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 3rd May 2019, 14:45
  #4801 (permalink)  
 
Join Date: Mar 2006
Location: England
Posts: 845
A0283,
Simple answer, I don’t know.
I’m looking for photos - found (Aerospaceweb.org | Ask Us - Nacelle Vortex Generator), but as you describe this does not fit my experience with vortilons - underwing leading edge with sharp/ pointy bits protruding forward. Nor any experience with engine cowl / nacelle strikes, attachments, bent metal, etc (my ‘jet’ although using stall breakers and stick push, had no vortex generators or other aero adjustments at all - match that).

https://en.m.wikipedia.org/wiki/Vortilon

Aerospaceweb.org | Ask Us - Wing Vortex Devices

Takwis -I doubt your explanation; see photo above


PEI_3721 is offline  
Old 3rd May 2019, 14:50
  #4802 (permalink)  
 
Join Date: Dec 2014
Location: Schiphol
Posts: 331
@Takwis - Thanks for responding . So no aerodynamic impact. Solved. @PEI_3721 thanks for your time.

Edit1: After PEI's response to Takwis's post I tried to dig up one of my images to put us on a level 'playing field'.


A0283

Edit2: In PEi's http://www.aerospaceweb.org/question...cs/q0255.shtml the dual strakes are visible on its 1st photo. The article says the big strake is on the -600 upto -900.

@Takwis - Could you tell me what the names of the big strake, the small strips, and the trapdoor are in 'Boeing speak'.

Last edited by A0283; 3rd May 2019 at 15:48. Reason: Adding photo after PEI's response to Takwis and two more edits
A0283 is offline  
Old 3rd May 2019, 15:02
  #4803 (permalink)  
 
Join Date: Mar 2019
Location: UK
Posts: 4
Originally Posted by 737 Driver View Post
I pretty much agree with everything you say except for the "any human" reference in the second to last sentence. I think that there is broad, though not unanimous, agreement that the accident crews made some serious errors that led to the final loss of aircraft control. Where I and some other participants here differ is that I strongly believe that much of the human factors element you refer to is amenable to training. One only has to look at the performance of the crew on the Lion Air 610 flight the day prior to the original accident. Despite being presented with a novel malfunction, one of the pilots kept flying the aircraft. IMHO, that crew took a bit too long to get to the trim cutout switches, but the takeaway is that every time MCAS made an input, the flying pilot took it right out again. At no time was there evidence that they were losing that fight.

It has been suggested that this crew would have ultimately crashed if not for the jumpseater suggesting that they try the cutout switches, but frankly that is an unwarranted assumption. Having been both in the flying seat and the jumpseat on many occasions, it is absolutely true that the jumpseater may catch something quicker, but that does not mean the flying crew will not catch it at all. There definitely appears to been a limited understanding of the stab trim system by both the Lion Air and Ethiopian crews (very much amenable to training), but it did not prevent the crew above from maintaining aircraft control.

I will agree that any human pilot at some stage in his training will be easily overwhelmed by even the most basic aircraft emergency scenarios. That is why we train so extensively for them. I had previously posted that in the Ethiopian accident, the Captain did fly the aircraft after a certain fashion, and that he had defaulted to his training. The problem was that he defaulted to the wrong training. Just about all of the ET302 Captain's initial actions can be understood in the context of a normal takeoff profile. Unfortunately, a normal takeoff profile left him in a highly unstable position from which dealing with the ultimate stab trim problem became a bridge too far.

When I and other posters keep saying that the pilots should have kept FLYING THE AIRCRAFT, we do not say this from a perspective that operating a malfunctioning aircraft is some inborn capability that every person has. Heck, walking isn't even an inborn capability. However, it is a skill that is amenable to training. That is, as long as you get the right kind of training. As has been already discussed extensively, training in modern commercial airliners has largely devolved into a process of following scripts. Pilots are presented with known problems with known solutions. Even at my airline, there is much less of the relatively unscripted training that really drove home the need to set aside any distractions and focus on the basics of flying the aircraft without the benefit of any automation until the situation was stabilized.

