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Comment by disillusioned | Hacker News Reader

>At one point during the examination, the air-safety agency observed mechanics at Spirit using a hotel key card to check a door seal, according to a document that describes some of the findings. That action was “not identified/documented/called-out in the production order,” the document said.

>In another instance, the F.A.A. saw Spirit mechanics apply liquid Dawn soap to a door seal “as lubricant in the fit-up process,” according to the document. The door seal was then cleaned with a wet cheesecloth, the document said, noting that instructions were “vague and unclear on what specifications/actions are to be followed or recorded by the mechanic.”

As always, the issue isn't the _process_, but rather the lack of _documentation_ of said process...

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There's a lot of shoot from the hip emotional/sarcastic responses to this, but the lack of documentation is absolutely one of the main issues.

If mechanics are improvising with questionable practices, what are you going to do? Fire the dozen mechanics who used Dawn soap and now everything's fixed and we can trust all 737 doors for the foreseeable future? No, of course not, because that doesn't solve the underlying systems issue. You need to create a workplace culture of sticking to the documented process, and you can't do that if there isn't a clearly documented process to begin with. Sloppy engineering culture and QA culture trickles its way down, and that's what we're seeing here.

Both using commercial soap as lube, and a plastic card as a gague seem like symptoms rather than the actual root of problems here. I have to assume the same time crunch that caused them to use quicker to acquire materials than what they ought to have used (and likely had stocked nearby) is what cut down on documenting these processes.

Documentation of what was actually done would certainly be another useful layer in the swiss-cheese safety model commercial aviation relies on.

I’ve written tech manual procedures and maintenance instructions. It’s common to add alternative solutions for cleaning or lubricating parts.

I’m sure there’s a more appropriate way to put it other than dawn plus hotel card because that would not pass the approval process for my organization.

> Clean with a general purpose soap and water with a firm applicator card, plastic or nylon spudger, or plastic spackle knife.

Seems like the clearest example of damage from the iron law of bureaucracy here. As @dboreham mentioned in another thread, there is a culture of management suppressing documentation. Not that management is entirely to blame, as documentation is oftentimes not appreciated by anybody except regulators

https://news.ycombinator.com/item?id=39623522

Related: in the small GA aircraft world Dawn dish soap may as well be a MIL spec with how often it's used.

I don't know about that, the process itself sounds pretty fucked to me.

You're defending the hotel card Dawn soap stuff, as long as it's documented. Got it!

Dish soap and baby powder are commonly used in aerospace maintenance for finding pressurization leaks.

That's quite different to using them as a lubricant. They're not applied to internal surfaces for one.

It very much sounds that parts are not manufactured to proper tolerances, and as a result Boeing uses undocumented lubricants to make things fit (badly). If this were anticipated there would be a documented process, but there isn't, and it means nothing good.

Ajax or Dawn? These things matter.

I think you're assuming that those could never be valid tests or processes for the manufacturing process.

I'm not saying they are or defending Boeing by any stretch, but I know my knowledge of manufacturing details for aircraft is limited enough that I couldn't make that assumption.

> I think you're assuming that those could never be valid tests or processes for the manufacturing process.

Given that Dawn dish soap isn't manufactured to any kind of useful tolerance, purity or performance guarantee, I'd say that's a safe bet.

I really wonder what the effects of Dawn dish soap residue on doors that go through huge pressure and temperature cycles is.

This position makes sense. You do not have enough knowledge to assume that the Dawn soap thing is bad, only enough knowledge to discourage folks from pointing out that it sounds bad

I honestly can't judge if that's bad or good to use those things. Just because it seems stupid from an initials laymen's glance certainty doesn't mean it is.

If it's safe for ducks it's safe for planes, right?

Because they both fly.

Ah yes, if there was documentation, it would specify that a Hilton key card should be used. Otherwise, a Hyatt or Westin key card being used may cause an incorrect check result of the door seal and cause possible loss of life.

Well it should specify the thickness, length, and width of the keycard, since brands might change vendors

And of course it should specify which way it should be inserted.

And it needs to specify the amount of bend allowable given some amount of pressure. No point in using a bendy card.

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