Ethiopian airliner down in Africa
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Still concentrating on the Human Factor - the miserable consuming confusion while under stress.
Recently I said.
However, Lord Farringdon put it far better, and in commoner's language.
Hopefully by now the ET captain may well have linked the duff AoA with an airspeed error and stick-shake, but not the failure of the AP to stay locked on for more than three seconds. He was probably processing that while the wheel spun for 9 seconds.
I recall leaving the classrooms after Type conversions with a reasonable knowledge of system interactions . . . at best. Usually, the light-bulb would come on after 300 to 500 hours and a lot of work. How one system affected another was the most difficult part of any type conversion for me, and in the modern world, I'd imagine the MAX is an order of magnitude more involved. I have to concede 737 Driver's 'Fly and then press on with the drills', rather than analyse too deeply is vital. It's simply too complex these days.
Recently I said.
However, Lord Farringdon put it far better, and in commoner's language.
Hopefully by now the ET captain may well have linked the duff AoA with an airspeed error and stick-shake, but not the failure of the AP to stay locked on for more than three seconds. He was probably processing that while the wheel spun for 9 seconds.
I recall leaving the classrooms after Type conversions with a reasonable knowledge of system interactions . . . at best. Usually, the light-bulb would come on after 300 to 500 hours and a lot of work. How one system affected another was the most difficult part of any type conversion for me, and in the modern world, I'd imagine the MAX is an order of magnitude more involved. I have to concede 737 Driver's 'Fly and then press on with the drills', rather than analyse too deeply is vital. It's simply too complex these days.
Then it all hit the fan on short order with AP disconnect followed by MCAS.
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Threat and Error Management
Part 3
Continuing the Threat and Error Management discussion..... If you are joining midway through, I highly recommend that you go back to the beginning (Part 1) starting with the post with the TEM graphic.
The TEM model posits that there will always be threats, that there will always be errors, but that by intelligently designing and employing sufficient barriers, threats can be identified and mitigated, and errors can be trapped before they lead to an undesired aircraft state, incident, or accident.
Threats and errors were covered in the previous post, and a list of potential barriers were identified. I left off with what I thought were two germane questions:
Why did the existing barriers fail?
What happens when a barrier actually becomes a threat?
Once again, traditional aviation barriers that apply to flight deck operations include policies and procedures (SOP's), checklists, crew resource management (CRM), knowledge and aircraft handling skills, as well as external resources (ATC, maintenance, etc). CRM procedures would include briefings, communication, active monitoring, deviation callouts, assignment and execution of pilot flying/non-flying pilot (PF/NFP) duties. Knowledge and aircraft handling skills would determined by the particular training and experience of each pilot.
Which of these barriers failed? (easier question) Why did they fail? (harder question)
Unfortunately, not enough is known of the specific Ethiopian SOP's, crew discussions prior to takeoff, or specific training and experience to definitively address some of these questions. However, we can still make some (hopefully) useful observations. The data that has been released to date suggests that the ET302 Captain did not fully process the nature of the malfunction (perception error). Having not perceived the true nature of the malfunction, he proceeded to apply inappropriate procedures (attempting to engage A/P, retracting the flaps before the AOA/UAS malfunction was resolved). The repeated attempts to inappropriately engage the autopilot and subsequent aircraft handling (particularly the lack of aggressive trimming against the MCAS input) suggest a lack of comfort with hand-flying. At this point, it is impossible to say how much of the Captains actions were driven by a particular lack of knowledge or skill, or rather, the inability to draw upon that knowledge or skill under pressure. However, I think it is a reasonable observation that, to the degree that any barriers resided within the mind of the Captain (perception, SOP's, knowledge, aircraft skills), these barriers were ineffective. In short, the Captain could not trap his own errors. When errors are not properly trapped, they can convert to new threats. Or to put it another way, what should have been barriers actually became threats.
How did these barriers become threats? There are signs that the Captain was experiencing cognitive overload. Contributing issues could include fatigue, distraction, pressure to meet schedule, inadequate training, and/or perception that he was effectively single pilot (more on that in a moment). Whatever the reason, the TEM model does suggest an appropriate response when barriers become threats.
Before that discussion, I need to touch on one other aspect of this accident. Based upon some of the previous feedback, I suspect some of you are not going to like this part, but I feel this is a necessary exercise. There was another potentially useful barrier on the flight deck that day - the First Officer. This is an interesting case in that I have already identified a low-time FO and the possible existence of a steep authority gradient on the flight deck as potential threats. So was the FO a threat or a barrier? Or a little of both?
One piece of information we do not have is whether any steps were taken to mitigate the FO as threat. How well did the Captain know the FO and how did he perceive the FO's competency? Did he enquire as to his recent experience or if he had any particular questions? How thoroughly did the Captain brief his FO? Did the Captain perceive that there was a potentially hazardous authority gradient, and if so, did he attempt to mitigate it with clear guidance to the FO that he was expected to speak up as necessary?
