Ethiopian airliner down in Africa
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The Australian suspension affects Singapore's SilkAir (which has already grounded its fleet) as well as Fiji Airways that will have to substitute their two 737 Maxs on routes to Australia for other aircraft. So they have bought a spine within some, albeit limited impact.
Last edited by Drjojo; 12th Mar 2019 at 09:27.
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Is this a good summary of what the crew may have experienced:
normal rotation to takeoff attitude and within a few seconds;
GEAR RETRACTION
IAS DISAGREE WARNING
ALT DISAGREE WARNING
STICK SHAKER ACTIVATION
STAB OUT OF TRIM WARNING (?)
MASTER CAUTION FLIGHT CONTROLS
TROUBLESHOOTING AND MEMORY ITEMS
DISCONNECT AUTOTHRUST
TURN OFF BOTH FLIGHT DIRECTORS
SET 10 DEGREES PITCH UP
SET 80%N1
CHECK PROBE HEAT ON
SPEED TRIM SYSTEM ACTIVATION (in background) - PUSHING THE NOSE DOWN
FLAP RETRACTION AT 1000ft OR AS SPEED INCREASES, OR OVERSPEED OF FLAPS
MCAS ROLLING IN NOSE DOWN STAB TRIM INCREMENTLY (NOT A RUNAWAY)
PM GETS OUT THE QRH TO READ CHECKLIST
PF IS ON THE RADIO AND STARTING TO FIGHT AGAINST THE NOSE DOWN BIAS
VARIOUS ALERTS SOUNDING:
”TOO LOW GEAR”
”CAUTION TERRAIN”
”TERRAIN TERRAIN”
“DONT SINK”
”PULL UP”
At this stage either the PF remembers the Bulletin and goes for the MCAS cutout switches - AKA STAB TRIM CUTOUT SWITCHES or he doesn’t.
The difference between an excellent pilot and an average pilot at this point is minuscule due to information overload and serious anxiety - a bad result is highly possible.
PLEASE sit in a quiet space, close your eyes and imagine its you sitting in that flightdeck. Just like the Air France and Perpignan accidents the AoA played a part - so its not just a Boeing problem.
normal rotation to takeoff attitude and within a few seconds;
GEAR RETRACTION
IAS DISAGREE WARNING
ALT DISAGREE WARNING
STICK SHAKER ACTIVATION
STAB OUT OF TRIM WARNING (?)
MASTER CAUTION FLIGHT CONTROLS
TROUBLESHOOTING AND MEMORY ITEMS
DISCONNECT AUTOTHRUST
TURN OFF BOTH FLIGHT DIRECTORS
SET 10 DEGREES PITCH UP
SET 80%N1
CHECK PROBE HEAT ON
SPEED TRIM SYSTEM ACTIVATION (in background) - PUSHING THE NOSE DOWN
FLAP RETRACTION AT 1000ft OR AS SPEED INCREASES, OR OVERSPEED OF FLAPS
MCAS ROLLING IN NOSE DOWN STAB TRIM INCREMENTLY (NOT A RUNAWAY)
PM GETS OUT THE QRH TO READ CHECKLIST
PF IS ON THE RADIO AND STARTING TO FIGHT AGAINST THE NOSE DOWN BIAS
VARIOUS ALERTS SOUNDING:
”TOO LOW GEAR”
”CAUTION TERRAIN”
”TERRAIN TERRAIN”
“DONT SINK”
”PULL UP”
At this stage either the PF remembers the Bulletin and goes for the MCAS cutout switches - AKA STAB TRIM CUTOUT SWITCHES or he doesn’t.
The difference between an excellent pilot and an average pilot at this point is minuscule due to information overload and serious anxiety - a bad result is highly possible.
PLEASE sit in a quiet space, close your eyes and imagine its you sitting in that flightdeck. Just like the Air France and Perpignan accidents the AoA played a part - so its not just a Boeing problem.
Last edited by SMYDSTS; 12th Mar 2019 at 14:01. Reason: More distraction
Thread Starter
Meanwhile over on TUI's Facebook and Twitter pages they are Inundated with their 1000's of their customers who are really not happy to be going on their holidays on a TUI or a Norwegian MAX right now...
