Byron Bailey, The Australian, MCAS
GG and LS you are talking about an analogue only aircraft. I have flown a 737 in full manual reversion and it was a non-event. What you are not considering is that MCAS is a digital system that applies a control input independent of the pilots. Pilots who were not told about the existence of the system or the full failure modes of it. To just dump it on the crew does not explain why the thing has been grounded and even then they have found other issues with MCAS. LS Airbus have included the" fly the aircraft" in their Golden Rules since they introduced FBW so the A350 is nothing special in that regard. Interestingly the A330 was not grounded after a legacy carrier crew put one into a stall and killed all on board and the A320 was not grounded after the Air Asia fatal accident off Surabaya. So there must be a lot more going on than you are willing to acknowledge. Boeing through their shortcuts and corporate greed have presented a product to market that has killed over 300 people. Therein lies the issue.
Just a couple of points:
(1) If you place the stab trim cutout switches to OFF, you have full manual control, leaving you without any complicating input ---- nothing to do with analogue v. digital.
(2) Go read what Airbus, themselves, had/has to say about the redesigned syllabus introduced with the A350, it aint't the same as "years ago" --- and all as a result of the demonstrated fall in manual flying standards --- for which Airbus has a major responsibility.
Tootle pip!!
PS: High hours does not equal high competence, any more than low hours means the reverse ---- as I have found out over a career.
(1) If you place the stab trim cutout switches to OFF, you have full manual control, leaving you without any complicating input ---- nothing to do with analogue v. digital.
This is even recognised by Airbus in the A350 syllabus, which starts in the sim phase with just "flying the aeroplane".
High hours does not equal high competence, any more than low hours means the reverse ---- as I have found out over a career.
BTW I am enjoying the shellacking your claims and statements are getting on the other thread, especially your doubts about Sulley's understanding of the 737 systems.
My inexpert reading of all of the currently-available evidence leads me to conclude that systems design was a causally relevant factor in a couple of accidents that have resulted in Max 8 hull loss and consequential loss of life. But I’m a nobody amateur.
Given my amateur understanding, it saddens me that some would try to attribute blame to the pilots. So many accidents and their investigated outcomes tend not to support a ‘blame the pilot’ approach. This was a lesson that was supposed to have been learned a long time ago.
Given my amateur understanding, it saddens me that some would try to attribute blame to the pilots. So many accidents and their investigated outcomes tend not to support a ‘blame the pilot’ approach. This was a lesson that was supposed to have been learned a long time ago.
(1) If you place the stab trim cutout switches to OFF, you have full manual control, leaving you without any complicating input ---- nothing to do with analogue v. digital.
then you don't understand MCAS
Do you know something that is not publically available? The official line is by moving the stab trim cut off to off will stop the trim wheel from moving electrically.
That is public and well known - just not in the required documents or simulated correctly in the simulators!!! FACT
It is critical to cut the stab trim cut offs - but more critical that it is in a correct part of available use of what is left to control the aircraft.
Clearly, I am not afraid to NOT go along with the majority opinion
If your statement above is the case, every civil jet aircraft Boeing has ever built is fatally flawed; Why would I say that ---- because the MCAS system is a stability aid, these in one form or another, have been on every aircraft since the B707. Yaw dampers are another example of a stability aid --- in early days pilots in bulk did not trust yaw dampers --- unless they could disconnect them, like early B707.
As a relevant example, the B707 had a auto mach trim to counter mach tuck, and it was a continuous source of niggles, and, Murphy's law being what it is, a mach trim runaway was almost always nose down.. It was distinguished from a main electric stab runaway by the speed of movement ---- quite slow, like the MCAS. Lightning reflexes, no, but don't muck around, either.
The fact remains, as was demonstrated by Lion Air Bali to Djakarta, an MCAS malfunction in the hands of an adequately trained crew (actioning the un-commanded stab trim checklist --- whatever its current B737 QRH name) does not/should not result in the loss of the aircraft.
By the Sullenberger yardstick, the Vickers VC-10 should never have been certified --- if you know something about its natural aerodynamic characteristics. Likewise probably the MD-11.
Tootle pip!!
PS: Lookleft, please let us know what experience/knowledge. you have on relevant aircraft.
PS: Lookleft, please let us know what experience/knowledge. you have on relevant aircraft.
