Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] 24

[Sparweb]

This post is the continuation from this series of previous threads:

thread815-445840
thread815-450258
thread815-452000
thread815-454283
thread815-457125
thread815-461989
thread815-466401

This topic is broken into multiple threads due to the length to be scrolled, and images to load, creating long load times for some users and devices.
If you are NEW to this discussion, please read the above threads prior to posting, to avoid rehashing old discussions.

Thank you everyone for your interest! I have learned a lot from the discussion, too.

Some key references:
Ethiopian CAA preliminary report (Link from Ethiopia is now broken. See link from NTSB Investigations below)

Indonesian National Transportation Safety Committee preliminary report

NTSB Investigations

NTSB Safety Recommendation Report: Assumptions Used in the Safety Assessment Process and the
Effects of Multiple Alerts and Indications on Pilot Performance

A Boeing 737 Technical Site

Washington Post: When Will Boeing 737 Max Fly Again and More Questions

BBC: Boeing to temporarily halt 737 Max production in January

Pulitzer Prize, For groundbreaking stories that exposed design flaws in the Boeing 737 MAX that led to two deadly crashes and revealed failures in government oversight.

http://www.sparweb.ca

 

[Comcokid]

So that's where they hide the Chemtrails control!

 

[dik]

Boeing orders:

Boeing had no orders for new airliners in October, its second consecutive month, and orders for 37 of its Max jets came off the books as the company continues to struggle with the grounding of the Max and a pandemic that has crippled the airline industry.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[1503-44]

United will allow passengers to avoid flying on 737-Frankensteins.

https://edition.cnn.com/travel/article/737-max-return-passenger-impact/index.html

 

[dik]

I no longer trust the certifiers... I would avoid them...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Alistair_Heaton]

15% tariffs just got applied to all delivery in EU.

To be honest I can't see then flying in EU for two years anyway. The biggest owner Norwegian is likely to go tits up soon.

 

[waross]

I really don't care how safe the plane is.
I do not trust Boeing.
I will pay a premium to avoid flying on any Boeing aircraft.


Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[Alistair_Heaton]

I wouldn't fly on the max....

The rest of the 737 fleet no problem.

The only other reservations on Boeing types would be to do with etops and engine types. Which isn't really Boeing's fault.

If it's a 747 or 757 proper old school Boeing aircraft go for it.

 

[1503-44]

Now we're talking

 

[waross]

It's not just the plane, Alistair.
I have no trust in Boeing's honesty or corporate values.
They screwed up and killed 189 people.
That was bad enough, but instead of taking immediate corrective measures they stonewalled and refused to act in a morally acceptable manner.
As a result of their failure to act, they killed 157 more people.
I try to avoid doing business with people who are so willing to put my live at risk for financial gain.



Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[Alistair_Heaton]

To be honest I wouldn't put any more trust in anyone else in the industry be it the operators or the OEM's

 

[Alistair_Heaton]

https://canadianaviationnews.wordpr...boeings-737-max-set-for-wednesday-by-u-s-faa/

But I suspect its not going to be a boon for the bank balance as they think. I suspect it will force a number of airlines into bankruptcy if they insist delivery on their schedule unless they sink the finance onto Boeings books.

Lets hope to what every deity you prefer that one of them doesn't crash in the next year. The situation is utterly ripe for a none related crash to the certification issues. Aircraft sat on the ground for 18 months plus aircraft really don't like being on the ground. Expect a huge list of gear, electrical and flap issues over the next 6 months. Its nothing to do with the original issues with the MAX just long term storage.

 

[LittleInch]

Here's the announcement

https://www.faa.gov/news/updates/?newsId=93206

The AD runs to 115 pages(!)

https://www.faa.gov/foia/electronic_reading_room/boeing_reading_room/media/737_AD_2019-NM-035fr.pdf

I'll let someone better qualified than me digest that.

Talks about adequately separating airplane wiring and has emasculated the MCAS system, so it is now virtually useless as far as I can see (lower stab angle movement, only operates once per flight high AOA and then resets) and can be held against by column movement. Plus all the checking one to the other (5.5 degrees difference it all shuts down)

The AD seems to be addressing all the comments and issues raised by the various parties.

Looks like the stick shaker is still there.

Basically it's all about - we've fixed MCAS from going off so now we don't need to do anything to address the other issues which appeared along the way....

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[dik]

LittleInch... I think that Alistair summed it up, "Lets hope to what every deity you prefer that one of them doesn't crash in the next year."