(Even Enter Air who flies for some UK Greek tour operators is getting flack for not grounding their Max for now)
The bog standard tweeted reply continually coming from TUI has a slight smack of arrogance about it which, if that has come from the TUI PR department is rather disconcerting.
Although I doubt some little social media customer agent would be allowed to pass off a message like that...
However,
I would like to think that (as has been mentioned here in other posts) that all well respected TUI or DI MAX pilots would have burnt the midnight oil late into the night reading up on the MACS systems and how to deal with that - plus any spurious data that may occur. (and how to switch it all off)
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Rostov.
I wonder because the report said that the Fly Dubai pilots trimmed forward for 10 seconds. And everyone was aghast by that news, because no pilot would ever trim forward for 10 seconds. We were thinking in terms of a health issue, with someone freezing on the controlls. But as it happens, this is exactly what MCAS does - it trims forward for 10 seconds. So was the Fly Dubai fitted with a Max speed-trim computer?
I wonder because the report said that the Fly Dubai pilots trimmed forward for 10 seconds. And everyone was aghast by that news, because no pilot would ever trim forward for 10 seconds. We were thinking in terms of a health issue, with someone freezing on the controlls. But as it happens, this is exactly what MCAS does - it trims forward for 10 seconds. So was the Fly Dubai fitted with a Max speed-trim computer?
Gender Faculty Specialist
and whilst you have two hands on the yoke, the FAA directive to follow the trim runaway memory checklist, requires you to operate the guarded stabilizer trim cut out switches. Maybe the FO can do this. Once done, you still have the aircraft out of trim but now your trim switches on the yoke wont work. You need to shout at the copilot, to operate the trim wheels manually. If way out of trim, he's got plenty of spinning to do. Too much speed? Will reducing thrust result in more pitch down or give more time for the copilot to save the aircraft?
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I don’t agree at all.
If the f/o was flying, he only had 200 hours. After flaps up, the stick shaker goes off, which is mighty disconcerning, and MCAS bungs in a load of trim. The captain cannot see why the trim is trimming, and the low-hours f/o has no clue (seen that many times). The captian thinks he has an airspeed problem and is stalling, and tells the f/o to lower the nose - which the f/o does rather easily, because he is holding a load of back pressure. MCAS then bungs in another load of trim, and the f/o is now really struggling with the controls - never having felt an aircraft behave like this (at this stage, you need about 30 kg of force to hold the aircraft level).
The captain is still convinced the airspeed is wrong and they may be stalling (stick shaker still going), and shouts “I have control”, but does not realise so much pitch force is necessary, so the aircraft instantly pitches forward into a steep dive. Captain is mighty startled by this - is this pitch down the result of a stall? He has forgotten all about the previous trim episodes, and just hauls back on the stick. But MCAS now gives another load of forward trim, which makes the aircraft completely unflyable (60 kg of force necessary on the stick). And here comes terra firma....
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and whilst you have two hands on the yoke, the FAA directive to follow the trim runaway memory checklist, requires you to operate the guarded stabilizer trim cut out switches. Maybe the FO can do this. Once done, you still have the aircraft out of trim but now your trim switches on the yoke wont work. You need to shout at the copilot, to operate the trim wheels manually. If way out of trim, he's got plenty of spinning to do. Too much speed? Will reducing thrust result in more pitch down or give more time for the copilot to save the aircraft?
The FAA Boeing Bulletin might seem simple in hindsight, but with a cacophony of noise and spurious alerts and call outs, it is not too hard to imagine a sense of overwhelm.
Have Boeing unknowingly introduced a single point of failure into the aircraft?
That the SWA 737MAX fleet was 'fitted' with a Boeing factory option displaying AOA on both PFD, not just the Captain's HUD is suggestive that at least some airlines consider that indications need cross checking.
The sense one gets is that the pilots with the AOA displayed can cross-check and likely the display would assist a rapid diagnosis of the issue.
Indeed the early QF orders of the 738, were destined for another customer and had the option already 'fitted' , all additional aircraft have the same indication.
Perhaps it is time Boeing 'fitted' it to all 737 MAX? Or are their lawyers suggesting to do so implies a problem?
https://theaircurrent.com/aviation-s...737-max-fleet/
The FAA look the odd one out as increasingly a risk aversion mindset takes hold.
Regulatory capture it may well be, but other aircraft have been grounded for a lot less, all in the name of safety.
