Boeing 737 Max8 Aircraft Crashes and Investigations [Part 5] 19

[Sparweb]

This is the continuation from:

thread815-445840
thread815-450258
thread815-452000
thread815-454283

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

Indonesian National Transportation Safety Committee preliminary report

A Boeing 737 Technical Site

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

No one believes the theory except the one who developed it. Everyone believes the experiment except the one who ran it.
STF

 

[Alistair_Heaton]

I think there is also issues with rear mounted engines with uncontained disk failures and protecting the control runs after Soux I think the regs changed.

With rear mounted then they have to have a T tail which brings issues with a thing called super stall. When the aircraft stalls the vortex's off the wings then cover the elevator airflow so the elevator becomes ineffective for reducing angle of attack. I believe that the rear engine biz jets have such a huge power to weight ratio they can power out of it but that's into Sparweb's area of expertise.

Also you have issues with services and fuel lines as the fuel is normally around the same place as the centre of lift and C of G. Otherwise you get colossal trim changes between full and empty. Fuel is heated during flight and returned to the tank if this can't happen then the aircraft will have to fly lower which makes it less effecient. So you have two fuel pipes to the engines both capable of shifting tons per hour long fuselage and that a huge penalty in weight for armoured large bore high pressure fuel pipe.

Those are the reasons why they have gone pod underwing mounted engines in the last 40 years that I can think of off the top of my head, but I am sure there is loads more.

The high wing V low wing I am not so sure about. The BAe 146 wasn't a bad plane in fact those that flew it said it was pretty good for 5 hairdryers flying in formation with virtually a complete services spares back carried but called an APU (hence 5 hairdryers not 4 hairdryers in formation)

Anyway it seems the regulators are fighting back in the media battle with Boeing and re certification in December. Its good to hear from Sparweb that the person that sent that email is so well regarded and by the sound of it is an old school engineer and at that point in his career bullying will just not work and he will do what's morally right not what the Bean counters/politicians want. Quiet what would happen if they recertified it and there was a public announcement that regulator engineers world wide don't think it should be flying I really don't know. All it would take is 2-3 from each authority towards the end of their careers to make a statement and the 737-dodo will come into excisitance.

Just found this

https://theaircurrent.com/aviation-...to-2020-ryanair-model-faces-new-design-issue/

 

[Alistair_Heaton]

The RVI report is out today for the 738 crash during a windshear escape manoeuvre.

It has quite a few pics of various aircraft components including screwjack.

Also has a surprisingly high content about the cockpit environment.

It also has details about trimming forces on the 737 NG.

https://www.mak-iac.org/upload/iblock/3d1/report_a6-fdn_eng.pdf

 

[moon161]

^ Do you think there was an MCAS activation in the transition to climb out after the go around with the flaps coming up?

EDIT: Nevermind, not the same plane, not a MAX

 

[Alistair_Heaton]

As you say different aircraft so the speed trim system will have been running which is a common augment to both.

It was more for situations where the aircraft has to get to high alpha on purpose. In the situation in the above report the pilots would have had none linear control forces to deal with as well on a max no mcas.

 

[Comcokid]

IRStuff - I too am leery of 'The Atlantic' as a news source. But as the Boeing 787 battery incidents, and later as the 737 Max incidents happened, I thought about what I had read and heard over the years about the internal culture changes at Boeing. For me the executive management move to Chicago away from all of the company operations evidence that the Boeing of old was gone. The Atlantic article has a good summary of what I have heard and gathered about Boeing over the years.

I experienced a 'reverse takeover' at a company I worked for. A couple high-up managers were hired from a failing corporation, who then made way for more of their buddies, and soon similar flawed management culture and decisions took hold and the company began to circle the drain. I left. Today that company exists only as a marketing brand-name-only owned by a foreign firm.

