Ethiopian airliner down in Africa
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I would say yes. But they have not forgotten, They have just been taught not how to do it on the particular model they are flying. The current generation of "computer pilots" only use the computers as far as they are taught to do so. I had a "guru" come and sort out my communications systems on the ship I was running, and It took him 3 days of "trial and error" to fix the faults in the system... and he was the guy that designed the system..! If Boeing software engineers are going to take 2 months to analyse and then generate a software fix, then how do us mere mortals that actually know how to fly planes get to learn how to disable the system or modify or fix it in flight..? I actually welcomed computers onto my bridge to help us to pilot the ships, but increasingly we are only operators and the computers are controlling us. Increasingly, we are limited as to what kind of access we can get to setup menus and and excluded from interrogating the computers or turning them off, when we sense that something is wrong.
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Ethiopian officials asked the French aviation accident investigation bureau BEA, which downloaded data from the black boxes, to permanently delete that information from its servers once it had been transmitted to Ethiopian authorities. The BEA has confirmed complying with the request.
This may be formally justified by the fact that, unlike the NTSB, BEA is not an official party to the investigation, but it still strikes me as an odd request. BEA have always respected annex 13 protocol, and even a harsh case like the Yemenia crash, where the Comores investigators pondered the flight recorder data endlessly without making any progress, got no more than an angry letter by Jean-Paul Troadec.
Officials in Addis Ababa, for their part, are still smarting from the results of an investigation into the deadly 2010 crash of an Ethiopian Airlines plane shortly after takeoff from Beirut. That probe, led by Lebanese authorities, found that the airline’s pilots failed to respond adequately to stormy weather during the aircraft’s ascent. Ethiopia at the time disagreed with the findings of the investigation, attributing the crash to bad weather.
“With this investigation, we are the ones who are in charge,” the chief of Ethiopia’s civil aviation authority, Col. Wosenyeleh Hunegnaw, said in a March 20 interview.
If Boeing software engineers are going to take 2 months to analyse and then generate a software fix, then how do us mere mortals that actually know how to fly planes get to learn how to disable the system or modify or fix it in flight..
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Nose down trimming of the MCAS several times as I mentioned, which shows they were able to do it. The question is why did they stop. News reports suggest that the Captain was pilot flying at first. After a while he handed control to the first officer who then did not counter the MCAS induced nose down trimming sufficiently ( information cannot be verified though).
If the forces on TRIM are that high that even Boeing mentions one may be forced to do it manually because the TRIM motor ist not powerful enough, why do you assume that it is capable of going back&forth unter max. load all the time?
Would be interesting to know if the flight recorder is recording the manual TRIM command or the actual movement of the motor after overheat etc.
Also, at the end of the recording, it seems to me that the trim position does not longer correlate with the commands, but this is hard to recognize in this one plot.
Is it otherwise possible that the pilot handed control BECAUSE his TRIM commands were no longer compensating MCAS sufficiently?
As far as I understood there are increasing forces with speed which help the motor to trim down as commanded by MCAS but could maybe block/overheat the motor trimming up.
However, being able to maintain a certain pitch attitude and trimming out the forces felt as one is doing that... are you suggesting pilots have even forgotten to do that?
I’m not suggesting that’s what happened here at all, but I am aware that the difference in pilot standards around the world is significant. I’m of the belief that we need to double up on mandated sim time and make the extra all manual flying. Tickets would have to go up about a buck per passenger. So be it.
I know it will never happen but I think it anyway
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I have a feeling Boeing's idea that the pilot has to save the day will fall short of regulators' approval. They can no longer maintain after two accidents (where in the second one the crew almost certainly knew about the first) that any pilot "without exceptional skill" (which is the regulatory requirement, and, if you think about it, is a lot less than "average") will be able to handle it.
Bernd
IMO no amount of software patching can turn a Level C software package into a Level A.
