Ethiopian airliner down in Africa
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As the crew cannot do anything about it ie cannot select which one, why bother giving them that info, Ground crew need to know IF it switches because if there is a fault reported not being able to tell which one was in use means they HAVE to check both, personally I don't believe this to be correct info.. However if it is true my suggestion would IMHO improve the system.
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Lastly, as I understand it, MCAS only dials in *ONE* nose-down increment (2 degrees or whatever it is) and then deactivates itself, until something happens to reactivate MCAS allowing it to dial in another increment. I can't recall all of the crew activities that result in MCAS being reactivated, but I believe one is operation of the manual trim. This is why the last four "blipped" manual trim inputs in the Lion flight result in four unmitigated MCAS nose-down events, because any manual trim input resets MCAS and allows it to reasses the AoA / speed picture and dial in another MCAS trim input.
Application of electric trim pauses MCAS (5 seconds). Selecting TRIM CUTOUT to OFF deactivates MCAS (much like Speed Trim, Mach Trim and Column switch electric trim)
So if they were manually trimming the stab wheel as you say, one would assume they'd have tried either of those two options which begs the question why wouldn't they have been able to control the aircraft in the pitch axis thereafter? Time will tell.
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On the reliability of witnesses: I was once watching through binoculars a Starfighter display. It was flying erratically. My interest and concentration were at a peak. The pilot ejected and the aircraft exploded in the air. Or maybe it was the other way round. And since then I have not really trusted anyone's account of things they have seen.
(Frankfurt Airport/Rhein-Main AFB, about 1990)
(Frankfurt Airport/Rhein-Main AFB, about 1990)
Last edited by AndyJS; 12th Mar 2019 at 12:30.
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The famous eye witness accounts!
Lately I've been flying a 1948 Grumman Mallard with a good friend of mine, We landed and docked by a nice hotel and went inside for lunch, the military showed up asking if we were OK! When we asked why, they said that people have called reporting an airplane that crashed in the ocean and was on fire!
Lately I've been flying a 1948 Grumman Mallard with a good friend of mine, We landed and docked by a nice hotel and went inside for lunch, the military showed up asking if we were OK! When we asked why, they said that people have called reporting an airplane that crashed in the ocean and was on fire!
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The system was obiously never designed to recognise that the aircraft was not stalled - it took the word of one AoA sensor as being gospel. Never mind that the airspeed and attitude were correct, the system reacted solely, and incorrectly, to the erroneous AoA sensor.
It did not even bother checking with the other AoA sensor. All you need is one line of code that says: “if AoA1 not equal to AoA2, deactivate system”. I mean, how hard was that? Ok, it would be nice to have three sensors, but even two can resolve that there is an error somewhere, so the system should not start trimming.
And while we are at it, why was there not a line of code that says: “if ASI greater than 210 kts, deactivate system”. I mean, how hard was that? Please don’t say that high speed stalls are a real problem with the Max, because I will not buy that one.
Silver
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Okay, after perusing through this multi-page thread of, frankly, mostly useless and uninformed speculation and, in some cases, pure garbage, I have a few items to contribute:
Background: my first Boeing was the 737-200 and 300, left seat on the 757 and 767, currently flying the 737NG, never been closer to a Max than across the ramp. I have never operated MS Flight Sim. Multiple carriers, all overseas for the last 12 years. I spent a year flying the NG at ET a few years ago. Total flying career 32 years and counting.
