Go Back  PPRuNe Forums > Flight Deck Forums > Rumours & News
Reload this Page >

Ethiopian airliner down in Africa

Rumours & News Reporting Points that may affect our jobs or lives as professional pilots. Also, items that may be of interest to professional pilots.

Ethiopian airliner down in Africa

Old 7th May 2019, 06:19
  #5061 (permalink)  
Thread Starter
 
Join Date: Feb 2008
Location: UK
Age: 62
Posts: 37
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.
rog747 is offline  
Old 7th May 2019, 06:38
  #5062 (permalink)  
 
Join Date: Jun 2003
Location: UK
Posts: 2,234
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.
HundredPercentPlease is online now  
Old 7th May 2019, 06:48
  #5063 (permalink)  
Thread Starter
 
Join Date: Feb 2008
Location: UK
Age: 62
Posts: 37
Originally Posted by HundredPercentPlease View Post
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.
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?
rog747 is offline  
Old 7th May 2019, 06:51
  #5064 (permalink)  
 
Join Date: Dec 2015
Location: Cape Town, ZA
Age: 58
Posts: 424
Originally Posted by rog747 View Post
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?
Its buried in the thread, but if you want an up to date reference, the 60 Minutes documentary (video and text) provides some interviews. For example Dennis Tajer (APA union). See: https://www.9news.com.au/national/60...6-a0c47ddfe293
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."

Last edited by GordonR_Cape; 7th May 2019 at 06:52. Reason: Change quoted text.
GordonR_Cape is offline  
Old 7th May 2019, 08:46
  #5065 (permalink)  
 
Join Date: Jun 2003
Location: UK
Posts: 2,234
Originally Posted by rog747 View Post
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?
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.
HundredPercentPlease is online now  
Old 7th May 2019, 09:01
  #5066 (permalink)  
 
Join Date: Nov 2010
Location: Denver
Age: 52
Posts: 49
Originally Posted by rog747 View Post
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.
Not to derail the tread, but this is the standard today. I am only trained in the A 320 CEO, but fly A319/320/321/320NEO (which has different engine instrument). 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.........
hans brinker is offline  
Old 7th May 2019, 09:21
  #5067 (permalink)  
 
Join Date: Jun 2002
Location: Scotland
Posts: 36
Originally Posted by HundredPercentPlease View Post
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.
Apart from this lack of 'fail safe', add the failure to inform pilots of MCAS having been fitted, to install an 'MCAS on' warning and to signal the need for appropriate training including how to disable MCAS if required. Did Boeing also not fail to advise the FAA of a change in the scale or parameters of MCAS*?

*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.
dufc is offline  
Old 7th May 2019, 09:44
  #5068 (permalink)  
 
Join Date: Mar 2018
Location: Central UK
Posts: 415
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).
Which rather vindicates Boeing's position on this; they reacted exactly as Boeing intended by identifying it as an STS runaway (which most assuredly is a runaway trim event) and dealt with it by using the correct pre-existing technique.

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.
I very much doubt that could be the case. Single input failures would be top of the list to explore if the system only had one input. I think suggesting otherwise is being far too simplistic in automatically assuming gross incompetence where there really is no evidence of it. I read somewhere they spent 205 hours test-flying MCAS. What do you suppose they were looking at in all that time? That single-input failures hadn't occurred to anyone? No one at all? That is simply preposterous.

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.........
Where are the howls of outrage over this 'cynical corporate cover-up' then, if adding automatic systems and not telling is so iniquitous?
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.
meleagertoo is offline  
Old 7th May 2019, 09:46
  #5069 (permalink)  
 
Join Date: Jun 2001
Location: The middle
Posts: 400
Originally Posted by rog747 View Post
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.
I did my MAX transition for an operator in the ME. No sim, classroom or line training, just CBT on company iPad that was mandated to be done in the pilots time off. Completed the CBT and then flew the NG for four months before first flight in the MAX, which was also the F/O’s first flight in the MAX.

