More MAX information

[Zimme83]

http://www.ecaa.gov.et/documents/20435/0/Preliminary+Report+B737-800MAX+%2C%28ET-AVJ%29.pdf/4c65422d-5e4f-4689-9c58-d7af1ee17f3e initial report.

2I N I T I A L   F I N D I N G SOn the basis of the initial information gathered during the course of the investigation, the following facts have been determined:
The Aircraft possessed a valid certificate of airworthiness;
The crew obtained the license and qualifications to conduct the flight;
The  takeoff  roll  appeared  normal,  including  normal  values  of  left  and  right  angle-of-attack (AOA).
Shortly  after  liftoff,  the  value  of  the  left  angle  of  attack  sensor  deviated  from  the  right  one and  reached  74.5  degrees  while  the  right  angle  of  attack  sensor  value  was  15.3  degrees;then after; the stick shaker activated and remained active until near the end of the flight.
After  autopilot  engagement,  there  were  small  amplitude  roll  oscillations  accompanied  by lateral acceleration,  rudder  oscillations  and  slight  heading  changes;  these  oscillations also continued after the autopilot disengaged.
After the autopilot disengaged, the DFDR recorded an automatic aircraft nose down (AND) trim command  four  times  without  pilot’s input.  As a  result,  three motions  of  the  stabilizer trim wrere corded.The FDR data also indicated that the crew utilized the electric manual trim to counter the automatic AND input.
The  crew  performed  runaway  stabilizer  checklist  and  put  the  stab  trim  cutout  switch  to cutout position and confirmed that the manual trim operation was not working.

[ACE]

Nevermind.

[bustr]

How do two data sensors sensing for the same conditions show two different conditions of such extremes? In that scenario which one is the MCAS supposed to take as valid, and did the MCAS never accept the pilot input to disengage? Can they tell if the MCAS itself was faulty as a system and no system diagnostic was in place to signal that to the crew?

[FLS]

The preliminary report says the MCAS was disengaged and the pilots were unable to manually trim.

If they were unable to trim because the yoke wasn't neutral isn't that a training issue?

[Vraciu]

http://www.ecaa.gov.et/documents/20435/0/Preliminary+Report+B737-800MAX+%2C%28ET-AVJ%29.pdf/4c65422d-5e4f-4689-9c58-d7af1ee17f3e initial report.

CYA document by the E-topians.   I noticed the partial quote ending at a convenient point. 

[Zimme83]

How do two data sensors sensing for the same conditions show two different conditions of such extremes? In that scenario which one is the MCAS supposed to take as valid, and did the MCAS never accept the pilot input to disengage? Can they tell if the MCAS itself was faulty as a system and no system diagnostic was in place to signal that to the crew?

One sensor showed an AOA of ~70 degrees so it was without a doubt faulty... Even the system itself should have been able to recognize that.

The preliminary report says the MCAS was disengaged and the pilots were unable to manually trim.

If they were unable to trim because the yoke wasn't neutral isn't that a training issue?

You mean exercise issue i guess since, as discussed yesterday, is the load too high on the control surfaces you wont be able to move the trim wheels if you are not superman.

[Vraciu]

One sensor showed an AOA of ~70 degrees so it was without a doubt faulty...

You mean exercise issue i guess since, as discussed yesterday, is the load too high on the control surfaces you wont be able to move the trim wheels if you are not superman.

#Equality

Gawd forbid you tell a 105 lb. man or woman they’re not qualified.

Hey, at least the Boeing has a manual trim wheel.   In every jet I’ve flown you’re stuck with what you have once you engage the cutout.

[pembquist]

Begging the question doesn't mean what you think it means. It's the fallacy of assuming the conclusion. It's often misused to mean suggesting a question or leading to a question. Assuming the conclusion is a staple of forum posts so there's plenty of opportunity to use it properly. 

For the love of god man don't be a pedant it is unseemly.  I speka da engrish good and I know full well the "appropriate use" of the phrase is but I find the vernacular usage actually useful as opposed to the slightly obscure meaning with regard to sophistry.

However to protect your delicate ears I have fixed it for you, all I ask is that you punch the next person that says irregardless full in the face and if somebody raises the issue of how something impacted something else or starts to explain how they architected the solution I want you to shoot them dead without compuction.

[pembquist]

We build items for chemical plants, NASA, Military, Public..... we do not control how they install or use what we build.

Good point However I would argue that aircraft are different because how you use them legally is in some part determined by the manufacturer and the FAA. In the case of the MAX my understanding is that more of that decision was done by the manufacturer, specifically with regard to deciding that they did not have to develop new training materials or require training specific to the MCAS. Clearly if a pilot breaks the law by flying an airplane by themselves in conditions that require a minimum crew size of more than one the manufacturer is not responsible (except maybe in minds of plaintiffs counsel ) but failing to require a minimum crew size for conditions when in fact the conditions do require a minimum crew would be a mistake on the manufacturers part. Honest mistake, dishonest mistake who knows. I don't know enough about the details of aviation law and certification but I do know that more of the job of it is being done by the manufacturer. I am not saying that this is Boeing's fault but I am saying I can see an obvious argument why in some circumstances they might be considered partially at fault because of a bunch of rules and training materials and not mechanical parts.

[Shuffler]

You can go buy a car or a bus with no license. It is not the manufacturer that requires a license.

Is Boeing responsible for licensing pilots or is it the airlines/end user?

I do not hold a pilots cert but I have flown all over in small single and twins with family members that do.

I am licensed to fly my cartoon 38 and I get carded often.

[FLS]

...
You mean exercise issue i guess since, as discussed yesterday, is the load too high on the control surfaces you wont be able to move the trim wheels if you are not superman.

No I don't mean exercise. I read the comment. It said the trim is hard to turn when the yoke isn't trim neutral. That means when you hold the yoke back the trim is harder to turn, release the yoke and the trim is easier to turn.  That matches the preliminary report.

[FLS]

For the love of god man don't be a pedant it is unseemly.  I speka da engrish good and I know full well the "appropriate use" of the phrase is but I find the vernacular usage actually useful as opposed to the slightly obscure meaning with regard to sophistry.

However to protect your delicate ears I have fixed it for you, all I ask is that you punch the next person that says irregardless full in the face and if somebody raises the issue of how something impacted something else or starts to explain how they architected the solution I want you to shoot them dead without compuction.

Calm down. Have a nice glass of cold water. I'm afraid I lack the poor impulse control you recommend.

I literally said it was an OT nitpick.   

[Zimme83]

No I don't mean exercise. I read the comment. It said the trim is hard to turn when the yoke isn't trim neutral. That means when you hold the yoke back the trim is harder to turn, release the yoke and the trim is easier to turn.  That matches the preliminary report.

But releasing the yoke will drop the nose. So it assumes that you have enough altitude to work with and it doesnt really seems like they had that much to work with.

[FLS]

But releasing the yoke will drop the nose. So it assumes that you have enough altitude to work with and it doesnt really seems like they had that much to work with.

The short time span is part of the argument for more experienced crews.
 
I have no idea how difficult the trim wheel is to turn relative to how much the yoke is pulled back.

I'm not saying I know why they crashed.

So far we don't know.  The Ethiopian preliminary report is what was expected. It may be true.

It doesn't answer what happened.

[Vraciu]

But releasing the yoke will drop the nose. So it assumes that you have enough altitude to work with and it doesnt really seems like they had that much to work with.

You don't need to neutralize the yoke to use the manual trim!   Stop talking already.   

Meanwhile.  These two had 159 hours COMBINED on the 737.   That's a Green-On-Green that is generally prohibited by USA carriers.