There are multiple links in the chain of causation leading to these accidents. I don't think anyone is questioning that MCAS needs to be fixed, or the FAA needs to step up its oversights, or that airlines need to review their internal training and operations policies. The professional pilot corps, however, needs to look at what we can do to correct the airmanship deficiencies that were exposed by these accident.
When you say that you "strongly believe" the issue is amenable to training, is that based on research or on intuition? I ask because my understanding of the broad sweep of behavioural research is that actual human behaviour is often deeply unintuitive, and in a safety-critical environment I'd be very wary of relying on any assumptions about human behaviour that haven't been rigorously validated.

(I fully agree that pilots need to do their part in correcting any systemic errors contributing to these incidents; my concern is that treating them as "human error" or "poor training" passes up an opportunity to better understand how and why people actually make mistakes, and how to avoid falling into the same traps. Like, I read wonkazoo's underlying point about his crash as being "I knew exactly what to do and I *still* almost killed myself, because a real incident is not like a simulated one", and that seems like it argues against more of the same sort of training as a solution to that class of problem.)
SystemsNerd is offline  
Old 3rd May 2019, 15:06
  #4804 (permalink)  
 
Join Date: Apr 2019
Location: USA
Posts: 217
Originally Posted by Cows getting bigger View Post

737 driver, I have an itch and please take this comment with the best of intent.

When I was taught to fly, PPL through CPL etc, it was instilled in me to understand what every switch/knob did before I played with it (initial thanks to Norman Buddin, ex Hunter pilot and CFI). We were not in the business of altering things without understanding the impact.

So, please correct me if I am wrong, but earlier versions of the 737 had two distinct outcomes associated with the two stab trim switches whilst the Max basically has two switches in series? Somewhere along the line a change operating procedures seem to have pre-dated the wiring change. I’m trying to understand why pre-Max pilots didn’t know, or weren’t told about, the difference between the switches. Isn’t it better airmanship to understand why, what and how when managing aircraft systems, or are we witness to the pre-cursor of ‘Children of the Magenta’ in pilots who never questioned why they threw two switches and what each did?


If it hasn't already become evident, I am also a product of the old school philosophy of pilot training. That being said, there were plenty of times where even I thought we were being required to know far too much technical knowledge than was necessary.

Somewhere along the way, our training started to change. There was far less emphasis on understanding the systems and far more emphasis on following the written procedures. Our training has become highly scripted, and we almost always know the sim training scenarios in advance. I suspect that this change has largely been driven by costs, with modern airlines being reluctant to provide anything other than the minimum training required by the FAA. (You've probably heard the saying, "If the minimum wasn't good enough, it wouldn't be the minimum!")

Frankly, some pilots welcomed this change because it is less work and less threatening. There has always been lip service to the concept that, in some circumstance, the pilot may not have a well-defined checklist or procedure to follow and was expected to use their best judgement. Unfortunately, that sentiment has rarely been backed up with any kind of training. Unfortunately, I think we have seen enough accidents and incidents to in the last decade to show that there is a real, if unaccounted for, cost to this approach to training. Sadly, I still don't see any motivation to make the needed changes to the typical industry training regime. We apparently haven't produced a high enough body count to justify it.

As to your specific question, I have gathered from some of the other posters here that there was no change to their runaway stab trim procedure, that they always used both cutout switches. All I know is that at my airline, we used to be allowed to use them separately. This procedure was changed a few years back (can't remember exactly when, and I don't have any of the old manuals). At the time, I remember being told that this was a Boeing-preferred change driven by a larger trend of removing most types of troubleshooting activities from our non-normal procedures. In my current 737NG manual, there is no longer a reference to the functionality of the two cutout switches. I only know because my experience predates the change. Since current 737NG pilots aren't taught how these switches are wired, I guess there would be little point to telling them how the MAX switches are wired, and as I have previously stated, there is absolutely no difference in the aircraft from a procedural perspective.

Last edited by 737 Driver; 3rd May 2019 at 16:30.
737 Driver is offline  
Old 3rd May 2019, 15:30
  #4805 (permalink)  
 
Join Date: May 2010
Location: Boston
Age: 68
Posts: 429
35 Seconds is all it took.

