MAX’s Return Delayed by FAA Reevaluation of 737 Safety Procedures
Join Date: Nov 2007
Location: dublin
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
This emergency AD was prompted by analysis performed by the manufacturer showing that if an erroneously high single angle of attack (AOA) sensor input is received by the flight control system, there is a potential for repeated nose-down trim commands of the horizontal stabilizer. This condition, if not addressed, could cause the flight crew to have difficulty controlling the airplane, and lead to excessive nose-down attitude, significant altitude loss, and possible impact with terrain.
This AD requires revising certificate limitations and operating procedures of the airplane flight manual (AFM) to provide the flight crew with runaway horizontal stabilizer trim procedures to follow under certain conditions.Runaway Stabilizer
Disengage autopilot and control airplane pitch attitude with control column and main electric trim as required. If relaxing the column causes the trim to move, set stabilizer trim switches to CUTOUT. If runaway continues, hold the stabilizer trim wheel against rotation and trim the airplane manually.
Note: The 737-8/-9 uses a Flight Control Computer command of pitch trim to improve longitudinal handling characteristics. In the event of erroneous Angle of Attack (AOA) input, the pitch trim system can trim the stabilizer nose down in increments lasting up to 10 seconds.
In the event an uncommanded nose down stabilizer trim is experienced on the 737-8/-9, in conjunction with one or more of the indications or effects listed below, do the existing AFM Runaway Stabilizer procedure above, ensuring that the STAB TRIM CUTOUT switches are set to CUTOUT and stay in the CUTOUT position for the remainder of the flight.
An erroneous AOA input can cause some or all of the following indications and effects:
Disengage autopilot and control airplane pitch attitude with control column and main electric trim as required. If relaxing the column causes the trim to move, set stabilizer trim switches to CUTOUT. If runaway continues, hold the stabilizer trim wheel against rotation and trim the airplane manually.
Note: The 737-8/-9 uses a Flight Control Computer command of pitch trim to improve longitudinal handling characteristics. In the event of erroneous Angle of Attack (AOA) input, the pitch trim system can trim the stabilizer nose down in increments lasting up to 10 seconds.
In the event an uncommanded nose down stabilizer trim is experienced on the 737-8/-9, in conjunction with one or more of the indications or effects listed below, do the existing AFM Runaway Stabilizer procedure above, ensuring that the STAB TRIM CUTOUT switches are set to CUTOUT and stay in the CUTOUT position for the remainder of the flight.
An erroneous AOA input can cause some or all of the following indications and effects:
- Continuous or intermittent stick shaker on the affected side only.
- Minimum speed bar (red and black) on the affected side only.
- Increasing nose down control forces.
- IAS DISAGREE alert.
- ALT DISAGREE alert.
- AOA DISAGREE alert (if the option is installed).
- FEEL DIFF PRESS light.
- Autopilot may disengage.
- Inability to engage autopilot.
Join Date: Apr 2019
Location: Toronto
Posts: 20
Likes: 0
Received 0 Likes
on
0 Posts
To those saying "use the runaway stab procedure", and claiming that it clearly says to put the plane back in trim with the MET (which, as a programmer, I don't read from the posted checklist at all, but I digress), how would that work if the runaway is not caused by MCAS, but rather an actual, possibly intermittent, electrical fault in the trim motor?
"Oh, it's trimming down? Weird. Might be STS. Wait, it's going pretty far down. Might be MCAS. Oh, it's stopped. But this is a bit too far down, let me trim back. Hmm, the pickle switches work, I'm trimming back up. Seems OK now. Wait, it's trimming down again, a lot. It's got to be MCAS. Stupid thing, didn't they fix the software? Hm, it's not responding to the pickle switch now. I thought MCAS stopped when I try to trim up? Am I remembering right? Might be a glitch? MCAS will only run for 10 seconds anyway. Once it stops, I'll trim up. Obviously I don't wanna throw the cutouts while I'm trimmed so far down. I know how that ends. Okay, MCAS should definitely be stopping now. It's... not stopping? Oh ****. This is something else! Okay, stab tirm cutout! Oh hell, this is way nose down now. Try the manual trim wheel. Nope, it won't budge. Well, crap. What do I do now?"
My point is that trying to trim back to normal with MET in a suspected runaway trim scenario is a gamble. If it's MCAS, you win. But if it's not, then while you're fumbling with the pickle switches trying to see how the trim responds, the trim could be running further and further away, leaving you even worse off than if you had hit the cutouts earlier. How much time do you allow for this "troubleshooting"? How large of a decision tree are you expecting "average" pilots to be able to recall in this situation, especially if they've got other alarms going on?
