Boeing 737 Max8 Aircraft Crashes and Investigations [Part 7] 16

[Sparweb]

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

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

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 is now broken. See PDF download below, 3 MB)

Indonesian National Transportation Safety Committee preliminary report

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

www.sparweb.ca

 

[waross]

Thanks SWComposites.

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

 

[Alistair_Heaton]

Here is a bit of info for you Bill

https://www.ntsb.gov/investigations/AccidentReports/Reports/AAB1302.pdf

Some are more prone to it than others. And individual models have different areas which usually go first. You will always get it with cyclic loading of aluminium eventually.

As you can see from the report manufacturing quality also plays a large role in when it happens.

Unique to Boeing jets no.... it will happened to all of them eventually, number of incidents which have occurred on Boeing products.... that is worth looking at, my gut feel from the reports I have read is that it seems to occur more on Boeing than other OEM's.

Definitely not 737 only issues they have had it on 747 and 757 as well. Both old school proper Boeing aircraft.

In theory its not a huge safety issues. Most aircraft through ram pressurisation and the engines can keep the cabin pressure for long enough to get down to 10 000ft with surprisingly large holes. Bigger than a cabin window. And they have well defined checks that should catch it.

It will be interesting to see if it is one of the aircraft that ASW got a fine for not doing due diligence on when putting them onto the N reg. So I sort of agree with SWC's answer but its not the whole picture. As I hinted at with the reference to the issues with the Q400 gear I see it as more an indication of issues at ASW maint department than a design issue.

 

[LittleInch]

Alastair,

I wasn't trying to throw the ET pilot under the bus, just noting that he went into the EAL aviation academy at 18 for 2 years before he got his CPL. He was then FO on 737 6 months later. The point being was that was all he had ever done.

I think and hope that one thing which does come out is a much better set of information and training to aircrew in similar circumstances. The delayed and very simple note which Boeing eventually produced was unclear and unspecific (can be used...) in the key aspect if the plane suddenly dives which was trim it back to level flight before you pull the switches (but once you let go the thumb switches you only had 4 seconds to act and it kept on doing it). The fact that it then also said you can manually trim at any time was clearly not thought through or correct or tested. Also that it worked on one sensor and the FCC which was in command and couldn't be changed.

I've just re-read the AD issued and it doesn't mention any of these key aspects - i.e. it kept doing it unless you cut the stab trim and you only had 4 or 5 seconds after getting the plane level before it did it again. Oh and the trim down would be 4 units.

If the aircrew knew then what we know now and had been trained accordingly then they should have had a better chance.

But at the rate we're going with flight cancellations and undoubted airline failure(s) the loss of the Max might not be as bad as it was a few months ago.

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

 

[Alistair_Heaton]

His training and experience is no different to an extremely large percentage of pilots that trained in the last 20 year in Europe.

The bulk of EasyJet and Ryanair Captains will have a similar profile. The only thing different about him is that he did a stint flying long haul.

To be honest that AD stinks of lawyer input. The way they worded it is not normal. And its not as black and white as they normally are. I suspect everyone from both Boeing and the FAA that were involved in it now no longer work in either. Its main purpose was to keep the MAX flying and portray it as a pilot error. its main objective was zero responsibility of a design issue or for poor oversight by the FAA.

I would take anything from that period with a pinch of salt. Per say the AD is now obsolete as the aircraft will never fly again in that configuration.

 

[moon161]

No one was injured in those incidents, but in 1988 an Aloha Airlines flight attendant was blown out through a hole of a Boeing 737 as it flew over the Pacific Ocean.

'Hole' sort of understates it. The stewardess blew away because the plane no longer had a roof and she wasn't seated with a belt on.:

 

[Alistair_Heaton]

To be fair, I don't think a modern aircraft would have survived that with only 1 fatality.

It also had 90k sectors/pressurisation cycles.

Which is the life limit for 737's for most of the major parts such as the main spar etc.

http://libraryonline.erau.edu/online-full-text/ntsb/aircraft-accident-reports/AAR89-03.pdf

Here is the report.

Quiet how you can't spot a split in the fuselage skin during walk round during the day I really can't understand. I can only put it down to shite standards by the crew. Ie it was bounce multi sectors and they couldn't be bothered getting out the FD to do a proper walk round. And that's old school American home boy's. I know its boys because it was purely a male job in the 80's apart from under 100 females who all worked for the likes of UA and AA and the like.

But you have to be impressed though that sort of failure and they still managed to land it and the fuselage stayed in one piece. Proper Boeing engineering. Not some Macdonald Douglas MBA designed crap like the MAX.

