Ethiopian airliner down in Africa
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.... and now, because this is a pilots forum, the subject of Airspeed. Although a lot was going on, it seems to me, sitting on my couch, that if A/S was controlled, the misbehaviour of the trim would have been easier to deal with at a lower A/S.
The previous LionAir flights controlled A/S (obviously). When we “hand fly” (flight directors and auto throttle on) it’s analogous to me on my couch. Fly toward the FD. Hell, I even have a Heads Up display. If you want to see the other guys squirm, turn off the AT
Much of this so-called “hand flying” isn’t really. I think it would be very human to miss the AS during an event such as this. I think pulling the throttles back once unreliable AS was identified would be key to gaining some time to think. Hand flying with AT on isn’t doing much good and has made me less aware of flying using the throttles.
I also believe the MCAS was not adjusting its trim input for AS. From what I’ve read in the discription of MCAS, it shouldn’t have been using 2.5 degree ANU at higher AS
The previous LionAir flights controlled A/S (obviously). When we “hand fly” (flight directors and auto throttle on) it’s analogous to me on my couch. Fly toward the FD. Hell, I even have a Heads Up display. If you want to see the other guys squirm, turn off the AT
Much of this so-called “hand flying” isn’t really. I think it would be very human to miss the AS during an event such as this. I think pulling the throttles back once unreliable AS was identified would be key to gaining some time to think. Hand flying with AT on isn’t doing much good and has made me less aware of flying using the throttles.I also believe the MCAS was not adjusting its trim input for AS. From what I’ve read in the discription of MCAS, it shouldn’t have been using 2.5 degree ANU at higher AS
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True, none of us were there when the pins all lined up. Guilty as charged.
Might I also point out that none of us were there when the aircraft designers were designing, the project managers were managing, the regulators were regulating, and the airlines were training. Yet, there seems to be a pretty broad consensus in these parts that their were critical lapses in those parts despite the fact that no one here (at least that I've seen) has claimed to be current in qualified in those specialties. Odd, don't you think?
No, I was not there, and no I have never seen an MCAS failure in the sim or in life. However, over the course of 35+ years in aviation and perhaps a dozen different aircraft, I've dealt with more emergencies in the sim than I can count and more in the air than I ever wished to have had. I've encountered pilots of all different skill levels, and I've observed the traits that separate the good from the bad. Having reviewed perhaps hundreds, if not thousands, of incident reports over the years, I think I have a fairly good sense for what types of malfunctions should have been survivable without resort to extraordinary means, which ones required some combination of luck and superior skill, and which ones were pretty much hopeless from the start. In the case of Lion Air, I'd put that one somewhere between the first and second categories mainly due to the novelty. For Ethiopian, that one falls squarely in the first batch. Sorry you disagree, but I strongly suspect the final accident reports will fall closer to my position than yours.
Might I also point out that none of us were there when the aircraft designers were designing, the project managers were managing, the regulators were regulating, and the airlines were training. Yet, there seems to be a pretty broad consensus in these parts that their were critical lapses in those parts despite the fact that no one here (at least that I've seen) has claimed to be current in qualified in those specialties. Odd, don't you think?
No, I was not there, and no I have never seen an MCAS failure in the sim or in life. However, over the course of 35+ years in aviation and perhaps a dozen different aircraft, I've dealt with more emergencies in the sim than I can count and more in the air than I ever wished to have had. I've encountered pilots of all different skill levels, and I've observed the traits that separate the good from the bad. Having reviewed perhaps hundreds, if not thousands, of incident reports over the years, I think I have a fairly good sense for what types of malfunctions should have been survivable without resort to extraordinary means, which ones required some combination of luck and superior skill, and which ones were pretty much hopeless from the start. In the case of Lion Air, I'd put that one somewhere between the first and second categories mainly due to the novelty. For Ethiopian, that one falls squarely in the first batch. Sorry you disagree, but I strongly suspect the final accident reports will fall closer to my position than yours.
Last edited by 737 Driver; 27th Apr 2019 at 21:57.
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Having reviewed perhaps hundreds, if not thousands, of incident reports over the years, I think I have a fairly good sense for what types of malfunctions should have been survivable without resort to extraordinary means, which ones required some combination of luck and superior skill, and which ones were pretty much hopeless from the start. In the case of Lion Air, I'd put that one somewhere between the first and second categories mainly due to the novelty. For Ethiopian, that one falls squarely in the first batch. Sorry you disagree, but I strongly suspect the final accident reports will fall closer to my position than yours.
This illustrates yet another factor of national/corporate pride hindering global safety objectives, and yes Boeing/FAA are in same category.