"Oh, it's trimming down? Weird. Might be STS. Wait, it's going pretty far down. Might be MCAS. Oh, it's stopped. But this is a bit too far down, let me trim back. Hmm, the pickle switches work, I'm trimming back up. Seems OK now. Wait, it's trimming down again, a lot. It's got to be MCAS. Stupid thing, didn't they fix the software? Hm, it's not responding to the pickle switch now. I thought MCAS stopped when I try to trim up? Am I remembering right? Might be a glitch? MCAS will only run for 10 seconds anyway. Once it stops, I'll trim up. Obviously I don't wanna throw the cutouts while I'm trimmed so far down. I know how that ends. Okay, MCAS should definitely be stopping now. It's... not stopping? Oh ****. This is something else! Okay, stab tirm cutout! Oh hell, this is way nose down now. Try the manual trim wheel. Nope, it won't budge. Well, crap. What do I do now?"
My point is that trying to trim back to normal with MET in a suspected runaway trim scenario is a gamble. If it's MCAS, you win. But if it's not, then while you're fumbling with the pickle switches trying to see how the trim responds, the trim could be running further and further away, leaving you even worse off than if you had hit the cutouts earlier. How much time do you allow for this "troubleshooting"? How large of a decision tree are you expecting "average" pilots to be able to recall in this situation, especially if they've got other alarms going on?
Last edited by Tobin; 6th Oct 2019 at 04:16.
Join Date: Jun 2019
Location: VA
Posts: 210
Likes: 0
Received 0 Likes
on
0 Posts
Excerpted from the Aviation Herald at Crash: Ethiopian B38M near Bishoftu on Mar 10th 2019, impacted terrain after departure
Coverage released on Apr 16th:
On Apr 11th 2019 The Aviation Herald received a full copy of the Flight Operations Manual (FOM), Revision 18B released on Nov 30th 2018, which is currently being used by Ethiopian Airlines (verified in April 2019 to be current). Although Boeing had issued an operator's bulletin on Nov 6th 2018, which was put into Emergency Airworthiness Directive 2018-23-51 dated Nov 7th 2018 requiring the stab trim runaway procedure to be incorporated into the FOM ahead of the sign off of this version of the FOM (the entire document is on file but not available for publishing), there is no trace of such an addition in the entire 699 pages of the FOM.
Quite the opposite, in section 2.6 of the FOM "Operational Irregularities" the last revision is provided as Revision 18 dated "Nov 1st 2017".
According to information The Aviation Herald had received in March 2019, the Airline Management needed to be reminded to distribute the Boeing Operator's Bulletin as well as the EAD to their pilots, eventually the documents were distributed to the flight crew. However, it was never verified, whether those documents had arrived, were read or had been understood. No deeper explanation of the MCAS, mentioned but not explained in both documents, was offered.
It turned out, that only very cursory knowledge about the stab trim runaway procedure exists amongst the flight crew of Ethiopian Airlines even 5 months after the EAD was distributed. In particular, none of the conditions suggesting an MCAS related stab trim runaway was known with any degree of certainty. In that context the recommendation by the accident flight's first officer to use the TRIM CUTOUT switches suggests, that he was partially aware of the contents of the EAD and reproduced some but not all of the provisions and not all of the procedure, which may or may not explain some of the obvious omissions in following the procedure in full.
On Apr 11th 2019 The Aviation Herald received a full copy of the Flight Operations Manual (FOM), Revision 18B released on Nov 30th 2018, which is currently being used by Ethiopian Airlines (verified in April 2019 to be current). Although Boeing had issued an operator's bulletin on Nov 6th 2018, which was put into Emergency Airworthiness Directive 2018-23-51 dated Nov 7th 2018 requiring the stab trim runaway procedure to be incorporated into the FOM ahead of the sign off of this version of the FOM (the entire document is on file but not available for publishing), there is no trace of such an addition in the entire 699 pages of the FOM.
Quite the opposite, in section 2.6 of the FOM "Operational Irregularities" the last revision is provided as Revision 18 dated "Nov 1st 2017".
According to information The Aviation Herald had received in March 2019, the Airline Management needed to be reminded to distribute the Boeing Operator's Bulletin as well as the EAD to their pilots, eventually the documents were distributed to the flight crew. However, it was never verified, whether those documents had arrived, were read or had been understood. No deeper explanation of the MCAS, mentioned but not explained in both documents, was offered.
It turned out, that only very cursory knowledge about the stab trim runaway procedure exists amongst the flight crew of Ethiopian Airlines even 5 months after the EAD was distributed. In particular, none of the conditions suggesting an MCAS related stab trim runaway was known with any degree of certainty. In that context the recommendation by the accident flight's first officer to use the TRIM CUTOUT switches suggests, that he was partially aware of the contents of the EAD and reproduced some but not all of the provisions and not all of the procedure, which may or may not explain some of the obvious omissions in following the procedure in full.
Last edited by Tomaski; 5th Oct 2019 at 21:12.