Originally Posted by 737 Driver View Post
I will agree that any human pilot at some stage in his training will be easily overwhelmed by even the most basic aircraft emergency scenarios. That is why we train so extensively for them. I had previously posted that in the Ethiopian accident, the Captain did fly the aircraft after a certain fashion, and that he had defaulted to his training. The problem was that he defaulted to the wrong training. Just about all of the ET302 Captain's initial actions can be understood in the context of a normal takeoff profile. Unfortunately, a normal takeoff profile left him in a highly unstable position from which dealing with the ultimate stab trim problem became a bridge too far.
The ET pilot possibly followed the Boeing UAS flow chart I posted earlier that covered AoA failure as a 'false' positive ending with "pilot with correct display becomes pilot flying" which apparently did not happen.

He was able to engage autopilot for 30 seconds (again a questionable move). Until the AP disconnected as flaps were retracted the situation was not extreme, I will leave it to others how 'normal' the profile was.

At 05:40:00 the first MCAS input occurs followed by insufficient re-trim, surprise, lack of training experience with magnitude of MCAS input? This led to rapid speed increase

At 05:40:20 the second MCAS input occurs, interrupted by pilot trim at 04:40:27.
The crew carried out the runaway stab procedure at 05:40:35. From the trace it appears that the pilot may have been trimming at this point and was interrupted by the cutout switches.
Had they waited until AC was in trim we likely would not be discussing this..

Looking at the sequence above: At 05:40:00 the AC was not in extreme state By 05:40:35 they were left with likely inoperable manual trim and approaching, but not yet at VMO.
Things went from "interesting to extreme" in 35 seconds during which the crew followed the runaway trim procedure, albeit without first fully trimming the AC.

From other posts they may not have seen the update procedure with the 'note' about first trimming.

That is 35 seconds with only 2 MCAS inputs to get to an extreme state.

One thing that the prelim report does not cover is what was going on during the two and a half minutes until the final sequence. Surely they were not just sitting there with a couple of ATC exchanges.

Here is one scenario:

Trim cutout, both switches as per procedure

Attempts to use manual trim are not successful due to loading (speed still < VMO)

Pilot remembers 737NG had 2 cutout modes, auto and all, depending on slide ware version he "trained" with the change in MAX may not have been mentioned, even if it was it was not stressed.
They try first one then the other switch, no electric trim.
Further attempts to use manual trim?
Next relevant snip from the report:
At 05:41:46, the Captain asked the First-Officer if the trim is functional. The First-Officer has replied that the trim was not working and asked if he could try it manually. The Captain told him to try.
At 05:41:54, the First-Officer replied that it is not working.
Final puzzle is why only brief trim inputs after they re-enabled trim.









MurphyWasRight is online now  
Old 3rd May 2019, 15:46
  #4806 (permalink)  
 
Join Date: Apr 2019
Location: USA
Posts: 217
Since we have seemingly now moved onto a focus on the human factor element (i.e. the why behind the flight crew errors), I think it might be worthy to expand this topic a bit.

Clearly, these accidents have exposed a case where some presumably highly-trained and experienced professionals were put in a position where that training and experience did not rise to the task. Obvious errors were made that had fatal consequences. Since most of us would like to assume that this wasn't a case of malicious or negligent behavior, then presumably there were some significant human factor element behind these lapses.

I am referring, of course, to the various engineers, technical and supervisory staff that designed and approved MCAS for service.

Imagine, if you will, a parallel online forum in which aircraft-related engineer specialties debate over the various elements of these accidents from their perspective. One could imagine certain individuals saying, "Why didn't they just design the friggin' software/hardware correctly?!" Others might defend their tribe by saying the design was sufficient, it was just that the operators weren't sufficiently skilled/trained to handle a malfunction. Still others might concede that, while yes, errors were made, the individuals who had their hands on the design/approval process were working under various constraints and pressures and that their errors were perfectly understandable from a human factors perspective. They would plead that, please, everyone take a breath and quit trying to blame the engineers when it is obvious they were doing the best they could under the circumstances.

What would we make of such a conversation?

What I am trying to point out is that while some of us like to say "Boeing" messed up or "the FAA" messed up, the reality is that these organizations are simply made up of human beings who respond to their training, experience, and environment. Being human, they are just as much subject to the fallibilities of the human mind as were the pilots. There is even one study that lists precisely 188 types of cognitive errors that the human mind is subject to (click here to read). These errors may be different than the ones the pilots were exposed to, but they were ultimately human errors.