 

[verymadmac]

The window belt on the 737 classic is only good for 50,000 cycles before required modification, for the airframe to make 75000 cycles. For many examples 50,000 cycles became the effective life limit cost wise.
Relevant Boeing article on airframe limits.

https://www.boeing.com/commercial/aeromagazine/articles/2012_q4/pdfs/AERO_2012q4_article2.pdf

A freight operator I worked for a few years ago, had an incident where one Saturday morning while washing an aircraft they found a fuselage skin crack on a 737 Classic freighter(lower aft fuse, classic acoustic fatigue resulting in chem milled step cracking), by the time they had washed all 4 airframe, three of them had been found to have the same crack. The last one of which wasn't found officially till Wednesday. It wasn't great but we didn't find it greatly concerning, having no paying punters simplifies things a lot (& we had bigger fish o fry).

 

[SWComposites]

The FO on the Aloha plane was a woman, who was PIC at time of incident.

 

[Alistair_Heaton]

Glad to be wrong on the sex of the pilot flying.

Where does the 90k come from is that the wing spar limit?

 

[3DDave]

"If the aircrew knew then what we know now and had been trained accordingly then they should have had a better chance."

They should have known because the Preliminary report from the Lion Air crash had been published long before, there is more tech description in the FCOM (Flight manual) pages that are custom sent to each airline and

https://www.youtube.com/channel/UCJiw_egCKvL8JnrxlcCW76w/videos

was on both management and fellow pilots to get them to pay attention to the problem. He says he quit the airline in frustration that they were going to get someone killed a month or so before the crash.

The Ethiopian CAA, the Ethiopian Airlines management, and the Ethiopian Chief Pilot did nothing, even though they were all aware of the likelihood of fatality if the crews were off even a little bit. Instead of grounding their own fleet until Boeing certified a fix, they decided to just not know. So far their plan to try to blame Boeing is working. Notice that none of those three levels of the company are named in their preliminary report.

The Ethiopian pilots were handed on a silver platter two ways to handle the situation, complete with symptoms, and the AD and the FCOM and a pilot begging them to pay attention and they did every single thing the AD said not to do.

The reason for the last enabling of the trim, the one that let MCAS have a last shot? To try the autopilot one more time, as evidenced by the AP fail alarm, which only happens when someone tries to enable the AP when the AP cannot function. They know that the AP cannot be enabled with a stall warning; at least that is how they are supposed to be trained. They tried at least 3 times; first item is to disable AP, then disable AT. They never disabled the AT. And they were told to never re-enable the trim after having selected it off.

So where in the preliminary report do they discuss the frequent review sessions, the special simulator training for just this failure, the extensive testing and scrutiny from the Ethiopian CAA, the Ethiopian Airlines management, the memos and responses and personal oversight of the Chief Pilot? How about their respective decisions to proceed after doing exactly nothing?

All pilots agree that Boeing lied completely about every thing forever about MCAS and the FAA covered it up. So why did Ethiopian proceed on the belief that Boeing and the FAA were telling the entire truth when they did not describe the steps as one might tell a 5 year old locked alone in the cockpit for the first time?

We know from the successful flight that it's a matter that humans can intervene with successful results. It takes what should be the bottom-of-the class skill to trim the plane with a thumb and the ability for 1 of 2 pilots to recall the trim cutout. That, tragically, is it.

The main bulk of the interim report is second guessing every engineering step. Interesting as it is, almost nothing of it has to do with putting that plane into the ground on that day based on what was known to the operator months before. The lack of introspection required to keep the lawyers from blowing Ethiopian Airlines, the nationalized airline, to smithereens by a report by the same government as owns and operates the airline is appalling.

(edits for typos. damn typos.

 

[waross]

Yes, and they tried to trim manually, just like they were supposed to.
The old Boeing knew that that may not be possible, but the new Boeing culture falsely assured them of the possibility of manually trimming when the stabilizer was at an extreme pitch.
Manual with the trim wheels, not the switches.
In retrospect, a simple instruction to not leave the Stab Trim switches on for more than 4 seconds after a trim event would have saved a lot of lives.
As for the super trained and experienced American pilots being able to easily handle a MAC ATTACK, That was well and truly blown out the window when they did the series of simulator tests with mostly American super pilots.
By then everyone knew of the issues and the pilots should have been expecting an MCAS malfunction.
Most of the pilots did not follow procedures properly.
I understand that a couple of super pilots screwed up so badly that the simulator needed repairs when they finished their session.
Boeing said that the pilots didn't need more training.
Boeing downplayed more training.
Boeing opposed an airline who wanted a Max 8 simulator.
Boeing has messed up so royally, so many different ways, that the blame the pilots card won't play anymore.
I think that Boeing's latest leader has blown his credibility out of the air with his renewed attempt play the American Super Pilot versus Third World Pilots card after the sim tests.
First world pilots may be and probably are better able to handle an emergency, but proven in the sim, are not good enough to handle a MAC Attack.

