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.
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.
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.
Ex-aircraft mechanic here. Nothing will have been done in this situation without paperwork backing the decision. There are often small niggles that could ground an aircraft, but there are manuals that can be consulted to see how many more flights can be taken before it must be grounded for rectification - the MEL (minimum equipment list) and CDL (configuration deviation list). So the airline will not have made the ultimate decision to keep flying, Boeing will.
The fact that this has now been found in two different airlines means that it’s a design flaw again, either the locking mechanism on the bolts is insufficient, or the reinstallation instructions in the maintenance manual is incorrect (the Alaska airlines aircraft door plug was recently removed to carry out maintenance on another part)
As an airline customer, I would much rather have the airline tell me the plane was grounded due to parts being ready to fall off than the 3 hours I had to wait one time because of a busted tray table.
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 United Alaska did.
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:
Which makes it sound like they couldn’t find the source of that warning but weren’t willing to completely write it off.Nevermind:
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!
Ex-aircraft mechanic here. Nothing will have been done in this situation without paperwork backing the decision. There are often small niggles that could ground an aircraft, but there are manuals that can be consulted to see how many more flights can be taken before it must be grounded for rectification - the MEL (minimum equipment list) and CDL (configuration deviation list). So the airline will not have made the ultimate decision to keep flying, Boeing will.
The fact that this has now been found in two different airlines means that it’s a design flaw again, either the locking mechanism on the bolts is insufficient, or the reinstallation instructions in the maintenance manual is incorrect (the Alaska airlines aircraft door plug was recently removed to carry out maintenance on another part)
As an airline customer, I would much rather have the airline tell me the plane was grounded due to parts being ready to fall off than the 3 hours I had to wait one time because of a busted tray table.
If it’s not in the MEL or CDL then you can’t fly without it. They’re basically a book of approvals for how long you can get away with stuff.
Btw If the tray table can’t be stowed, you can’t take off with anyone in that row because of the danger in an emergency landing.
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.
I think you mean Alaska.
Yep. I can’t read.
Thanks.
The Swiss Cheese Stack of failure modes
Failure is a chain.