussion. Unfortunately they are not about pilot actions so somebody needs to turn every discussion about new developments into rehashing old stuff about pilots.

planecane wrote:
Indonesians are offended because Boeing essentially blamed the crew following the Lion Air crash.
Therefore, Indonesian authorities are speaking out more strongly against Boeing.


Indonesians lost hundreds of lives in these crashes. Would you imagine if similar crashes with similar type of causes would have happened in other countries their people would have reacted more mutedly than Indonesians have?

Even without any casualties some countries can suddenly jump trying to ban Huawei equipment from all over the world almost trying to put Huawei whole company into bancruptcy without even half of a PROOF why this needs to happen presented either publicly or to the officials of other countries which are supposed to also needed to join the ban without any room for them make their own decisions.

But yes. Constant blaming of pilots coming from the general direction of where Boeing has home can have the effect of turning some people against Boeing exactly as you say.

planecane wrote:
If they do all of this and a country refuses to lift the grounding, then they are doing it for reasons other than putting safety first.


Don't you think you are jumping the gun when making this determination even before you have analyzed the reasons that are given as a justification for actions that are maybe going to be made in the future? Are you perhaps doing this for some other reasons than putting safety first?
Last edited by Ertro on Tue May 21, 2019 11:50 am, edited 3 times in total.
 
planecane
Posts: 1031
Joined: Thu Feb 09, 2017 4:58 pm

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 11:32 am

PixelFlight wrote:
planecane wrote:
I'd like to request that the anti-Boeing and/or anti-American posters please stop using the MCAS related MAX crashes to "get" Boeing or "put the U.S.A. in its place." I'd suggest the moderators lock this thread and start a news/facts only thread on the grounding. The only reason that I keep responding to things that I view as wrong is that I'm sure there is non-aviation media that reads this site for background information on MAX stories and I don't want them taking opinions or incorrect statements as facts and presenting them to the "average Joe" audience.

THIS is the thread for the 737-8/9 MAX grounding. A few posters hijacked it to make is a "dead pilots errors" and now one of them reclaims new grounding thread... :crazy:

From my point of view, the primary reason why this "dead pilots errors" discussion did not evolve constructively is because some posters assume pilots do act like automates executing procedures and refuse to take in account the human factor that introduce errors. I like to quote a part of the (generally praised) US1549 final report that describes well that factor. The chapter was about the divergence the captain have between his perception of "maintained a speed “safely above V LS" and the fact that the "FDR data indicated that the airplane was below green dot speed and at V LS or slightly less for most of the descent, and about 15 to 19 knots below V LS during the last 200 feet":

[emphasis mine]
During emergency situations, such as the accident event, pilots experience high levels of
stress resulting from high workload, time pressure, and noise. Stress can distract pilots from
cockpit duties and result in pilot errors or performance degradation
. 133 For example, stress can
lead to a phenomenon known as “tunnel vision,” or the narrowing of attention in which simple
things can be overlooked
(for example, airspeed and descent rate) and an individual focuses on a
narrow piece of information perceived to be most threatening or salient
(for example,
surrounding terrain and a suitable landing location). 134 During the emergency, the flight crew
was faced with a series of GPWS and TCAS aural alerts and many ATC communications, which
can also present distractions during an emergency. Further, during postaccident interviews, the
captain stated that, during the emergency situation, time was very compressed and that, because
he was intensely focused on maintaining a successful flightpath, his attention was narrowed
.
[...]
The NTSB concludes the captain’s difficulty maintaining his intended airspeed during the
final approach resulted, in part, from high workload, stress, and task saturation.


JT043, JT610 and ET302 did not perceived that there could act in an other way that there did (an extra guy saved JT043). The constructive attitude is now to understand why and to propose improvement where it will be effective. What have been proposed so far ?
1) Multiple MCAS fixes, there are so official that nobody can ignore them.
2) Safety assessment activity and certification improvement, this point is subject of various legal probes, difficult to ignore.
3) Documentations, procedures, references, checklists improvement. A minimum was done post JT610, but there are strong signals that more will be required, to date no big statement on this from Boeing.
4) Training. The most debated point. Maybe runaway stabilizer are so rare that there are not trained enough, especially when repetitive, coupled with others problems and low altitude. To date Boeing still publicly keep his goal to not require additional training for the 737-8/9 MAX.

The human factor need to be addressed in the "safety assessment activity and certification" point. Boeing and FAA jobs.


"One of them?" Well you are "one of them" that insists everything is Boeing's fault and they created an unrecoverable death trap. Like it or not, the dead pilots did make errors just like Boeing engineers made errors. They aren't immune from criticism because they perished. It is 100% true that if MCAS had been designed properly these crashes wouldn't have happened because these two flights wouldn't have faced a runaway stabilizer. It is also true that crews are expected to know how to recover from a runaway stabilizer as it is a memory item NNC. You can argue semantics in the FCOM and QRH caused the Lion Air crew not to recognize a runaway stabilizer. However, after the documentation changes ordered by the EAD, all subsequent crews should have been able to recognize it. I certainly hope that the WN crew of the MAX I flew on in December 2018 would have.
 
OldAeroGuy
Posts: 3870
Joined: Sun Dec 05, 2004 6:50 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 12:42 pm

XRAYretired wrote:
So. you require the crew to follow procedure with precision. Which one, since you now offer two again?

Stall recovery- when there is no stall?
or
Runaway Stabiliser - when there is no runaway?

Perhaps they should run Airspeed Unreliable, since Airspeed unreliable is present, and in climb since they are at low altitude in climb. Seems this likely what they did. Quelle surprise.

Ray


Please recall that it was RickNRoll who suggested that the ET crew follow the "Stabilizer Runaway" NNC based on the EAD saying one side stick shaker was a symptom of a potential MCAS malfunction.

The order of NNC should have been:

- Stall Recovery (perhaps performed as speed was increased to 250 KIAS but Flaps retracted with an active stick shaker)
- Unreliable Airspeed (not performed as pitch was not increased to 10 deg and power was not reduced to 80% N1)
- Runaway Stabilizer (performed but incorrectly as the airplane was out of trim when the Stab Trim Cutout switches were thrown)
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
OldAeroGuy
Posts: 3870
Joined: Sun Dec 05, 2004 6:50 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 12:53 pm

XRAYretired wrote:

Lion Air Preliminary Report relating to JT043-
"The PIC performed three Non-Normal Checklists and none contained the instruction “Plan to land at the nearest suitable airport”.

JT043 followed your much vaunted NNCs to the letter. surely you support this?

Ironically, JT043 was the one of three that elected to continue the flight and landed successfully. It is quite possible that if JT043 had elected to return any time in the first ~6mins of flight, prior to Stab Trim Cut-Off, it would have been JT043 that crashed rather than JT610.

Ray


I certainly support the actions of the JT043 crew except for retracting Flaps with an active stick shaker. They performed the three NNC (at least in part) and didn't crash. If the decision had been made to return in the first 6 minutes, extending the Flaps would have stopped the malfunctioning MCAS.

The decision to continue the flight with an active stick shaker is questionable. Good Airmanship needs to kick in at some point.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
OldAeroGuy
Posts: 3870
Joined: Sun Dec 05, 2004 6:50 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Tue May 21, 2019 12:59 pm

mjoelnir wrote:
So you want really insist on Boeing telling everybody about MCAS and allowing training for that new dangerous situation, would not have prevented the crashes? Really?


After the EAD, the world knew about MCAS and Boeing did not prevent any airline operating the MAX from training for a Stabilizer Runaway.

Yet ET 302 still crashed.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis

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