Join Date: Jun 2019
Location: VA
Posts: 210
Likes: 0
Received 0 Likes
on
0 Posts
Here’s that other article:
https://www.businessinsider.com/ethi...737-max-2019-5
https://www.businessinsider.com/ethi...737-max-2019-5
A pilot urged Ethiopian Airlines senior managers for more training on the Boeing 737 Max aircraft in December, two months after the Lion Air Flight 610 crash that killed 189 people, according to emails and documents seen by Bloomberg News.
Bernd Kai von Hoesslin, the Ethiopian Airlines pilot and a 737 instructor, reportedly warned managers that more training was required following the October Lion Air crash. He also suggested greater communication between crew members. Three months after von Hoesslin delivered the warning, Ethiopian Airlines Flight 302 crashed, killing all 157 people on board.
Von Hoesslin was concerned with how pilots would handle an issue with the 737 Max's flight-control feature in conjunction with cockpit warnings, according to the emails seen by Bloomberg.
"It will be a crash for sure," von Hoesslin said in an email in December, Bloomberg reported.
Von Hoesslin also expressed his concerns on aircraft maintenance and pilot fatigue in 418 pages of communications. Von Hoesslin reportedly left the airline in April and included his previous advice with his resignation letter. He declined to comment for the Bloomberg story.
"Some of these concerns were safety-related and well within the duty of the airline to adequately address," von Hoesslin said in his resignation letter, according to Bloomberg.
An Ethiopian Airlines spokesman told Bloomberg they could not comment on the story.
Early investigations suggest that a faulty sensor played a role in both crashes. An issue with a sensor could have triggered an automated system meant to point the plane's nose downward to prevent the plane from stalling.
Von Hoesslin mentioned the automated system in his correspondence, though as Bloomberg noted, it is unclear whether the Ethiopian Airlines crash would have been prevented had the airline heeded his warning.
.
Bernd Kai von Hoesslin, the Ethiopian Airlines pilot and a 737 instructor, reportedly warned managers that more training was required following the October Lion Air crash. He also suggested greater communication between crew members. Three months after von Hoesslin delivered the warning, Ethiopian Airlines Flight 302 crashed, killing all 157 people on board.
Von Hoesslin was concerned with how pilots would handle an issue with the 737 Max's flight-control feature in conjunction with cockpit warnings, according to the emails seen by Bloomberg.
"It will be a crash for sure," von Hoesslin said in an email in December, Bloomberg reported.
Von Hoesslin also expressed his concerns on aircraft maintenance and pilot fatigue in 418 pages of communications. Von Hoesslin reportedly left the airline in April and included his previous advice with his resignation letter. He declined to comment for the Bloomberg story.
"Some of these concerns were safety-related and well within the duty of the airline to adequately address," von Hoesslin said in his resignation letter, according to Bloomberg.
An Ethiopian Airlines spokesman told Bloomberg they could not comment on the story.
Early investigations suggest that a faulty sensor played a role in both crashes. An issue with a sensor could have triggered an automated system meant to point the plane's nose downward to prevent the plane from stalling.
Von Hoesslin mentioned the automated system in his correspondence, though as Bloomberg noted, it is unclear whether the Ethiopian Airlines crash would have been prevented had the airline heeded his warning.
.
Join Date: Nov 2007
Location: dublin
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
QUOTE:
Von Hoesslin was concerned with how pilots would handle an issue with the 737 Max's flight-control feature in conjunction with cockpit warnings, according to the emails seen by Bloomberg.
"It will be a crash for sure," von Hoesslin said in an email in December, Bloomberg reported.
Von Hoesslin also expressed his concerns on aircraft maintenance and pilot fatigue in 418 pages of communications. Von Hoesslin reportedly left the airline in April and included his previous advice with his resignation letter. He declined to comment for the Bloomberg story.
"Some of these concerns were safety-related and well within the duty of the airline to adequately address," von Hoesslin said in his resignation letter, according to Bloomberg.
An Ethiopian Airlines spokesman told Bloomberg they could not comment on the story.
UNQUOTE
Tomaski. That is the very point isn't it. Lack of training and learning from other operator's accidents and near accidents, as well as internal ones. That is part of the safety culture that keeps us safe, or should. That an ET instructor should have stated as early as December that he had concerns, and that these were not acted upon is going to weigh heavily on the judgement of the public.
If Bloomberg truly have that resignation letter with reasons which impact (no pun intended) on the subsequent crash then that may be discoverable and will become known in due course I hope.
When I was involved in these sort of issues we published a monthly report of all accidents, near accidents and safety related events to our pilots (de-identified sometimes) whether internal or external. These reports were avidly read and had the macabre name of "the horror comic" but everyone read it and everyone learned. I still have many copies of them and they make interesting reading even today since many of the learning points still hold true. There isn't much new in aviation really. It just gets forgotten and is lost to the collective knowledge pool.