I still won't fly on one and wonder what companies would purchase this somewhat tarnished craft.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[LittleInch]

The argument seems to be that yes you need MCAS in order to meet the requirement to have increased force on the controls as you pull back at high AoA when everything is working as it should.

However if MCAS is inoperative ( now for multiple reasons), this is OK as this apparently this single fault does not prevent "continued safe flight and landing" and that the pilot can stop the plane increasing the AoA and therefore potentially going into a stall by pushing forward on the control column(!!).

WOW

There's no particular mention I can find of how they have managed to reduce the amount of nose down trim required from previous to now and still have the same effect.

It seems any deactivation also kills the Speed Trim system. I've never quite worked out what this does, but is that an issue now?

They dismissed the return to the two switch system as now not being required because they've made the system so safe and also dismissed the force needed to manually trim the plane for the same reason. Also they state that they don't believe the manual system can't be used.

So there we have it.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[dik]

So, you are saying that if it activates and you don't need it, you can disable it, and you can fly the craft fine without it... have to shake the sawdust out...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Sparweb]

Well, as the news has trumpeted all morning, the AD has been revised with a means of compliance: a series of service bulletin remedies and training requirements to be fulfilled, then the planes can reenter service in the USA. Europe has indicated that they're not far behind, and Canada has sent mixed messages, both acknowledging that the process is nearly complete, but at the same time it's not good enough, yet.

I can't square the circle on the necessity of the trim VS the necessity of the flight control feedback forces, the issue that started it all. Plenty of other issues that have reared up, such as pilot training (in sim's or on the sofa) cockpit advisory confusion, ability to disable items such as the trim and the stick pusher, the stab's range of motion, the might and muscle needed to turn the trim wheels, and the proportional feedback that the yoke is supposed to give the pilots - and that's just off the top of my head (I may have missed some important ones).

At this time, Boeing and their operators have access to the maintenance and upgrade data that defines what changes are required before flight. They don't so much define what needs to be done, but instead they "embody Alert Service Bulletin #####" and so on, which cross-references to a document I don't have. The general public only has the records published so far from the FAA, which don't shed much light, yet. I'm still looking.

Trust Dominic's team in Seattle to get their hands on it soon, and offer us a run-down. It ain't over yet, I bet.

http://www.sparweb.ca

 

[LittleInch]

Dik,

What it means is that if mcas goes off when it shouldn't then the reduced angle it now moves the stab compared to before (I can't find out how much less) can be over identify by pulling the control column alone. This gives the pilots time to figure it out and trim the stab back into the right position.

Then unless the AoA goes back to normal mcas shouldn't keep going off.

But if mcas is disabled and you go into one of these high AoA situations that is now ok as the pilot can stop the plane going into a stall by pushing forward on the control column contrary to the normal requirement about increasing force as the AoA increases.

I presume the fault then needs to be fixed before the plane can fly again

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[dik]

new news:

"After nearly two years and a pair of deadly crashes, U.S. Federal Aviation Administration has cleared Boeing’s 737 Max for flight.

The nation’s air safety agency announced the move early Wednesday, saying it was done after a comprehensive and methodical 20-month review process.

Regulators around the world grounded the Max in March 2019, after the crash of an Ethiopian Airlines jet. That happened less than five months after another Max flown by Indonesia’s Lion Air plunged into the Java Sea. A total of 346 passengers and crew members on both planes were killed.

The planes won’t return to the skies for a while. The FAA says it must approve pilot training changes for each U.S. airline and airlines must perform required maintenance on the planes."

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[dik]

Thanks... my mistake... I was trying to be cute...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Alistair_Heaton]

Speed trim system was another fudge to correct dodgy aerodynamics as far as I can tell.

They don't have to actually correct all these issues just prove that there is 1 to a very large number that the issue will not cause a fatality. Half the stuff apparently they couldn't force them to change because there is no regulation that requires it to be so. eg the manual trimming and stick shaker stuff.

They are all going to be inspected as well for production debris and also some lightning conductivity stuff By FAA engineers not Boeing. This may throw up other issues.

There is also a rather large wiring mod to be done.

There is apparently legal stuff with law changes currently going on to do with the FAA which might also have had an effect.

Personally I think they had basically hit the end of the road with the changes they could make and not scrap all the aircraft that they have already made.

We shall see what the other regulators com up with. I have a gut feel something may come up when the FAA starts doing airworthiness inspections. But as I have said before its the long term storage issues which concern me the most after it starts flying again. Gear issues, flap issues, fume events, bizarre electrical issues etc.