Author Topic: More MAX information  (Read 35533 times)

Offline ACE

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Re: More MAX information
« Reply #225 on: April 03, 2019, 01:12:58 PM »
From what I've read there is a bypass  switch on the yoke that doesn't work the same way as turning MCAS off on the console. This may have been the critical pilot mistake.

Good point. Still, the MCAS was faulty. Granted there are measures in place to by pass it. It has *probably* caused two crashes. It should be adjusted or reengineered. In my world of fixing equipment nothing has just 1 sensor that’s just bad design. Everything has backups. It seems there’s an underlying issue with the MCAS fix it first.
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Offline Zimme83

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Re: More MAX information
« Reply #226 on: April 03, 2019, 01:16:30 PM »
From what I've read there is a bypass  switch on the yoke that doesn't work the same way as turning MCAS off on the console. This may have been the critical pilot mistake.

Ive seen nothing that suggest that they didnt use the correct cutoff switch. But as was demonstrated in the now deleted video in my link, at the speed they where flying at the aerodynamic loads would have prevented them from trimming the plane manually.

Quote
In subsequent discussions with MentourPilot, a YouTube channel with millions of viewers, I was informed this would probably not be true for higher speeds. MentourPilot’s experience when examining hundreds of pilots as Type Rating Examiner for the 737 was the elevator got exceedingly heavy at higher speeds and manual trimming at the slightest miss-trim of the Stabilator from neutral Yoke forces was very difficult.

He also pointed out the high speeds observed in ET302’s FlightRadar24 trace (Figure 1) were logical. It’s a consequence of following the Emergency checklist for “IAS disagree” (IAS is Indicated Airspeed, i.e. the dynamic air pressure experienced by the aircraft) after takeoff.

The combination of the preceding checklist followed by an MCAS Trim Runaway checklist could create a situation where manual trimming after a Trim Cut-Out would be difficult to impossible and would require non-checklist actions.
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Offline FLS

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Re: More MAX information
« Reply #227 on: April 03, 2019, 01:34:28 PM »
Ive seen nothing that suggest that they didnt use the correct cutoff switch. ...

Flight path.

Offline Zimme83

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Re: More MAX information
« Reply #228 on: April 03, 2019, 01:37:29 PM »
Flight path.

does not suggest that. Especially if the system was reactivated..
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Offline FLS

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Re: More MAX information
« Reply #229 on: April 03, 2019, 01:44:56 PM »
Good point. Still, the MCAS was faulty. Granted there are measures in place to by pass it. It has *probably* caused two crashes. It should be adjusted or reengineered. In my world of fixing equipment nothing has just 1 sensor that’s just bad design. Everything has backups. It seems there’s an underlying issue with the MCAS fix it first.

The pilot is the backup. Works in the US.

If you're fighting the trim you turn the trimmer off and trim manually. Like our 'combat trim' in AH.

Bypassing the trim so it automatically re-engages is the wrong reaction.

BTW if you ever turned on auto climb in AH when too slow to climb you quickly notice a problem.

does not suggest that. Especially if the system was reactivated..

Was it reactivated manually or automatically?


Offline Zimme83

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Re: More MAX information
« Reply #230 on: April 03, 2019, 01:52:05 PM »
The pilot is the backup. Works in the US.

If you're fighting the trim you turn the trimmer off and trim manually. Like our 'combat trim' in AH.

Bypassing the trim so it automatically re-engages is the wrong reaction.

BTW if you ever turned on auto climb in AH when too slow to climb you quickly notice a problem.

Was it reactivated manually or automatically?



Quote
MentourPilot’s experience when examining hundreds of pilots as Type Rating Examiner for the 737 was the elevator got exceedingly heavy at higher speeds and manual trimming at the slightest miss-trim of the Stabilator from neutral Yoke forces was very difficult.

You missed some vital info... If your auto trim is messing with you, you disable it and finds out that you cannot trim manually. What are you doing then?

Ethiopian btw owns one of the 4 MAX simulators currently in operation, so in theory they could have practiced the procedure in the sim - too bad its not featured in the MAX-simulator...
« Last Edit: April 03, 2019, 01:54:57 PM by Zimme83 »
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Offline Busher

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Re: More MAX information
« Reply #231 on: April 03, 2019, 05:20:54 PM »
Zimme and Ace, may I presume to ask how much experience each of you have accumulated flying transport category or military jet aircraft? Your assuredness would suggest thousands of hours.

Thanks.
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Offline FLS

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Re: More MAX information
« Reply #232 on: April 03, 2019, 05:49:58 PM »


You missed some vital info... If your auto trim is messing with you, you disable it and finds out that you cannot trim manually. What are you doing then?

