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Boeing 737 Max8 Aircraft Crashes and Investigations [Part 6] 17

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Sparweb

Aerospace
May 21, 2003
5,131
This post is the continuation from this series of previous threads:

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

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

BBC: Boeing to temporarily halt 737 Max production in January
 
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Spar your taxes will go up anyway. Boeing is going to have to pay by the min for EASA and others certification now.

Foreign OEM's will get it for free under the current FAA system.

Boeing is going to pay the full cost anyway because the FAA is deemed untrustworthy due having a utterly shite system which has been proven to kill.

Realistically the FAA market is reducing by the day, just look at its sale figures for last year never mind delivery's . If the eastern regulators accept EASA but don't FAA and FAA don't accept EASA due to willy waving a pissing contest then Boeing will have to walk the walk anyway because the N reg is just way way to small to pay for type certification with multiple type certs round the world.

Boeing might as well ditch the FAA and go for one that's trusted for initial type certification.

Nothing heard about the multiple investigations, most of us expect it to go the same way as the Challenger investigations and the banking collapses and absolutely zero people being held to account, just more air than out a hot air balloon and cock all changing inside the borders of the USA.

STC's will have to get dual approved for the foreseeable future. Which will mean more work for you. Although I suspect if you just do the EASA route initially then the rest will be tick boxes.
 
Not much changed lately then:

“There is hardly anything in the world that someone cannot make a little worse and sell a little cheaper, and the people who consider price alone are that person’s lawful prey. It’s unwise to pay too much, but it’s worse to pay too little. When you pay too much, you lose a little money — that is all. When you pay too little, you sometimes lose everything, because the thing you bought was incapable of doing the thing it was bought to do. The common law of business balance prohibits paying a little and getting a lot — it can’t be done. If you deal with the lowest bidder, it is well to add something for the risk you run, and if you do that you will have enough to pay for something better.”

John Ruskin (8 February 1819 – 20 January 1900)​


Politicians like to panic, they need activity. It is their substitute for achievement.
 
Seems the latest software issue is due to the fixing of the autopilot disconnect issue.

On start up and the systems running their internal bite tests. The computers are ready at different times and then produce errors and fail bite tests because other systems are not ready to talk to them.

End result the whole data bus system fails to sync and HAL goes in a sulk.

The fancy engineering simulator didn't get this issue. They only found out when they loaded it on a real aircraft.

 
Spar,

If one of your family members dies on a plane that was poorly designed by a company is too big to fail, the govt doesn't have enough money to review, and that company faces minimal punishment, you may feel differently.

Yes taxes maygo up if the FAA got proper funding. Good, that means they can do their job; otherwise just get rid of them so we can stop pretending. Companies, especially large companies, have shown repeatedly that society cannot rely on them to "self govern/regulate"; they need someone above them keeping them from pushing the line. Or, to avoid taxes going up, we could stop getting into endless "wars" costing trillions.
 
Thank you for bringing this to mind, Alistair.
The sub prime crisis was a made in America, too big to fail crisis, and the solution was political.
The automotive crisis was a made in America, too big to fail crisis, and the solution was political.
What most of us including Boeing, the FAA, the parent Department of Transportation and the American law makers may not be considering is that while this is a made in America crisis, a political solution may not be acceptable to the international community.
The approval of the Joint Committee is more important than anything the FAA does.

Bill
--------------------
"Why not the best?"
Jimmy Carter
 
To be fair I think the FAA does realise that the Joint Committee is the prime driver in all this.

Both the FAA and Boeing know fine that a FAA only approval doesn't fix the issue. It will just leave internal US airlines with a load of worthless airframes if they end up with N reg version and rest of the world version if it gets certified at all. The leasing company's won't be interested in them either. So I don't think Boeing would be interested in a FAA only certification.


It a bit worrying that the Engineering simulator didn't pick up this latest issue. If it doesn't pick up a cold start bootup BITE checking hang what else has it missed?

And this was meant to be the MCAS 2 which the FAA was meant to approve in October after watching a power point presentation and Boeing were going to start delivering before 2020.