Now let's discuss the FO as a potential barrier. In a two-pilot crew operation, each pilot is expected to back up the other and help identify and mitigate threats as well as trap errors. They are also expected to work together to resolve any non-normal procedure.
One of the remarkable aspects of the CVR discussions that have been released so far are not so much what was said, but what was not. There is very little discussion of the ongoing malfunction or the state of the aircraft. There is no discussion of airspeeds or altitudes. No one calls for any checklists, normal or otherwise. When the Captain tries to engage the autopilot with an active stick shaker (three times!) the First Officer does not question this action. By the time the aircraft reaches 1000' (and before MCAS ever showed up on the scene), the signs of unreliable airspeed were present. The Captain was absorbed in flying the aircraft and apparently greatly distracted. What was the First Officer doing? A fully qualified and proficient FO should have been monitoring both the aircraft and the Captain. He should have identified the UAS situation, but did not do so. If he had identified the UAS, he should have called for the appropriate NNC himself if the Captain did not do so. When the Captain called for the flaps to be retracted while they had an active stick shaker and before any non-normal procedure had been called for, the First Officer simply did as requested and did not question whether it was an appropriate action. As the airspeed increased toward VMO, the First Officer said nothing. When the Captain was obviously applying an excessive of back pressure on the control column without sufficient trimming, the First Officer did not prompt the Captain to trim or ask if the Captain needed help inputing trim. By not trapping any of the Captain's errors, those errors now converted to new threats. The First Officer failed to be an effective barrier.
Some have pointed out, seemingly to the First Officer's credit, that it was he who finally identified the runaway stab trim problem (we should note for the record that the First Officer only made this observation the second time MCAS began it's 9-second, 37 spin journey to oblivion). But rather than this being a positive result, it was actually the final link in a long chain of errors that doomed this aircraft. Yes, that's right, the First Officer introduced his own deadly error into the chain.
From the transcript:
.
When a non-normal checklist is needed, the procedure is for the first pilot seeing the problem to call out the problem (In this case "We have runaway stab trim") and then for the other pilot to confirm ("Yes, I agree. We have a runaway stab."). This is a quote from my airline's FCOM: "Prior to performing procedures, both pilots should communicate and verify the problem."
"Stab trim cutout" is not a problem. It is a command (maybe suggestion?). "Runaway Stab Trim" is a problem. When the First Officer said "stab trim cut-out", the (likely overloaded) Captain pounced on the suggestion, one of the pilots cutout the trim, and they were finally and fatally screwed with a stabilizer in an untenable position and no effective way to move it.
The next step in a non-normal situation is for one of the pilots (at some airlines it is the Captain, at some airlines it is the Pilot Flying) to call for the appropriate NNC procedure. Again from the FCOM: "Identifying the correct procedure is critical to properly managing the non-normal situation."
There is a bit of divergence here depending on whether the airline uses a Quick Reference Card (QRC) or the "Memory Item" method. My airline uses a QRC, but basically the goal is to work through the steps in a methodical fashion. Grabbing controls and switches without careful thought can lead to all sorts of misery. Think here of those accidents that resulted from crews shutting down the wrong engine during an engine fire/failure in flight response. From the FCOM: "Non-normal checklists use starts when the aircraft flight path and configuration are correctly established......Usually, time is available to assess the situation before corrective action is started. All actions must then be coordinated under the Captain's supervision and done in a deliberate, systematic manner. Flight path control must never be compromised." In other words, fly the aircraft first, and don't rush through the procedure.
Okay, I know some might find the preceding paragraphs tedious, but they are important to understand this final fatal error.
The Runaway Stabilizer checklist has been previously posted, so I won't duplicate it here except to enumerate two particular steps. Step 2 of this NNC states: "Autopilot (if engaged) .... Disengaged. Do not re-engage the autopilot. Control aircraft pitch attitude manually with control column and main electric trim as needed." It is not until Step 5 of this checklist that we get this: "If the runaway continues after the autopilot is disengaged: STAB TRIM CUTOUT switches (both)..... CUTOUT." It should be added that it is really not necessary that all the words be said correctly as long as all the actions are performed correctly.
By methodically following the published procedure (rather than responding reflexively to the First Officer calling out "Stab Trim Cutout!"), the Captain would have been prompted to trim the aircraft with the Main Electric trim - the very thing he most needed to do after MCAS kicked in. Only after the aircraft was returned to neutral trim was it appropriate to use the stab trim cutout switches, not before.
The First Officer should have been a barrier. Instead he was a threat.
The Captain should also have been a barrier to his own errors and the errors of his First Officer. Being unable to trap either set of errors, those errors became threats.
Too many threats, too many errors, not enough effective barriers.
So we are now left with (a variation of) my final question:
What should one do when a barrier actually becomes a threat?
Continuing the Threat and Error Management discussion..... If you are joining midway through, I highly recommend that you go back to the beginning (Part 1) starting with the post with the TEM graphic.
