There is a lot of 'chatter' online suggesting that the plug should have been oversized and installed from the inside, making it less likely/impossible to fall out. I suspect that cost was a deciding factor in choosing a solution that used the existing door design. Maybe.

IMHO the design is fine. If even one of the four "safety" bolts/nuts/cotter key is installed the door will not come out.

Theoretically fine, versus can't fail fine. One is good for my car, the other is what I expect on an airplane.

Aircraft are strange beasts. I flew on a regional in Greece with a 18-24" crease up the side of the tube aft of the entry. Someone signed it off as good to go. But something goes wrong (in design/maintenance) elsewhere in the structure and it's kaput under even the most ideal conditions.

The story will probably boil down to a forced-hire worker with stupidity or a grudge. Plus lack of oversight.
And it will never be told.

The worker was probably using a Crescent wrench.

Further compounding the design and production quality issues is the practice of outsourcing both. There was a time when we pretty much retained all design authority, outsourcing the manufacturing. That all changed dramatically under the 787 program and one Harry Stonecipher, the CEO we inherited from McDonnel Douglass when they "bought us with our own money" (we essentially adopted the management practices of the failed competitor whom we purchased). Our practice was to retain design authority, theirs was to outsource that as well. Lay down essential parameters and interfaces, but allow the company with the contract to do their own (or even outsource yet again) design work. Under this philosophy, we essentially lost control of our own aircrafts' design in many respects.

Spirit is a good example of this relationship. They used to be Boeing Wichita, but Harry sold them (along with billions in other hard assets) to bolster the bottom line in the late '90's and early 2000's. As an aside, just how long can a company show record "profits" by selling off its assets rather than by selling its products? MD fell into that trap and failed, Harry came to Boeing and went immediately down the same path. Anyway, that aside, when they were still Boeing Wichita, big mother Boeing still had control over design and manufacturing taking place in Wichita. Now that they are Spirit, that direct control is long gone. And, well, as an independent company now, their objective is to maximize their own profit. This door plug is only the most visible product of this new relationship. There are many, many more.

$1500 for each passenger....available only for off-season travel...lol

https://www.yahoo.com/news/alaska-airlines-offers-passengers-1-221000395.html

Jeff, thank you for taking the time to write that.

I was hoping Jeff would chime in. Not sure if he would / could.

I’m really pleased we have a subject matter expert in our midst that can explain the factors that lead to this mess.

Thanks Jeff.

I read read that as a line chef making 10 hamburgers on the same hot grill
vs
10 different types of grills heated up to make one item.

Is Spirit a manufacturing company as well as an airliner brand? Or is is just the maintenance side? I didn't catch that part.

Boeing shouldn't be held responsible for another company gluing cinder blocks on their own aircraft or installing parts made by crackhead bob. Only the original design and assembly. It should be tail light warranty after that.

Spirit Aerosystems is unrelated to Spirit Airlines.

Spirit is a manufacturing company supplying the whole of the aerospace industry. A "sub contractor". They do not manufacture entire aircraft.

Boeing is ultimately responsible for any aircraft that rolls out their doors. Just like, say, any auto manufacturer. They have their share of subs as well, but at the end of the day, the completed automobile is their product and they have full responsibility for it. Same for aircraft.

This was a brand new airplane with brand new parts. Spirit does not perform maintenance on in service aircraft. This fuselage section, supplied by Spirit, was assembled into a complete aircraft at a Boeing facility here in Washington.

Improperly

Jeff definitely has more experience and is our in-house SME, but I worked at Boeing in Charleston during the great recession. I saw good work, bad work and no work (by some). My friends and I said to ourselves, airplanes must be way over engineered to have people off the street building them, and them not falling out of the sky (most of the time).

Edit. To add to Jeff’s email below, they would move the plane section to the next station, no matter how many tasks were incomplete or not done at all, just to say that they were able to move the plane on time. As the plane moves further and further down line, it gets harder and harder to do the original task. I had a friend and a neighbor, both working on the flight line and they were finishing tasks from all the different stations not completed. They were having to borrow parts from other planes to get a plane ready for service.

My wheelhouse is building homes, and I only work there during the great recession, until I could get back to building houses. I couldn’t get out of there fast enough.

I remember when we started the second 787 line in Charleston. Our Everett IAM mechanics quickly adopted the acronym "SCAB" - South Carolina Airplane Builders. Every last single unit built in Charleston was flown to Everett where it spent months on the flight line getting all of the "travelers" fixed. For the rest of you, a "traveler" is a defect documented by Quality Assurance that does not get corrected where it happened, but instead "travels" with the aircraft awaiting disposition and repair. They will not hold an aircraft in position on the assembly line if it can be moved, so these "travelers" tend to accumulate.

I also remember at least Saudi Air refusing to take delivery on 787's built in Charleston, going so far as to cancel orders if they got stuck with one. The problem was yet another engendered by unrelenting cost cutting - move production of some of the most sophisticated equipment mankind builds to an area of the country with a depressed economy and resultant low labor rates. Anyone can build an airplane, after all. Right? How hard can it be?

Didn't Mercedes or someone learn a similar lesson prior to all of that? They left the American South in despair of the fact that they simply could not build cars there. The labor pool proved to be too uneducated and the "work ethic" anathema to large scale sophisticated manufacturing. Boeing learned the same lesson and fortunately had the Everett flight line available to fall back on. Unfortunately, they did not learn it well, and all 787 production is now in Charleston. And they have had to halt deliveries time and time again for various issues, like the failure of their "predictive shimming" scheme.

Oh well. Enough. I could go on and on and bore you guys to tears. It should be obvious by now that I am both deeply saddened and deeply ashamed of what has become of what used to be a proud company - "If it's not Boeing, I'm not going" used to really mean something. They have now joined the ranks of mediocrity, if not worse. Such a shame.

Will be interesting to find out if there are any safety-bolt witness marks. My bet is they were not installed. We'll see. This will be a key finding.

Matt Walsh
@MattWalshBlog
Ladies and gentlemen, meet the “dream team” at the manufacturer that made the plane door that just blew off in the middle of a flight
https://twitter.com/MattWalshBlog/status/1745524322138018064

The problem is no matter how robust your processes are and no matter how good your engineering is you still have humans as a possible point of failure . Let's say you are supposed to install hardware to a specific torque and torque stripe the hardware . As an assembler you are in a rush and because you have built the item for years you know how " good enough " tight feels like . So you forego the torque settings and apply the torque stripe .

Where I use to work this occasionally happened . We built military aircraft . You know how many fasteners are in an aircraft ? LOTS !!!!! This is just one simple example . Then throw in go faster . And leave no FOD . And make your rate . And come up with new ideas to lower cost . It's a meat grinder . Sometimes production catches their mistakes . Sometimes QA catches mistakes . Sometimes the customer ( DCMA ) catches the mistake , that is never good . And unfortunately sometimes there are escapes that don't get caught . That sometimes lead to catastrophic endings . Sad but true .

Ultimately in this case the investigation will determine the cause and corrective action will be implemented . Assembly instructions will be updated , QA will do follow up audits and life will go on . Engineering/production will sign off on additional mistake proofing . And the planes will continue down the line .

As expected....https://www.yahoo.com/news/passengers-file-class-action-lawsuit-055900810.html