BTW this boot issue/ loss of sync occurs on other types as well. The solution is you have to power down to black aircraft and leave for 30 seconds then bring everything back up. It can then take another 10 mins for the NAV stuff to get to within limits accuracy and re program the FMC etc.
 
Now at least July.


I'm not sure I agree that the"flaw has been fixed".

In trying to fix it I think they keep running into more dead ends. The report on the tv also mentioned something about wiring and needing to change it.

But July. Wow.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
To my mind this debacle is taking on all the elements of a Shakespearean tragedy.

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz
 
The specific engineering mistake(s) that lead to the MAX crashes are a relatively minor issue. Though a tragic oversight.

However the can of worms has been opened and the worms are ugly as hell. The previous generation the 737NG probably has a pile of 'issues' that never should have passed in the first place. But it has gotten away with it by a grandfathering and a bit of hoodwinking of the FAA. The fact that the 737NG has been largely reliable helps too even if it doesn't meet the letter of the law requirements.

The 737MAX has no such luxury. It started off as a hack job in the first place and now it being examined with a fine tooth comb.


It is a disaster all round that will cost many tens of billions not all on Boeing. The entire supply chain is hurting, airliners are hurting, consumers are hurting though they'll largely not notice it. Airbus is the only winner here. But the majority of European stakeholders would still be better off it Boeing was still in the game.


Also as said many times previously. This is less of an engineering mistake and more of a managerial mistake, decades in the making. And it will take as long for Boeing to dig itself out of this hole.
 
This article is running in quiet a few places.


Must admit I don't know too much about this one.

But from what I have seen last evening its similar 1 sensor wired "funny" and a presumption the pilots will instantly spot the issue and deal with it. Which they did 8 times and didn't on the 9th. But Boeing managed to get away dealing with it, they tried the same tactics with the MAX and it didn't work this time.
 
human909.

I would dispute your statement that the "mistake" - which one by the way? - was a relatively minor issue. The mistake it would seem was trying to extend the flight envelope of a 50 year old design and add on a semi FBW design to a system which simply isn't designed for it. That's not a minor issue, but a fundamental engineering design decision driven and forced by other factors (time, money, no SIM training). IMHO.



Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
The "wired funny" bit on the 737NG crash seems to be that whilst nearly everything else works Left and right side in terms of sensors and flight computer etc, the altitude sensing device which ran into the auto throttle preferentially used the left side. Thus although the pilots knew the left sensor wasn't working properly they thought it was OK as all the other flight controls were on the right side. There was no mention of this anomaly in any of the manuals or training - sounds familiar?

But the real key is this overall human factors / overload on the pilots of things happening to the aircraft which don't make sense and take more than a few seconds to work out what it is while all hell is breaking loose with alarms, stick shakers and dodgy information.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
There's a new phrase - "automation surprise" and "non event".

I wonder how many more automation surprises they are now finding out about.

Will this version fly again?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
If they'd had a crash with the 737 NG due to relying on only one of the sensors, and they upgraded the 737NG where they could to use two sensors data, why would they have persisted with the faulty single sensor concept in the 737 MAX? Did they just forget about it?
 
Different sensor. Altitude vs AoA.
They had a fix for the newer NGs, but not for the older models.

Bill
--------------------
"Why not the best?"
Jimmy Carter
 
Slow learners? No, they were able to fudge the accident report on the NG crash.
First rule; Blame the pilots.
Second rule; Second guess the pilots.
Any more rules to add Alistair?

Bill
--------------------
"Why not the best?"
Jimmy Carter
 
waross said:
Different sensor. Altitude vs AoA...

Same lack of system redundancy, same lack of effective documentation, same lack of systems training.
 
waross said:
Different sensor. Altitude vs AoA.

That's Boeing's excuse. Totally different. Apples and Oranges crashes. I would hope most engineers can see thru that.

waross said:
They had a fix for the newer NGs, but not for the older models.

Yes and they fixed it where they could, didn't they?

So why when building new planes wouldn't you just avoid the single sensor concept from the outset?
 
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