At some point, we will have two final accident reports detailing a list of primary and secondary causes to these accidents. Behind a fair number of these causes will be a human being who was not acting out of malicious intent or neglect. They were simply performing according to their training, experience, and environment. In the discussions on this and related threads, there quite often the refrain, "Stop blaming the pilots!" I don't have any problem with that sentiment since the act of "blaming" is largely an emotional response that tends to avoid getting to the root of the problem. That being said, identifying the root causes and proposing remedies isn't the same as blaming (unless someone chooses to interpret it that way).

So yes, how about we all stop blaming everybody who had a hand in these accidents, understand that behind every error there was likely a human factor element, and support those efforts to address and/or remediate those issues?
737 Driver is offline  
Old 3rd May 2019, 15:55
  #4807 (permalink)  
Pegase Driver
 
Join Date: May 1997
Location: Europe
Age: 69
Posts: 2,632
Final puzzle is why only brief trim inputs after they re-enabled trim.
I think ( but not sure and wait to be corrected ) what the FDR data published shows is 2 briefs trims movements , .If this is the case , it does not show the actual inputs physically made , it could have been a continuous trim input by the Capt but it only worked twice briefly , possibly because the aerodynamic load on the stab was already very high ? just an attempt to understand it . I do not think the actual trim switches positions are recorded , but as I said, waiting to be corrected .
ATC Watcher is offline  
Old 3rd May 2019, 16:09
  #4808 (permalink)  
 
Join Date: Mar 2019
Location: On the Ground
Posts: 103
A0283, the "Trapdoor" is a leading edge flap. The dual "strakes" physically push it up out of the way of the reverser door. They might be intentional vortex generators (they surely produce some vortices), and that may even be their purpose...none of my documentation over the last 20 odd years has mentioned them...but they definitely lift the leading edge flap out of the way when the reverser is moving. The ones in the picture are of a freshly painted aircraft...on a plane that has been is service for a little while, the paint gets rubbed off the top of them.
Takwis is offline  
Old 3rd May 2019, 16:19
  #4809 (permalink)  
 
Join Date: May 2010
Location: Boston
Age: 68
Posts: 429
Originally Posted by 737 Driver
One could imagine certain individuals saying, "Why didn't Still others might concede that, while yes, errors were made, the individuals who had their hands on the design/approval process were working under various constraints and pressures and that their errors were perfectly understandable from a human factors perspective.
...
So yes, how about we all stop blaming everybody who had a hand in these accidents, understand that behind every error there was likely a human factor element, and support those efforts to address and/or remediate those issues?
Totally agree with your post, nicely stated.
I snipped a couple of lines and added bolding.

There are parallel themes of degrading of pilot training to save money and Boeing management pushing for "in family" certification for MAX to save money and market share.

I would posit that neither of these decisions were made by people with hands on experience.
I will leave it at that.
MurphyWasRight is online now  
Old 3rd May 2019, 16:21
  #4810 (permalink)  
 
Join Date: Dec 2015
Location: Cape Town, ZA
Age: 58
Posts: 400
Originally Posted by 737 Driver View Post
Since we have seemingly now moved onto a focus on the human factor element (i.e. the why behind the flight crew errors), I think it might be worthy to expand this topic a bit.

Clearly, these accidents have exposed a case where some presumably highly-trained and experienced professionals were put in a position where that training and experience did not rise to the task. Obvious errors were made that had fatal consequences. Since most of us would like to assume that this wasn't a case of malicious or negligent behavior, then presumably there were some significant human factor element behind these lapses.

I am referring, of course, to the various engineers, technical and supervisory staff that designed and approved MCAS for service.

Imagine, if you will, a parallel online forum in which aircraft-related engineer specialties debate over the various elements of these accidents from their perspective. One could imagine certain individuals saying, "Why didn't they just design the friggin' software/hardware correctly?!" Others might defend their tribe by saying the design was sufficient, it was just that the operators weren't sufficiently skilled/trained to handle a malfunction. Still others might concede that, while yes, errors were made, the individuals who had their hands on the design/approval process were working under various constraints and pressures and that their errors were perfectly understandable from a human factors perspective. They would plead that, please, everyone take a breath and quit trying to blame the engineers when it is obvious they were doing the best they could under the circumstances.

