[FDOS]

@TonyR AIUI from the videos, the door plug is forced against the airframe by pressure differential (with mechanisms to transmit that pressure to the frame) and certain bolts stop the vertical movement required for the door to open out. I didn’t say that the mechanism was the same as the hatches (I should not have mentioned those, it muddied the waters, because they work differently, being oversize).

The door plug can only open when it is moved out of the roller guides and this requires vertical movement down. During maintenance, the hatch is kept open by springs at the bottom, that prevent it slipping back down into position.

So yes, the mechanism is different to the hatches, but they are both plug type openings.

It the stop bolts are missing, then vertical movement is possible and the plug can crack open, differential pressure will then do the rest.

The NTSB will report on the details

Capt Brady’s channel is excellent, isn’t it?

[cwoodward]

This ‘door bung’ incident is but the tip of a very large iceberg.
I had a look at some industry reports and articles and what I read I have found extremely alarming –

Spirit AeroSystems who manufactured the fuselage involved here ignored warnings that lead to the ‘door bung’ disaster.
This is a company that was spun out of Boeing in about 2005 and is managed by former Boeing executives. The company plays a crucial role in Boeing’s supply chain, especially for the B737 program.
Spirit has faced numerous allegations of prioritizing production over quality for a number of years. The FAA has been criticized for its inadequate oversight, particularly concerning outsourced manufacturing facilities and such as the Spirit- Boeing relationship.

Only weeks prior to the alarming incident where a door plug blew out of the Alaska Airlines flight, workers at Spirit AeroSystems had raised alarms about defects in aircraft components, but their concerns were seemingly ignored leading to a series of safety issues and a federal lawsuit only weeks prior to this alarming incident.

Boeing and Spirit have a deeply intertwined relationship, with former Boeing executives holding key positions in Spirit. The recent incident with Alaska Airlines 737-9 is not the first FAA action against Boeing involving Spirit.
Past allegations include non-compliant parts being accepted by Boeing for airworthiness certification. A class-action lawsuit was filed by Spirit AeroSystems’ shareholders in May 2023 and details extensive quality-control issues, including foreign object debris, missing fasteners, and poor skin quality in Spirit products.

In August 2023, Boeing discovered yet another defect in the 737 Max. This defect had been identified months earlier by a quality auditor at Spirit who’s report was ignored. It involved improperly drilled bulkhead holes crucial for maintaining cabin pressure. Spirit Aero had concealed the defect leading to months of delay in the aircraft rollout when the defect was finally picked up by Boeing.

I will never set foot on a 737max and be very reluctant to fly on the 777X if it finally enters service.

2 users thanked author for this post.

tomyam42, maxgeorge

[Johnnyg]

Jan 22nd 2024

FAA just announced that airlines operating the 737 900 ER jets to be inspected after some operators reported issues with bolts.

Alaska and United are the largest users of this model.

[Inquisitive]

Now FAA is highlighting that other Boeing model has similar door design. Could it be a bo bo and they have to correct the design?

[stevescoots]

I doubt it, this looks like a quality control issue rather than a design one. Boeing have had ongoing quality problems from their Sc plant that makes the 787, looks like they have leaked out to the Renton site as well. I wonder if SC bean counter transferred up there

1 user thanked author for this post.

cwoodward

[cwoodward]

Bloomberg is reporting today that the FAA top official said the “agency may expand its probe of Boeing Co.’s manufacturing practices beyond the 737 Max assembly operations if it finds evidence of problems elsewhere at the plane maker. Currently the agency is mainly focused on the mid-cabin door plugs on Max 9 aircraft”

He further added “Boeing manufactures a number of aircraft, so we’re going to look at the Max, but we’ll also look at the company systemically to see whether these issues run elsewhere,” Whitaker said in an interview. “It depends on where the evidence leads us.”

It is concerning that several airlines are now reporting finding loose bolts in their fleets of Max 9s and broken fasteners holding the door bung in place.
Bloomberg reported that Boeing representatives declined to comment on the reports.

Separately United Airlines chief executive officer Scott Kirby said the carrier is reconsidering its order for the largest 737 Max model, which is already years behind schedule. He warned that United was losing patience with the delays that seem certain to follow in certifying the larger Max 10 as US regulators step up their scrutiny of Boeing.
“United has already started to build an alternative plan that doesn’t have the Max 10 in it, Mr Kirby said, adding that it would probably entail changes to the airline’s order book.”

“The Max 9 grounding is probably the straw that broke the camel’s back for us,” he said.

[TonyR]

@FDOS. Yes, there are small pads preventing it blowing it out but it only needs to move a small amount to clear them whereas a standard door no movement vertically would clear it of the airframe which it contacts the whole way round. And it appears now that the roller guide channels had failed. The design is not intrinsically fail safe as the main doors – it depends on a lot of parts to keep it on.

Many echos of the MD DC10 cargo door disasters of the 70’s where the retention mechanisms failed to restrain the outward opening cargo doors against the internal air pressure.. The first flight fortunately suffered explosive decompression at 12,000 ft and superb piloting landed it safely despite many of the control lines being damaged by the collapsed cabin floor. Turkish airlines were not so fortunate and 346 souls were lost. After the first door loss the NTSB found the design to be dangerously flawed but no airworthiness directive was issue due to a gentleman’s agreement between the then head of the FAA and McDonnell Douglas which then led to the second fatal crash. Sound familiar?

6 users thanked author for this post.

Jacob, cwoodward, maxgeorge, GivingupBA, tomyam42, FDOS

[CathayLoyalist2]

To add to Boeing´s woes a nose wheel fell off a 757 waiting to depart Atlanta over the weekend.The aircraft was lining up on the centre line when the wheel came off and rolled down a small incline. Boeing have thus far declined to comment

[TonyR]

Separately United Airlines chief executive officer Scott Kirby said the carrier is reconsidering its order for the largest 737 Max model, which is already years behind schedule. He warned that United was losing patience with the delays that seem certain to follow in certifying the larger Max 10 as US regulators step up their scrutiny of Boeing.
“United has already started to build an alternative plan that doesn’t have the Max 10 in it, Mr Kirby said, adding that it would probably entail changes to the airline’s order book.”
“The Max 9 grounding is probably the straw that broke the camel’s back for us,” he said.

That’s a big one. That order is for 277 aircraft with an option on another 200 😳. It is also expecting delivery of 31 Max9’s this year that probably won’t happen this year.

1 user thanked author for this post.

cwoodward

[drflight]

Revised article in todays Seattle Times:

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

[Johnnyg]

Tonight 05-02-24, Sprit Aero systems announced that there will be further delays on fuselage supplies for the 737 Max due to an issue with misaligned drilled holes.

https://news.sky.com/story/boeing-may-delay-jet-deliveries-after-supplier-finds-glitch-with-fuselages-13064698

[Author]

Posts