First: ET pilots. I entered ET right at the introduction of the MPL program for FOs. As far as I know their new pilots are still graduating under the MPL: program. For those who don't know what that is, it's Multicrew Pilot License. It consists of 70 hours of actual airplane flight time and 130 hours of simulator. The pilot does not have a CPL. So the 200 hour copilot is plausible, though unless the Captain was an instructor the FO probably had a little more time than 200. I sometimes got a fresh FO with a grand total of 230 hours, having been signed off as meeting the standards. Here's the truth - none of them could fly an airplane. Plain and simple. No exaggeration, just the plain truth. There were multiple times I flew with an FO who, after almost a year on type still couldn't fly worth a darn. I'm not talking the finer points, I'm talking basic airmanship. Next, local captains. Most are competent but ET had (probably still has) difficulties with new upgrade captains. they move up the ranks strictly by seniority. After a year or so on the Q400 or 737 they go to junior FO on the widebody, then senior FO on the widebody, then back to the Q400 or 737 for upgrade. Big culture shock, big step backwards on technology, big change in route structure. Their upgrade line training program typically took 4 or 5 times as long as a current & qualified captain. There's a big difference between logging time droning along for 12 hours vs. short-haul. Not throwing rocks but I usually see a large quality gap between FOs who came from short-haul vs. long-haul. As was said previously, Addis is a captain only airport and almost certainly the captain was PF. Lastly on the pilot side, CRM is mostly non-existent there, it is very much a top down cockpit culture, though that probably was not a factor here.
Next, the FAA: I'm certainly glad that PPRUNE has, in three days, solved the crash! Hallelujah! The NTSB and local crash investigators need not even show up. The big uproar that the FAA has not grounded the Max is a good thing. It means they are doing their jobs, not acting rashly and on pure emotion, rather basing any decision on facts when they come. I notice that EASA has not issued a grounding order (which they certainly can). Considering that the bulk of the Max fleet is operating in the US and Europe, what on earth are they waiting for? (that's sarcasm, by the way). Maybe they are waiting for some actual data to come forth before condemning the aircraft. Maybe they know something we don't. Hmmmm....
Next, MCAS: I'm not weighing in on this as I have exactly zero more facts than anyone else. I do have a few questions though concerning the final few moments of both the ET crash and the Lion crash. Both times the aircraft was in day VMC conditions, both seemingly experienced speeds much higher than what could and should be considered normal for level flight at low altitude, so what gives? I can certainly tell my airspeed by looking out the window, regardless of how many alarms at whatever obscene volume are blaring any time. If the data is to be believed, 330+ knots at around 1000AGL to me means someone forgot the cardinal rule: fly the airplane. Pitch, power, and if possible (it was) look out the damn window!
Next, basic airmanship: If I have, simultaneously, an A/S and/or ALT disagree, stick shaker, and an increasing need for backpressure on the yoke, my first action is to fix the flight control issue and that means assuming a trim problem. I can handle the airplane all day long without an altimeter or airspeed indicator (in VMC conditions) but aircraft control is first, second and third on the to-do list. Maybe airmanship is not taught anymore (it's not but that's another story) but basic airmanship teaches us that even in an airplane without a trimmable HS, a mistrimmed airplane will be harder to control at higher speeds. So grab the thrust levers and use them. Set pitch and power. The 737 can be flown, albeit with a lot of force required, with the pitch trim at either stop, but at full nose down the control forces will be massive at high speeds. Couple that with the elevator force diminishing with higher airspeeds and it may reach a point where at speeds above barber pole you may run out of elevator. I was taught this years ago, though I know it is not taught anymore. Moral: fly the damn airplane.
I could chime in on lots more but frankly, why bother? Based on most of what I've read (and could stomach) the PP needs to be removed from PPRUNE.
Background: my first Boeing was the 737-200 and 300, left seat on the 757 and 767, currently flying the 737NG, never been closer to a Max than across the ramp. I have never operated MS Flight Sim. Multiple carriers, all overseas for the last 12 years. I spent a year flying the NG at ET a few years ago. Total flying career 32 years and counting.