What would we make of such a conversation?

What I am trying to point out is that while some of us like to say "Boeing" messed up or "the FAA" messed up, the reality is that these organizations are simply made up of human beings who respond to their training, experience, and environment. Being human, they are just as much subject to the fallibilities of the human mind as were the pilots. There is even one study that lists precisely 188 types of cognitive errors that the human mind is subject to (click here to read). These errors may be different than the ones the pilots were exposed to, but they were ultimately human errors.

At some point, we will have two final accident reports detailing a list of primary and secondary causes to these accidents. Behind a fair number of these causes will be a human being who was not acting out of malicious intent or neglect. They were simply performing according to their training, experience, and environment. In the discussions on this and related threads, there quite often the refrain, "Stop blaming the pilots!" I don't have any problem with that sentiment since the act of "blaming" is largely an emotional response that tends to avoid getting to the root of the problem. That being said, identifying the root causes and proposing remedies isn't the same as blaming (unless someone chooses to interpret it that way).

So yes, how about we all stop blaming everybody who had a hand in these accidents, understand that behind every error there was likely a human factor element, and support those efforts to address and/or remediate those issues?
The article that I just posted got lost in a flurry of comments, but is worth reading. It carefully describes the chain of human decisions involved in the design of MCAS, without apportioning blame: https://www.theverge.com/2019/5/2/18...error-mcas-faa

So MCAS was designed to compensate. It would use an angle of attack (AoA) sensor to detect when the airplane entered a steep climb. It would activate the airplane’s pitch trim system, which is routinely used to help stabilize the airplane and make it easier to control, especially during climb and descent. And it would trim the airplane in modest increments for up to nine seconds at a time until it detected that the airplane had returned to a normal AoA and ended its steep climb. It seems simple enough — on paper, that is.
MCAS received a “hazardous failure” designation. This meant that, in the FAA’s judgment, any kind of MCAS malfunction would result in, at worst, “a large reduction in safety margins” or “serious or fatal injury to a relatively small number of the occupants.” Such systems, therefore, need at least two levels of redundancy, with a chance of failure less than 1 in 10 million.
Worse still: the FAA did not catch the fact that the version of MCAS actually installed on the 737 Max was much more powerful than the version described in the design specifications. On paper, MCAS was only supposed to move the horizontal stabilizer 0.6 degrees at a time. In reality, it could move the stabilizer as much as 2.5 degrees at a time, making it significantly more powerful when forcing the nose of the airplane down.
But why had nobody caught it in the first place? The answer might be infuriatingly simple: nobody read the paperwork.

Although the FAA is responsible for the safety of any airplane manufactured in the United States, it delegates much of the certification to the manufacturers themselves.
So had anyone checked, they might have flagged MCAS for one of several reasons, including its lack of redundancy, its unacceptably high risk of failure, or its significant increase in power to the point that it was no longer just a “hazardous failure” kind of system.
In a strange way, the 737 Max’s story is less about what did happen and more about what didn’t. Nobody did anything criminal. Nobody did anything malicious. Nobody did anything wrong, in a strictly technical sense.
It’s a perfect example of the cross purposes at which business, technology, and safety often find themselves. With its bottom line threatened, Boeing focused on speed instead of rigor, cost-control instead of innovation, and efficiency instead of transparency. The FAA got caught up in Boeing’s rush to get the Max into production, arguably failing to enforce its own safety regulations and missing a clear opportunity to prevent these two crashes.
GordonR_Cape is online now  
Old 3rd May 2019, 16:22
  #4811 (permalink)  
 
Join Date: Apr 2019
Location: USA
Posts: 217
Originally Posted by Takwis View Post
They might be intentional vortex generators (they surely produce some vortices), and that may even be their purpose...none of my documentation over the last 20 odd years has mentioned them...
The engine strakes generate vortices that energize the airflow going over the leading edge devices immediately behind and help delay airflow separation over the wing as the angles of attack increases.
737 Driver is offline  
Old 3rd May 2019, 17:23
  #4812 (permalink)  
 
Join Date: Dec 2014
Location: USA
Posts: 33
Originally Posted by 737 Driver View Post
So yes, how about we all stop blaming everybody who had a hand in these accidents, understand that behind every error there was likely a human factor element, and support those efforts to address and/or remediate those issues?
I agree. This is how commercial aviation has become as safe as it is. When accidents happen, we seek not to blame individuals, but to understand root causes, and prevent or reduce the chance of the same thing happening again by correcting design or materials defects, augmenting training, changing procedures, improving regulatory oversight, documentation, and communication, or all of those things.