The TEM model posits that there will always be threats, that there will always be errors, but that by intelligently designing and employing sufficient barriers, threats can be identified and mitigated, and errors can be trapped before they lead to an undesired aircraft state, incident, or accident.
Threats and errors were covered in the previous post, and a list of potential barriers were identified. I left off with what I thought were two germane questions:
Why did the existing barriers fail?
What happens when a barrier actually becomes a threat?
Once again, traditional aviation barriers that apply to flight deck operations include policies and procedures (SOP's), checklists, crew resource management (CRM), knowledge and aircraft handling skills, as well as external resources (ATC, maintenance, etc). CRM procedures would include briefings, communication, active monitoring, deviation callouts, assignment and execution of pilot flying/non-flying pilot (PF/NFP) duties. Knowledge and aircraft handling skills would determined by the particular training and experience of each pilot.
Which of these barriers failed? (easier question) Why did they fail? (harder question)
Unfortunately, not enough is known of the specific Ethiopian SOP's, crew discussions prior to takeoff, or specific training and experience to definitively address some of these questions. However, we can still make some (hopefully) useful observations. The data that has been released to date suggests that the ET302 Captain did not fully process the nature of the malfunction (perception error). Having not perceived the true nature of the malfunction, he proceeded to apply inappropriate procedures (attempting to engage A/P, retracting the flaps before the AOA/UAS malfunction was resolved). The repeated attempts to inappropriately engage the autopilot and subsequent aircraft handling (particularly the lack of aggressive trimming against the MCAS input) suggest a lack of comfort with hand-flying. At this point, it is impossible to say how much of the Captains actions were driven by a particular lack of knowledge or skill, or rather, the inability to draw upon that knowledge or skill under pressure. However, I think it is a reasonable observation that, to the degree that any barriers resided within the mind of the Captain (perception, SOP's, knowledge, aircraft skills), these barriers were ineffective. In short, the Captain could not trap his own errors. When errors are not properly trapped, they can convert to new threats. Or to put it another way, what should have been barriers actually became threats.
How did these barriers become threats? There are signs that the Captain was experiencing cognitive overload. Contributing issues could include fatigue, distraction, pressure to meet schedule, inadequate training, and/or perception that he was effectively single pilot (more on that in a moment). Whatever the reason, the TEM model does suggest an appropriate response when barriers become threats.
Before that discussion, I need to touch on one other aspect of this accident. Based upon some of the previous feedback, I suspect some of you are not going to like this part, but I feel this is a necessary exercise. There was another potentially useful barrier on the flight deck that day - the First Officer. This is an interesting case in that I have already identified a low-time FO and the possible existence of a steep authority gradient on the flight deck as potential threats. So was the FO a threat or a barrier? Or a little of both?
One piece of information we do not have is whether any steps were taken to mitigate the FO as threat. How well did the Captain know the FO and how did he perceive the FO's competency? Did he enquire as to his recent experience or if he had any particular questions? How thoroughly did the Captain brief his FO? Did the Captain perceive that there was a potentially hazardous authority gradient, and if so, did he attempt to mitigate it with clear guidance to the FO that he was expected to speak up as necessary?
Now let's discuss the FO as a potential barrier. In a two-pilot crew operation, each pilot is expected to back up the other and help identify and mitigate threats as well as trap errors. They are also expected to work together to resolve any non-normal procedure.
One of the remarkable aspects of the CVR discussions that have been released so far are not so much what was said, but what was not. There is very little discussion of the ongoing malfunction or the state of the aircraft. There is no discussion of airspeeds or altitudes. No one calls for any checklists, normal or otherwise. When the Captain tries to engage the autopilot with an active stick shaker (three times!) the First Officer does not question this action. By the time the aircraft reaches 1000' (and before MCAS ever showed up on the scene), the signs of unreliable airspeed were present. The Captain was absorbed in flying the aircraft and apparently greatly distracted. What was the First Officer doing? A fully qualified and proficient FO should have been monitoring both the aircraft and the Captain. He should have identified the UAS situation, but did not do so. If he had identified the UAS, he should have called for the appropriate NNC himself if the Captain did not do so. When the Captain called for the flaps to be retracted while they had an active stick shaker and before any non-normal procedure had been called for, the First Officer simply did as requested and did not question whether it was an appropriate action. As the airspeed increased toward VMO, the First Officer said nothing. When the Captain was obviously applying an excessive of back pressure on the control column without sufficient trimming, the First Officer did not prompt the Captain to trim or ask if the Captain needed help inputing trim. By not trapping any of the Captain's errors, those errors now converted to new threats. The First Officer failed to be an effective barrier.
Some have pointed out, seemingly to the First Officer's credit, that it was he who finally identified the runaway stab trim problem (we should note for the record that the First Officer only made this observation the second time MCAS began it's 9-second, 37 spin journey to oblivion). But rather than this being a positive result, it was actually the final link in a long chain of errors that doomed this aircraft. Yes, that's right, the First Officer introduced his own deadly error into the chain.