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

 

[Alistair_Heaton]

I wouldn't put to much value in the ET report, as I said before it stinks and agree with Dave over the bum covering by ET and the authorities. It won't wash though globally. I hope its a copy and paste job to satisfy the requirement to publish something inside 1 year.

To be honest though the other issues with the MAX have overtaken the initial accidents. There is no way they can roll back the clock and unground the MAX even if the ET is deemed to be 100% airline and pilot fault. Its been proven now that it should never have been certified in the first place. And the fundamental risk analysis for a multitude of systems was false.

Its looking pretty certain now that a 3rd AoA sensor will be required on all new types what ever the grandfather rights are. Which will pretty much blow out all grandfather cockpits.

And this corona virus is likely to take out an extremely large number of the orders anyway. Airbus is in the same predicament.

I am grounded until at least the 17th of April. The borders are shut to none citizens/resident holders. And commercial air transport has been banned by the government.

Within the next 2 months I expect at least a 25% reduction in operating Airlines in the world. Its going to take years for things to normalise in aviation. By the time this runs its course I suspect Boeing and Airbus will have substantially reduced order books. And its going to be an extremely slow 5-6 years before things pick up again.

I suspect the USA will be in the same state in 2-3 weeks with basically all commercial air transport grounded for a month plus.

We shall see, I have been on vacation for most of this month so am away from it all. But got the phone call "where are you?" "ok good stay there" at least I have something to do building my holiday house. But once the materials I have already bought run out then it will be into save money mode.

Thankfully the locals don't seem to be as stupid as my nationality country, there is still toilet rolls etc in the supermarkets.

 

[Lou Scannon]

That's bog rolls, to you!

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz

 

[moon161]

In the US, we have normal people and then a few that if bog rolls were money, they would be billionaires. A bidet is looking more useful every day now.

 

[IRstuff]

"Ask the audience" usually results in the correct answer; binge buying reduces the number of trips to the store at a later date, when the virus is running amuck, while it's still a relatively safe gamble right now.

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]

Just put a bidet sprayer in both toilets.

The Mrs is quiet happy telling everyone it's a fanny washer in English. I will leave it for a bit until I tell her that fanny in Scotland is not the same as fanny in America.

 

[Lou Scannon]

The Mrs is quiet happy telling everyone it's a fanny washer in English. I will leave it for a bit until I tell her that fanny in Scotland is not the same as fanny in America.

Stop it, you're killing me!

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz

 

[Alistair_Heaton]

Well I suspect USA not that far behind Europe now. They shut midway airport due to 3 technicians testing positive.

And a mate who was in Daytona last week is now at home feeling sorry for himself with it in the UK. Knowing him that will be half the strip clubs in Daytona and Miami contaminated.

Anyway last year I ordered 2 workshop blue elephant bog rolls and 2 bales of 8 were delivered with a 15ltr tub of lemon Swarfega so that's the hand cleaner/shower gel sorted as well. So maybe Jan 2021, I would need to start the second roll. Although I suspect I would end up with a baboon's bum after a week.

 

[Alistair_Heaton]

I know some Boeing peeps will be reading this, my heart felt feelings to loosing a colleague. Its too late now and you will have more.. Its a bitch this virus thing....

Anyway a bit of humour with a slight engineering disaster bent...

I like copper pipe I don't like plastic...

I did my place up with it and bonded everything to 4 huge earth spikes. Plastic into the basement after that copper and bonded to old school regs including the kitchen sink with a 6mm2 bit of wire to the main earth.

Brother in law due to my copper bent has done his shower room plumbing using copper pipe. The supply to the hot water and inlet cold is plastic.... No bonding....

Said "fanny washer" is now a thing with the local lady's. They all want one... I gave a spare to the BIL.

It was put on line today...

The screams when the fanny washer earthed through the toilet were unbelievable after 20m of copper pipe building up static.... 3 bar...

my ribs are hurting with laughing...

I have 20m of 6mm2 wire in stock and earthing bands so will sort it tomorrow, but I had tears in my eyes tonight after we worked out what the screaming was about.

Apparently singing various lines out of rock horror show is not funny....

I am a Mechie what do I know about electrical stuff?

 

[waross]

I had a call to a diving resort.
A guest was brushing his teeth and got a nasty shock when he tried to get a drink directly from the faucet.
I put my meter on it and zero volts.
Continuity test.
Well grounded.
I put my meter between the faucet and the floor where the victim would have been standing and read 60 Volts.
Down under the cabin and found a cable stapled on edge with a fence staple.
The staple had been over driven, pushed through the plastic insulation and contacted the hot wire.
Measuring the floor joist to ground a couple of inches away from the staple I saw over 100 Volts.
North America is a continent.
South America is a continent.
Central America is not a continent.
Must be incontinent.
The joys of working in the turd world.

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