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Alaska Airlines flight 1282 NTSB preliminary report [pdf]

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Re: Alaska Airlines flight 1282 NTSB preliminary report [pdf]

#181

Post by flutas »

skywhopper wrote: post #94
belltaco wrote: post #29

>The CVR was downloaded successfully; however, it was determined that the audio from the accident flight had been overwritten. The CVR circuit breaker had not been manually deactivated after the airplane landed following the accident in time to preserve the accident flight recording In addition to local storage, why isn't the audio(along with location, altitude and some sensor information) also streamed using somethi…

This is an old system that works well and reliably for pretty much every incident. I’m not aware of another case of this sort of thing (relevant flight recorder data being overwritten) happening in recent years anyway. If you spend time constantly upgrading systems like this you’re asking for a higher failure rate, for very little gain. That said, there’s a standard and reliable 25-hour flight voice recorder that sol…

> I’m not aware of another case of this sort of thing (relevant flight recorder data being overwritten) happening in recent years anyway.

Got me curious how often this happened.

Last example I can find of a CVR being overwritten and not just exploded/missing was in 2018 for an engine fire, similar to this where the flight had to emergency land shortly after take-off. Before that...well a lot of complete failures ("not operative at time of flight") but not many like this scenario.

https://en.wikipedia.org/wiki/List_of_unrecovered_and_unusab...

Re: Alaska Airlines flight 1282 NTSB preliminary report [pdf]

#182

Post by NordSteve »

aftbit wrote: post #19

Depressurization happened around 17:12:33 PST but the aircraft continued to climb until 17:13:41 PST, and the autopilot was configured for 10k ft at 17:13:56 PST. Why did it take the pilots a full minute to begin an emergency descent after the failure? I would expect that the nature of the accident would be clear nearly immediately, at least in the need to descend the aircraft.

Let's imagine you're the pilot, and you're super busy with an emergency. You also know that there are mountains to the east of the airport. You also have ATC on the radio and they know about all of the meaningful obstacles in your area. Asking for lower in this situation (rather than using your emergency authority) is exactly what you want to do.

Looking at the track, they descend to 10000' until they start their downwind to base turn. Once they start that turn, they get a lower altitude (looks like 7000') until they are established on final and can fly an approach.

Re: Alaska Airlines flight 1282 NTSB preliminary report [pdf]

#183

Post by seo-speedwagon »

imoverclocked wrote: post #43
mcmatterson wrote: post #3

The fact that a critical piece of the evidence was cell phone photos sent between workers coordinating door re-assembly doesn't exactly instill a whole lot of confidence in their permit-to-work process. I didn't like it when it was medical teams doing shift handover via a Google Doc, and I don't like it when it's a matter of flight safety either. Or, as Homer might eruditely say: "guess I forgot to put the bolts back…

> The investigation continues to determine what manufacturing documents were used to authorize the opening and closing of the left MED plug during the rivet rework. I mean, there is already a ton of documentation and process surrounding the construction of an airplane. Adding more process doesn't safety make. Having a safety culture without the fear of retaliation, on the other hand, makes a world of difference.

If the door was removed (which the NTSB report and the whistleblower post linked elsewhere around here say must have happened) there should be documentation for, at minimum, the removal and reattachment. If the door was not removed but was opened and closed, there should be documentation for both of those actions instead.

I don't know if this should be considered "adding more process" because it has been standard process for a very long time. All work done on an airplane is authorized, by someone, and after completion is recorded, by someone. Discrepancies and deviations from this standard operating procedure are a big deal.

Re: Alaska Airlines flight 1282 NTSB preliminary report [pdf]

#184

Post by jiggawatts »

hn8305823 wrote: post #65
jiggawatts wrote: post #47

Earlier quoted context omitted.

IMHO surgical theatres should have permanent multi-perspective cameras recording everything for the same reason.

Only if the patient consents (or their family if they are unable to give legal consent), otherwise no for patient privacy.

Patients are typically covered with a cloth, head do toe.

Re: Alaska Airlines flight 1282 NTSB preliminary report [pdf]

#185

Post by bzax »

peteradio wrote: post #180
Rapzid wrote: post #168

Earlier quoted context omitted.

It's crazy their supplier is delivering so many must-fix defects they have to have a warranty team on site to help fix them. Crazier that Boeing just let that get more and more out of hand instead of making Spirit get their shit together on their end. https://www.youtube.com/watch?v=xIAfCupuZ3w Edit: Also that entire culture and dynamic between Boeing and Spirit on the production floor seems very toxic and driven by…

Spirit has no competition. How do you threaten the supplier who owns your production when you have no other options?

It sure would be great if they just owned the supplier outright and could align incentives that way.

