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Comment by rebuilder | Hacker News Reader

Huh, the pitch indicator is known to be off by a huge margin on some planes and the problem is not fixed?

The problem is fixed by extending the flap one notch to turn off the MCAS. no big deal.

I'm sure no offence was intended, but I'd be quite upset if I heard an engineer say a fix is "no big deal" if I were grieving a lost family member.

Pretty sure that was sarcasm. Boeing is basically saying, there is an automated system that causes planes to crash, and to turn it off you need to perform some completely unintuitive sequence of actions. These planes should not be allowed to fly.

That's not a fix it's a workaround. The pitch being off is the problem. Turning off mcas solves it but it does no4 fix mcas

I’ve been trying to understand how the vertical pitch measurement is supposed to be suitable for use as part of the MCAS decision process at all. Seems to me wind shear and other atmospheric effects are going to make an airspeed based measurement of angle of attack _always_ subject to condition dependent measurement error. The fact that the pilot is assumed to have a more navigationally useful estimate for angle of attack (in that they are able to know when the angle of attack measurement from the sensor is wrong) makes me think there is something fundamentally flawed about the way this quantity is being estimated by the existing sensor — the modality of measurement might not be an appropriate way to control this flight process if atmospheric effects can bias the measurement in a way that can be calibrated by pilot knowledge but with these corrections not reintroduced into the flight process ...

Planes can have multiple AoA sensors, and often do. An indicator which makes the pilot aware of divergent AoA sensor readings is a paid upgrade.

Though I also have to agree, as soon as this sensor's input became crucial to determining operational boundary conditions, the system needed some rather stringent hardening. It's a bit like leaving your auto-scaling load balancing infrastructure exposed and getting upset at your AWS bill the first time someone DDoS's it to inflate your hosting footprint.

Yes, like if your car overaccelerates what you have to do is just turn the volume one notch up.

This is more like car over-accelerates, open the boot door.

Flap deployment speed limit on the 737 Max is 230kts. ETH302 was already at least 50% beyond that.

So now you have an aeroplane with its flaps ripped off, perhaps asymmetrically for additional control challenges. Next step?

This is the most deadpan comment I've ever read.

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