Then the legal boys moved in and now I understand that airlines are not as forthcoming on broadcasting internal errors for fear of the media getting hold of them and mis-using the information. If so it is a massive step backwards.
I remember a captain stalling a big jet over a very large city and doing a good stall recovery. Ended well, but what about the learning from it? Had that been lost it could have happened again. So the pilot wrote to every pilot in the airline, with his name on it, through the newsletter explaining how he had come to do the unthinkable. And he was regarded as one of the best by his peers. He was too, and he made a mistake. But through his honesty, and that of the management in publishing the letter without fear, that did more for flight safety than any single act I can remember in a long career. I am seeing a lot of the opposite right now and that is very worrying.
I get a daily report of every incident world wide and read it avidly still to see what is happening out there. www .aeroinside.com. There is great learning to be had every day right there.
Cheers
Yan
Von Hoesslin was concerned with how pilots would handle an issue with the 737 Max's flight-control feature in conjunction with cockpit warnings, according to the emails seen by Bloomberg.
"It will be a crash for sure," von Hoesslin said in an email in December, Bloomberg reported.
Von Hoesslin also expressed his concerns on aircraft maintenance and pilot fatigue in 418 pages of communications. Von Hoesslin reportedly left the airline in April and included his previous advice with his resignation letter. He declined to comment for the Bloomberg story.
"Some of these concerns were safety-related and well within the duty of the airline to adequately address," von Hoesslin said in his resignation letter, according to Bloomberg.
An Ethiopian Airlines spokesman told Bloomberg they could not comment on the story.
UNQUOTE
Tomaski. That is the very point isn't it. Lack of training and learning from other operator's accidents and near accidents, as well as internal ones. That is part of the safety culture that keeps us safe, or should. That an ET instructor should have stated as early as December that he had concerns, and that these were not acted upon is going to weigh heavily on the judgement of the public.
If Bloomberg truly have that resignation letter with reasons which impact (no pun intended) on the subsequent crash then that may be discoverable and will become known in due course I hope.
When I was involved in these sort of issues we published a monthly report of all accidents, near accidents and safety related events to our pilots (de-identified sometimes) whether internal or external. These reports were avidly read and had the macabre name of "the horror comic" but everyone read it and everyone learned. I still have many copies of them and they make interesting reading even today since many of the learning points still hold true. There isn't much new in aviation really. It just gets forgotten and is lost to the collective knowledge pool.
Then the legal boys moved in and now I understand that airlines are not as forthcoming on broadcasting internal errors for fear of the media getting hold of them and mis-using the information. If so it is a massive step backwards.
I remember a captain stalling a big jet over a very large city and doing a good stall recovery. Ended well, but what about the learning from it? Had that been lost it could have happened again. So the pilot wrote to every pilot in the airline, with his name on it, through the newsletter explaining how he had come to do the unthinkable. And he was regarded as one of the best by his peers. He was too, and he made a mistake. But through his honesty, and that of the management in publishing the letter without fear, that did more for flight safety than any single act I can remember in a long career. I am seeing a lot of the opposite right now and that is very worrying.
I get a daily report of every incident world wide and read it avidly still to see what is happening out there. www .aeroinside.com. There is great learning to be had every day right there.
Cheers
Yan
Join Date: Nov 2007
Location: dublin
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
Every week that passes we learn more information about the flawed & corrupt certification process for the 737-MAX, a plane that burns less fuel at the expense of safety.
Boeing prioritizes profits above safety, the FAA is infiltrated by Boeing, and the eventual loss of life has been deemed acceptable.
Boeing's PR machine still tries to disseminate the "just fly the aircraft" mantra in many ways to try and divert attention from a flawed 737-MAX design, while trying to imbue pilots with some sort of blame.
Boeing prioritizes profits above safety, the FAA is infiltrated by Boeing, and the eventual loss of life has been deemed acceptable.
Boeing's PR machine still tries to disseminate the "just fly the aircraft" mantra in many ways to try and divert attention from a flawed 737-MAX design, while trying to imbue pilots with some sort of blame.
Good evening Byros.
I don't think you have been paying attention to the thousands of postings on this forum. They fall into three main groups and none have a right to claim the moral high ground yet since we don't really know, do we? So you asserting that 'Boeing prioritizes profits above safety, the FAA is infiltrated by Boeing, " is a touch in dodgy territory I would suspect.
CAMPS
1 Boeing is the devil and deliberately created a flawed machine and are wholly culpable for everything that happened. Boeing should hang its head in shame. FAA too.
2 Boeing created a very good plane with a bad fault which went to to contribute to two crashes, which however were avoidable if the pilots had acted correctly. Remember that the first Lionair did land safely. So fix the Max AND train the rest of the world's pilots to a higher standard.