Then, I worked for an 25+ Mil engineering-oriented company. One that had 90% of it's niche high-end technical market and had dominated it for two decades. The company was bought by a large acquisition corporation who's focus was quarterly return-on-the-dollar. They brought in a lot of newly minted MBA's with no industry background. Within 4 years they had destroyed this company. Today, a core group of the original engineers who were 'downsized' as an annoying expense now work for a competitor who has taken about 60% of that niche market for themselves. The original company and it's brand name no longer exist, unless you go to eBay where their old products still have demand.

The Boeing of today is not the Boeing of yesterday. Maybe they can change and get their successful technical culture back. The technical culture is not the one at the engineering levels, but is one that has to start at the executive levels and permeate down from the top.

 

[Alistair_Heaton]

How many MBA's work at the FAA?

They are also double digit percentage to blame for this thing having even one innocent clueless passengers bum in a max.

 

[LittleInch]

Having gone through the report this looks like a "manual" version of MCAS to me.

Twelve (12) seconds holding the trim button down and going negative G looks very much like the end of the ET plane where they went too fast and went negative G when they turned the trim back on and then MCAS kicked in.

I didn't realize that max power and a light plane with flaps down would require such a control column forward force (unless I've read this wrong) to prevent too fast a climb.

But an interesting thought process about the difference between the trim on a light aircraft versus a large commercial aircraft where the elevator trim is so much more powerful.





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

 

[Alistair_Heaton]

Light aircraft accelerate fast.

When I say light it means the power to mass ratio is high.

Lift = 1/2 rho v^2 Cl area the elevator on the Ng is huge. So as you accelerate the stick forces change very rapidly.

The pitch couple of those powerful engines is also huge as they go from 40% Nr up to ToGa max chat power.

Some of us cheat and put a bit of power on pitch to the GA attitude start climbing and get the gear up and flap to climb flap, while doing this we trim the aircraft from approach trim to climb trim. Then we feed in the rest of the power. Unfortunately you can't do that with windshear escape. It all happens extremely fast.

 

[IRstuff]

I've no doubt that the article represents some version of what happened, but like I say, I think Boeing was already on that road, having decided to expand by acquisition and to depend on subcontractors, which were financial and political decisions. They had instituted a plan to become a "system of systems" integrator, spreading development and manufacturing to subcontractors to garner political support and influence. Northrop Grumman and others became major suppliers of wing systems, etc., at least a decade before the purchase of McDonnell Douglas.

Boeing lost its way in other arenas, in any case; what happens at the top isn't necessarily impactful at the bottom. Their vaunted "world class" systems engineering was built on a premise that assumed that the "process" was everything, and that knowledge and experience was irrelevant. Boeing has failed miserably to manage programs such as FCS, because while they had the process, they had zero experience in ground systems, resulting in massive failures in requirements understanding, allocation, and flowdown. And again, since they depended heavily on subcontractors who had their own inertias and cost incentives.

Hiring people from failed endeavors, in of itself, isn't necessarily a bad thing. Ostensibly, someone from a failed operations has had the opportunity to learn from a bunch of mistakes. In some instances in Silicon Valley, people with failure experiences were actually highly sought after. We used to joke at another company and called ourselves "F- University," where you learn what not to do. The caveat, of course, is that there are thousands of ways to fail, but only a few ways to succeed; Edison supposedly said, "Results? Why, man, I have gotten lots of results! If I find 10,000 ways something won't work, I haven't failed. I am not discouraged, because every wrong attempt discarded is often a step forward...."



TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

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[Alistair_Heaton]

Today's news is that the FAA have pulled Boeing's ability to issue cert of airworthiness certs and also export permits for the max.

Which basically means every MAX now has to be inspected by FAA personnel physically and also a paperwork audit carried out after Boeing has released it. Normally the OEM would release and issue paperwork using their own qa system during manufacture.it could easily triple the time taken to process the parked aircraft.

Second item is easa and uae have refused FAA certification of the 777x so Boeing will have to run two/three sets of certification paperwork.

 

[Sparweb]

Today's news is that the FAA have pulled Boeing's ability to issue cert of airworthiness certs

That was always in the cards.