The Level A process is a full life-cycle development process, starting with the top level system requirements down through the coding process and then through the validation and verification processes; a lot of the reviewing and compliance checking has to be carried out “independently”, i.e. not by the supplier. In addition any “safety critical” item of data, such as AoA, has to be at the appropriate level. Typically this means triplex sensors, BUT without Common Mode Failure characteristics. So, another (same technology) vane on the nose would not be suitable.
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Spot on Icarus. You know I am starting to think Boeing and FAA are off the hook with this one. That is assuming something new doesn't turn up. If the thing malfunctions at approach to stall speeds control loads are light and any runaway is a non-event. If it malfunctions at higher speed, accelerating after flaps up for instance, it is a straight forward runaway. In either case, follow the memory items in the QRH. So how did it get away from them? Yes. Well. Pre-employment history. The country regulator. Training and checking systems. After that we may be heading into the murky waters of leadership, culture, etc..
It is going to take a while.
It is going to take a while.
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I know it sounds unlikely but I have seen one pilot so taken aback by the aircraft misbehaving that he was angrily pushing the A/P button hoping it would engage even though the flight path was not where he wanted it to be. ( why not? he’s virtually never flown an aircraft anyway, why start now when things are turning to custard?)
I’m not suggesting that’s what happened here at all, but I am aware that the difference in pilot standards around the world is significant. I’m of the belief that we need to double up on mandated sim time and make the extra all manual flying. Tickets would have to go up about a buck per passenger. So be it.
I know it will never happen but I think it anyway
At time 00:39:40 the captain was heard saying in Amharic “OK, engage autopilot”. However, the DFDR data does not show any engagement of any auto-pilot throughout the flight. At the time of the call the DFDR shows the control wheel was Aft from the neutral position and the aircraft roll angle reaching 64° left bank
That is an excerpt from the final report of Ethiopian flight 409 in 2010 in which the Captain attempted to engage the autopilot when it was at a 64° left bank.
I agree with you that there should be a much greater emphasis on manual flying. At my company manual raw data flying is allowed at any time and I believe on a clear day, with little traffic, at a familiar airport, it adds greatly to a pilot's confidence and skill set to regularly fly manually (this subject has been discussed endlessly at pprune already though). Practicing in the simulator will work as well of course.
Overall you may be right, that among other reasons the actions of the Lion Air crew could be explained by a lack of manual flying skills, which has to be countered by more training in this regard.
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I absolutely agree. The aviation authorities have the hardest of evidence possible that “average” pilots are unlikely to cope. Boeing’s dilemma is this then means the MCAS system (at least) has to be considered as a “catastrophic” safety critical system. The MCAS software then has to be “Level A” according to DO-178C.
IMO no amount of software patching can turn a Level C software package into a Level A.
The Level A process is a full life-cycle development process, starting with the top level system requirements down through the coding process and then through the validation and verification processes; a lot of the reviewing and compliance checking has to be carried out “independently”, i.e. not by the supplier. In addition any “safety critical” item of data, such as AoA, has to be at the appropriate level. Typically this means triplex sensors, BUT without Common Mode Failure characteristics. So, another (same technology) vane on the nose would not be suitable.
IMO no amount of software patching can turn a Level C software package into a Level A.
The Level A process is a full life-cycle development process, starting with the top level system requirements down through the coding process and then through the validation and verification processes; a lot of the reviewing and compliance checking has to be carried out “independently”, i.e. not by the supplier. In addition any “safety critical” item of data, such as AoA, has to be at the appropriate level. Typically this means triplex sensors, BUT without Common Mode Failure characteristics. So, another (same technology) vane on the nose would not be suitable.
As soon as pilots start to say 'we cannot cope in manual flight; we cannot switch off systems that are in error - even though the switches have been there for decades as have the NNC for the failure and we were specifically told of the issues..... THEN money will be spent on automation that does not hand back to a pilot but manages itself even in cases of unknown error. There will then be no pilot shortage as the automation will have taken over entirely and automation doesn't need a pension or a union and doesn't care about hours worked.