3 As per 2/ above but that it was not recoverable or avoidable by an "average pilot". So if we fix the MCAS on the Max, problem solved. No need for further training except of course to do a course on how MCAS works in its new incarnation.,
You seem to be in camp 1 with a dash of Camp 3 thrown in.
I really wish you were correct because in two months or so, in your view, it will all be over and the fix will be in place and nothing like this will happen again.
Unless and until we get another multiple failure like AF 447, or ET or Turkish 738 at AMS, (and many others) where the pilots are "overwhelmed". QF 32 was a situation which could have overwhelmed the crew were it not for their training and airmanship.
And note that AF and QF were not Boeings.
Cheers
Yan
yanrair, In QF32 they had more than an extra pilot. Given the type of flight and the training happening I expect there was a bit of adrenaline floating around the cockpit the heightened initial reaction. The comment before take-off indicates this, it was never going to be an everyday flight for the PIC or the pilot checking the PIC. They did a great job and were very lucky also.
I simply do not believe the jump seat pilot on the first Lion Air MCAS event flight picked up a "runaway trim" there certainly has not been any evidence of that been made public. What has been reported has been the entry in the Tech Log. This entry was alone the line of "STS running in wrong direction/reverse".
This to me means that all three pilots were not surprised to have the trim activate, in fact they expected it - just it was working opposite to what they expected.
If they thought they had a runway trim would you not expect a Tech Log entry to be something like - Runaway nose down trim (intermittently).
I simply do not believe the jump seat pilot on the first Lion Air MCAS event flight picked up a "runaway trim" there certainly has not been any evidence of that been made public. What has been reported has been the entry in the Tech Log. This entry was alone the line of "STS running in wrong direction/reverse".
This to me means that all three pilots were not surprised to have the trim activate, in fact they expected it - just it was working opposite to what they expected.
If they thought they had a runway trim would you not expect a Tech Log entry to be something like - Runaway nose down trim (intermittently).
Join Date: Sep 2019
Location: leftcoast
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
Good evening Byros.
I don't think you have been paying attention to the thousands of postings on this forum. They fall into three main groups and none have a right to claim the moral high ground yet since we don't really know, do we? So you asserting that 'Boeing prioritizes profits above safety, the FAA is infiltrated by Boeing, " is a touch in dodgy territory I would suspect.
CAMPS
1 Boeing is the devil and deliberately created a flawed machine and are wholly culpable for everything that happened. Boeing should hang its head in shame. FAA too.
2 Boeing created a very good plane with a bad fault which went to to contribute to two crashes, which however were avoidable if the pilots had acted correctly. Remember that the first Lionair did land safely. So fix the Max AND train the rest of the world's pilots to a higher standard.
3 As per 2/ above but that it was not recoverable or avoidable by an "average pilot". So if we fix the MCAS on the Max, problem solved. No need for further training except of course to do a course on how MCAS works in its new incarnation.,
You seem to be in camp 1 with a dash of Camp 3 thrown in.
I really wish you were correct because in two months or so, in your view, it will all be over and the fix will be in place and nothing like this will happen again.
Unless and until we get another multiple failure like AF 447, or ET or Turkish 738 at AMS, (and many others) where the pilots are "overwhelmed". QF 32 was a situation which could have overwhelmed the crew were it not for their training and airmanship.
And note that AF and QF were not Boeings.
Cheers
Yan
I don't think you have been paying attention to the thousands of postings on this forum. They fall into three main groups and none have a right to claim the moral high ground yet since we don't really know, do we? So you asserting that 'Boeing prioritizes profits above safety, the FAA is infiltrated by Boeing, " is a touch in dodgy territory I would suspect.
CAMPS
1 Boeing is the devil and deliberately created a flawed machine and are wholly culpable for everything that happened. Boeing should hang its head in shame. FAA too.
2 Boeing created a very good plane with a bad fault which went to to contribute to two crashes, which however were avoidable if the pilots had acted correctly. Remember that the first Lionair did land safely. So fix the Max AND train the rest of the world's pilots to a higher standard.
3 As per 2/ above but that it was not recoverable or avoidable by an "average pilot". So if we fix the MCAS on the Max, problem solved. No need for further training except of course to do a course on how MCAS works in its new incarnation.,
You seem to be in camp 1 with a dash of Camp 3 thrown in.
I really wish you were correct because in two months or so, in your view, it will all be over and the fix will be in place and nothing like this will happen again.
Unless and until we get another multiple failure like AF 447, or ET or Turkish 738 at AMS, (and many others) where the pilots are "overwhelmed". QF 32 was a situation which could have overwhelmed the crew were it not for their training and airmanship.
And note that AF and QF were not Boeings.
Cheers
Yan
1 Boeing is the devil and deliberately created a flawed machine and are wholly culpable for everything that happened. Boeing should hang its head in shame. FAA too.