Re: Alaska Airlines flight 1282 NTSB preliminary report [pdf]

#186

Post by xenadu02 »

aniftythrifrty wrote: post #129
gtmitchell wrote: post #55

A very thorough preliminary report. I've worked for a long time in quality systems, and this is a perfect example of a systemic failure. They've got work being handed off between Boeing employees and 3rd party contractors with insufficient controls in place to verify that very basic tasks are being performed. I'd be curious to know how many non-conformances they typically see during assembly of a plane and whether ma…

[flagged]

On the contrary Boeing has spent the past 2-3 decades trying to screw over the workers as hard as possible. They've massively outsourced parts manufacturing. They don't even make the fuselages anymore!

The whole point is to make those people contractors so the contractors can hire cheaper labor and even push work to cheap overseas locations.

Can a system like that be made to work? Yes it certainly can. But it says something about Boeing's priorities: find the cheapest labor possible to goose profits (management bonuses).

Re: Alaska Airlines flight 1282 NTSB preliminary report [pdf]

#187

Post by WalterBright »

runarb wrote: post #162
koyote wrote: post #108

Earlier quoted context omitted.

So were the bolts missing because the Spirit team did not know they had to be put back (i.e. it was not recorded as a task that needed to be done) or was that simply just another mistake in the long line of mistakes they've made? Reading through that post gave me nightmares of dealing with outsourcing software teams where you send them a small issue to fix and their fix breaks 3 existing items.

> were the bolts missing because the Spirit team did not know they had to be put back It would be interesting to know what ultimately happened to the bolts if they indeed were removed. When I disassemble something, I do as I was taught in my mechanical class in high school, and always keep all parts I take of in the same box. If I am left with some extra bolts when finished, that would be a worrisome sign.

When I was a teen, I rebuilt the engine on my first car. When done, there was a spring left over. I had no idea what it was for, the engine ran fine.

So I drove it around. The oil pressure was very low, but I figured it was just a broken gauge.

Then, the engine got way, way too hot.

It turns out, the spring was for the pressure regulator from the oil pump. The oil was pumped out of the pan right back into the pan. The engine needed to be rebuilt again.

Re: Alaska Airlines flight 1282 NTSB preliminary report [pdf]

#188

Post by iamevn »

flutas wrote: post #181
skywhopper wrote: post #94

Earlier quoted context omitted.

This is an old system that works well and reliably for pretty much every incident. I’m not aware of another case of this sort of thing (relevant flight recorder data being overwritten) happening in recent years anyway. If you spend time constantly upgrading systems like this you’re asking for a higher failure rate, for very little gain. That said, there’s a standard and reliable 25-hour flight voice recorder that sol…

> I’m not aware of another case of this sort of thing (relevant flight recorder data being overwritten) happening in recent years anyway. Got me curious how often this happened. Last example I can find of a CVR being overwritten and not just exploded/missing was in 2018 for an engine fire, similar to this where the flight had to emergency land shortly after take-off. Before that...well a lot of complete failures ("no…

Here's one in 2017 that was recorded over because they didn't report until after another flight https://en.m.wikipedia.org/wiki/Air_Canada_Flight_759

Re: Alaska Airlines flight 1282 NTSB preliminary report [pdf]

#189

Post by maxerickson »

toast0 wrote: post #126
cezart wrote: post #117

Earlier quoted context omitted.

At a company I worked in, we had a joke about this: "Good thing we don't build nuclear reactors". In some software projects the level of rush, and the fact that bugs sometimes would leak into production was kinda horrifying. It would've been way more so, if it would've been the kind of project that could kill people in case of failure. Like it happened in Chernobyl with nuclear reactors, or at Boeing with planes. I c…

Quality is always a trade-off. If you're deeply into economics, you wonder about the trade-offs of cost to find defects before shipping, difference in cost of addressing defects before and after shipping including costs of mitigation from consequences of defects, % of defects that will never be found after shipping (and are therefore a real cost savings), and in the long game costs of having a reputation for shipping…

Quality is always a trade-off.

That's a pretty huge assumption.

For instance, compare firearms prior to replaceable parts to firearms after.

Better, cheaper, easier to make (because craft was replaced with process). Some up front cost, but absolutely not a trade off, it was a huge advancement.

Of course modern process control does more or less let you relax conformance rules to reduce cost, but it's farcical to call sacrificing reasonable conformance "quality".

Arguably, the idea that quality is obviously a trade off and you can make money by letting it slide is one of the sources of rot in our society.

Re: Alaska Airlines flight 1282 NTSB preliminary report [pdf]

#190

Post by resolutebat »

zmgsabst wrote: post #176
albert_e wrote: post #169

Earlier quoted context omitted.

> removed for removing the door plug there was apparently two (identical) procedures -- one for "removing" the door plug and one for "opening" the door plug -- but only one of them actually called for paper-work and quality inspection after it is done. It seems they decided to "open" the door plug instead of "remove" it to work on the sealing issue? -- and thereefore documentary record of the work performed and inspe…

I don’t think there were two approved procedures. I think there was an approved procedure (“removing the plug”) and a deviance from process, justified with ad hoc semantic games.

I doubt this was intentional? It sounds more like mistakenly applying the procedure for opening a normal door, which requires no followup, to opening a door plug, which does.
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