One thing is certain, the persons who are the main drivers of these accidents had a lot more time to consider the outcome of their actions than the pilots. They have a CPA, MBA and/or JD. They received large salaries and bonuses. They live in the suburbs of Chicago, and will be receiving far less scrutiny than the engineers and pilots. They will cost out the lives lost vs. the cost of doing things properly. Their profession will insulate them from their true share of the culpability. In the end a very few will get a golden handshake and pursue other interests. Let’s take a minute to remember them.
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And leaving flaps down seems a bit too convenient.
If you just add a bit of delay in pulling the stick shaker CBs, and you happen to clean up (which would be perfectly good airmanship), then the MCAS genie is out of the bottle and you're in test pilot mode.
Therein lies your answer. What you have at this point is runaway stab trim. Our procedures really don’t care what the source of the runaway is. If you have an undesired and unexplained stab trim input, you are expected to intervene.
Reality is more complex, time is more flexible, cognitive skills are worse than the scripts that we write after the event.
Again I think everyone agrees with you that there needs to be more emphasis on hand flying skills throughout the whole industry and that 200h is ludicrous for a FO.
Again I think everyone agrees with you that there needs to be more emphasis on hand flying skills throughout the whole industry and that 200h is ludicrous for a FO.
Last edited by 737 Driver; 27th Apr 2019 at 22:45.
So, there I am hand-flying, bring the flaps up, and BAM!, MCAS kicks in. What MCAS will then attempt to do is run the trim nose down for 9 continuous seconds and spin the trim wheel about 37 times. I’ve asked this before, and I’ll ask this again: Starting from a stabilized, in-trim platform, exactly how long should a qualified 737 type-certified Captain who is hand-flying the aircraft let the trim run in one direction before he/she does something about it? Therein lies your answer. What you have at this point is runaway stab trim. Our procedures really don’t care what the source of the runaway is. If you have an undesired and unexplained stab trim input, you are expected to intervene.
I do not disagree, but there really is a limit to how much befuddlement should be expected of a professional flight crew entrusted with the lives of 150+ souls. If a pilot cannot overcome the initial surprise factor in pretty short order, fall back on basic airmanship skills and executed known procedures, then perhaps they should reconsider their chosen career.
I do not disagree, but there really is a limit to how much befuddlement should be expected of a professional flight crew entrusted with the lives of 150+ souls. If a pilot cannot overcome the initial surprise factor in pretty short order, fall back on basic airmanship skills and executed known procedures, then perhaps they should reconsider their chosen career.
Oh? Ten charaters minimum? +100,000,000 then
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I haven't seen the original reports (would appreciate a pointer to the source if someone has it)
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737 Driver ASRS database link.. https://asrs.arc.nasa.gov/overview/database.html
OK, first post, and not a pilot. But I have read all posts here. Simple question. If the pilots of Lion Air 610 and Ethiopian Airlines 302 had been flying Airbus A320s would these accidents have happened? I am a frequent passenger (I hate TLAs, especially SLF - we simply pay your wages after all) so I would like to have some objective feedback.
The A320 uses the two best of three vanes, so discarding the faulty one. This makes a fault very unlikely. However, it has happened! 2 froze in a fixed position causing the aircraft to pitch down (it thought those 2 were correct and the 1 truly correct one was incorrect). The pitch down was overcome by the pilots using half backstick. They then worked out the two side by side buttons that needed switching off to correct the situation.
Since then Airbus underwent a huge program to ensure pilots knew how to recognise the problem (you can catch it well well before it pitches you down) and which two buttons to press. Google: OEB48. The issue has now been engineered out and I don't think it happened a second time.
The A320 is a proper FBW aircraft that has been pottering around since the 80s. The max is a conventionally controlled aircraft with a bit of totally inadequate FBW bolted on, to fix a fundamental aerodynamic problem that would be forbidden if the aircraft was new.
And yes, I received sim training to recognise and recover from an OEB48 event.
Incident: Lufthansa A321 near Bilbao on Nov 5th 2014, loss of 4000 feet of altitude
737 Driver ASRS database link.. https://asrs.arc.nasa.gov/overview/database.html
Excuse the length & potential ignorance;
I'm still really, seriously struggling to get my head around the specifying of MCAS & it's method of operation. It's apparently there to increase feel at high AOA, but its driving a primary flight control surface. I understand that increasing feel at increasing AOA is necessary for certification requirements & I understand that feel reduces as AOA increases in the MAX due to the additional lift generated by the larger, repositioned engine cowlings.
