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thewayneOh, 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
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
no subject
Date: 2024-01-26 02:39 am (UTC)While not perfect, sounds like a much smarter system than Boeing has. Dependencies upon dependencies, I can appreciate how deep it can get.
no subject
Date: 2024-01-26 03:35 pm (UTC)