From the transcript:
.
At 05:40:35, the First-Officer called out “stab trim cut-out” two times. Captain agreed and First- Officer confirmed stab trim cut-out.
When a non-normal checklist is needed, the procedure is for the first pilot seeing the problem to call out the problem (In this case "We have runaway stab trim") and then for the other pilot to confirm ("Yes, I agree. We have a runaway stab."). This is a quote from my airline's FCOM: "Prior to performing procedures, both pilots should communicate and verify the problem."
"Stab trim cutout" is not a problem. It is a command (maybe suggestion?). "Runaway Stab Trim" is a problem. When the First Officer said "stab trim cut-out", the (likely overloaded) Captain pounced on the suggestion, one of the pilots cutout the trim, and they were finally and fatally screwed with a stabilizer in an untenable position and no effective way to move it.
The next step in a non-normal situation is for one of the pilots (at some airlines it is the Captain, at some airlines it is the Pilot Flying) to call for the appropriate NNC procedure. Again from the FCOM: "Identifying the correct procedure is critical to properly managing the non-normal situation."
There is a bit of divergence here depending on whether the airline uses a Quick Reference Card (QRC) or the "Memory Item" method. My airline uses a QRC, but basically the goal is to work through the steps in a methodical fashion. Grabbing controls and switches without careful thought can lead to all sorts of misery. Think here of those accidents that resulted from crews shutting down the wrong engine during an engine fire/failure in flight response. From the FCOM: "Non-normal checklists use starts when the aircraft flight path and configuration are correctly established......Usually, time is available to assess the situation before corrective action is started. All actions must then be coordinated under the Captain's supervision and done in a deliberate, systematic manner. Flight path control must never be compromised." In other words, fly the aircraft first, and don't rush through the procedure.
Okay, I know some might find the preceding paragraphs tedious, but they are important to understand this final fatal error.
The Runaway Stabilizer checklist has been previously posted, so I won't duplicate it here except to enumerate two particular steps. Step 2 of this NNC states: "Autopilot (if engaged) .... Disengaged. Do not re-engage the autopilot. Control aircraft pitch attitude manually with control column and main electric trim as needed." It is not until Step 5 of this checklist that we get this: "If the runaway continues after the autopilot is disengaged: STAB TRIM CUTOUT switches (both)..... CUTOUT." It should be added that it is really not necessary that all the words be said correctly as long as all the actions are performed correctly.
By methodically following the published procedure (rather than responding reflexively to the First Officer calling out "Stab Trim Cutout!"), the Captain would have been prompted to trim the aircraft with the Main Electric trim - the very thing he most needed to do after MCAS kicked in. Only after the aircraft was returned to neutral trim was it appropriate to use the stab trim cutout switches, not before.
The First Officer should have been a barrier. Instead he was a threat.
The Captain should also have been a barrier to his own errors and the errors of his First Officer. Being unable to trap either set of errors, those errors became threats.
Too many threats, too many errors, not enough effective barriers.
So we are now left with (a variation of) my final question:
What should one do when a barrier actually becomes a threat?
Last edited by 737 Driver; 7th May 2019 at 13:23.
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737 Driver
I see the wisdom in much of your post, one thing to keep in mind though is that we have glaringly incomplete CVR facts, not a transcript just some snips possibly selected to shore up a particular point of view.
This makes it impossible to know all of what was discussed etc during (and before) the flight or the full extent of interactions.
As I have said before something was going on while the trim was in cutout mode, we just have not been told what.
I see the wisdom in much of your post, one thing to keep in mind though is that we have glaringly incomplete CVR facts, not a transcript just some snips possibly selected to shore up a particular point of view.
This makes it impossible to know all of what was discussed etc during (and before) the flight or the full extent of interactions.
As I have said before something was going on while the trim was in cutout mode, we just have not been told what.
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737 Driver
I see the wisdom in much of your post, one thing to keep in mind though is that we have glaringly incomplete CVR facts, not a transcript just some snips possibly selected to shore up a particular point of view.
This makes it impossible to know all of what was discussed etc during (and before) the flight or the full extent of interactions.
As I have said before something was going on while the trim was in cutout mode, we just have not been told what.
I see the wisdom in much of your post, one thing to keep in mind though is that we have glaringly incomplete CVR facts, not a transcript just some snips possibly selected to shore up a particular point of view.
This makes it impossible to know all of what was discussed etc during (and before) the flight or the full extent of interactions.
As I have said before something was going on while the trim was in cutout mode, we just have not been told what.
As far as what was going on while the the trim switches were in the cutout position, are you referring to the gradual movement from 2.3 to 2.1 units? It apparently occurred over two and half minutes. I'm interested in seeing what the board's thoughts are on that as well, but I should point out that in the context of the overall trim movement, it is a very small and slow creep.