Ethiopian btw owns one of the 4 MAX simulators currently in operation, so in theory they could have practiced the procedure in the sim - too bad its not featured in the MAX-simulator...

You are referring to the 'high speeds' normal at takeoff?  :headscratch:  So when do you suppose manual trim actually works?


Offline ACE

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Re: More MAX information
« Reply #233 on: April 03, 2019, 06:00:15 PM »
Zimme and Ace, may I presume to ask how much experience each of you have accumulated flying transport category or military jet aircraft? Your assuredness would suggest thousands of hours.

Thanks.

I have about 30 mins of flying time in a Cessna. To be fair busher, I don’t have to have a PHD in aeronautics. I don’t have to have thousands of hours to form an opinion based on information gathered. Arguing from authority never is a good argument busher. There’s a couple things that 100% happened. The MCAS system is known to be faulty. Why not fix it?  The pilots where not trained well. Why not fix it? 
I’m all for grounding the airplane until the MCAS is fixed. Why fly something, even if it can be simply shut off with a few steps, that is total fubar? I put people over profits.  Why can’t we just fix the MCAS and ship out orders to immidately train the pilots further?  Obviously the USA pilots have either more training, or simply been lucky with it not total screwing them on take off or final.

I just want the MCAS fixed. No need to really argue about that we all know it’s a ongoing issue. Why risk lives?
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Offline Busher

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Re: More MAX information
« Reply #234 on: April 03, 2019, 06:24:25 PM »
I have about 30 mins of flying time in a Cessna. To be fair busher, I don’t have to have a PHD in aeronautics. I don’t have to have thousands of hours to form an opinion based on information gathered. Arguing from authority never is a good argument busher. There’s a couple things that 100% happened. The MCAS system is known to be faulty. Why not fix it?  The pilots where not trained well. Why not fix it? 
I’m all for grounding the airplane until the MCAS is fixed. Why fly something, even if it can be simply shut off with a few steps, that is total fubar? I put people over profits.  Why can’t we just fix the MCAS and ship out orders to immidately train the pilots further?  Obviously the USA pilots have either more training, or simply been lucky with it not total screwing them on take off or final.

I just want the MCAS fixed. No need to really argue about that we all know it’s a ongoing issue. Why risk lives?

Thank you. That's what I suspected. Your entire argument is founded in "I just want the MCAS fixed" which presumes in its very content that it was broken to start with. The media certainly believes that.
One level of safety does not exist within the airlines of the United States let alone throughout the world.
Pilot candidate experience levels are dropping worldwide but airlines still need to crew their fleet and they will do so with lowest financial commitment possible.
I suggest to you that what needs fixing is the requirement to place highly trained and experienced pilots in the cockpit of all airliners without regard to the cost of assuring they have that experience. It is that experience that leads aircrews to react calmly and correctly in stressful situations when they do arise.
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Offline Vraciu

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Re: More MAX information
« Reply #235 on: April 03, 2019, 06:27:42 PM »
Redacted.    So many idiots.   So little time. 
« Last Edit: April 03, 2019, 06:37:26 PM by Vraciu »
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Offline Vraciu

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Re: More MAX information
« Reply #236 on: April 03, 2019, 06:28:17 PM »
Thank you. That's what I suspected. Your entire argument is founded in "I just want the MCAS fixed" which presumes in its very content that it was broken to start with. The media certainly believes that.
One level of safety does not exist within the airlines of the United States let alone throughout the world.
Pilot candidate experience levels are dropping worldwide but airlines still need to crew their fleet and they will do so with lowest financial commitment possible.
I suggest to you that what needs fixing is the requirement to place highly trained and experienced pilots in the cockpit of all airliners without regard to the cost of assuring they have that experience. It is that experience that leads aircrews to react calmly and correctly in stressful situations when they do arise.

Well said. 

I’m no apologist for Boeing.   I will take an Embraer 145-series over any plane built today...I might, maybe, even take the the ERJ-170...but to trash the 737 MAX absent hard evidence is just nuts.  Maybe it’s whacked, maybe it’s not.    We don’t know.  But as you noted, if the system is messed up the only salvation when the SHTF is an experienced and well-trained crew.   

The one thing you do NOT do when you shut down the system that’s trying to kill you is to turn it back on.

I’ve flown some trim runaway scenarios in the sim.   I’ve asked to let it go further than when I caught it to see the degree of effort involved.   They can be a b-tch.    I’ve had to put my feet on the foot rests under the display panels and use them to help me leverage the controls (after having been out of the gym a bit too long).   It’s not fun.   But it’s doable. 