So, for whatever reason, MAX reaches high AOA which isn't indicated as is normal by stick feel - Pilot needs to be informed of the situation - this part seems to be neglected / skipped & dubious automation takes over & starts driving the big guy at the back. Why does the requirement for increased stick force / feel to the pilot morph immediately into a substantial control surface deflection?
I'm seeing it that MCAS is doing nothing to meet the certification requirements of increasing feel, but rather forcefully avoiding the flight regime where the certification requirement exists - "don't go there" rather than "we are approaching there"
In my simplistic terms, I have a car that has lightening steering input as steering angle increases - it makes it a bit misleading to drive & the feel isn't right;
In my garage & in an ideal world the steering system is redesigned so that it works in the generally accepted manner. In a less ideal world, due to cost or time constraints a damper or progressive restrictor of some form is added. Either will resolve the issue & give the desired feel.
In the Boeing garage, skip the feel issue & add in a hidden & complex system that powerfully steers the car in the opposite direction of what's requested when the steering angle gets high. Control this complexity from a steering angle sensor which is know to be susceptible to damage & occasional failure. This is not adding feel, its taking control & in a questionable manner.
The more that I think about this something tells me that the characteristics of the MAX in the high AOA regime may have more issues than simple feel alone - hence the utilisation of a pile driver to crack what is apparently a nut.
I'm still really, seriously struggling to get my head around the specifying of MCAS & it's method of operation. It's apparently there to increase feel at high AOA, but its driving a primary flight control surface. I understand that increasing feel at increasing AOA is necessary for certification requirements & I understand that feel reduces as AOA increases in the MAX due to the additional lift generated by the larger, repositioned engine cowlings.
So, for whatever reason, MAX reaches high AOA which isn't indicated as is normal by stick feel - Pilot needs to be informed of the situation - this part seems to be neglected / skipped & dubious automation takes over & starts driving the big guy at the back. Why does the requirement for increased stick force / feel to the pilot morph immediately into a substantial control surface deflection?
I'm seeing it that MCAS is doing nothing to meet the certification requirements of increasing feel, but rather forcefully avoiding the flight regime where the certification requirement exists - "don't go there" rather than "we are approaching there"
In my simplistic terms, I have a car that has lightening steering input as steering angle increases - it makes it a bit misleading to drive & the feel isn't right;
In my garage & in an ideal world the steering system is redesigned so that it works in the generally accepted manner. In a less ideal world, due to cost or time constraints a damper or progressive restrictor of some form is added. Either will resolve the issue & give the desired feel.
In the Boeing garage, skip the feel issue & add in a hidden & complex system that powerfully steers the car in the opposite direction of what's requested when the steering angle gets high. Control this complexity from a steering angle sensor which is know to be susceptible to damage & occasional failure. This is not adding feel, its taking control & in a questionable manner.
The more that I think about this something tells me that the characteristics of the MAX in the high AOA regime may have more issues than simple feel alone - hence the utilisation of a pile driver to crack what is apparently a nut.
Still confusion about MCAS
Salute!
@Ricky Answer to your original question is easy----- NO!
@Thrust... Great analogy with the power steering. I used that same one with my wife. Last thing I want, and sje agreed, was the power steering to get easier the more I turned the wheel. And the auto folks figured this out back in the late 50's. My first experience with an inlaw's car was a surprise. But within a few years we had better control valve configurations and then some inputs from speed. Hmmmm..... starting to sound like some airplane systems intended to "help" as well as keep the pointy end forward.
Back at Ricky and Thrust........ It ain't "feel". It's the basic aero characteristic of the MAX when at high AoA. So they called it "Maneuvering CHaractersitic .........." Unlike previous versions, this new critter had less inherent aero resistance to increasing AoA than required/desireable. In other words, it could be possible that eventually your AoA might keep increasing while you had the yoke/column/stick neutral. Not good.
The Boeing fix was not to screw with the "feel". Instead, by moving the stab, then the existing flight control stuff could save the day and the plane would pass the certification requirements. Although intended for high altitude and maneuvering flight, the accident MCAS scenarios happened at low altitude and slow speed and at the tail end of a critical phase of flight. Oh yeah........ the damned wheel was shaking like crazy and there were various warning lights.
In the 'bus, there is a last ditch feature called "direct law". So even if the AoA data and air data is FUBAR, your stick movement will command control surface movement at some default ratio. It's like the cable/pulley/pushrod stuff our 737 golden arms talk about. It's like your auto power steering as far as you can tell. And the 'bus is more aerodynamically capable of meetinfg the cert requirements due to its basic design, unlike the new 737 MAX.
Gums.....
@Ricky Answer to your original question is easy----- NO!