Sadly it seems there is a trend in society (I call it "outrage culture") where the response to any calamity is one driven by anger and blame, and not one seeking to solve actual problems. Or maybe I'm just getting old.
ams6110 is offline  
Old 3rd May 2019, 17:25
  #4813 (permalink)  
 
Join Date: Mar 2019
Location: On the Ground
Posts: 103
Originally Posted by 737 Driver View Post
The engine strakes generate vortices that energize the airflow going over the leading edge devices immediately behind and help delay airflow separation over the wing as the angles of attack increases.
Yes, they do. I have a picture of an Engine Strake for you; have to figure out how to post it. It is many times larger than the little roller ramps.

Can't post urls, can't post pictures.Try https://i.ytimg.com/vi/_vkgXtuEN34/maxresdefault.jpg




Last edited by Senior Pilot; 4th May 2019 at 01:52. Reason: Add images
Takwis is offline  
Old 3rd May 2019, 17:39
  #4814 (permalink)  
 
Join Date: Apr 2019
Location: Toronto
Posts: 9
Thumbs up

Originally Posted by Lost in Saigon View Post
In November 2018, after Lion Air, some (or all) operators, changed the checklist list and removed the word “continuous”.
As a programmer, I really like this checklist a lot more. Besides scrapping the misleading word "continuous", it also tells pilots to control pitch with electric trim as an explicit step prior to using the CUTOUT switches, rather than having it be an apparently conditional substep of disengaging the autopilot if it is engaged.

As a tangent to that, it seems to me that it is difficult to establish a definition of "runaway stabilizer" that includes erroneous MCAS but doesn't include normal STS. Words like "continuous" apply to neither, nor do phrases like "cannot be stopped by pilot electric trim". I'm not at all happy to have Potter Stewart writing emergency checklists; "I know it when I see it" seems not enough for something this critical.
Tobin is offline  
Old 3rd May 2019, 18:29
  #4815 (permalink)  
 
Join Date: Apr 2019
Location: USA
Posts: 217
Originally Posted by Takwis View Post
Can't post urls, can't post pictures.Try https colon //i.ytimg.com/vi/_vkgXtuEN34/maxresdefault dot jpg
.
Not off probation yet? Let's see if I can assist:


Inboard engine strake

For the non-aero types, the need for the strake is due in large part to the disruption of airflow over the wing caused by the engines themselves, particularly as the AOA increases. The strake creates a vortex that adds energy to the airflow and helps delay airflow separation over the wing.
737 Driver is offline  
Old 3rd May 2019, 18:43
  #4816 (permalink)  
 
Join Date: Mar 2006
Location: England
Posts: 845
Takwis,
Thanks for the further explanations clarifying your previous answer, which I now accept.
At least until I understand the Boeing logic of using two vanes to lift a LE flap
A simple mechanical solution vs the electronic logic of MCAS ?!!

The use of a large (larger) engine cowl strake adds questions to the originating theme of the extent aerodynamic changes.
If the overall change requires additional inner-wing stall strips, then why use an aerodynamic cowl ‘fence’ to isolate the inner wing, normally achieved by the stall strip.
PEI_3721 is offline  
Old 3rd May 2019, 19:07
  #4817 (permalink)  
 
Join Date: Apr 2019
Location: USA
Posts: 217
Originally Posted by MurphyWasRight View Post

There are parallel themes of degrading of pilot training to save money and Boeing management pushing for "in family" certification for MAX to save money and market share.