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.
excrab is offline  
Old 7th May 2019, 09:52
  #5070 (permalink)  
Thread Starter
 
Join Date: Feb 2008
Location: UK
Age: 62
Posts: 37
Many thanks to you all for your honest and concise replies
rog747 is offline  
Old 7th May 2019, 10:52
  #5071 (permalink)  
 
Join Date: Dec 2014
Location: Hungary
Posts: 26
Originally Posted by 737 Driver View Post
Continuing the Threat and Error
What should one do when a barrier actually becomes a threat?
If you only have the runaway trim nnc , but now there is a crash few months earlier and some vague ad from the manufacturer.
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.
maxxer is offline  
Old 7th May 2019, 11:30
  #5072 (permalink)  
Psychophysiological entity
 
Join Date: Jun 2001
Location: Tweet Rob_Benham Famous author. Well, slightly famous.
Age: 80
Posts: 4,856
Murphy's correction - Thanks.

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.

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.
Loose rivets is offline  
Old 7th May 2019, 12:05
  #5073 (permalink)  
 
Join Date: Jun 2010
Location: Netherlands
Age: 37
Posts: 4
Originally Posted by meleagertoo View Post
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.
Isn't that exactly the problem (next to MCAS operation relying on a single AoA vane naturally)?
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
Portallo is offline  
Old 7th May 2019, 13:11
  #5074 (permalink)  
 
Join Date: May 2010
Location: Boston
Age: 69
Posts: 440
Originally Posted by 737 Driver View Post
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.
I was actually wondering more about what was discussed and actioned during that time. Two and and half minutes is long enough for the initial startle factor to dissipate, hopefully some insight can be gained into pilots actions during the preceding critical time.
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.
MurphyWasRight is offline  
Old 7th May 2019, 13:12
  #5075 (permalink)  
 
Join Date: Jan 2010
Location: UK
Posts: 143
Originally Posted by meleagertoo View Post
Which rather vindicates Boeing's position on this; they reacted exactly as Boeing intended by identifying it as an STS runaway (which most assuredly is a runaway trim event) and dealt with it by using the correct pre-existing technique.


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.
Except it was the jumpseater that identified the issue NOT the crew and it seems that neither the crew or the jumpseater understood what the issue was. No mention of stab trim runaway was made in the writeup as I recall.

SamYeager is offline  
Old 7th May 2019, 13:14
  #5076 (permalink)  
 
Join Date: Apr 2019
Location: USA
Posts: 217
Originally Posted by rog747 View Post
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.
MAX was added to our fleet of NG's about a year ago. All training was either online or bulletins pushed to our Ipads. There is a quick reference card in the cockpit with key reminders. I had a couple of opportunities to fly the MAX before it was grounded. It actually flies very nicely, and the only real issue for me was that some of the switches and indicators were in different places. It would be comparable to transitioning from a 2001 Ford F-150 to a 2019 model. Drives pretty much the same, some new bells and whistles, some new switchology for the radios and climate control, but still a Ford F-150.

Our company continually stressed that the transition would be relatively straightforward, and to a certain point that was true in the context of normal operations. However, my contention always was (and this is not 20/20 hindsight) that any issues with the MAX would be less a case of normals operations, but rather non-normal ops. As we have seen in aviation time and time again, it is very difficult to predict all the unique failure modes that may arise with a new aircraft. Given that, my concern with the MAX was not with adapting to any differences when things were going right, but rather how different it might be when things were going wrong. Sadly, those concerns were not misplaced.
737 Driver is offline  
Old 7th May 2019, 13:44
  #5077 (permalink)  
 
Join Date: Jan 2013
Location: UK
Age: 59
Posts: 33
Boeing's biggest mistake was design not underestimating the public

Originally Posted by meleagertoo View Post
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..
I am not a pilot so my view may not be correct but I do design systems with functional safety requirments and I profoundly disagree with this. A system which cannot tolerate a single fault without entering a dangerous state which requires prompt action to prevent a catastrophe is not safe paticularily when at least one of the failures can occur in a high workload situation, must be responded to within a time limit and will generate misleading and distracting warnings. I am confident that I and all the teams I have worked in would have anticipated this would cause problems and would not have considered it an acceptable design.

Yes we are all human and may overlook failure modes with common causes or fail to understand complex interactions between sub-systems but this was just straightforwardly poor design which should have been identified as such.