@Thrust... Great analogy with the power steering. I used that same one with my wife. Last thing I want, and sje agreed, was the power steering to get easier the more I turned the wheel. And the auto folks figured this out back in the late 50's. My first experience with an inlaw's car was a surprise. But within a few years we had better control valve configurations and then some inputs from speed. Hmmmm..... starting to sound like some airplane systems intended to "help" as well as keep the pointy end forward.
Back at Ricky and Thrust........ It ain't "feel". It's the basic aero characteristic of the MAX when at high AoA. So they called it "Maneuvering CHaractersitic .........." Unlike previous versions, this new critter had less inherent aero resistance to increasing AoA than required/desireable. In other words, it could be possible that eventually your AoA might keep increasing while you had the yoke/column/stick neutral. Not good.
The Boeing fix was not to screw with the "feel". Instead, by moving the stab, then the existing flight control stuff could save the day and the plane would pass the certification requirements. Although intended for high altitude and maneuvering flight, the accident MCAS scenarios happened at low altitude and slow speed and at the tail end of a critical phase of flight. Oh yeah........ the damned wheel was shaking like crazy and there were various warning lights.
In the 'bus, there is a last ditch feature called "direct law". So even if the AoA data and air data is FUBAR, your stick movement will command control surface movement at some default ratio. It's like the cable/pulley/pushrod stuff our 737 golden arms talk about. It's like your auto power steering as far as you can tell. And the 'bus is more aerodynamically capable of meetinfg the cert requirements due to its basic design, unlike the new 737 MAX.
Gums.....
Last edited by gums; 28th Apr 2019 at 00:06.
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Found them, thanks! The reports were misfiled with the 737NG's for some reason.
The search is tough, one has to search the different variants with what is reported in the ASRS system. (there is no 737-8MAX, etc)
So far, there are reports under, 737-800, B737 Next Generation Undifferentiated, and B737 Undifferentiated or Other Model..
the nomenclature of this model has created some issues.
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Salute!
In the 'bus, there is a last ditch feature called "direct law". So even if the AoA data and air data is FUBAR, your stick movement will command control surface movement at some default ratio. It's like the cable/pulley/pushrod stuff our 737 golden arms talk about. It's like your auto power steering as far as you can tell. And the 'bus is more aerodynamically capable of meetinfg the cert requirements due to its basic design, unlike the new 737 MAX.
Gums.....
In the 'bus, there is a last ditch feature called "direct law". So even if the AoA data and air data is FUBAR, your stick movement will command control surface movement at some default ratio. It's like the cable/pulley/pushrod stuff our 737 golden arms talk about. It's like your auto power steering as far as you can tell. And the 'bus is more aerodynamically capable of meetinfg the cert requirements due to its basic design, unlike the new 737 MAX.
Gums.....
i have a question that has been in my mind for very long. Does any other commercial airframe needs a software patch to pasd a certification requirement? Or to a certain extent certification was designed with software patches as remedies?
In a statement to CNN, the FAA claims that they knew that MCAS would cause a stabilizer runaway but they just expected pilots to deal with it.
My question for the FAA representative would have been "if you had found some faulty hardware component on a 737 that increased the risk of a trim runaway, would you have directed airlines to fix it, or would it be OK because pilots know how to deal with it?"
Engine shutdown on takeoff? No prob, pilots are trained for that one. Dual failure over water? Hey, it worked for Sully! There is a lot about my country that I no longer recognize, and our engineering safety culture seems to be the latest casualty of whatever infection is messing with our brains. I'm waiting for one of the talking heads to inform us that randomly pitching the nose down on rotation is actually a good thing because it keeps the pilots from getting bored and lazy!
My question for the FAA representative would have been "if you had found some faulty hardware component on a 737 that increased the risk of a trim runaway, would you have directed airlines to fix it, or would it be OK because pilots know how to deal with it?"
Engine shutdown on takeoff? No prob, pilots are trained for that one. Dual failure over water? Hey, it worked for Sully! There is a lot about my country that I no longer recognize, and our engineering safety culture seems to be the latest casualty of whatever infection is messing with our brains. I'm waiting for one of the talking heads to inform us that randomly pitching the nose down on rotation is actually a good thing because it keeps the pilots from getting bored and lazy!
And why is the 767 tanker MCAS so different to the MAX- anything to do with training required?
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I'm not cutting Boeing, the FAA, or the airlines any slack for their role in these accidents. They all need to address their lapses. But as I've already stated, this is not a forum for Boeing. Or for the FAA. Or for airline managers. We don't really have the power to address their issues. We do have the power to address ours.
