Boeing 737 Max8 Aircraft Crashes and Investigations [Part 2] 44

[Alistair_Heaton]

This thread is a continuation of:

thread815-445840


****************************
Another 737 max has crashed during departure in Ethiopia.

To note the data in the picture is intally ground 0 then when airborne is GPS altitude above MSL. The airport is extremely high.

The debris is extremely compact and the fuel burned, they reckon it was 400knts plus when it hit the ground.

Here is the radar24 data pulled from there local site.

It's already being discussed if was another AoA issue with the MCAS system for stall protection.

I will let you make your own conclusions.

 

[WKTaylor]

A friend clued me into reporting by Dominic Gates, long-time-all-things-Boeing reporter for the Seattle Times...

Flawed analysis, failed oversight: How Boeing, FAA certified the suspect 737 MAX flight control system

https://www.seattletimes.com/busine...-max-system-implicated-in-the-lion-air-crash/

Reporter told Boeing, FAA of possible safety issues with 737 Max four days before fatal plane crash

https://www.philly.com/news/nation-world/boeing-max-plane-news-crash-faa-warning-20190318.html

Also, 'Sully' Sullenberger had s some words of concern regarding Boeing and the flight crew... specifically the 200-Hr total time copilot...
Captain Sully Weighs In On Boeing 737 MAX Crash

https://liveandletsfly.boardingarea.com/2019/03/16/sullenberger-737-crash/

There have been several incidents of runaway/uncontrolled stabilizer-trim systems causing mishaps... some caused by jack-screw-stripping failures due to maintenance... some due to inadvertent trim actuation by non-pilots in the pilot's seat [yes-gag-for-real] and these... 737-Max that [at time] appear related to flight control software 'bugs'. Hmmmm... maybe this is why Southwest Airlines maintenance was being fined by FAA for poor practices regarding weight and balance calculations?!

The term 'sneak circuit' applies whenever circuit-designs create unintended electrical/electronic pathways. There appears to be an equivalent concept for computer code... 'sneak-computer-code' or 'sneak-software-code' is very real... leading to unintended consequences if not fully/completely vetted by simulations and flight testing. This 'sneak-software-code' is relevant to aviation as it has been to space exploration.

NOTE. At-least-two-possibly-three Mars orbiters/landers have encountered catastrophic software bugs... and of course there was [quietly covered-over] software bug for the Huygens-probe that landed on Saturn's moon Titan.

NOTE. RE the Huygens probe... the highly calibrated/sensitive transmitter [for precision Doppler tracking on atmospheric entry and parachute descent]... and which was connected to certain sensors and a second landing camera system... was turned-on in 'stand-by mode' to warm-up... but the computer code sequence failed to include a 'turn-on the transmitter and send-data' command-line... so all of that channel-data was 'lost'. Good-thing that the non-precision transmitter worked 'well-enough' to send good quality images/sensor-data and good-enough signal data for Doppler tracking/images.

Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

 

[Alistair_Heaton]

I will admit I fly with 200 hour fresh meat in the cockpit. And I also fly with 1500 hour fresh meat in the cockpit.... To be honest they are both clueless until they get a couple of 100 sectors under their belts sector length doesn't change things. This whole hours as a gauge is utter bollocks. I have 8.5k hours with an average sector length of 1 hour. A mate that went heavy early but qualified at the same time has 9000 hours with an average sector length of 5.5 hours. Giving him 950 landings when he has been at the controls. I have way over 4000 landings in commercial aircraft who is the most experienced? Mind you he is still a first officer and I have been a Captain for some 12 years now. I fly regional turbo prop short haul.

If you stick a pilot with 2000 hours single pilot single engine into a multi crew transport aircraft they are in the same state as a 200 hour out of school pilot. They both need 150-200 sectors before they know what they are doing. And there is only way they are going to get that experience.. Fly with bald grumpy moaning bastards like me. Don't worry I do try and fill there heads with the reason why we do things the way we do and it not because I said so.

