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Comment by tntn | Hacker News Reader

The checklist in question has three steps. Step two is "move stab trim to cutout," which disables automatic systems that adjust the stabilizer. The pilots in lion air had ~10 minutes to do this.

It is extremely unlikely that the pilots were trying to work through the checklist. More likely they simply did not know what to do.

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This one's actually a memory item, not a checklist. But it's the memory item for "runaway trim", which is a very different qualitative experience than the slow march of an MCAS system that you didn't know existed.

This doesn't make jive with disaster being averted by a third pilot. Assuming the third was totally dedicated to checklist vs preventing the plane from diving, it was only his insight that stopped the plane from going down.

The MCAS system apparently increased downward trim without any speed considerations, to over 2.5 degrees in 10 seconds. I don't have the full flight control details but it sure sounds like pilots would lose control within minutes at most. In the LionAir crash the pilot reported control problems and asked to return to airport within 3 minutes, and they slammed into the ocean in 12.

Not sure where you're getting this info but I'm more than sure they knew something was wrong in the last 2 minutes (while they were heading into the earth at almost the speed of sound).

You really think they have ten minutes to react when by then everyone on LionAir was doomed to die?

This "human" factor was also characterized in the movie Sully when it was apparent that just a few extra seconds for pilots to process the issue made all the difference between landing safely at a nearby airport vs. landing in the Hudson River.

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