No boeing did NOT deliberately create a flawed machine - they did it in the name of schedule and profit and cost decisions made by incompetent people in command posItions in both FAA and Boeing. Those that disagreed were ignored, and others were never informed as to ' subtle changes - again all in the service of schedule and profit and bonus coupled with a fair amount of ignorance. There is absolutely NO excuse for allowing a single sensor to HAL the pilot and the aircraft.
And the rest of the game re legalese wordsmithing the manual and explanations is nearly as bad. Adk why the yo yo game was deleted many decades ago from the manuals and the training, and why no notice re the limits on speed and stab angle were such that the manual trim was an impossible ' solution' unless neutral trim was first accomplished.
As to the crew and the continued bit about IF IDA coulda woulda shouda .... pushed by CEO and legal types - its all about the $$$$$. period !
Join Date: Mar 2019
Location: On the Ground
Posts: 155
Likes: 0
Received 0 Likes
on
0 Posts
You've thrown together three impressive straw men, Yanair. There is another view, though. Boeing, because of decisions driven by cost, and potential lost profit, cobbled together a Frankenstein of an aircraft. It was so poorly designed that the end result won't fly without a computer program to make extreme flight control inputs to keep it from *increasing AOA too quickly with too little backpressure.* Then they deliberately left that system out of training manuals and system descriptions, to complete the illusion that it was just another 737, hiding it's full effect from the FAA, as well as customers. Then they pressed on, due to the economic pressure from a re-engined Airbus, and promises made to traditional Boeing customers, producing the plane as quickly as possible. When the first one crashed, they covered their a**es by saying that there was a procedure that could have prevented it...even though it didn't really fit the description of "runaway trim". The situation was confusing enough that another crew had the same results. In all, 346 people are dead, and Boeing says, "not our fault." And now, they are coming up with a long promised solution that still appears to allow multiple MCAS applications of AND trim, for as long as the system is somehow reset. We don't know the current conditions of that reset (as the original pilots did not know those conditions in their version of MCAS). Seven months after the second crash, no new MCAS program has been submitted, nor training revealed ... but somehow the pilots, and lack of pilot training, are to blame for the whole thing. More training is a good idea. I am at a loss as to how you train a pilot on a system while revealing as little as possible about it.
*some might call that instability, leading to a stall.
*some might call that instability, leading to a stall.
Last edited by Takwis; 6th Oct 2019 at 00:14.
Takwis
very well said. If you have an engine failure there is not much you can do about the cause and as pilot you have to deal immediately with it. So you have to train for that because it might very well happen in your career.
If a computer program makes life threatening control surface inputs due to some false data, first an automated system should deal with that and check the data and system if that makes sense at all. If the outcome is likely fatal you need a DAL-A system. An airplane is a too complex machine as that you can use the pilots as first line of defense against any problem coming up. If it is life threatening and there is no technical line of defense possible then the pilots have to train for it.
Pilots should be the last line of defense.
There is a myriad of redundancy build in an airplane for exactly that reason. You can not take 100% of the pilots capability only to save some bucks on system design.
If you technical can prevent a fatal outcome, you should do with technology.
very well said. If you have an engine failure there is not much you can do about the cause and as pilot you have to deal immediately with it. So you have to train for that because it might very well happen in your career.
If a computer program makes life threatening control surface inputs due to some false data, first an automated system should deal with that and check the data and system if that makes sense at all. If the outcome is likely fatal you need a DAL-A system. An airplane is a too complex machine as that you can use the pilots as first line of defense against any problem coming up. If it is life threatening and there is no technical line of defense possible then the pilots have to train for it.
Pilots should be the last line of defense.
There is a myriad of redundancy build in an airplane for exactly that reason. You can not take 100% of the pilots capability only to save some bucks on system design.
If you technical can prevent a fatal outcome, you should do with technology.
Didn't the FAA fly it with the latest mods by now? At least in the sim? What was their verdict? It has become so quiet again.
This secrecy and and lack of transparency was probably 99% of Boeing's fall from grace, yet they still insist on it.
Take the gag orders of the recent simulator pilots and explain what you subjected them to, and let them talk about what they thought.
Join Date: Jul 2019
Location: Mass
Posts: 23
Likes: 0
Received 0 Likes
on
0 Posts
I could have a lengthy argument about your statement, but that would take us off topic. Regulators clearly think that pilot workload played a role in the crashes, and the MAX will remain grounded until training issues are dealt with: https://www.reuters.com/article/us-e...-idUSKBN1WJ2IU
And it's far from clear why that would be off topic. The thread has to do with reevaluation of 737 safety procedures and the need for clearer crew alerting has been discussed here extensively.