It's really surprising how deeply embedded Boeing has become in the FAA organization. Here's an "org-chart" for a branch of the FAA:

Looking carefully at all the offices listed, you'll see an array of FAA regional offices named - and one company.
Boeing actually has two FAA offices: the BASOO (top of the left column) and the Boeing CMO (second column).

I have very little moral high-ground to stand on. As a Canadian, I know just how overwhelming Bombardier has been with Transport Canada.
And nobody would be surprised if I accused EASA of doing Airbus's bidding sometimes.

http://www.sparweb.ca

 

[Alistair_Heaton]

more than sometimes....with easa.

They are all at it. Just the FAA has been caught with there pants down with a sheep in front of them.

 

[moon161]

That's a BAAAAAAAAAAAAD place to be.

 

[RVAmeche]

With regards to the 737 NG, Boeing will be fined #3.9 million

Boeing knowingly submitted aircraft for final FAA airworthiness certification after determining that the parts could not be used due to a failed strength test.

In mind that kind of fine is an absolute joke. $3.9 million is a rounding error for a company like Boeing.

 

[Alistair_Heaton]

The cost of late delivery penalties on the aircraft will have been more on 130 aircraft.

 

[IRstuff]

$3.9 million is the rounding error on late penalties. Assuming the oft-quoted $5000/day penalty, they're in the $250 million range for penalties, although they may have made alternative arrangements.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

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[Alistair_Heaton]

Update on that "documentation" issue which Boeing said was due to changing of required format. Quick fix was said and then nothing for over a month now.

https://theaircurrent.com/aviation-...sion-adds-new-complication-to-737-max-return/

Rumour has it that it wasn't just MCAS related procedures that were the issue it was pretty much across the board with the 737 funny's which have been present, some of them since the 60's. But as the NG has such a good safety record they don't want to touch them with a barge pole.

Boeing are contending that everything is fine because nobody crashed and they sorted it out by doing their own thing not what the book says. So release the aircraft and ipad training will do....

More on the subject giving mid FEB as the easiest date for it being certified.

And it looks like the FAA is growing some balls.

https://www.seattletimes.com/busine...boeing-ceo-to-back-off-over-737-max-schedule/

 

[moon161]

737 Max production scheduled to stop in January

https://www.bbc.com/news/business-50817124

 

[Alistair_Heaton]

What a horrible thing for 1000's of people to find out just before xmas.

Nothing concrete from this side of the pond.

EASA will have shut down on Friday with nothing going to happen before Jan 2020.

Only rumours that are going around is that Boeing have refused to release the MACAs removed performance to anyone even though its was demanded by JTAR.

The Canadians have issued a bluff that they will certify the aircraft without MCAS if said performance is acceptable. Still no performance provided.

This leads to the suspicion that the MAX flight envelope is uncertifiable under none FBW regulations (and possibly even with them, as well) and only a hardware change will get it flying again.

Another elephant in the basement is because the engine is so far forward and up and is producing lift, has this been accounted for in the fatigue and stress models of the engine pylons and mounts?. And if its still within limits has the model for the Pickle forks been done as well because they will have an additional torque load to deal with. Or have Boeing decided that because the areas of the envelope are not routinely visited that MCAS would trigger, they are going to not change anything even though the safety factor is below norm using Boeings unique risk maths.

Boeings bluffing has been called by the FAA and production shut down. Quite what the fall out from that will be is unknown.

The training side issue is a cover for the real issues. To cover the cost of penalty clauses in regards to training is well under 500 million $, Beginning of Dec the bill so far is estimated to be 9 billion $ without including late delivery payments and compensation to airlines. The day the production shuts down it will be 11 billion. So if it was just the case of a software upgrade and then stick everyone through a Sim session after being grounded for 9 months when your racking up costs a 1 billion a month then its a no brainer to pay the penalty. Get the plane flying again start delivery's and keep the production and parts side of things running.

Boeing has to release a statement mid Jan to wall street. BUt even with that many doubt that it will even a fraction of the story about what's going on.

 

[davefitz]

Prior CEO DM is out, new CEO is in today.

"...when logic, and proportion, have fallen, sloppy dead..." Grace Slick