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737 Driver
"the possible existence of a steep authority gradient on the flight deck as potential threats."
Cue to possible existence of a steep authority gradient on a flight deck by employing metrics used to evaluate and judge Korean Air and third world cockpits.
Cactus fifteen fifty minus one, UsAir flight 1539 revisited.
15:29:45.4 hot-1 ok lets go put the flaps out, put the flaps out. ( this is not a proper command)
15:29:48 hot-2 flaps out? (Skiles not sure about what his captain wants him to do, Sully silent.)
15:30:01 hot-2 got flaps out.
15:30:06 cam-2 hundred and seventy knots.
15:30:09 cam-2 got no power on either one? try the other one.
15:30:16 hot-2 hundred and fifty knots.
15:30:17 hot-2 got flaps two, you want more? (Skiles somehow sensed that Sully wants to stay airborne so he gave him best glide flaps.)
Mitigated Speech and Plane Crashes (Outliers, p 195)
1- Command: “Turn thirty degrees right.” That’s the most direct and explicit way of making a point imaginable. It’s zero mitigation.
2- Crew Obligation Statement: “I think we need to deviate right about now.”Notice the use of “we” and the fact that hte request is now much less specific. It’s a little softer.
3- Crew Suggestion: “Let’s go around the weather.” Implicit in that statement is “we’re in this together.”
4- Query: “Which direction would you like to deviate?” That’s even softer than a crew suggestion, because the speaker is conceding that he’s not in charge.
5- Preference: “I think it would be wise to turn left or right.”
6- Hint: “That return at twenty-five miles looks mean.” This is the most mitigated statement of all.
In that scale above ” you want more?” is a “querry” in line 4 and a “hint” ( you should have more ) in line 6. Both indicative of mitigating speech is employed. By mitigating speech being employed we deduce that there is a strong authority gradient in the cockpit.
"the possible existence of a steep authority gradient on the flight deck as potential threats."
Cue to possible existence of a steep authority gradient on a flight deck by employing metrics used to evaluate and judge Korean Air and third world cockpits.
Cactus fifteen fifty minus one, UsAir flight 1539 revisited.
15:29:45.4 hot-1 ok lets go put the flaps out, put the flaps out. ( this is not a proper command)
15:29:48 hot-2 flaps out? (Skiles not sure about what his captain wants him to do, Sully silent.)
15:30:01 hot-2 got flaps out.
15:30:06 cam-2 hundred and seventy knots.
15:30:09 cam-2 got no power on either one? try the other one.
15:30:16 hot-2 hundred and fifty knots.
15:30:17 hot-2 got flaps two, you want more? (Skiles somehow sensed that Sully wants to stay airborne so he gave him best glide flaps.)
Mitigated Speech and Plane Crashes (Outliers, p 195)
1- Command: “Turn thirty degrees right.” That’s the most direct and explicit way of making a point imaginable. It’s zero mitigation.
2- Crew Obligation Statement: “I think we need to deviate right about now.”Notice the use of “we” and the fact that hte request is now much less specific. It’s a little softer.
3- Crew Suggestion: “Let’s go around the weather.” Implicit in that statement is “we’re in this together.”
4- Query: “Which direction would you like to deviate?” That’s even softer than a crew suggestion, because the speaker is conceding that he’s not in charge.
5- Preference: “I think it would be wise to turn left or right.”
6- Hint: “That return at twenty-five miles looks mean.” This is the most mitigated statement of all.
In that scale above ” you want more?” is a “querry” in line 4 and a “hint” ( you should have more ) in line 6. Both indicative of mitigating speech is employed. By mitigating speech being employed we deduce that there is a strong authority gradient in the cockpit.
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Imagine if your airplane had a third, previously unneeded engine that contributed nothing to the performance, stability, safety or functionality of the aircraft. I'm even going to give us the benefit of the doubt and say you know this third engine exists. If engines 1 or 2 fail you just do everything like you always have. Pull out the proper checklist, do your memory items and find someplace to land. But if engine #3 fails, well then you have 30 seconds to a minute to identify the correct engine, diagnose it and shut it down using an exact mechanism that has zero tolerance for deviation. If you fail to do this exactly right your third engine explodes and rips off the tail in the process and you and your airplane are toast on a stick.
That's what I mean when I say MCAS will try to kill you (it will...) and that's why I believe this is a unique circumstance and finally: That's why I place the responsibility for the entirety of the outcome for both flights at the feet of Boeing and the FAA.
That's what I mean when I say MCAS will try to kill you (it will...) and that's why I believe this is a unique circumstance and finally: That's why I place the responsibility for the entirety of the outcome for both flights at the feet of Boeing and the FAA.
The above quoted strawman is not an accurate allegory for the actual events which occur when the MCAS system is activated. It does not demand "zero tolerance for deviation", nor does it require "using an exact mechanism" to diagnose what is essentially a runaway stabilizer trim event.