Icarus2001, #2923; ( jafa, #2926)
From your ‘immortal’ view, have you considered the difficulty in identifying a trim malfunction, particularly with a mindset of unreliable airspeed since takeoff. Add to which an immensely annoying - distracting stick shake. See many other posts, and reports from some who have evaluated this in the simulator.
Also, with the strength of wax wings, what magnitude of force can be pulled, both hands, both pilots; and for how long. MCAS training should have involved some visits to the gym.
I don’t have the stick force gradients immediately to ‘hand’, but with trim offset they can be large, and further increase with airspeed increase due to the marginally - uncontrollable nose down trim situation.
Who is going to release the stick - allowing more nose down input, to inhibit the trim, which might not be at the forefront of thought.
A third person on the flight deck; another mod option for Boeing.
From your ‘immortal’ view, have you considered the difficulty in identifying a trim malfunction, particularly with a mindset of unreliable airspeed since takeoff. Add to which an immensely annoying - distracting stick shake. See many other posts, and reports from some who have evaluated this in the simulator.
Also, with the strength of wax wings, what magnitude of force can be pulled, both hands, both pilots; and for how long. MCAS training should have involved some visits to the gym.
I don’t have the stick force gradients immediately to ‘hand’, but with trim offset they can be large, and further increase with airspeed increase due to the marginally - uncontrollable nose down trim situation.
Who is going to release the stick - allowing more nose down input, to inhibit the trim, which might not be at the forefront of thought.
A third person on the flight deck; another mod option for Boeing.
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I am actually not surprised by that story. In fact, I know of at least one accident where the same thing happened:
At time 00:39:40 the captain was heard saying in Amharic “OK, engage autopilot”. However, the DFDR data does not show any engagement of any auto-pilot throughout the flight. At the time of the call the DFDR shows the control wheel was Aft from the neutral position and the aircraft roll angle reaching 64° left bank
That is an excerpt from the final report of Ethiopian flight 409 in 2010 in which the Captain attempted to engage the autopilot when it was at a 64° left bank.
I agree with you that there should be a much greater emphasis on manual flying. At my company manual raw data flying is allowed at any time and I believe on a clear day, with little traffic, at a familiar airport, it adds greatly to a pilot's confidence and skill set to regularly fly manually (this subject has been discussed endlessly at pprune already though). Practicing in the simulator will work as well of course.
Overall you may be right, that among other reasons the actions of the Lion Air crew could be explained by a lack of manual flying skills, which has to be countered by more training in this regard.
At time 00:39:40 the captain was heard saying in Amharic “OK, engage autopilot”. However, the DFDR data does not show any engagement of any auto-pilot throughout the flight. At the time of the call the DFDR shows the control wheel was Aft from the neutral position and the aircraft roll angle reaching 64° left bank
That is an excerpt from the final report of Ethiopian flight 409 in 2010 in which the Captain attempted to engage the autopilot when it was at a 64° left bank.
I agree with you that there should be a much greater emphasis on manual flying. At my company manual raw data flying is allowed at any time and I believe on a clear day, with little traffic, at a familiar airport, it adds greatly to a pilot's confidence and skill set to regularly fly manually (this subject has been discussed endlessly at pprune already though). Practicing in the simulator will work as well of course.
Overall you may be right, that among other reasons the actions of the Lion Air crew could be explained by a lack of manual flying skills, which has to be countered by more training in this regard.
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Boeing, FAA say more time needed for fix of troubled 737 Max
Boeing and U.S. aviation regulators say the company needs more time to finish changes in a flight-control system suspected of playing a role in two deadly crashes.The Federal Aviation Administration said Monday it anticipates Boeing’s final software improvements for 737 Max airliners “in the coming weeks.”
Boeing was expected to complete the work last week, but FAA spokesman Greg Martin said the company needs more time to make sure it has identified and addressed all issues.
Chicago-based Boeing offered the same timetable as it works to convince regulators that it can fix software on the planes.
“Safety is our first priority, and we will take a thorough and methodical approach to the development and testing of the update to ensure we take the time to get it right,” said Boeing spokesman Charles Bickers.