As we accelerate (when Ops Normal) we trim nose down, so going faster might have helped that crew.  It might not have.  But putting the darned trim back online after a runaway is a sure way to become worm food. 

Also, any hint or suggestion we don’t care about lives flies in the face of our job descriptions/responsibilities as Captains and First Officers.    That’s always rule number one for any professional pilot:  SAFETY. 

« Last Edit: April 03, 2019, 08:49:56 PM by Vraciu »
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Offline MiloMorai

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Re: More MAX information
« Reply #237 on: April 03, 2019, 06:56:31 PM »
And Self Preservation as you are the first to the scene of the crash.

Offline Vraciu

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Re: More MAX information
« Reply #238 on: April 03, 2019, 07:00:30 PM »
And Self Preservation as you are the first to the scene of the crash.

Amen, brother. 

If I kill myself well, okay, so be it.   However, if I kill dozens of people along with me because I was at fault in some way...   That’s not a legacy (pun) I ever want attached to my name.   But I sure don’t want to die first by default, either.

I have ten thousand hours and not an ounce of courage.   I’ll leave bravery to guys with ejection seats.   My personal mins are pretty large and I’m okay with that.   I’m also an airplane nerd.  I have the QRH memorized (cover to cover—or close to it), at least for anything that can kill me.  The day may come where I can’t read it for some reason, like smoke in the cockpit, a busted out windscreen, an incapacitated co-pilot, or fighting a control problem.   I need to know it intimately enough to salvage the situation.    That’s what they pay me to do after all.

Anyone can be a pilot I suppose.   That said, just because monkeys can fly in outer space doesn’t make them astronauts.   

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« Last Edit: April 03, 2019, 08:47:53 PM by Vraciu »
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Offline pembquist

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Re: More MAX information
« Reply #239 on: April 03, 2019, 09:35:05 PM »
Well this has been a fun 16 pages! I personally don't think there is much point forming an opinion about this until there is an actual conclusion, this goes both ways by the way.

As a LAYPERSON what I see as a problem is the mix of comprehensive and non comprehensive aircraft design training and operation. What I mean is with the complexity of the industry and the systems involved it isn't really clear who is responsible for the safe operation of the plane or maybe more accurately where the boundaries are between the responsible parties. It seems like part of the certification of these kinds of aircraft includes the certification (this might not be the right word, apologies,) of the crews that operate and maintain them. The dodgy bit about the MCAS for me isn't that it malfunctioned it is that Boeing did not "explain" that it existed nor how it worked. Also it seems that the design of the system was a bit less than perfect with the possibility that some initial design constraints about speed change and maximum angle trim were pushed back on in order for the system to provide adequate stall protection. Again the full explanation is not in yet so who knows. There is a strong argument that despite the failure of the MCAS it should have been within the pilot skill envelope to recognize react and disable without much drama. That may well be the case however, should doesn't really help and to my eye the question becomes: if you are selling a jet to customers across the world and you have added a completely new software driven path to the trim actuation system in order to be able to certify that jet with new engines which change the aerodynamics of that jet such that it wouldn't certify without it shouldn't part of the certification of that jet be manuals and training on that system and how do deal with its particular failure?

Another question is if the pilots of some of these airlines are so lousy, should you be selling them airplanes? Don't you have any say as to what the training requirements are for the airplane you produce? It is obvious that there is a nascent conflict of interest between sales/price and cost of safety. At some point you put a price on life and decide just how much you are going to spend to protect it, this is just basic. What becomes an issue is when there is the appearance, valid or not, that some suit has trimmed a little close to the edge. I am not saying this is the case but it is a fact that the normalization of deviance happens in these kind of complicated engineering systems and one of the unfortunate reasons is that there is often the perception that there is a large margin of error built in for safety reasons so a little bit of it can be used up, do that enough times and then there is no more margin.

As for politics, I can only say "of course it is political." Airplanes like defense are hugely political. It is easy to make up a bunch of BS and point the finger and the news is by and large going to mangle the details but all of that aside I don't think that this is a non event that is being blown way out of proportion, (I think it is a little out of proportion,) but the fact that two plane loads of people died demands an answer to the question: how do you keep that from happening again. Given the complexity of the systems, (the planes, the training, the laws, the blah blah blah,) I don't think you can just go "lousy pilots" and wash your hands.

If you read this far you win! :)
« Last Edit: April 03, 2019, 10:47:30 PM by pembquist »
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