First: ET pilots. I entered ET right at the introduction of the MPL program for FOs. As far as I know their new pilots are still graduating under the MPL: program. For those who don't know what that is, it's Multicrew Pilot License. It consists of 70 hours of actual airplane flight time and 130 hours of simulator. The pilot does not have a CPL. So the 200 hour copilot is plausible, though unless the Captain was an instructor the FO probably had a little more time than 200. I sometimes got a fresh FO with a grand total of 230 hours, having been signed off as meeting the standards. Here's the truth - none of them could fly an airplane. Plain and simple. No exaggeration, just the plain truth. There were multiple times I flew with an FO who, after almost a year on type still couldn't fly worth a darn. I'm not talking the finer points, I'm talking basic airmanship. Next, local captains. Most are competent but ET had (probably still has) difficulties with new upgrade captains. they move up the ranks strictly by seniority. After a year or so on the Q400 or 737 they go to junior FO on the widebody, then senior FO on the widebody, then back to the Q400 or 737 for upgrade. Big culture shock, big step backwards on technology, big change in route structure. Their upgrade line training program typically took 4 or 5 times as long as a current & qualified captain. There's a big difference between logging time droning along for 12 hours vs. short-haul. Not throwing rocks but I usually see a large quality gap between FOs who came from short-haul vs. long-haul. As was said previously, Addis is a captain only airport and almost certainly the captain was PF. Lastly on the pilot side, CRM is mostly non-existent there, it is very much a top down cockpit culture, though that probably was not a factor here.
Next, the FAA: I'm certainly glad that PPRUNE has, in three days, solved the crash! Hallelujah! The NTSB and local crash investigators need not even show up. The big uproar that the FAA has not grounded the Max is a good thing. It means they are doing their jobs, not acting rashly and on pure emotion, rather basing any decision on facts when they come. I notice that EASA has not issued a grounding order (which they certainly can). Considering that the bulk of the Max fleet is operating in the US and Europe, what on earth are they waiting for? (that's sarcasm, by the way). Maybe they are waiting for some actual data to come forth before condemning the aircraft. Maybe they know something we don't. Hmmmm....
Next, MCAS: I'm not weighing in on this as I have exactly zero more facts than anyone else. I do have a few questions though concerning the final few moments of both the ET crash and the Lion crash. Both times the aircraft was in day VMC conditions, both seemingly experienced speeds much higher than what could and should be considered normal for level flight at low altitude, so what gives? I can certainly tell my airspeed by looking out the window, regardless of how many alarms at whatever obscene volume are blaring any time. If the data is to be believed, 330+ knots at around 1000AGL to me means someone forgot the cardinal rule: fly the airplane. Pitch, power, and if possible (it was) look out the damn window!
Next, basic airmanship: If I have, simultaneously, an A/S and/or ALT disagree, stick shaker, and an increasing need for backpressure on the yoke, my first action is to fix the flight control issue and that means assuming a trim problem. I can handle the airplane all day long without an altimeter or airspeed indicator (in VMC conditions) but aircraft control is first, second and third on the to-do list. Maybe airmanship is not taught anymore (it's not but that's another story) but basic airmanship teaches us that even in an airplane without a trimmable HS, a mistrimmed airplane will be harder to control at higher speeds. So grab the thrust levers and use them. Set pitch and power. The 737 can be flown, albeit with a lot of force required, with the pitch trim at either stop, but at full nose down the control forces will be massive at high speeds. Couple that with the elevator force diminishing with higher airspeeds and it may reach a point where at speeds above barber pole you may run out of elevator. I was taught this years ago, though I know it is not taught anymore. Moral: fly the damn airplane.
I could chime in on lots more but frankly, why bother? Based on most of what I've read (and could stomach) the PP needs to be removed from PPRUNE.
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The captain of this flight has been reported to have 8000 flight hours -- and was 28 years old. Does this seem anomalous to anyone. That is a lot of hours for someone so young. And has there been any information as to how many hours he had on either the MAX 8 or his previous types?
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Interesting details/analysis by a control guru which **may** help explanation of which sensor does what and how
https://www.satcom.guru/2018/11/737-...n-command.html
Obviously put together after LionAir . .
https://www.satcom.guru/2018/11/737-...n-command.html
Obviously put together after LionAir . .
The link is to an article by someone worthy of the title "expert" in system design. very interesting and detailed analysis of the system, how it should function, what could go wrong, and what should be done going forward.
Has Boeing issued any Maintenance or Crew notices since the Ethiopian accident? If not, what has prompted some countries to ground the Max. Although there is speculation on this site about a similar cause to that of Lion Air crash, I have not seen anything from official sources to confirm the idea.
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was always in that checklist, even for the -200
This ist meant as last resort and was always included, nothing to do with MCAS! Airloads could drive the elevator, etc..