I have flown a 737 in full manual reversion and it was a non-even
Dora-9 it was a post maintenance flight and yes we were flying without the benefit of hydraulics to the controls. In no way am I claiming to be an ace but LS certainly is as he has had to turn stab trim switches off therefore his knowledge of the 737 (and Airbus apparently) is absolute although he has never flown either and he still does not understand what MCAS does. He also doesn't seem to understand the difference between aerodynamic difficulties worked through on prototypes and pre-production aircraft that are subsequently certified and documented by the authorities and the MCAS system that was installed on an existing design with minimal oversight and deliberate obfuscation by Boeing. Boeing even went so far as to make a warning light that told the crew MCAS was operating an optional extra! I'm sure Sully is keen to chat to LS so that he can glean some crumbs of aviation knowledge that might fall from LS rather bloated table.
there have been several incidences of MCAS activation
The pilots couldn't be expected to report on the activation of something that they didn't know was installed in the first place. Flight data monitoring may have picked it up similar to how it would record an unstable approach or a limit being exceeded.
Did he mean to say that there had been previous incidents where the MCAS had malfunctioned in a similar way to the two disasters but the pilots had managed to prevent an accident ?
Lookleft,If your statement above is the case, every civil jet aircraft Boeing has ever built is fatally flawed; Why would I say that ---- because the MCAS system is a stability aid, these in one form or another, have been on every aircraft since the B707. Yaw dampers are another example of a stability aid --- in early days pilots in bulk did not trust yaw dampers --- unless they could disconnect them, like early B707.
False equivalence. Did any of these preceding Boeing aircraft suffer a series of fatal accidents in a very short space of time due to the failure of these 'stability aids'? Stability aids is a broad term that does not make the various forms contained within that umbrella equitable.
The fact remains, as was demonstrated by Lion Air Bali to Djakarta, an MCAS malfunction in the hands of an adequately trained crew (actioning the un-commanded stab trim checklist --- whatever its current B737 QRH name) does not/should not result in the loss of the aircraft.
"Does not?" I know of 346 people who would probably disagree with that statement if they were able. Regulators worldwide also appear to share this view, which is why the max is currently located in the only safe operating environment that exists for it.
By the Sullenberger yardstick, the Vickers VC-10 should never have been certified --- if you know something about its natural aerodynamic characteristics. Likewise probably the MD-11.
So because aircraft with potentially fatal handling characteristics were certified 50 years ago or more, then we should simply accept this in the modern era and sign off on the same now? Do you not remember that after a series of identical accidents during landing that the software for the flight control system was modified by Boeing? I thought we were trying to improve air safety over time, not use the template of past failure to ensure we repeat it.
False equivalence. Did any of these preceding Boeing aircraft suffer a series of fatal accidents in a very short space of time due to the failure of these 'stability aids'? Stability aids is a broad term that does not make the various forms contained within that umbrella equitable.
The fact remains, as was demonstrated by Lion Air Bali to Djakarta, an MCAS malfunction in the hands of an adequately trained crew (actioning the un-commanded stab trim checklist --- whatever its current B737 QRH name) does not/should not result in the loss of the aircraft.
"Does not?" I know of 346 people who would probably disagree with that statement if they were able. Regulators worldwide also appear to share this view, which is why the max is currently located in the only safe operating environment that exists for it.
By the Sullenberger yardstick, the Vickers VC-10 should never have been certified --- if you know something about its natural aerodynamic characteristics. Likewise probably the MD-11.
So because aircraft with potentially fatal handling characteristics were certified 50 years ago or more, then we should simply accept this in the modern era and sign off on the same now? Do you not remember that after a series of identical accidents during landing that the software for the flight control system was modified by Boeing? I thought we were trying to improve air safety over time, not use the template of past failure to ensure we repeat it.
These crew did not suffer a simple MCAS failure in isolation. They had to deal with all manner of unreliable speed indications, a non stop stick shaker and the fact MCAS is masked within these failures, and does not behave like a 'vanilla' stab trim runaway. Not to mention of course they were never told about MCAS, trained on its failure modes or had an opportunity to witness this failure, one that was clearly inevitable given the stupidity of Boeing's design to include a single data input. Further, given the speed at which it operates (with everything else going on), you can disconnect the trim switches and no longer have that spurious input, yet in a very short space of time it wont make a difference as the forces required to rectify the out of trim situation are too significant to overcome anyway, as the Ethiopian crew found out.
Boeing needs to build a plane that can be safely operated by all crew, not just the Ace of the Base such as yourself.
Dora-9 it was a post maintenance flight and yes we were flying without the benefit of hydraulics to the controls. In no way am I claiming to be an ace but LS certainly is as he has had to turn stab trim switches off therefore his knowledge of the 737 (and Airbus apparently) is absolute although he has never flown either and he still does not understand what MCAS does. He also doesn't seem to understand the difference between aerodynamic difficulties worked through on prototypes and pre-production aircraft that are subsequently certified and documented by the authorities and the MCAS system that was installed on an existing design with minimal oversight and deliberate obfuscation by Boeing. Boeing even went so far as to make a warning light that told the crew MCAS was operating an optional extra! I'm sure Sully is keen to chat to LS so that he can glean some crumbs of aviation knowledge that might fall from LS rather bloated table.