Lets face it... its exactly the same with baby engineers...

 

[WKTaylor]

Alistair_Heaton ... don't recall hearing Your name... but interesting/valuable comments...

"Lets face it... its exactly the same with baby engineers..." .... SOOOOOO TRUE!

My dad was a fighter pilot and long-time GA pilot... He always expressed doubt at how much time-experience a bomber or transport pilot and copilot should actually record... especially when they had the luxury to eat or drink and leave their seats to go to the head... etc.

A couple of favorite quotes comes to mind...

"Flying is long hours of boredom, punctuated by moments of stark terror." [paraphrased, W Churchill]

"Experience is a cruel teacher. First she gives you the test; then she teaches you the lesson.” [often cited version of Vern Law’s quote]



Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

 

[Alistair_Heaton]

Fast jet ex mil have other issues in commercial transport. Some of them get over them and are a pleasure to work with/for. And others are a danger to themselves and others.

But that's not really significant to this thread or the problems with the MAX.

But it does highlight the liveware aspect to most issues in aviation. Its how the operator interacts with the hardware especially when it goes wrong that is crucial.

 

[IRstuff]

Haven't seen any mention of this:

https://abcnews.go.com/US/wireStory/pilots-reported-issues-us-boeing-jet-61641142

A couple of incidents where the 737 Max nosed down after engagement of autopilot.

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

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

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[Alistair_Heaton]

I wouldn't put to much into them because they didn't go through the full investigation process and were only pilot reports.

The problem with pilots reports is in the heat of the moment our memory's are not very good because our bodies are putting all the resources into reacting. We all experience this in sim debriefs the TRE starts going on about something that happened 4 hours ago and you really can't remember what you did after the session. Which is why the more progressive company's video them and we can watch them in the de brief and they are then deleted in front of us.


Here is a similar nose down incident on my type...... was it a problem with the aircraft... Was it hell.

https://assets.publishing.service.g...d0b0349a662/DHC-8-402_Dash_8_G-ECOE_11-18.pdf

Unless the FDR is pulled and they run it through the variable machine nobody has a clue what was going on. BTW in my area of the world all our flight data is pulled for every flight for set of variables. And it has to go through a quality process to ensure we are not flying like cowboys. But that data doesn't have the same number of variables as the FDR.

 

[waross]

I am wondering about the initial trigger.
Why are those AoA sensors failing so frequently?
Are they a new type used only on the Max8?
Is it a problem with the mounting location?


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

 

[RVAmeche]

Aside from the Lion Air flight which had documented maintenance issues, I don't think it's confirmed the sensors are failing (or is it?)

 

[itsmoked]

Don't forget it could be purely a SW problem too. With complex systems people often scream hardware when it's actually software.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[VEBill]

It's how the operator interacts with the hardware especially when it goes wrong that is crucial.

KC beat me to it.

I was going to mention that you spelled "software" incorrectly. ;-)

The design decisions made in this example will become 'poster children', or case studies. Both hardware and software. And certification.

 

[Alistair_Heaton]

Sorry the way I was using the term is in relation to the shell human factors model.

https://en.m.wikipedia.org/wiki/SHELL_model

When you live and breathe this stuff its easy to forget that people might not know.

 

[RolMec]

In current developments, there seems to be some troubling logic.

First
The rudder increment of 2.5 deg shall be reduced back to something alike the original .6 deg, but: it has has been altered for a reason! As is it said that it became necessary during testing, for stall protection, this runs in a circle. Meaning: You'll not have the needed feature in that other flight situation, as .6 deg increment has been proven to be too low then.

Second
If MCAS is, say, mimicking a well known flight behavior of a previous model range, you can't just switch off auto during an emergency, because then you'll meet someone new: The airplane flying AS IT IS, with its flight characteristics of an elder airframe coupled with superfar forward big size modern powerplants.
Mr. Sullenberger is correct to require two qualified pilots in the cockpit, but these pilots should be able to fly two planes at the same time, them being just the flip of a switch away from each other. This seems to be high end professionalism i can't fathom to be standard all over the world.
Correct me if I'm wrong.