How much short open interest in BA (NYSE) ? How much of an eye has the regulator on the economics?
That this event occurred in the same phase of flight is the concern. Until they categorically rule out that the MCAS system was at play here, the aircraft ought be sitting idle on the ground.
Last edited by Rated De; 12th Mar 2019 at 10:06.
If it gets to the forward stop there's no rush to get to the stab trim cut outs cos it ain't going any further. Fly it away from the ground, might take both of you, then distribute work load accordingly. It'll take something like 30 odd turns to get it back to somewhere more manageable.
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MCAS and AS (artificial stupidity)
Engineer here - trying to look at MCAS out of the box...
So they say, one AoA sensor outputting wrong data alone can activate the MCAS erroneously.
If that is so, which engineering workgroup at Boeing could in their sane minds design such a system, that is supposed to save you from a stall but instead:
Why would an engineer think it is a good idea to implement such a system that ignores all other available data (which indicates nothing like a stall)? Even if you want to take the pilot/human out of the equation, assuming he put the airplane into an attitude that will result in a stall in the first place, you still have lots of other available data the system can read, that tells it that you are in fact not stalling and that most likely the AoA sensor is telling you nonsense.
Probably the MCAS subsystem will enter the course books of engineering schools, as a textbook example of AS, artificial stupidity, a system designed to be stupid, when you actually need a smart system.
Or are these engineers disciples of the Church of the AoA sensor, since they believe the one and only AoA sensor never fails?
Someone can enlighten me? What did I overlook?
So they say, one AoA sensor outputting wrong data alone can activate the MCAS erroneously.
If that is so, which engineering workgroup at Boeing could in their sane minds design such a system, that is supposed to save you from a stall but instead:
- decisively flies you into the ground
- on a calm sunny cloudless day
- with a (except from the AoA sensor) perfectly functioning airplane and engines
- with the same system getting indications for:
- positive vertical (upward) speed within normal margins
- positive horizontal (forward) speed and acceleration within normal margins
- secondary parameters like radar AGL data, GPS groundspeed
- last but not least two pilots, able to look out of the window and able to assess AoA visually
Why would an engineer think it is a good idea to implement such a system that ignores all other available data (which indicates nothing like a stall)? Even if you want to take the pilot/human out of the equation, assuming he put the airplane into an attitude that will result in a stall in the first place, you still have lots of other available data the system can read, that tells it that you are in fact not stalling and that most likely the AoA sensor is telling you nonsense.
Probably the MCAS subsystem will enter the course books of engineering schools, as a textbook example of AS, artificial stupidity, a system designed to be stupid, when you actually need a smart system.
Or are these engineers disciples of the Church of the AoA sensor, since they believe the one and only AoA sensor never fails?
Someone can enlighten me? What did I overlook?
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Why doesn’t Boeing do what another OEM didn’t hesitate to do?
On May 24th 2011 a Dassault Falcon 7X experienced a pitch anomaly resulting in a sudden and rapid pitch up in Malaysian airspace. This was recovered by some quick and good thinking on the part of the flying pilot.
2 days later, the manufacturer asked EASA to ground the entire fleet. One day later, the FAA followed.
A key Dassault employee acknowledged that ‘our design was not perfect’. Pretty honorable thing to do for a (rightfully) proud French engineer.
Shouldn’t Boeing do the honorable thing, too?
(see article below)
2 days later, the manufacturer asked EASA to ground the entire fleet. One day later, the FAA followed.
A key Dassault employee acknowledged that ‘our design was not perfect’. Pretty honorable thing to do for a (rightfully) proud French engineer.
Shouldn’t Boeing do the honorable thing, too?
(see article below)
Gender Faculty Specialist
Most definitely is. I haven't seen the Lion Air data so I don't know if it ran full forward and stayed there or something else. Obviously startle factor might play a part as well but I'm not sure how startling the trim running slowly forward would be but maybe combined with the stall warning going off wouldn't encourage you to haul back as hard as you can.
I'm only saying that it is controllable at either extreme. Just.
I'm only saying that it is controllable at either extreme. Just.
Engineer here - trying to look at MCAS out of the box...
So they say, one AoA sensor outputting wrong data alone can activate the MCAS erroneously.