Mitigation does require correct diagnosis and reaction. The actions of the ET 302 crew were sadly deficient in both regards. Discussion of their response and examination of aircrew training and competency overall is of more interest to me than your insistent claims of nefarious negligence by Boeing and the FAA.
Thread Starter
Any MAX pilots here?
Are there any contributors here who are 737 pilots who transitioned to the MAX?
May I ask please,
If you did, did you have any SIM, classroom, or Line training on the MAX and it's differences, or was it purely on-line modules, thus was your first flight on a ''pax on board'' flight?
Were you made fully aware of the adverse pitch up changes, and CG issues of the new MAX due to the design enforced forward location of the new larger engines (which can now cause lift) at low weights/high power applications resulting in a (unrecoverable?) high AOA? (which we now are aware, necessitated the MCAS software patch)
Were you (before the 2 fatal and 1 nearly accidents) fully informed/trained on the new MCAS systems and it's functionality, implications, and what to do if it went rogue?
Thanks.
May I ask please,
If you did, did you have any SIM, classroom, or Line training on the MAX and it's differences, or was it purely on-line modules, thus was your first flight on a ''pax on board'' flight?
Were you made fully aware of the adverse pitch up changes, and CG issues of the new MAX due to the design enforced forward location of the new larger engines (which can now cause lift) at low weights/high power applications resulting in a (unrecoverable?) high AOA? (which we now are aware, necessitated the MCAS software patch)
Were you (before the 2 fatal and 1 nearly accidents) fully informed/trained on the new MCAS systems and it's functionality, implications, and what to do if it went rogue?
Thanks.
Rog,
No one knew about MCAS until the AD a couple of weeks after the Lion Air accident. Have a look at the thread. The crew that saved the situation described the problem as the STS running the wrong way, possibly a huge clue as to how the human mind interpreted what was happening (rather than a trim runaway).
All operators used CBT rather than real training.
No one knew about MCAS until the AD a couple of weeks after the Lion Air accident. Have a look at the thread. The crew that saved the situation described the problem as the STS running the wrong way, possibly a huge clue as to how the human mind interpreted what was happening (rather than a trim runaway).
All operators used CBT rather than real training.
Thread Starter
Rog,
No one knew about MCAS until the AD a couple of weeks after the Lion Air accident. Have a look at the thread. The crew that saved the situation described the problem as the STS running the wrong way, possibly a huge clue as to how the human mind interpreted what was happening (rather than a trim runaway).
All operators used CBT rather than real training.
No one knew about MCAS until the AD a couple of weeks after the Lion Air accident. Have a look at the thread. The crew that saved the situation described the problem as the STS running the wrong way, possibly a huge clue as to how the human mind interpreted what was happening (rather than a trim runaway).
All operators used CBT rather than real training.
so what you are saying would also confirm that no pilots (putting aside MCAS as you say) were ever made aware of the adverse pitch up effect of the new MAX due to the location of the larger engines (which can now cause lift) at low weights/high power applications resulting in a (unrecoverable?) high AOA?
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OK thanks -
so what you are saying would also confirm that no pilots (putting aside MCAS as you say) were ever made aware of the adverse pitch up effect of the new MAX due to the location of the larger engines (which can now cause lift) at low weights/high power applications resulting in a (unrecoverable?) high AOA?
so what you are saying would also confirm that no pilots (putting aside MCAS as you say) were ever made aware of the adverse pitch up effect of the new MAX due to the location of the larger engines (which can now cause lift) at low weights/high power applications resulting in a (unrecoverable?) high AOA?
Days after the Lion Air disaster, Boeing finally revealed the existence of the MCAS system, shocking pilots around the world.
American Airlines veteran pilot Dennis Tajer told Hayes, “I called our safety experts and said, ‘Where is this in a book?" And they said, ‘It's not’.”
Tajer said the admission from Boeing felt like “betrayal”.“This is an unforgiving profession that counts very heavily on the pilot's knowledge, background, and training, and there are lives depending on that."
American Airlines veteran pilot Dennis Tajer told Hayes, “I called our safety experts and said, ‘Where is this in a book?" And they said, ‘It's not’.”
Tajer said the admission from Boeing felt like “betrayal”.“This is an unforgiving profession that counts very heavily on the pilot's knowledge, background, and training, and there are lives depending on that."
Last edited by GordonR_Cape; 7th May 2019 at 06:52. Reason: Change quoted text.
OK thanks -
so what you are saying would also confirm that no pilots (putting aside MCAS as you say) were ever made aware of the adverse pitch up effect of the new MAX due to the location of the larger engines (which can now cause lift) at low weights/high power applications resulting in a (unrecoverable?) high AOA?
so what you are saying would also confirm that no pilots (putting aside MCAS as you say) were ever made aware of the adverse pitch up effect of the new MAX due to the location of the larger engines (which can now cause lift) at low weights/high power applications resulting in a (unrecoverable?) high AOA?
Are there any contributors here who are 737 pilots who transitioned to the MAX?
