Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Alaska Airlines flight 1282 NTSB preliminary report [pdf]

ntsb.gov

Post reply on HN
Print view View original

101–110 of 285 posts

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

#101

Post by shadowgovt »

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…

Rumor has it the controls are there, but subvert-able.

Apparently, there are two ticketing systems (one for "history of plane," Boeing internal, and one for "day-to-day onsite work," visible by contractors and Boeing management). The work to fix the rivets was logged in the day-to-day, but management and the onsite staff managed to convince themselves that merely opening the plug to fix the vacuum-seal trim did not constitute "removing" the plug, and since there was only an entry in the history-of-plane log for removing, not opening, they didn't log it there (when the intent was "there's no entry for 'just opening' because there's no such thing as 'just opening', breaching the pressure vessel at all constitutes 'removal of plug'").

The final inspection that should have caught the error would have been triggered by the update in the history-of-plane ticketing queue.

(And as for 'how many non-conformances,' the same source claims that Spirit is one of the few subcontractors with on-site staff at the factory because their parent company delivers such consistently shoddy out-of-compliance product that they are continuously doing final warrenty-work onsite. So maybe "fire that vendor" should be on the docket too).

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

#102

Post by cjbprime »

imoverclocked wrote: post #85
cjbprime wrote: post #60

Earlier quoted context omitted.

That document is an in-progress proposal to amend a rule, no? I think there was strong opposition to this rule before this accident flight, and the blowback from the missing data here might be strong enough to be able to get it passed anyway.

> the blowback from the missing data here might be strong enough to be able to get it passed anyway Nice pun. What do you think would have been gained from the CVR data in this case? Do you think pilot error had anything to do with the door-plug failure? Do you think the CVR was left running on purpose/accident? If I were one of those pilots, the first words out of my mouth probably would have been, "what the $&#*?!"…

I'm not an accident investigator and don't know what exactly would turn out to be useful, but I think changing your intuition for why we study the CVR away from "because there might have been a large pilot error" to "so that we can learn more about how pilots react to emergencies with a goal of seeing if we can come up with process improvements" may help. If there was some aspect of the response that was not perfect, we could develop training on it for other pilots, right?

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

#103

Post by zer0x4d »

lisper wrote: post #59
throwworhtthrow wrote: post #28

Earlier quoted context omitted.

You can't leave your assigned altitude/trajectory without coordinating with ATC. Otherwise you may collide with another plane, which would make a bad situation worse.

In an emergency you can do anything you think is necessary to address it. Source: I’m a private pilot.

You're conflating the right to do something with whether it is advisable to do something.

Sure, you are ~allowed~ to begin an immediate descent in an emergency, but it is not a good idea considering from the pilot's perspective, the bang is most likely an engine going out and altitude is always your friend in this condition.

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

#104

Post by ceejayoz »

wkipling wrote: post #71
RankingMember wrote: post #58

Earlier quoted context omitted.

See also: police bodycams If you have the capacity to end peoples' lives with an arm spasm I think your privacy should rightfully take a backseat.

Absolutely not. Body cams mute the first part of the audio for this exact reason. Privacy is important.

The issue with police body cam audio is that they are regularly recording non-police who do have a right to privacy. That's not an issue for pilot cockpit recordings. (If it is, you've got an incident that should be recorded.)

The muting you observe of police footage isn't of the first part of the audio, it's the prior 30 seconds from before the record button is pressed. They have a constant buffer going, as things can happen... unexpectedly.

This caught a cop in Baltimore; he wasn't aware of or had forgotten the feature. The 30 second buffer caught him planting drugs, then faking the finding. https://www.npr.org/sections/thetwo-way/2017/07/20/538279258...

Side note: It took years to charge him (https://www.baltimoresun.com/2020/03/09/caught-fabricating-e...) and he served no jail time for trying to send an innocent person to jail (https://www.wbaltv.com/article/officer-testifies-in-own-defe...).

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

#105

Post by margalabargala »

dmitrygr wrote: post #98
margalabargala wrote: post #63

Earlier quoted context omitted.

I don't think the problem you're describing is actually a problem. Exposure to super-high temps occurs in a small set of circumstances, all of which overlap with the destruction of the recording device and the cessation of incoming data. So we only need the same 1.2GB (or whatever) of high-temperature-tolerant storage. The 25 hour storage can be on normal flash, as if we're more than 2 hours past the incident and dat…

Multiple investigations in the past have recovered data from FDR and/or CVR after an extensive high-temperature fire. I do not think that FAA will give that requirement up.

Yes. As I said. The existing system can remain in place, with all of its existing high-temperature-tolerant components.

In addition to not giving up that requirement, we could also add a longer, not-heat-tolerant storage. If it gets destroyed in a fire, see the above paragraph. If there is an incident where the data is of interest and the aircraft is not destroyed in a fire, then this will maintain the data long after the above system has deleted it.

No one has advocated giving up the high temperate storage.

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

#106

Post by Hamuko »

WheatMillington wrote: post #41
CPLX wrote: post #23

Earlier quoted context omitted.

Do you have a voice recording of you doing your entire job, every day of your life?

No but I also don't have the lives of 300 people in my hands.

Pilots can have the lives of quite a lot more than that on their hands since an airplane makes for a great kinetic weapon. The pilots of KLM Flight 4805 took the lives of almost 600 people.

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

#107

Post by reddit_clone »

hn8305823 wrote: post #75

I wonder how close the door plug was to hitting the tailplane or vertical stabilizer/rudder?

Considering all those scary scenarios, what happened was probably the most favourable outcome. It could have been a major disaster hundred different ways..

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

#108

Post by koyote »

krona wrote: post #14
nostromo wrote: post #11

> Overall, the observed damage patterns and absence of contact damage or deformation around holes associated with the vertical movement arrestor bolts and upper guide track bolts in the upper guide fittings, hinge fittings, and recovered aft lower hinge guide fitting indicate that the four bolts that prevent upward movement of the MED plug were missing before the MED plug moved upward off the stop pads. Ooofff. No bo…

> How did this pass Boeing QA? https://www.airlinepilotforums.com/safety/146074-boeing-inte...

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.

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

#109

Post by cjbprime »

zer00eyz wrote: post #100
hencq wrote: post #76

Earlier quoted context omitted.

I think there's some validity to the privacy concerns, but it seems those could be addressed with proper access controls and rules. The recordings should only really be listened to in the aftermath of an accident, in which case, as you say, the expectation of privacy should (in my opinion) take a backseat.

On one hand I agree with you. On the other hand, if someone recored my whole work day every day I would not be happy. I don't think you would stay at your job of that was a condition of it. There has to be a better solution to this issue.. extended recordings in an emergency, triggers based on conditions, private keys for pilots... IDFK, cause I try not to get involved in engineering that might KILL someone.

I don't understand. Are you implying that recording a pilot's voice for more than two hours could kill someone? Or just that aviation is stressful and high stakes?

(I agree that it's stressful and high stakes, which is why we record it.)

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

#110

Post by SoftTalker »

rootusrootus wrote: post #80
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.

A minute is a long time when you're sitting at your computer. But after the sudden depressurization, I imagine the pilot is focused first on making sure he has complete control of the airplane, assessing the situation, running checklists. Besides, 10K is just barely above the normal pressurization altitude anyway, it doesn't pose an immediate risk to the passengers that justifies just nosediving towards the ground. E…

First and most importantly the pilots have to get their own oxygen masks on, if they delay this at all they will become hypoxic, unable to think clearly, then pass out, and then it's over for all on board.
Post reply on HN