A Boeing whistle-blower reveals what happened with the door plug blow-out!

[thewayne]

Oh, boy! LUCY, YOU HAVE SOME 'SPLAININ' TO DO!

There are SOOO MANY problems here!

First off, the problem appears to be entirely Boeing's fault. Spirit manufactured the fuselage - including installing the door plug - then the fuselage was transported from Kansas to Seattle via train for final assembly. Okay, not unreasonable.

Except these fuselages are riddled with defects, or 'non-conformities'. Spirit has a team of technicians permanently based in Seattle to work on these at Boeing's assembly line. These are 'warranty repairs' by Spirit. No idea how big this team is, I expect pretty sizeable.

This particular fuselage, like all the others, had lots of problems. They immediately spotted a number of bad rivets on the door plug on the RIGHT side of the fuselage, but didn't spot problems on the door plug on the LEFT side, which was the one that blew out. They then discovered problems with the plug on the left side.

Now two other things need to be explained.

First, Boeing has two computer systems to deal with repair ticketing. One is used to broadly discuss issues, the other is used to specifically ticket the issue, and more particularly, mark when it's done. And hey, guess what! The two systems do not talk to each other! And it takes time to update tickets in the second system, and since we know companies do not like paying overtime, this sometimes doesn't happen.

This failure to update tickets is definitely a factor in the door plug blow-out.

The second thing to explain is a matter of basic physics, specifically, atmospheric pressure. At ground level, the air is much denser. The higher you climb, pressure is lower. Think about an airplane. It's pressurized. That means that as it climbs, the pressure on it decreases, and it's going to expand.

Now we're back to the door plug. And, for that matter, the doors on an aircraft. I'm definitely going to try to remember to look at this the next time I fly! The door plug is not welded in place, it's removeable, just like an emergency exit door is. It's just that it's not removeable from the inside - normally - without that trim panel being taken out first. To overly simplify it, bolts are screwed into the side of the plug. The head of the bolt sticks out. On the side of the aircraft, in the nook where the plug is, are these little guide tracks. As the plane gains altitude, the door plug actually slides up a little bit - but this isn't a problem as the guide tracks hold the plug in place. And pressurization isn't a problem because there's an excellent rubber seal around the door plug to maintain the cabin pressure.

Of course, this assumes that the bolts are in place. No bolts, nothing for the guide tracks to catch. And when the plane gets to a high enough altitude, the door plug goes sailing.

Boeing removed the door to service it - NOT SPIRIT. And they screwed the pooch when they reinstalled it. The bolts were not put back in place. It was not documented, and apparently when the door was recovered from that teacher's back yard, there were no bolts in the door.

The whistle-blower provided full documentation to the Seattle Times, and presumably the National Transportation Safety Board, as to what happened from Boeing's internal systems.


This article is a long read, but pretty understandable.

https://www.seattletimes.com/business/boeing-aerospace/boeing-not-spirit-mis-installed-piece-that-blew-off-alaska-max-9-jet/

https://news.slashdot.org/story/24/01/25/0314242/boeing-not-spirit-mis-installed-piece-that-blew-off-alaska-max-9-jet

Comments

[gingeriana]

OMG, this is so incredibly SILLY!
they are very lucky the outcome was not particularly tragic

[thewayne]

Yeah, they really are.  They need to turn around their corporate culture big-time!  They should also look at redoing their IT system, but I, as a retired IT guy, can completely visualize how big a mess that would be.

[armiphlage]

It's really hard to automate, unfortunately.

At our factory, we have a wonderful electronic shop floor control system. Every time someone touches a product, they scan its unique barcode. The system checks what operation needs to be performed on that specific unit, and checks that the person has the training needed to do that operation. If the person finds a defect on the product, they select the location of the defect from a drop-down menu, and select the nature of the defect from another drop-down menu.

Our system then won't let that unit of product have anything else done on it until someone trained to rework (fix) that issue makes the fix. If there are multiple defects, each one has to be fixed.

The system then won't let that unit of product have anything else done on it until a separate person, who is trained in inspection, verifies that each fix was done properly.

The system then makes the unit go back to the previous test or inspection step, to make sure nothing else got messed up. Then the unit is allowed to go on through the other operations in the factory.

So, any defects that are found get fixed, and get inspected by a separate, independent person to ensure they are fixed. Good?

EXCEPT, sometimes you can't easily get to what you're fixing, because another part is in the way. So you might need to loosen another part, or take another part off completely, just to get to the part that needs to be fixed. And you might forget to reinstall the other part, or might not do it properly.

And the person verifying the fix doesn't know that you had to loosen or remove the other part. And each fix is a little bit different, needing to come in from different angles. And some people doing the fixing have bigger hands than others. So you can't program the electronic shop floor control system to automatically know that fixing Part ABC requires you to loosen part XYZ.

So, we're really good at fixing defects that we know about. And we're really good at catching problems at the exact location that was fixed. But we sometimes get secondary defects created by the initial fix, and those are really hard to catch.

[thewayne]

While not perfect, sounds like a much smarter system than Boeing has.  Dependencies upon dependencies, I can appreciate how deep it can get.

[murakozi]

Something as simple as sticking a tag with "Parts Removed" on it on the plug(s) during maintenance would sure help.

[disneydream06]

If Boeing makes planes, why are they buying planes or at least significant pieces from another company? :o :o :o
And when you say Spirit, are you talking Spirit airlines? :o
Hugs, Jon

[murakozi]

In this case, Spirit is a company in (I think) the midwest that manufactures fuselage parts for Boeing. I seem to recall reading that it was a part of Boeing that got split off a while back.

[disneydream06]

Ahh.....

[thewayne]

Yep.  Used to be a Boeing plant.  Located in Kansas, which has a lot of aircraft manufacturing.

[thewayne]

So.  Boeing decided it was more cost effective to contract out some of their airplane construction.  Spirit AeroSpace in Kansas (mentioned previously in posts about this incident) used to be a Boeing plant, they're now their own independent business entity.  They make several different fuselages for Boeing, apparently with numerous defects, and ship them via train to Seattle where the rest of the bits are put on to make them into flyable aircraft.

[disneydream06]

That just sounds like it's asking for trouble. :o

[thewayne]

They're wanting to distribute financial risk, making someone else take potential losses.  I think it's stupid because they're also losing quality control reach, and given that it appears every fuselage received from Spirit requires serious rework, it obviously is a QC loss.

[disneydream06]

And to say nothing of the fact that it has to travel half way across the country. :o

[silveradept]

To read the summary of the insider's description, it sounds like the process continues to be a problem from manufacture all the way through inspection, with a lot of left hand not knowing the right hand had needed to do repairs or other adjustments. Boeing is extremely lucky this was not a fatal situation.

[thewayne]

The output of Congressional hearings for Boeing and Spirit may be interesting to see how they try to spin the blame elsewhere.  One of my uncles worked at a car dealership, his job was to prep cars coming off transports before they went up for sale.  This was probably back in the '60s or '70s, I don't know exactly when.  He was used to things like missing arm rests and such.  He had this one car that just didn't want to run smoothly.  Finally, he removed the spark plugs and did a compression test on each cylinder.  On one cylinder he got NO compression!  He took the head off the engine and found out why there was no compression, and the reason why it was running rough: NO PISTON!  Minor little OOPS! from the factory.

[silveradept]

Oops.

There's likely be popcorn as everyone tries not to be the person holding the bag when the feds come calling.

[kaishin108]

What a great post, thank you. But what a big mess. Thank goodness for whistleblowers.

[thewayne]

Yeah, like Boeing would explain all this to a Congressional panel if the whistleblower hadn't leaked it to the press?!