May I ask please,
If you did, did you have any SIM, classroom, or Line training on the MAX and it's differences, or was it purely on-line modules, thus was your first flight on a ''pax on board'' flight?
Were you made fully aware of the adverse pitch up changes, and CG issues of the new MAX due to the design enforced forward location of the new larger engines (which can now cause lift) at low weights/high power applications resulting in a (unrecoverable?) high AOA? (which we now are aware, necessitated the MCAS software patch)
Were you (before the 2 fatal and 1 nearly accidents) fully informed/trained on the new MCAS systems and it's functionality, implications, and what to do if it went rogue?
Thanks.
May I ask please,
If you did, did you have any SIM, classroom, or Line training on the MAX and it's differences, or was it purely on-line modules, thus was your first flight on a ''pax on board'' flight?
Were you made fully aware of the adverse pitch up changes, and CG issues of the new MAX due to the design enforced forward location of the new larger engines (which can now cause lift) at low weights/high power applications resulting in a (unrecoverable?) high AOA? (which we now are aware, necessitated the MCAS software patch)
Were you (before the 2 fatal and 1 nearly accidents) fully informed/trained on the new MCAS systems and it's functionality, implications, and what to do if it went rogue?
Thanks.
Rog - you don't have that quite right. It's high AoA that results in different stick forces. In normal operations the pilot would not ever create an AoA that would allow him to explore the new stick forces. Boeing logic was that if the pilot inadvertently found himself in such a high AoA condition, then all would feel normal because MCAS would trigger. Boeing just failed to explore what would happen if the single input to MCAS failed causing it to repeatedly trigger when not wanted.
*Ref Schmerik above : "There's the change of the rate of trim applied made late in the testing stages (from 0.6 units to 2.5 units per time period?)"
Last edited by dufc; 7th May 2019 at 10:04.
The crew that saved the situation described the problem as the STS running the wrong way, possibly a huge clue as to how the human mind interpreted what was happening (rather than a trim runaway).
And as such, why is it really so necessary to inform pilots of this system? There is no specific control over it, just the generic runaway trim procedure. Surely telling people about systems they have no specific influence over is merely muddying the waters? If it presents itself as failure event X which is dealt with by checklist Y does anyone need to know that it could be system A or A.1 at fault, when both are addressed by the same checklist, show effectively the same symptoms and actually are components of the same system?
That, I am sure, was Boeing's rationale and though I'm not 100% comfortable with it I'm certainly not condemning it in the absolute and fundamental way some others are.
Boeing just failed to explore what would happen if the single input to MCAS failed causing it to repeatedly trigger when not wanted.
Boeing's big 'mistake' was to underestimate the public and to some extent the industry's interpretation of two failures due almost exclusively to bad handling and incorrect procedures that they could hardly have anticipated. At least, Boeing thought they could hardly have been anticipated at the time, and I doubt (m)any of us would have thought otherwise either before these accidents had we known about the system. Their mistake was to underestimate the amount and volume of criticism that would unexpectedly come their way because crews, maintenance and at least one airline screwed up in spades and the world retrospectively devined faults therefrom in Boeing that no one had thought were faults before and in a vindictive and vitriolic way unprecedented in the history of aviation.
Caught out by the 'told you so' all-seeing retrospective 'wisdom' of the internet more than anyting else.
I'm not saying they're whiter than white, just some light-ish shade grey a very long way from the midnight black some others are portraying.
We just received a company memo (after over a year of flying the NEO) that is has a “Rotation Mode” to prevent tail strike. Nothing was mentioned in the manual.........
Or could it be this falls into the same category as MCAS before the accidents? It's not hurt anyone so no one is outraged? (not suggesting this is an exact parallel but appears a similar concept). I expect Airbus' view on this was very similar to Boeing's on MCAS though; it is a sub-system of something else and failures in it can be identified and grouped under a common, pre-existing drill and as you have no control over it's operation what is the point of confusing people with knowledge of something they can't affect independently.
Last edited by meleagertoo; 7th May 2019 at 12:02.
Are there any contributors here who are 737 pilots who transitioned to the MAX?
May I ask please,
If you did, did you have any SIM, classroom, or Line training on the MAX and it's differences, or was it purely on-line modules, thus was your first flight on a ''pax on board'' flight?
Were you made fully aware of the adverse pitch up changes, and CG issues of the new MAX due to the design enforced forward location of the new larger engines (which can now cause lift) at low weights/high power applications resulting in a (unrecoverable?) high AOA? (which we now are aware, necessitated the MCAS software patch)
Were you (before the 2 fatal and 1 nearly accidents) fully informed/trained on the new MCAS systems and it's functionality, implications, and what to do if it went rogue?
Thanks.
May I ask please,
If you did, did you have any SIM, classroom, or Line training on the MAX and it's differences, or was it purely on-line modules, thus was your first flight on a ''pax on board'' flight?