This is a forum for professional pilots. Yes, we could sit back, point fingers, and opine about how badly someone else screwed up. Or we could take a hard look at our profession and ask why multiple crews had such difficulty and/or reluctance in applying some very basic airmanship techniques to resolve an aircraft malfunction that, while being unique and baffling, ultimately did not render the aircraft unflyable.
I'm not cutting Boeing, the FAA, or the airlines any slack for their role in these accidents. They all need to address their lapses. But as I've already stated, this is not a forum for Boeing. Or for the FAA. Or for airline managers. We don't really have the power to address their issues. We do have the power to address ours.
This is a forum for professional pilots. Yes, we could sit back, point fingers, and opine about how badly someone else screwed up. Or we could take a hard look at our profession and ask why multiple crews had such difficulty and/or reluctance in applying some very basic airmanship techniques to resolve an aircraft malfunction that, while being unique and baffling, ultimately did not render the aircraft unflyable.
Look, I agree with pretty much everything you say, up to the point where it was the crews' fault for what happened. They had no control over their training. They had no control over Boeing's clear abuse of the certification process, and they had no input on a system which (as I have described previously) would try to kill you if you didn't get the diagnosis right. And that's an important distinction. In an earlier reply you spoke of numerous failures that you experienced which were nearly catastrophic. IIRC you mentioned engine failures as an example of a potentially fatal event. The problem is twofold: First, you need engines to fly. Like, I mean, you can't live without them right?? And second: Yes, an engine failure can be (and many times is) fatal. But it doesn't have to be, and if you goof a little bit the outcome isn't a 100 percent fatal conclusion. Even if you goof a lot the outcome is frequently far less than fatal.
If an engine failure happens there are a gazillion possible outcomes, all of which rely on you, the pilot, to select and control the final result.
But with MCAS there are only two possible outcomes, one is you keep flying if you line up the dots within roughly a minute (40 seconds if you believe media reports) the other is you are d-e-d dead.
I know of no other binary system/operational outcome that aligns with this and I once again submit this to the community: Anyone got an equivalent they can share??
Here is another attempt to try to illustrate how unique this circumstance is, and how profound Boeing's errors were in bringing this airplane forward for commercial use. (And how culpable they are as a consequence)
Imagine if your airplane had a third, previously unneeded engine that contributed nothing to the performance, stability, safety or functionality of the aircraft. I'm even going to give us the benefit of the doubt and say you know this third engine exists. If engines 1 or 2 fail you just do everything like you always have. Pull out the proper checklist, do your memory items and find someplace to land. But if engine #3 fails, well then you have 30 seconds to a minute to identify the correct engine, diagnose it and shut it down using an exact mechanism that has zero tolerance for deviation. If you fail to do this exactly right your third engine explodes and rips off the tail in the process and you and your airplane are toast on a stick.
That's what I mean when I say MCAS will try to kill you (it will...) and that's why I believe this is a unique circumstance and finally: That's why I place the responsibility for the entirety of the outcome for both flights at the feet of Boeing and the FAA.
As professional pilots I would think you would be equally interested (for the sake of your own preservation) in holding the manufacturer that created this Rube-Goldberg piece of utter BS to account, certainly as much, if not more than you want to hold a deceased and clearly under-trained crew to account. And I cannot imagine a more powerful lobby or forum- the pilots who fly the planes themselves for sharing your views and insights into what happened and how utterly unnecessary both hull losses were.
We can go round and round picking apart the numerous ways both crews could have and should have done better. What I would rather see is a discussion on how the community is going to hold the feet of Boeing and the FAA to the fire- for real (even incremental) change going forward. All so that the next "MCAS" never even gets to the drawing board because the concept was shot down in flames earlier in the process due to the manufacturer's desire to build safe airplanes no matter the cost.
Warm regards,
dce
Now that the Mainstream media are scrutinizing this thing, hopefully there are some journalists left with the Moxy and intellect to see through the double talk, and hold those responsible to account.
Last edited by KRUSTY 34; 28th Apr 2019 at 04:54.
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not sure if this has been mentioned before..
https://edition.cnn.com/2019/04/26/p...tline-reports/
https://edition.cnn.com/2019/04/26/p...tline-reports/
The FAA tells CNN it received the four hotline submissions on April 5, and it may be opening up an entirely new investigative angle into what went wrong in the crashes of two Boeing 737 Max commercial airliners -- Lion Air flight 620 in October and Ethiopian Air flight 302 in March.
Among the complaints is a previously unreported issue involving damage to the wiring of the angle of attack sensor by a foreign object, according to the source.
Among the complaints is a previously unreported issue involving damage to the wiring of the angle of attack sensor by a foreign object, according to the source.