If that is so, which engineering workgroup at Boeing could in their sane minds design such a system, that is supposed to save you from a stall but instead:
-decisively flies you into the ground
-on a sunny cloudless day
-with a (except from the AoA sensor) perfectly functioning airplane and engines
-with the same system getting indications for:
So they say, one AoA sensor outputting wrong data alone can activate the MCAS erroneously.
If that is so, which engineering workgroup at Boeing could in their sane minds design such a system, that is supposed to save you from a stall but instead:
-decisively flies you into the ground
-on a sunny cloudless day
-with a (except from the AoA sensor) perfectly functioning airplane and engines
-with the same system getting indications for:
positive vertical (upward) speed within normal margins
positive horizontal (forward) speed and acceleration within normal margins-secondary parameters like radar AGL data, GPS groundspeed-last but not least two pilots, able to look out of the window and able to assess AoA visually
Why would an engineer think it is a good idea to implement such a system that ignores all other available data (which indicates nothing like a stall)? Even if you want to take the pilot/human out of the equation, assuming he put the airplane into an attitude that will result in a stall, you still have lots of other available data the system can read, that tells it that you are in fact not stalling and that most likely the AoA sensor is telling you nonsense.
Probably the MCAS subsystem will enter the course books of engineering schools, as a textbook example of AS, artificial stupidity, a system designed to be stupid, when you actually need a smart system.
Or are these engineers disciples of the Church of the AoA sensor, since they believe the one and only AoA sensor never fails?
Someone can enlighten me? What did I overlook?
positive horizontal (forward) speed and acceleration within normal margins-secondary parameters like radar AGL data, GPS groundspeed-last but not least two pilots, able to look out of the window and able to assess AoA visually
Why would an engineer think it is a good idea to implement such a system that ignores all other available data (which indicates nothing like a stall)? Even if you want to take the pilot/human out of the equation, assuming he put the airplane into an attitude that will result in a stall, you still have lots of other available data the system can read, that tells it that you are in fact not stalling and that most likely the AoA sensor is telling you nonsense.
Probably the MCAS subsystem will enter the course books of engineering schools, as a textbook example of AS, artificial stupidity, a system designed to be stupid, when you actually need a smart system.
Or are these engineers disciples of the Church of the AoA sensor, since they believe the one and only AoA sensor never fails?
Someone can enlighten me? What did I overlook?
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If it gets to the forward stop there's no rush to get to the stab trim cut outs cos it ain't going any further. Fly it away from the ground, might take both of you, then distribute work load accordingly. It'll take something like 30 odd turns to get it back to somewhere more manageable.
If any of you would like to try manual trim on your next flight, remember to place the stabilizer cut out switches to OFF. That trim wheel can be very nasty if it starts to trim when you hold the handle.
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Could the authorities give effected airlines a quick 'heads up' to remove or divert their aircraft before any bar comes into force?
Most definitely is. I haven't seen the Lion Air data so I don't know if it ran full forward and stayed there or something else. Obviously startle factor might play a part as well but I'm not sure how startling the trim running slowly forward would be but maybe combined with the stall warning going off wouldn't encourage you to haul back as hard as you can.
I'm only saying that it is controllable at either extreme. Just.
I'm only saying that it is controllable at either extreme. Just.
There are many more moving parts to this story, and I’m afraid we’re not just referring to the trim wheel.
Gender Faculty Specialist
Believe me Chesty I’m not attempting to downplay your expertise, nor the basic nuts and bolts required to save this situation. Unfortunately it appears that two professional airline crews have been unable to prevent their aircraft from flying them into the ground/sea.
There are many more moving parts to this story, and I’m afraid we’re not just referring to the trim wheel.
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It has been reported that crew in the following aircraft at holding point (tower frequency) heard the crew advise ATC of 'an airspeed issue' and 'controllability problems' whilst declaring their intention to turn back.
This is not something that appears to be reported at present, which seems odd. (media)
Where is the manufacturer in all this? Funny how the party line always refers to safety, however those in the industry know and understand all too well the commercial prerogative will normally (covertly) take precedence.
Condolences to those people who have been directly affected by this tragic event.
This is not something that appears to be reported at present, which seems odd. (media)
Where is the manufacturer in all this? Funny how the party line always refers to safety, however those in the industry know and understand all too well the commercial prerogative will normally (covertly) take precedence.
Condolences to those people who have been directly affected by this tragic event.