Were you made fully aware of the adverse pitch up changes, and CG issues of the new MAX due to the design enforced forward location of the new larger engines (which can now cause lift) at low weights/high power applications resulting in a (unrecoverable?) high AOA? (which we now are aware, necessitated the MCAS software patch)
Were you (before the 2 fatal and 1 nearly accidents) fully informed/trained on the new MCAS systems and it's functionality, implications, and what to do if it went rogue?
Thanks.
until the Lion Air crash there was no mention of MCAS and as far as I remember no mention of the change in aerodynamics due to the new engines and their installation, at least not on the CBT or in any manuals from the company I was working for. Obviously other companies could have had different training material.
Thread Starter
Many thanks to you all for your honest and concise replies
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Which might flag uas or it might flag as and it might leave you aircraft in a state you cant manually trim it back.
There is nowhere in the nnc saying if trim goes weird after raising flaps drop flaps back and reduce power.
Psychophysiological entity
Murphy's correction - Thanks.
I had the AP time on as 3 seconds. Corrected. Indeed, the real 30 seconds it would give time for a feeling of having overcome the problem - until the 9 seconds of trim. But looking back again, it might be that feeling of success, coupled with the fact STS runs the wheels (albeit briefly) anyway, that made him miss the sheer length of the run time. Hard to imagine missing that clunking, but the Stick Shake is quite loud, and as we've discussed, very distracting.
Let's face it. Than run time of 9 seconds, the lack of sustained ANU via the electric trim and the power so high are the main indicators of his state of mind. It's a terrible shame that he'd not got more height as I've a feeling he was starting to go down the right logic route. But only just starting, and coping with too much of a handful to really focus.
Yes, AVIATE comes first, and it's really shouting loud that the stresses were drowning what skill he had.
Minor correction, after a couple of false starts the autopilot was engaged for more than 30 seconds, just long enough to provide a false sense of "not that bad"?
Then it all hit the fan on short order with AP disconnect followed by MCAS.
Then it all hit the fan on short order with AP disconnect followed by MCAS.
I had the AP time on as 3 seconds. Corrected. Indeed, the real 30 seconds it would give time for a feeling of having overcome the problem - until the 9 seconds of trim. But looking back again, it might be that feeling of success, coupled with the fact STS runs the wheels (albeit briefly) anyway, that made him miss the sheer length of the run time. Hard to imagine missing that clunking, but the Stick Shake is quite loud, and as we've discussed, very distracting.
Let's face it. Than run time of 9 seconds, the lack of sustained ANU via the electric trim and the power so high are the main indicators of his state of mind. It's a terrible shame that he'd not got more height as I've a feeling he was starting to go down the right logic route. But only just starting, and coping with too much of a handful to really focus.
Yes, AVIATE comes first, and it's really shouting loud that the stresses were drowning what skill he had.
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Obviously, in case of the 737 MAX MCAS accidents there was a lack of a clean manual override path similar to that present in case of the 737 NG STS and/or allegedly the MCAS variant installed on the KC-46 tanker where, in both cases, the automatic trim procedure could be overridden by manual column input? Had that been in place in case of the 737 MAX MCAS along with appropriate pilot training and full disclosure of the new system(s) and changes, I dare say we would not be having this lengthy thread here.
Wasn't Boeing's design philosophy supposed to be "pilot can always override automation"? And why was it so poorly respected in this instance as opposed to the cases when similar systems were introduced by Boeing in the past ? These are the questions one truly needs to raise to assess the "what went wrong here?" conundrum.
Last edited by Portallo; 7th May 2019 at 12:07. Reason: fixed typos
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I agree it is an incomplete picture (which I did acknowledge), but there are some broad enough outlines from which we can draw some conclusions. If anything comes out that substantially alters our current understanding, then I'll be happy to make a correction.
As far as what was going on while the the trim switches were in the cutout position, are you referring to the gradual movement from 2.3 to 2.1 units? It apparently occurred over two and half minutes. I'm interested in seeing what the board's thoughts are on that as well, but I should point out that in the context of the overall trim movement, it is a very small and slow creep.
As far as what was going on while the the trim switches were in the cutout position, are you referring to the gradual movement from 2.3 to 2.1 units? It apparently occurred over two and half minutes. I'm interested in seeing what the board's thoughts are on that as well, but I should point out that in the context of the overall trim movement, it is a very small and slow creep.
The prelim report mentions only one attempt at manual trim at 05:41:46, roughly half way through the cutout period, surely there was other activity during that 150 seconds.
One possibility is that the trim creep was due to attempts at manual trim causing a bounce in the cables that each time resulted in slight movement in the wrong direction. In the mentour pilot video you can see this bounce as attempts are made.
Another possibility is that one of the brakes is not holding against the load but that would be a seperate failure/design flaw that is probably not needed to explain the traces.
Access to the raw FDR data should resolve this since if it was a slipping brake it would likely be continuous whereas manual trim efforts would be seen as (slight) steps with pauses.