The US National Transportation Safety Board (NTSB), which is leading an investigation into the incident, said pilots had reported pressurisation warning lights on three previous flights made by the specific Alaska Airlines Max 9 involved in the incident.
As bad as it is if a manufacturing issue caused a piece to fall off an airplane, there’s a huge amount of negligence in an airline continuing to fly an airplane that has triggered pressure warnings multiple times without investigating and resolving the issue.
And the next paragraph:
The jet had been prevented from making long-haul flights over water so that the plane “could return very quickly to an airport” in the event the warnings happened again, NTSB chief Jennifer Homendy said.
Which makes it sound like they couldn’t find the source of that warning but weren’t willing to completely write it off.“An additional maintenance look” was requested but “not completed” before the incident, Ms Homendy said.
I mean I’d much prefer they didn’t fly a plane that was repeatedly saying there’s a serious issue with it.
So the blinking engine light in my car isn’t just for festive vibes?
It’s there to let you know that your damn O2 sensor is on the fritz again.
I’ll wait to pass judgement because, not being an expert, I have no idea what the standard procedure is for that warning appearing in 3 out of however many (hundreds of?) flights this plane engaged in over that period of time. With hindsight of course we can say “duh don’t fly the plane with the door about to blow off if it says it has pressurization issues” but maybe this is not actually a particularly serious warning in different circumstances.
If I’m not mistaken, the Alaska Airlines accident aircraft completed 99 flights, as it went into service only a couple months ago.
Not an expert myself but I binge air crash investigation shows like nobody’s business, and this seems to speak to QC and maintenance workload/culture issues.
Apparently it started immediately after Alaska installed their wifi equipment, which some sources have indicated requires opening that door plug. They apparently assumed it was due to the wifi install. Should have grounded it until the figured it out.
Alaska does have a history of poor maintenance causing crashes.
Surely this bodes well for their acquisition of Hawaiian, which famously operates long trans-Pacific routes across thousands of miles of open water!
Agreed. This is a multi-layered fuckup. The manufacturer probably didn’t tighten things down all the way, their QA didn’t catch the critical defect, the plane inspectors didn’t catch it during inspection, the airline didn’t ground it after a pressurization warning, the pilot flew a plane with a known issue. There are several cultures of complacency at play. Hopefully the FAA can scare everyone into flying right.
The reason I added the “if” is because I didn’t see any information about age and don’t know the specifics of the engineering/specs. Bolts needing the be checked annually and tightened every 5 on average could be perfectly reasonable with how much stress is on airplanes. There’s a reason frequent inspection is enforced more heavily on airplanes, and it’s not just because failures mean potentially falling out of the sky.
But yeah, it’s entirely possible they fucked up, but it’s for sure
UnitedAlaska did.The plane was delivered in October so it was brand new
That’s helpful extra context. Then hard to argue Boeing didn’t shit the bed too.
The Swiss Cheese Stack of failure modes
Failure is a chain.
United Airlines make it sound like a mundane event finding those loose bolts.
There’s a one-sentence quote here, what do you expect them to say exactly as they find things wrong?
“Oopsie-daisy!”
— Unities Airlines
After looking at that diagram I have to ask - why in the everliving fuck would a pressure bearing panel like that be hung by bolts and not inserted into the cabin and held in place by the ribs of the fuselage? I mean seriously?
I don’t get why they don’t just make it a bit bigger on the inside so that when pressurized, the pressure itself seals it. Seems like a fail safe solution instead of this shadiness.
I think it’s to save space. See: DC-10 Cargo Door fiasco
It does. It is still a plug-type door. It pushes against 12 stop pads. This design has been used for many years, including on the 737-900 that predated the Max9. You can see the exit plug in this photo form 2007, before the Max was even a thing. Also, cargo doors have worked the same way for many more years than that.
They do it so that the door does not have to swing the whole way inside to fit out.
It is, kind of. The plug is secured by 6 stops (or tabs) along each side. The positive pressure differential pushes the plug outwards into those stops.
To remove the plug you uninstall 4 bolts which allow the plug to go up and over the stops, after which it can hinge outwards on a hinge found at the bottom of the plug.
Just seems like a better design would be if no bolts existed (like from them loosening over time and falling off), it would still be sealed perfectly fine. The obvious failure point is the bolts and seems they could do better.
That’s how the normal doors work because they aren’t permanently secured in place. The reason is weight as it pretty much always is in aviation design.
Lovely, I’m flying united to Ireland in two months. Fingers crossed I get an older version.
Ah, playin’ it safe, are ya? Why not spice things up a bit? Flyin’ United, might as well throw in a bit of turbulence for the craic!
So are they just going to tighten them up real well and call it a day? Also are these the same planes they were urging the FAA to let them flight without further inspection?
Picture of one of the aircraft’s bolts: https://x.com/byerussell/status/1744460136855294106?s=46
Not clear if this is the cause of the Alaska accident. Those bolts hold on the hinges at the bottom, and the photos appear to show those hinges still attached on the incident aircraft.
I am glad to read all these reports, investigations and of course the emotional laden criticisms of actors associated with this. Because each time I check aviation incidents in Russia, they determine in the first 24 hours it must have been the pilots fault.
I hope the front doesn’t fall off.
Well, as long as it’s not in the environment, at least.