Boeing needs approval not just from FAA, but elsewhere, including Europe and China, where safety officials have indicated they will conduct their own reviews.
The planes have been grounded around the world since mid-March...
- https://www.bostonherald.com/2019/04...-coming-weeks/
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Icarus, did you miss the lesson on Safety Management or were you too busy polishing your Ray-Bans?
I'll try and keep this simple. $120m aircraft has a single point of failure (AOA vane) that will subsequently cause HAL to become suicidal. The ONLY layer of safety in place now is Biggles and Biggles Minor who are expected to treat that failure with the flick of a switch. At this point any sensible person in our industry will already be sucking their teeth at the risks and lack of inherent safety protections. But this one gets better because Biggles didn't even know about the existence of this failure mode or how to resolve it (flick the switch). Nothing in his QRH/AFM, no training, nyada. For sure, there's something called a trim runaway but he's not sure this is a runaway because it's stopping.......... thump.
Perhaps Biggles could have done better. I'm pretty sure Boeing could have done far better.
Last edited by Cows getting bigger; 2nd Apr 2019 at 14:30.
Question
Has anyone knowledge of stab motor overheat scenarios or motor specs on the Max?
If the stab trim is trimmed continuously - down, then up, then down - etc. for minutes on end, is it possible that the motors can eventually overheat and quit?
If so, and the trim is at AND limit that could change a cockpit scenario from manageable to marginal.
This could and did happen for instance on the MD-80
If the stab trim is trimmed continuously - down, then up, then down - etc. for minutes on end, is it possible that the motors can eventually overheat and quit?
If so, and the trim is at AND limit that could change a cockpit scenario from manageable to marginal.
This could and did happen for instance on the MD-80
Last edited by bill fly; 2nd Apr 2019 at 14:49. Reason: Additional Info
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all automation systems currently have a predicate that in the 'otherwise case' or if things get difficult, the automation can drop out and give the aircraft to the pilot.
As soon as pilots start to say 'we cannot cope in manual flight; we cannot switch off systems that are in error - even though the switches have been there for decades as have the NNC for the failure and we were specifically told of the issues..... THEN money will be spent on automation that does not hand back to a pilot but manages itself even in cases of unknown error.
As soon as pilots start to say 'we cannot cope in manual flight; we cannot switch off systems that are in error - even though the switches have been there for decades as have the NNC for the failure and we were specifically told of the issues..... THEN money will be spent on automation that does not hand back to a pilot but manages itself even in cases of unknown error.
I think pilots will always be needed, real AI is still many decades away. And pilots should have the option to turn a system off, BUT the aircraft safety case (with Human Factor considerations) must show in detail how they will then cope. Perhaps, extra, specific to emergency, information needs to appear to assist them, also what warnings/alarms will be muted – who needs an 11 minute stick shaker!!
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A little excerpt from NY Times:
..
April 2 2019
When a new Boeing 737 Max 8 plunged into the waters off Indonesia last October, a terrifying mystery confronted the aviation industry: What could have caused Lion Air Flight 610, flown by experienced pilots in good weather, to fall out of the sky just 12 minutes after takeoff?
But it took the second, equally terrifying crash of an identical aircraft under similar conditions five months later, in Ethiopia, to reveal the climate of mistrust that has plagued inquiries into what caused the first disaster....
...In November, Haryo Satmiko, the deputy chief of Indonesia's National Transportation Safety Committee, known as KNKT, recounted confusing conversations he was having with Boeing employees who had arrived in Jakarta. Mr. Haryo said he brought up whether inaccurate data readings could have prompted Flight 610's sudden descent.
What Mr. Haryo was describing, though he did not know it at the time, was a malfunction of MCAS, which automatically forces the plane's nose down if data indicates that the jet is angled too sharply upward and might stall.
Nurcahyo Utomo, the head of the safety group's air-accident subcommittee, said he first learned of the term MCAS from news reports....
