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Comment by kozak | Hacker News Reader

I would be 100% comfortable flying the MAX if they either added a third AoA sensor or removed MCAS altogether (introducing a new type). They did neither.

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I also want ALL pilots trained on the differences on this plane. It is not the same as a 737 and we need to stop pretending it is. People should be in jail over this.

Training is required to my understanding.

Good, as long as the training teaches them how/when to disable this failed system.

> I would be 100% comfortable flying the MAX if they either added a third AoA sensor or removed MCAS altogether

You prefer a plane that stalls?

All planes stall. If you are type certified to fly the aircraft, you know how not to do that.

MCAS was a type certification workaround, not a stall workaround.

Exactly. Any half-decent pilot could keep the 737Max in the air without MCAS. It would just "feel" slightly different than a previous 737. The problem with MCAS is that it lies to the pilot in about four different ways.

MCAS is not there to prevent stalls, it's there to make the MAX fly like the NG.

Why is this being downvoted? It is entirely correct. The MAX is an entirely safe plane to fly without MCAS. It stalls more easily, but the safe flight regime is not in any way remarkable -- there are plenty of aircraft that stall even more easily than the MAX in wide use.

The problem was never that the plane's flight characteristics were unsafe, it was that they were different enough from the older 737's that it wasn't reasonable to fit them under the same type certificate. So MCAS was added not to make the plane not stall, it was added to make the plane not stall if flown like any other 737.

This is both why a failure of this magnitude could slip past the regulators (MCAS was never described as critical for flight, so it could do with less redundancy. In a failure condition, the crew could always just turn it off and fly without.), and why it's failure is so goddamn galling (a barely-tested computer program that was not needed for safe operation was given the controls to literally fly the plane into the ground for reasons that were best described as marketing).

The MCAS tries to help save a plane that has already gotten in a bad situation. To need it, the pilots have already let the plane get into a dangerous flight regime, your odds of recovery at that point even without MCAS are not ideal.

> your odds of recovery at that point even without MCAS are not ideal

That's why they added MCAS. Based on the FAA's testing, it helps when it works.

I understand the temptation to lean into anti-intellectualism when a plane crashes. But there is sunlight between criticizing an agency in general and playing armchair aerospace engineer.

This is incorrect. Both 737Max crashes took place during normal flight regimes, and they happened because of faulty AOA sensors. Pilots have multiple ways of determining AOA and would never have been fooled by a single bad sensor.

Finally, recovering from a stall (even if one happened, which it didn't in either crash) is Day 1 of every flight training course. It is probably the most basic and thoroughly-drilled skill in all of flying.

> Both 737Max crashes took place during normal flight regimes

I expected to see this fallacy.

MCAS does not operate normally during any flight regime routinely encountered. It should remain entirely inactive until things get more exciting than they should ever get on a passenger flight. What you are talking about is a malfunctioning MCAS, which isn't operating by design.

> recovering from a stall (even if one happened, which it didn't in either crash) is Day 1 of every flight training course

Yes, of course it is. It is also very rarely encountered by passenger jets, and when it does happen things are very exciting indeed. Your odds of hitting the ground have already gone up quite dramatically at that point, MCAS or not.

> MCAS does not operate normally during any flight regime routinely encountered.

I'm aware of this. I'm also aware that it failed twice within a couple of months -- which is far too frequently -- and the consequences of each failure were complete loss of the airframe. Anybody who has ever done risk analysis can see that MCAS was improperly designed and poorly implemented and the people who signed off on it should probably go to jail.

No new system whose failure could result in all souls lost and is known to have a single point of vulnerability should ever have been added to a commercial passenger aircraft. Period.

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