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Comment by ams6110 | Hacker News Reader

I see this playing out in a couple of possible ways. One is that it ends up like the DC-10. Public confidence is lost, even though the problem is fixed. The aircraft end up going into freighter service.

The other is that they make a convincing case that the problem is resolved. I don't know if that's possible given today's default hate for big corporations, we'll see. They've done it before with the 737 and the rudder problem it had in the 1990s or so. That problem led to a few fatal crashes, but I'm not sure it ever got the attention that this story is getting. The news cycle was different then.

I would absolutely fly on one once the problem is corrected.

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Be my guest. For sure I won’t be aboard one of these death traps in the next accident. And we’ll have another accident if they let this killing machine take off again given that they are just doing a useless software fix.

In all fairness this plane is only a danger to its crew (and to regular commuters). Even without the software fix, the probability that you get into a crash in one of the few times in a year when you make a leg in this plane is still infinitesimal. For the crew that spends the whole year in there, different story.

I assume that AoA sensor disagree would have been warned about still on the ground. Even if both fail, a new take off checklist will probably include comparing AoA information with analog instruments. If one sensor failure is 10E-5, two simultaneous should be 10E-10, multiplied with assumption of competence (say 99/100 will now know how to deal with it), which gives 10E-11 - 10E-12. I.e. I wouldn't worry about MCAS anymore after every plane has been updated.

What I would worry about is departure stalls, as MCAS doesn't seem to solve these. I wonder whether there isn't another 10E-5 to 10E-6 risk in there and people have just been lucky so far. Another MAX8 crash involving a stall would kill this plane I think, as it would prove much more that it's inherently unsafe.

> If one sensor failure is 10E-5, two simultaneous should be 10E-10.

That only holds if errors are statistically independent. See also Common Mode Failure [1].

[1] https://en.wikipedia.org/wiki/Common_cause_and_special_cause...

From the FDR data in the report, it seems that the AoA sensor disagreements on this flight didn't start until after takeoff. I don't know if this is the normal failure mode.

Indeed. The speculation is that it was caused by a bird strike during takeoff.

That is not how plane safety is done.

By my calculation the plane was flying roundabout 100.000 days with 2 accidents. Assuming 2 round-trips a day maybe 200.000 takeoff during this time. One crash every 100.000 take-offs.

Now assuming 40.000 road deaths per year in the US and 300.000.000 citizens we have 0.000133 probability to suffer a road death a year. Assuming one 737MAX round trip per quarter we have 8 take-offs so .00008 probability to die in a 737MAX. Assuming commuter 40 trips a year we have a risk much higher than the average road death risk.

> I would absolutely fly on one once the problem is corrected.

The problem is Boeing, not the MCAS system.

I don't think Boeing can be fixed.

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