...Days after Flight 610 crashed, Polana Pramesti, the head of Indonesia's civil aviation authority, waited for visiting Boeing and F.A.A. officials to talk to her. As head of Indonesia's version of the F.A.A., she wanted advice on whether to ground Max 8 jets in Indonesia. But the Americans, who did spend time with transportation safety committee officials, never came to her, she said.
The official in her office in charge of airworthiness and aircraft operation, Avirianto, who like many Indonesians goes by one name, fired off messages to the F.A.A. asking for an explanation of MCAS, which at the time was only vaguely understood, even by aviation experts, because Boeing had failed to put information about it in the plane's manual.
Although he conducted four teleconferences with F.A.A. officials, Mr. Avirianto said he was never given a clear explanation of how MCAS worked or whether it was safe. "They kept saying they were still analyzing, evaluating," he said. "We never received any guidance because there were never any clear answers for us.",,,
...Ms. Polana also sent a letter to Boeing in November, asking for guarantees about the Max. But Boeing was not forthcoming, either, she said. "Of course, we were worried," Ms. Polana said. "We wanted reassurance that the Boeing 737 Max 8s in Indonesia are airworthy."
Boeing and the F.A.A. have come under scrutiny since the Lion Air crash. The United States Department of Transportation is examining the F.A.A.'s certification of the Max model, amid revelations that Boeing employees may have facilitated that process.
Only after the Ethiopian Airlines crash, Ms. Polana said, did the F.A.A. and Boeing become more responsive. On March 22, she had her inaugural teleconference with F.A.A. officials -- the first time Indonesian officials received a precise explanation of how MCAS worked and how Boeing was planning to fix it, they said...
...After the crash, the replaced angle of attack sensor was shipped to Minnesota, home of Rosemount Aerospace, the Boeing subcontractor that made it, Mr. Nurcahyo said. He and other Indonesian investigators went to Minneapolis in December. The sensor, he said, was deemed defective...
...For Lion Air Flight 610, even after the vane was changed, the Max 8 continued to malfunction, producing an array of errant data. Some aviation experts believe the variety of airspeed problems points not to a defective sensor but a more fundamental problem with the processor that collects the data displayed in the cockpit.
"I don't think it's a vane failure. It makes no sense," said Bjorn Fehrm, an aeronautical engineer. "It's more like a computer failure or a component failure, a system failure."
The air data inertial reference unit is the processor that helps collect data from the probes and vanes on the plane. A malfunction in that system could be consistent with data inaccuracies that triggered MCAS, aviation experts said.
Mr. Nurcahyo acknowledged that Indonesian investigators were looking into the possibility of an issue with the air data inertial reference unit...
Source:
- https://www.nytimes.com/2019/04/02/w...-lion-air.html
..
Between Two Boeing Crashes, Days of Silence and Mistrust
..April 2 2019
When a new Boeing 737 Max 8 plunged into the waters off Indonesia last October, a terrifying mystery confronted the aviation industry: What could have caused Lion Air Flight 610, flown by experienced pilots in good weather, to fall out of the sky just 12 minutes after takeoff?
But it took the second, equally terrifying crash of an identical aircraft under similar conditions five months later, in Ethiopia, to reveal the climate of mistrust that has plagued inquiries into what caused the first disaster....
...In November, Haryo Satmiko, the deputy chief of Indonesia's National Transportation Safety Committee, known as KNKT, recounted confusing conversations he was having with Boeing employees who had arrived in Jakarta. Mr. Haryo said he brought up whether inaccurate data readings could have prompted Flight 610's sudden descent.
What Mr. Haryo was describing, though he did not know it at the time, was a malfunction of MCAS, which automatically forces the plane's nose down if data indicates that the jet is angled too sharply upward and might stall.
Nurcahyo Utomo, the head of the safety group's air-accident subcommittee, said he first learned of the term MCAS from news reports....
...Days after Flight 610 crashed, Polana Pramesti, the head of Indonesia's civil aviation authority, waited for visiting Boeing and F.A.A. officials to talk to her. As head of Indonesia's version of the F.A.A., she wanted advice on whether to ground Max 8 jets in Indonesia. But the Americans, who did spend time with transportation safety committee officials, never came to her, she said.