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Has Boeing issued any Maintenance or Crew notices since the Ethiopian accident? If not, what has prompted some countries to ground the Max. Although there is speculation on this site about a similar cause to that of Lion Air crash, I have not seen anything from official sources to confirm the idea.
Seeing two brand new planes crash in a relatively likely manner, within such a short time of each other and within two years of the plane's release. They are probably not taking any chances until it is clear that this is not the same issue.
Last edited by SigWit; 12th Mar 2019 at 13:03. Reason: spelling
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Hi EV,
Let me start by offering my condolences to all involved in two horrific crashes.
No idea about the technical merits of the aircraft but I wholeheartedly agree. With attitude information available and control of pitch and power it is surprising these types of crashes happen. Looking out the window and seeing if the ground is getting closer or further away and where the aircraft is pointing seems to be a lost art.
Like you I worry about true experience, I have quite a lot of hours but in the last 10,000 or so gained less true experience (dealing with new/different issues) than in some 1 hour long flights a couple of decades ago. My experience is now measured by hours and the industry even considers me to be gaining experience (competence?) when asleep in a bunk
The standards set in regulation allow for an if you don’t succeed try, try again and you will eventually be successful.
That is jumping ahead, we don’t have the reason for these crashes but if simple procedures and aviation skill in handling a malfunction were contributory, the industry as a whole needs to wake up and realize that the training being given and more importantly the regulatory standards being applied were causal and cost these crews and several hundred passengers their lives.
Let me start by offering my condolences to all involved in two horrific crashes.
No idea about the technical merits of the aircraft but I wholeheartedly agree. With attitude information available and control of pitch and power it is surprising these types of crashes happen. Looking out the window and seeing if the ground is getting closer or further away and where the aircraft is pointing seems to be a lost art.
Like you I worry about true experience, I have quite a lot of hours but in the last 10,000 or so gained less true experience (dealing with new/different issues) than in some 1 hour long flights a couple of decades ago. My experience is now measured by hours and the industry even considers me to be gaining experience (competence?) when asleep in a bunk
The standards set in regulation allow for an if you don’t succeed try, try again and you will eventually be successful.That is jumping ahead, we don’t have the reason for these crashes but if simple procedures and aviation skill in handling a malfunction were contributory, the industry as a whole needs to wake up and realize that the training being given and more importantly the regulatory standards being applied were causal and cost these crews and several hundred passengers their lives.
Gender Faculty Specialist
Not common but plausible.
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Not my understanding. The logic of the system was posted in the extensive Indonesian thread, and if I recall correctly the MCAS system will continue operating as long as it thinks the aircraft is in a stall situation. So it gives 10 secs of trim, 5 secs waiting, and then another 10 secs of trim. That is why the Indonesian aircraft got multiple trim events (about 12 or so) in quick succession.
The system was obiously never designed to recognise that the aircraft was not stalled - it took the word of one AoA sensor as being gospel. Never mind that the airspeed and attitude were correct, the system reacted solely, and incorrectly, to the erroneous AoA sensor.
It did not even bother checking with the other AoA sensor. All you need is one line of code that says: “if AoA1 not equal to AoA2, deactivate system”. I mean, how hard was that? Ok, it would be nice to have three sensors, but even two can resolve that there is an error somewhere, so the system should not start trimming.
And while we are at it, why was there not a line of code that says: “if ASI greater than 210 kts, deactivate system”. I mean, how hard was that? Please don’t say that high speed stalls are a real problem with the Max, because I will not buy that one.
Silver
It won't directly affect many flights as there are no Max 8s in service with Australian carriers yet (Virgin Australia have over 30 on order). Only Fijian among the operators flying Max 8s to Australia hadn't already stopped operations.
https://www.abc.net.au/news/2019-03-...ralia/10894426
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the Trim switch cutout removes all electric power to the trim system including the MCAS, it does mean that you need to manually trim the aircraft.
Apparently you can be through the school system at age 17 in Ethiopia. An integrated ATPL(A) course can be done in 12-18 months if all runs smooth. Let's say 19 when he started flying. At 900hrs a year it would be possible. Just saying, the math can work out. So let's not jump to conclusions.