The idea that Boeings big mistake was 'to underestimate the public and to some extent the industry's interpretation of two failures' is shockingly callous given the death toll and relatively small timespan. As far as we know the scenario concerned has occured three times and only been survived once and then perhaps a little fortuitously.
PiggyBack is offline  
Old 7th May 2019, 14:29
  #5078 (permalink)  
 
Join Date: Jul 2004
Location: Found in Toronto
Posts: 609
Originally Posted by PiggyBack View Post
I am not a pilot so my view may not be correct but I do design systems with functional safety requirments and I profoundly disagree with this. A system which cannot tolerate a single fault without entering a dangerous state which requires prompt action to prevent a catastrophe is not safe paticularily when at least one of the failures can occur in a high workload situation, must be responded to within a time limit and will generate misleading and distracting warnings. I am confident that I and all the teams I have worked in would have anticipated this would cause problems and would not have considered it an acceptable design.

Yes we are all human and may overlook failure modes with common causes or fail to understand complex interactions between sub-systems but this was just straightforwardly poor design which should have been identified as such.

The idea that Boeings big mistake was 'to underestimate the public and to some extent the industry's interpretation of two failures' is shockingly callous given the death toll and relatively small timespan. As far as we know the scenario concerned has occured three times and only been survived once and then perhaps a little fortuitously.
There are many systems on an aircraft where one failure can cause entry to a "dangerous state".

MCAS was designed to be easily disabled by simply trimming the aircraft. There is no prompt action required. All that is need is for the pilot to FLY THE AIRCRAFT just as they were taught in their very first lesson. ATTITUDES and MOVEMENTS

Pilots are taught to always control the aircraft and to TRIM the aircraft to maintain that control. If the aircraft is not doing what you want it to, it is up to the pilot to MAKE it happen.

The MCAS "problem" is just a form of un-commanded or un-wanted trim. In addition to being a memory item, it is also just common sense to disable a system that is not performing correctly. In this case MCAS was causing nose down trim. If repeated nose up trim did not stop the unwanted nose down trim, turn off the electric trim.

Problem solved.

You can't really blame Boeing any more than you can blame Airbus for not predicting that the AF447 crew would forget that you need to lower the nose to unstall an aircraft, or that Airbus had designed the side sticks so that they cancel each other out.
Lost in Saigon is offline  
Old 7th May 2019, 15:03
  #5079 (permalink)  
 
Join Date: Mar 2019
Location: Washington
Posts: 2
The Refrain of Every Lousy Programer

Originally Posted by PiggyBack View Post
I am not a pilot so my view may not be correct but I do design systems with functional safety requirments and I profoundly disagree with this. A system which cannot tolerate a single fault without entering a dangerous state which requires prompt action to prevent a catastrophe is not safe paticularily when at least one of the failures can occur in a high workload situation, must be responded to within a time limit and will generate misleading and distracting warnings. I am confident that I and all the teams I have worked in would have anticipated this would cause problems and would not have considered it an acceptable design.

Yes we are all human and may overlook failure modes with common causes or fail to understand complex interactions between sub-systems but this was just straightforwardly poor design which should have been identified as such.

The idea that Boeings big mistake was 'to underestimate the public and to some extent the industry's interpretation of two failures' is shockingly callous given the death toll and relatively small timespan. As far as we know the scenario concerned has occured three times and only been survived once and then perhaps a little fortuitously.
Everyone who writes lousy software has the same excuse, blame the user.
DCDave is offline  
Old 7th May 2019, 15:10
  #5080 (permalink)  
 
Join Date: Apr 2019
Location: USA
Posts: 217
Threat and Error Management

Part 4

Continuing the Threat and Error Management discussion.....
If you are just joining this sub-topic, please go back to the first post with the TEM graphic (Part 1)

First, a quick refresher. There are three components of the TEM model that are relevant here:

Threats are external and internal factors that can increase complexity or introduce additional hazards into a flight operations. Weather, unfamiliar airports, terrain, placarded aircraft systems, language barriers, fatigue, and distraction are examples of threats. Once a threat has been identified, the crew can take steps to mitigate that threat.

Errors are divergences from expected behavior caused by human actions or inaction that increase the likelihood of an adverse event. The difference between an error and a threat is that an error can, with careful attention, be quickly identified and crew members can find prompt solutions to the error. This is sometimes known as "trapping" the error. Untrapped errors can turn into new threats.

