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Comment by WalterBright | Hacker News Reader

"In the deadly Lion Air crash in October, the pilots lost control after initially countering the Maneuvering Characteristics Augmentation System (MCAS)"

They successfully countered it 25 times before the crash, meaning they had 25 opportunities to remember to use the cutoff switches.

"Boeing advised the airline about it after the crash."

An Airworthiness Directive was issued to all MAX flight crews after the Lion Air crash specifically laying out the procedure of countering with the trim switches and then throwing the cutoff switches.

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I'm not an expert here at all but

> An Airworthiness Directive was issued [...] and then throwing the cutoff switches

So the response was "there's a known-lethal fault in our product X, when it happens, do Y"

but not

"there's a known-lethal fault in our product X, withdraw X from use immediately"

Edit: given C programmers have many, many of opportunity to learn "not to do that" in an unsafe language, instead you wrote D. That's silly, why not continue to tell C programmers "don't do <dangerous thing>"? I mean, you could have completely saved yourself year of your time writing a new language which makes it hard to do <dangerous thing>, right? Just tell them not to make mistakes is better, right?

Oh, I quite agree that Boeing screwed up the MCAS software design and needs to fix it. My experience with designing safe systems at Boeing has led to a lot of design decisions in D. I often look at lists of common bugs in programs to see if I can find a way to design such bugs out of the programming language.

I also regularly tell people that if you don't have a plan for when your software fails, you're going to be sorry. In this case, the plan is for the pilots to follow the runaway trim procedure.

As for software people, do you have a backup plan for when the software goes berserk? No? Well, someday it will go berserk and delete all your files. Have a backup plan. Suing the software maker won't get your files back.

About 90% of pilot training is dealing with emergencies that are never supposed to happen. One of them is runaway trim. Nobody has a plan to dispense with pilots and rely totally on automation.

Walter, what puzzles me with your line of argumentation is the single minded focus on the pilots behavior and ignoring everything else including the fact that we know training manuals were inadequate and MCAS proofed to not be airworthy. As the still missing FAA and EASA certification shows. Including one near crash during simulator flights, conducted with an updated MCAS, hyper-trained crew that knew more or less what would happen in a protected environment.

The manual thing is such a canard.

The directive issued is literally just reminding pilots of a procedure they should already know - reset the trim to stabilize the plane and throw the cutout switch. The issue with MCAS changing how the plane performed was remediated by skills pilots should have irrespective of feature descriptions in a manual.

You do know that training manuals are covered by certification procedures, right? It's not a canard, it's a fact.

Yes. That's orthogonal to whether or not the manual defeciency should have stopped pilots from following the checklist they should have down to rote memory.

(Hint: it shouldn't.)

This yet again pushes the issue onto just the pilots. Anything but the planemaker. I agree with the GP, there's far too much apologism for boeing here.

I'm not an apologist for Boeing and that's a mischaracterization of what I'm saying (and I'd argue Walter as well.)

Especially as my field of commercial aerospace was vendor agnostic.

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