[del82]

That's fair, but what does the checklist say? I mean, say there are a thousand different malfunctions that could cause an uncommanded nose-down. This one happens to be #359, but the pilots don't know that, they just know that they're pointed at the ground. Maybe it used to be the case that the first item on the checklist (pull back on the stick) fixed problem #359, and now it's the second. But there are several hundred other malfunctions that might have caused the problem that also aren't solved by pulling back on the stick, so the next move is to go to the next item on the checklist, right?

[peteradio]

Pull back wasn't in the original manual but was a relied upon method. Boeing fucked up years ago by not documenting the function so it was allowed to be dropped transparently. How is that defensible?

[lmm]

Why was a method that wasn't in the official checklist "relied upon"? Pilots following some undocumented, non-standard procedure sounds like their fault rather than Boeing's.

[peteradio]

Who knows? Have you ever been taught an undocumented procedure by the expert and been told to use it regardless of what the manual states? Happens all the time? Is a pilot in a position to affect Boeing beauracracy?

[lozenge]

Sorry but how could Boeing design any plane if they can't assume pilots will follow the manual or any checklists?

[rocqua]

By including features in the manual. The alternative is that they don't, people rely on the features, they change the features without notifying anyone, and when shit goes wrong they can say "It wasn't documented: shouldn't do that".

The real question here is how commonly this feature was used. If it was common, then not putting it in the manual is a big problem!