With your superior knowledge of the B737 ( as opposed to other Boeing aircraft) could you please explain to me how the MCAS keeps the stab running, if the two stab trim cutout switches have cut all power to the stab motors --- you have me really intrigued.
It is true I have never been endorsed on the B737, but I have a representative sample of Boeing products, and the basic design philosophy of the stab trim system has a family history dating back to the B-47.. I have also spent some years involved in technical development of Level D/D+ simulators, but that was all B737NG, not Max, so I am not unfamiliar with the B737 in general.
As for Captain Sullenberger, he did a magnificent job in ditching in the Hudson, placed in a near impossible situation, but nobody is perfect, he and his mate missed the ditching switch (whatever Airbus call it) , but that great effort and outcome does not make him an instant expert on all things aviation. Although the demands of the speaker circuit push him that way. It certainly does not make him an expert on certification of Boeing aircraft.
Hindsight is a wonderful thing, but having had a bit of experience internally with Boeing airworthiness people, I am certain they thought the way the aerodynamic characteristic that MCAs was directed at solving was a reasonable engineering solution at the time.
Tootle pip!!
PS:1 "----- LS certainly is as he has had to turn stab trim switches off therefor ------" You really are a twit --- are you suggesting that a normal response to a Non-Normal procedure is somehow to be criticised, because it hasn't happened to you. Given you aeronautical wisdom, suggest what we should have done, to avoid being classified as aces --- which traditionally means 5 or more combat victories. Perhaps you see dueling opinions on Pprune as some sort of moral (as opposed to mortal) combat.
PS2: If the B707 was to be certified today, it would need something like the MCAS, to prevent the pitch UP in the stall on Flap 50. "Back in the day", we coped.
The MCAS is supposed to activate and lower the nose if the pitch becomes excessive, it's hardly headline news when a system like this does what it's supposed to do. If the stall warning activates then it's notifiable and an investigation will be undertaken to determine how the aircraft got onto that situation in the first place.
The pilots couldn't be expected to report on the activation of something that they didn't know was installed in the first place. Flight data monitoring may have picked it up similar to how it would record an unstable approach or a limit being exceeded.
Did he mean to say that there had been previous incidents where the MCAS had malfunctioned in a similar way to the two disasters but the pilots had managed to prevent an accident ?
The pilots couldn't be expected to report on the activation of something that they didn't know was installed in the first place. Flight data monitoring may have picked it up similar to how it would record an unstable approach or a limit being exceeded.
Did he mean to say that there had been previous incidents where the MCAS had malfunctioned in a similar way to the two disasters but the pilots had managed to prevent an accident ?
You have got it right.
The reports in AW&ST (in the bodies of technical articles, not headline news) were in the context of occurrences that were logged for maintenance to look at, but were only realised to be possibly MCAS related in retrospect.
They have come to light during the MAX investigation.
Tootle pip!!
Last edited by LeadSled; 19th Oct 2019 at 04:13. Reason: minor edit
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as a relevant example, the b707 had a auto mach trim to counter mach tuck, and it was a continuous source of niggles, and, murphy's law being what it is, a mach trim runaway was almost always nose down.. it was distinguished from a main electric stab runaway by the speed of movement ---- quite slow, like the mcas.
Ahhhh the Sully factor... Remember the experts recreating the scenario and making it to the airport... until what the fark factor introduced.
No matter what anyone says on here, there but for the grace of god. I would hate to be in the position of the fatal Max crews. The airplane trying to kill you, screaming at you, shaking at you, no matter what you do it may fix for a second then all hell breaks loose again.
I am now trying to find the actual piece on the Boeing test flight where the test pilots knowing what was to come took 8000’ to get out of Max ****e!!!
Oh never flown a Boeing.
Ps As I’ve stated many times, how many times has anyone here done ****e in the sim due to over zealous instructors putting in un flyable scenarios??? If it ain’t gunna fly it ain’t gunna fly!
No matter what anyone says on here, there but for the grace of god. I would hate to be in the position of the fatal Max crews. The airplane trying to kill you, screaming at you, shaking at you, no matter what you do it may fix for a second then all hell breaks loose again.
I am now trying to find the actual piece on the Boeing test flight where the test pilots knowing what was to come took 8000’ to get out of Max ****e!!!
Oh never flown a Boeing.