As for what regulators think, it's far from clear from the Reuters article what regulators think about the role of startle and workload in the accidents. The actual quote was vague, and the rest was the reporter's interpretation. As I said, nobody would argue with the general proposition that lots of lights and alarms can be a distraction. But that doesn't mean fewer lights and alarms would have made any difference in these accidents.
Join Date: Dec 2015
Location: Cape Town, ZA
Age: 62
Posts: 424
Likes: 0
Received 0 Likes
on
0 Posts
There seems to be an assumption in the article and in the comments that a retrofitted EICAS would have been likely to have prevented these two accidents. How realistic is that assumption?
In JT610, the crew knew they had a malfunctioning stab trim system and they figured out they could keep the plane in the air using MET. They were focused on the stab trim problem but they just couldn't figure out that they needed to shut off electric trim. How would EICAS have fixed this? Presumably, it would have focused the crew on the principal problem (malfunctioning AoA) and suppressed some of the cascading warnings (e.g., stick shaker, IAS disagree) but the crew was already focused on solving the problem. Would EICAS have displayed a "Turn off the freakin electric trim" message?
In ET302, the crew knew they had a stab trim malfunction and they shut off electric trim, but didn't relieve control column forces first. They then knew they were out of trim, but were apparently confused about what to do about it. What would EICAS have added? Would it have displayed a "Don't turn the electric trim back on" message? Or maybe a message "If you turn electric trim back on, trim up fast and then turn it off"?
I understand the general assumption that less noise/flashing lights may lead to better decision making, particularly at the very beginning of an incident. But both crews were past that and were controlling the plane (even climbing in the case of ET302), albeit with significant effort. Isn't it hugely speculative to say that EICAS would have made any difference in the outcome?
In JT610, the crew knew they had a malfunctioning stab trim system and they figured out they could keep the plane in the air using MET. They were focused on the stab trim problem but they just couldn't figure out that they needed to shut off electric trim. How would EICAS have fixed this? Presumably, it would have focused the crew on the principal problem (malfunctioning AoA) and suppressed some of the cascading warnings (e.g., stick shaker, IAS disagree) but the crew was already focused on solving the problem. Would EICAS have displayed a "Turn off the freakin electric trim" message?
In ET302, the crew knew they had a stab trim malfunction and they shut off electric trim, but didn't relieve control column forces first. They then knew they were out of trim, but were apparently confused about what to do about it. What would EICAS have added? Would it have displayed a "Don't turn the electric trim back on" message? Or maybe a message "If you turn electric trim back on, trim up fast and then turn it off"?
I understand the general assumption that less noise/flashing lights may lead to better decision making, particularly at the very beginning of an incident. But both crews were past that and were controlling the plane (even climbing in the case of ET302), albeit with significant effort. Isn't it hugely speculative to say that EICAS would have made any difference in the outcome?
If you "could have a lengthy argument about [my] statement", then you could probably also summarize so it would be less lengthy.
And it's far from clear why that would be off topic. The thread has to do with reevaluation of 737 safety procedures and the need for clearer crew alerting has been discussed here extensively.
As for what regulators think, it's far from clear from the Reuters article what regulators think about the role of startle and workload in the accidents. The actual quote was vague, and the rest was the reporter's interpretation. As I said, nobody would argue with the general proposition that lots of lights and alarms can be a distraction. But that doesn't mean fewer lights and alarms would have made any difference in these accidents.
And it's far from clear why that would be off topic. The thread has to do with reevaluation of 737 safety procedures and the need for clearer crew alerting has been discussed here extensively.
As for what regulators think, it's far from clear from the Reuters article what regulators think about the role of startle and workload in the accidents. The actual quote was vague, and the rest was the reporter's interpretation. As I said, nobody would argue with the general proposition that lots of lights and alarms can be a distraction. But that doesn't mean fewer lights and alarms would have made any difference in these accidents.
1. EICAS on its own (on an unaltered airframe) might not make a difference to runaway trim.
2. Implementing EICAS would require detailed fault-tree documentation, which could flag the MCAS dependency on single AOA.
3. Implementing EICAS would offer an opportunity to detect faulty AOA, before passing the data on to MCAS.
4. The manufacturer would be unlikely to implement EICAS, without upgrading a lot of other stuff at the same time.
5. A design philosophy that implemented EICAS, would do a lot of other things better.
6. Adding EICAS would require a separate type rating, and likely better training and documentation.
Edit: HighWind addressed #3.
Grebe and Loose rivets discussed synthesised airspeed, which relates to #4.
IMO there is no way that an aircraft that included EICAS, would have the same MCAS/AOA faults and poor documentation.
IMO regulators are concerned about overall safety, not a recurrence of these specific accidents, which are extremely unlikely.
Last edited by GordonR_Cape; 6th Oct 2019 at 19:00.