Third:
The second AoA sensor shall be wired in. But then: As it has not been done until now, again there might be a reason. Boeing will not have been building in two sensors and then leave one out off for decoration. If, for whatever reason, they could not make those AoA-sensors synchronize, or the coupled sensors output is so prone to failure or mismatch or whatever, the improvement might again lead to systemic failure.

This reminds the Space Shuttle story all over again. So they, they had to learn the hard way to ask: What, if there's still more to it?

The Max planes, if made airworthy again by FAA in April, shall be on a continuous trial run.
But who will trust FAA now? They don't have the know-how, they don't have the manpower, they are not independent, they don't know the plane and they don't speak up when it matters.

Finally, there's people on board. My daughter, your wife, a beloved one.. anyone!
Talk shareholder value now.
And that so many dead people do not make open any mouth with a face to it from within Boeing engineering, let alone the company as a whole, this troubles deeply.
Flying with a plane, that's about trust, in engineering, and certification.



Roland Heilmann

 

[waross]

It's all about trust and the trust is gone;
I first posted this in the other 737 thread by mistake.
Boeing 737 MAX to face first congressional hearing Link
Europe and Canada Just Signaled They Don't Trust the FAA's Investigation of the Boeing 737 MAX Link

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

 

[Alistair_Heaton]

The poo is getting more intense for Boeing.

I am European but can only imagine the law suites that will be getting prepared.

https://www.seattletimes.com/busine...igation-into-certification-of-boeing-737-max/

 

[thebard3]

The poo is getting more intense for Boeing

From the article:
The FBI’s support role was described by people on condition of anonymity because of the confidential nature of the investigation.
The papers always have an anonymous source to quote.
Congress has to get involved, because well, that's what they do.
My money says no criminal charges will ever be filed. Boeing will pay some meager fine and one of the world's most popular and safest aircraft's reputation will be besmirched forever.


Brad Waybright

It's all okay as long as it's okay.

 

[LittleInch]

ROIMEC,

I think you've got it correct.

That's why Boeing didn't rush out a simple "software fix" because when they looked at it closely and, maybe, reran the safety review and analysis with the data they now have and are using, they realized that it didn't work.

To maintain the classification rating they need MCAS.
A faulty MCAS is now, most definitely in the catastrophic rating for safety
Therefore the input sensors now need to be at least one order if not two order of magnitude more "reliable" and able to self diagnose and take the correct reading before activating as it needs to and ONLY when it needs to, not spuriously.

How the pilot can override it to again not prevent it operating when it should becomes very tricky. Make it too easy and you could get planes stalling when they shouldn't - equally bad news.

I don't envy them.

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

 

[BrianPetersen]

"My money says no criminal charges will ever be filed. Boeing will pay some meager fine and one of the world's most popular and safest aircraft's reputation will be besmirched forever."

Add that to the points RolMec made, and it adds up to another 737 Max 8 crashing.

 

[Alistair_Heaton]

Well safest apart from the hard over rudder issue. Which they only really sorted in 2005 world wide.

But your right it is a sad note to end an aircraft line. Can't see anyone touching them now. The punters just won't want to fly in them

 

[waross]

This is growing beyond just Boeing.
With the FAA reportedly losing credibility worldwide, this issue now may have a devastating effect on the entire US aviation industry.
If the foreign regulators require the Max 8 to be certified as a new plane, it may be the end of the Max 8.
Even if foreign regulators accept the Max 8 as a modification, it still may not pass with those oversized engines and their negative effect on flight characteristics.
The reported lack of trust, worldwide for the FAA may double or more than double the approvals costs for all American aircraft manufactures for both new models and for modifications.


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

 

[RVAmeche]

Has the FAA been losing credibility for a long time? Or just in response to their delayed response to ground the Max 8?