Ps As I’ve stated many times, how many times has anyone here done ****e in the sim due to over zealous instructors putting in un flyable scenarios??? If it ain’t gunna fly it ain’t gunna fly!
krismiler,
You have got it right.
The reports in AW&ST (in the bodies of technical articles, not headline news) were in the context of occurrences that were logged for maintenance to look at, but were only realised to be MCAS related in retrospect.
They have come to light during the MAX investigation.
You have got it right.
The reports in AW&ST (in the bodies of technical articles, not headline news) were in the context of occurrences that were logged for maintenance to look at, but were only realised to be MCAS related in retrospect.
They have come to light during the MAX investigation.
Whilst I don'r have the quotes to hand, several articles in Aviation Week and Space Technology, which have been exhaustively covering the issue, have mentioned same. They never received any publicity at the time, because the crews involved just ran the uncommended stab trim checklist, as did the lost Indonesian aeroplane's crew the night before, Bali to Djakarta.
Did he mean to say that there had been previous incidents where the MCAS had malfunctioned in a similar way to the two disasters but the pilots had managed to prevent an accident ?
737 MAX - MCAS
N4790P
Lookleft,
With your superior knowledge of the B737 ( as opposed to other Boeing aircraft) could you please explain to me how the MCAS keeps the stab running, if the two stab trim cutout switches have cut all power to the stab motors --- you have me really intrigued.
It is true I have never been endorsed on the B737, but I have a representative sample of Boeing products, and the basic design philosophy of the stab trim system has a family history dating back to the B-47.. I have also spent some years involved in technical development of Level D/D+ simulators, but that was all B737NG, not Max, so I am not unfamiliar with the B737 in general.
As for Captain Sullenberger, he did a magnificent job in ditching in the Hudson, placed in a near impossible situation, but nobody is perfect, he and his mate missed the ditching switch (whatever Airbus call it) , but that great effort and outcome does not make him an instant expert on all things aviation. Although the demands of the speaker circuit push him that way. It certainly does not make him an expert on certification of Boeing aircraft.
Hindsight is a wonderful thing, but having had a bit of experience internally with Boeing airworthiness people, I am certain they thought the way the aerodynamic characteristic that MCAs was directed at solving was a reasonable engineering solution at the time.
Tootle pip!!
PS:1 "----- LS certainly is as he has had to turn stab trim switches off therefor ------" You really are a twit --- are you suggesting that a normal response to a Non-Normal procedure is somehow to be criticised, because it hasn't happened to you. Given you aeronautical wisdom, suggest what we should have done, to avoid being classified as aces --- which traditionally means 5 or more combat victories. Perhaps you see dueling opinions on Pprune as some sort of moral (as opposed to mortal) combat.
PS2: If the B707 was to be certified today, it would need something like the MCAS, to prevent the pitch UP in the stall on Flap 50. "Back in the day", we coped.
With your superior knowledge of the B737 ( as opposed to other Boeing aircraft) could you please explain to me how the MCAS keeps the stab running, if the two stab trim cutout switches have cut all power to the stab motors --- you have me really intrigued.
It is true I have never been endorsed on the B737, but I have a representative sample of Boeing products, and the basic design philosophy of the stab trim system has a family history dating back to the B-47.. I have also spent some years involved in technical development of Level D/D+ simulators, but that was all B737NG, not Max, so I am not unfamiliar with the B737 in general.
As for Captain Sullenberger, he did a magnificent job in ditching in the Hudson, placed in a near impossible situation, but nobody is perfect, he and his mate missed the ditching switch (whatever Airbus call it) , but that great effort and outcome does not make him an instant expert on all things aviation. Although the demands of the speaker circuit push him that way. It certainly does not make him an expert on certification of Boeing aircraft.
Hindsight is a wonderful thing, but having had a bit of experience internally with Boeing airworthiness people, I am certain they thought the way the aerodynamic characteristic that MCAs was directed at solving was a reasonable engineering solution at the time.
Tootle pip!!
PS:1 "----- LS certainly is as he has had to turn stab trim switches off therefor ------" You really are a twit --- are you suggesting that a normal response to a Non-Normal procedure is somehow to be criticised, because it hasn't happened to you. Given you aeronautical wisdom, suggest what we should have done, to avoid being classified as aces --- which traditionally means 5 or more combat victories. Perhaps you see dueling opinions on Pprune as some sort of moral (as opposed to mortal) combat.
PS2: If the B707 was to be certified today, it would need something like the MCAS, to prevent the pitch UP in the stall on Flap 50. "Back in the day", we coped.
Pardon my ignorance. What is a B737NG D+ simulator?
Thanks
How is it that every single thread in the Australian forums ends up in a slanging match from the same usual suspects.