Join Date: Sep 2006
Location: Pergatory
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
The Lion Air Crash was what triggered the public awareness, and apparently awareness among those flying the 737MAX, of this MCAS "feature". So it was one crash that happened where there was no knowledge of the existence. That was tragic enough; that the pilots didn't even know what was malfunctioning as they tried for what, six minutes, to get control of their aircraft back.
What is to me the greater tragedy is that the crew (and their passengers) from ET were in a variety of ways set up by the entire global aviation system: manufacturers, operators, regulators. That systemic failure was the failure to provide a clear statement of "if this thing breaks down, this is what it looks like and this is what you do" to that crew.
If the system had done that, they'd most likely have had a tool to (1) recognize and (2) deal with that particular malfunction, one that comes from a spurious AoA indication/signal that then creates a movement of a primary flight control.
In five month's time, "what's it doing and what do I do about it?" had not had an answer spread to the entire Max fleet operators and pilots effectively.
There are multiple links in that chain, and I'll not derail this discussion further.
Back to lurking.
......
If the system had done that, they'd most likely have had a tool to (1) recognize and (2) deal with that particular malfunction, one that comes from a spurious AoA indication/signal that then creates a movement of a primary flight control.
In five month's time, "what's it doing and what do I do about it?" had not had an answer spread to the entire Max fleet operators and pilots effectively.
There are multiple links in that chain, and I'll not derail this discussion further.
.....
If the system had done that, they'd most likely have had a tool to (1) recognize and (2) deal with that particular malfunction, one that comes from a spurious AoA indication/signal that then creates a movement of a primary flight control.
In five month's time, "what's it doing and what do I do about it?" had not had an answer spread to the entire Max fleet operators and pilots effectively.
There are multiple links in that chain, and I'll not derail this discussion further.
.....
In these discussions just after event 3, one contributor wrote that he would include in his TO brief, setting flaps if suspected MCAS rogue operation happened after take off, to kill the operation.
He was blasted from all sides for making up a procedure which was not official or in the books.
MCAS was not in the books either. Neither was a dedicated procedure available - just the stab runaway drill and we know how successful that can prove.
I have to say that if I were to have to fly a Max during that period before the grounding, I would have briefed something similar - with hindsight gained from the slowly emanating facts: If speed anomaly, stick shaker etc (first signs of the AOL problem) occurred on liftoff, to keep flaps extended while trouble shooting the speed indications, then land asap. I presume the AP, which would also kill MCAS ops, might well not engage with disagreements.
Very likely criticism would have come in stereo but we would have lived - and the tea and biscuits would have tasted very good.
That was then. Now is now. What is a few months more or less? We had better get it right.
Join Date: Nov 2007
Location: dublin
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
yanrair, In QF32 they had more than an extra pilot. Given the type of flight and the training happening I expect there was a bit of adrenaline floating around the cockpit the heightened initial reaction. The comment before take-off indicates this, it was never going to be an everyday flight for the PIC or the pilot checking the PIC. They did a great job and were very lucky also.
I simply do not believe the jump seat pilot on the first Lion Air MCAS event flight picked up a "runaway trim" there certainly has not been any evidence of that been made public. What has been reported has been the entry in the Tech Log. This entry was alone the line of "STS running in wrong direction/reverse".
This to me means that all three pilots were not surprised to have the trim activate, in fact they expected it - just it was working opposite to what they expected.
If they thought they had a runway trim would you not expect a Tech Log entry to be something like - Runaway nose down trim (intermittently).
I simply do not believe the jump seat pilot on the first Lion Air MCAS event flight picked up a "runaway trim" there certainly has not been any evidence of that been made public. What has been reported has been the entry in the Tech Log. This entry was alone the line of "STS running in wrong direction/reverse".
This to me means that all three pilots were not surprised to have the trim activate, in fact they expected it - just it was working opposite to what they expected.
If they thought they had a runway trim would you not expect a Tech Log entry to be something like - Runaway nose down trim (intermittently).
https://www.bloomberg.com/news/artic...-later-crashed
This and many other sources at the time reported that the third pilot did indeed save the day. But it doesn't really matter in the sense that the crew 2 - or 3 depending on which you believe did not crash, with the self same fault that resulted in a crash the next day.
At least thats how I read it. What do you think?
Yan
Join Date: Mar 2015
Location: North by Northwest
Posts: 476
Likes: 0
Received 0 Likes
on
0 Posts
Think mod status is not finished, about a dozen "airline pilots" and the new FAA chief have played in the simulator - but very few details have emerged.
This secrecy and and lack of transparency was probably 99% of Boeing's fall from grace, yet they still insist on it.
Take the gag orders of the recent simulator pilots and explain what you subjected them to, and let them talk about what they thought.
This secrecy and and lack of transparency was probably 99% of Boeing's fall from grace, yet they still insist on it.
Take the gag orders of the recent simulator pilots and explain what you subjected them to, and let them talk about what they thought.