The official in her office in charge of airworthiness and aircraft operation, Avirianto, who like many Indonesians goes by one name, fired off messages to the F.A.A. asking for an explanation of MCAS, which at the time was only vaguely understood, even by aviation experts, because Boeing had failed to put information about it in the plane's manual.
Although he conducted four teleconferences with F.A.A. officials, Mr. Avirianto said he was never given a clear explanation of how MCAS worked or whether it was safe. "They kept saying they were still analyzing, evaluating," he said. "We never received any guidance because there were never any clear answers for us.",,,
...Ms. Polana also sent a letter to Boeing in November, asking for guarantees about the Max. But Boeing was not forthcoming, either, she said. "Of course, we were worried," Ms. Polana said. "We wanted reassurance that the Boeing 737 Max 8s in Indonesia are airworthy."
Boeing and the F.A.A. have come under scrutiny since the Lion Air crash. The United States Department of Transportation is examining the F.A.A.'s certification of the Max model, amid revelations that Boeing employees may have facilitated that process.
Only after the Ethiopian Airlines crash, Ms. Polana said, did the F.A.A. and Boeing become more responsive. On March 22, she had her inaugural teleconference with F.A.A. officials -- the first time Indonesian officials received a precise explanation of how MCAS worked and how Boeing was planning to fix it, they said...
...After the crash, the replaced angle of attack sensor was shipped to Minnesota, home of Rosemount Aerospace, the Boeing subcontractor that made it, Mr. Nurcahyo said. He and other Indonesian investigators went to Minneapolis in December. The sensor, he said, was deemed defective...
...For Lion Air Flight 610, even after the vane was changed, the Max 8 continued to malfunction, producing an array of errant data. Some aviation experts believe the variety of airspeed problems points not to a defective sensor but a more fundamental problem with the processor that collects the data displayed in the cockpit.
"I don't think it's a vane failure. It makes no sense," said Bjorn Fehrm, an aeronautical engineer. "It's more like a computer failure or a component failure, a system failure."
The air data inertial reference unit is the processor that helps collect data from the probes and vanes on the plane. A malfunction in that system could be consistent with data inaccuracies that triggered MCAS, aviation experts said.
Mr. Nurcahyo acknowledged that Indonesian investigators were looking into the possibility of an issue with the air data inertial reference unit...
Source:
- https://www.nytimes.com/2019/04/02/w...-lion-air.html
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Icarus, did you miss the lesson on Safety Management or were you too busy polishing your Ray-Bans?
I'll try and keep this simple. $120m aircraft has a single point of failure (AOA vane) that will subsequently cause HAL to become suicidal. The ONLY layer of safety in place now is Biggles and Biggles Minor who are expected to treat that failure with the flick of a switch. At this point any sensible person in our industry will already be sucking their teeth at the risks and lack of inherent safety protections. But this one gets better because Biggles didn't even know about the existence of this failure mode or how to resolve it (flick the switch). Nothing in his QRH/AFM, no training, nyada. For sure, there's something called a trim runaway but he's not sure this is a runaway because it's stopping.......... thump.
Perhaps Biggles could have done better. I'm pretty sure Boeing could have done far better.
I'll try and keep this simple. $120m aircraft has a single point of failure (AOA vane) that will subsequently cause HAL to become suicidal. The ONLY layer of safety in place now is Biggles and Biggles Minor who are expected to treat that failure with the flick of a switch. At this point any sensible person in our industry will already be sucking their teeth at the risks and lack of inherent safety protections. But this one gets better because Biggles didn't even know about the existence of this failure mode or how to resolve it (flick the switch). Nothing in his QRH/AFM, no training, nyada. For sure, there's something called a trim runaway but he's not sure this is a runaway because it's stopping.......... thump.
Perhaps Biggles could have done better. I'm pretty sure Boeing could have done far better.