I would posit that neither of these decisions were made by people with hands on experience.
I will leave it at that.
.
I will posit that for every person connected to these accidents, from the lowly technician or pilot all the way up to the Boeing CEO or FAA Administrator, we could construct a "training, experience, and environment" description that explains the choices they made. The takeaway is that once these elements are identified, then a concerted effort should be made to change whatever it was in their training, experience or environment that led to those choices in the first place.
737 Driver is offline  
Old 3rd May 2019, 19:12
  #4818 (permalink)  
 
Join Date: Dec 2014
Location: Schiphol
Posts: 331
Takwis Re your remark about fresh paint - good observation ;-) it was freshly painted aircraft indeed ... was an Ethiopian MAX delivery flight.

737 Driver the image you posted has only one of the smaller strakes ... so when was the second strake introduced ... my guess based on Takwis answer and PEI's post is the -600 to -900 ... so you would expect a reason for that... do you know what 737-model that KLM plane was?

737 Driver in the image that I posted I indicated the difference between the 'trapdoor' and the 'leading edge' ...IIRC the trapdoor opens down and forward and is as far as I could see not a part of the moveable leading edge/slats ... it would require a detailed picture of a MAX to clear that up I guess (would be nice to see one),

PEI_3721 could it still be that these 2 strakes have both a mechanical and an aerodynamic function ? ... it appears that there where enough aerodynamic issues to solve, even going from Classic to NG and on to MAX, so you could expect some changes in these area's ... like difference in size and position of the big strake (it looked increased in size on the images that I had) ...
A0283 is offline  
Old 3rd May 2019, 20:01
  #4819 (permalink)  
 
Join Date: Apr 2019
Location: USA
Posts: 217
Originally Posted by A0283 View Post

737 Driver the image you posted has only one of the smaller strakes ... so when was the second strake introduced ... my guess based on Takwis answer and PEI's post is the -600 to -900 ... so you would expect a reason for that... do you know what 737-model that KLM plane was?

737 Driver in the image that I posted I indicated the difference between the 'trapdoor' and the 'leading edge' ...IIRC the trapdoor opens down and forward and is as far as I could see not a part of the moveable leading edge/slats ... it would require a detailed picture of a MAX to clear that up I guess (would be nice to see one),
The picture was found online by Takwis, and there was no explanation of its context. I was merely assisting him with posting it. As far as your other queries, I have reached the extent of my expertise in these matters except to say that apparently someone thought these devices were necessary to accommodate the changes in airflow around the new engines.
737 Driver is offline  
Old 3rd May 2019, 20:17
  #4820 (permalink)  
 
Join Date: Feb 2011
Location: Grand Turk
Age: 56
Posts: 64
Originally Posted by ams6110 View Post
I agree. This is how commercial aviation has become as safe as it is. When accidents happen, we seek not to blame individuals, but to understand root causes, and prevent or reduce the chance of the same thing happening again by correcting design or materials defects, augmenting training, changing procedures, improving regulatory oversight, documentation, and communication, or all of those things.

Sadly it seems there is a trend in society (I call it "outrage culture") where the response to any calamity is one driven by anger and blame, and not one seeking to solve actual problems. Or maybe I'm just getting old.
"This is how commercial aviation has become as safe as it is" I suspect that it is rather an Alice in Wonderland perspective. Every accident that involves loss of life, ultimately requires the investigation and apportionment of blame. Nothing has significantly changed in that respect. Air accident investigation does its best not to make legal findings because that is for the courts. Liability for mistakes is an important part of concentrating the mind... not just in the aviation world. Improving safety standards is largely due to commercial necessity. Public trust goes hand in hand with passenger volume. It is the breach of trust that can harm aviation. Countries have laws and hopefully those laws are respected and enforced when appropriate. Negligence, criminal negligence, dishonesty and corruption are possible in aviation as with every other walk of life. If individuals knowingly allowed or concealed unsafe systems being incorporated into the 737 MAX they will be be culpable. It is not a witch-hunt for the law to be enforced. The criminal test is an actus reus combined with mens rea. It is a high bar but one that could be reached. There are already signs that there have been some concealment and lack of candor. The circumstances demand that there will be further criminal and civil investigation to properly apportion blame. It may be that there were a series of innocent mistakes but that does not seem to be the most likely. Regardless of innocence, blame will still have to be apportioned to calculate compensation claims.
wheelsright is offline  

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

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