Barriers are structures, procedures and tools available to flight crew to trap errors and contain threats. Since no barrier is perfect, the goal is to build sufficient barriers so that all threats are contained and all errors trapped. Untrapped errors and uncontained threats can ultimately lead to an undesired aircraft state, incident, or accident.

The TEM model assumes that there are no perfect aircraft, perfect environments, or perfect humans. The goal is not to create a flawless system, but rater a resilient system.

The standard TEM model lists these available barriers for flight deck operations: Policies and procedures (SOP's), checklists, CRM, aircraft systems (particularly warning and alert systems), knowledge, and airmanship. Knowledge and airmanship are related to not only to training and experience, but also to an individual's commitment to develop their knowledge and airmanship. CRM includes such things as crew communications, monitoring, flight deck discipline, assignment and execution of specific duties. The Captain is the primary driver behind CRM, but the First Officer has obligations here as well.

In Part 3 of this series, I used the TEM model as a lens to analyze where and how the existing barriers failed. The primary reason that multiple barriers failed is that the effective employment of virtually all of these barriers depends heavily on the mental states of the two pilots. SOP's, checklists, CRM, knowledge, and airmanship only work as barriers when the crew can actually draw on them. It is unclear how much of this failure was due to lack of particular knowledge and/or skill as opposed to the inability to draw on existing knowledge and/or skill under pressure. There are indications that the Captain had achieved cognitive overload. This might have also applied to the First Officer, but we must also acknowledge that the FO had far less experience to draw on and may have had discomfort in speaking up. I believe one of the key takeaways from this accident is to appreciate the critical role of the First Officer in safe aircraft operations. A First Officer must not only be able operate the aircraft, run the checklists, and demonstrate knowledge of systems and procedures, he must be able to act as an effective barrier to trap not only his errors, but also the errors of the Captain.

When the traditional barriers failed, they effectively became new threats. These threats were subsequently uncontained and allowed errors to go untrapped leading ultimately to a hull loss and the death of all passenger and crew.

I ended Part 3 with the following question: What should one do when a barrier actually becomes a threat?

I'll be the first to admit that the "barrier as threat" is a bit different take on the TEM model, but I believe it is both valid and useful. From practical experience, I think TEM theory sometimes assumes that barriers are more resilient than they really are in practice and largely ignores the possibility that what was meant to be a barrier could actually become a threat.

However, by adopting a "barrier as potential threat" perspective, the TEM model actually provides some useful guidance. Threats should be identified or anticipated and steps should be taken to mitigate and contain those threats.

The key step here is awareness of the threat, or more specifically, awareness that what was initially considered a barrier might actually become a threat.

Let's go back to that list of potential barriers for flight deck operations - Policies and procedures (SOP's), checklists, CRM, aircraft systems, knowledge, and airmanship - and consider how these "barriers" might actually become threats.

Policy and procedures - I believe most airline SOP's provide useful barriers to the degree that the flight crew actually uses them. However, in some situations those policies may create unappreciated threats. For example, does the airline's policy drive an over-reliance on automation by mandating its use at all times? Do existing policies require/encourage Captains to do most of the actual flying leaving the First Officer ill-equipped to serve as an effective back-up? Do airline policies and/or culture create or sustain a steep authority gradient which discourages First Officers from speaking up or correcting errors by the Captain?

Checklists - Are the checklists (normal and non-normal) well designed? Do they help trap likely crew errors? If a crew member believes a checklist contains a potential threat, how amenable is their airline to modifying that checklist?

Crew resource management - Is the level of knowledge and proficiency of your Captain/First Officer sufficient to be an effective barrier? Is yours? Do the pilots use effective communication and social skills? Do they maintain cockpit discipline? Do they feel free to speak up and correct each other without creating tension?

Knowledge and airmanship - Does the crew receive the right kind of training to be effective? (Just refer to the "mantra" discussion if you need to be reminded of my position on this). Does that training prepare the crew for the known as well as the unknown? Does that training help mitigate the well-known startle and fear reflexes? Does that training emphasize systems management at the expense of basic aircraft skills? Does that training emphasize the need for the execution of NNC in a methodical and deliberate manner?

As we go through this list of questions (please add more if you like), we can develop a picture of where these barriers may actually morph into threats.

Once these new threats are identified, the next step is to attempt to mitigate those threats.

To be continued.....
737 Driver is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.