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Comment by onethought | Hacker News Reader

Yet four highly trained pilots plowed this "inherently stable aircraft" into the ground.

"keeping the same type rating" lead to creating an "inherently unstable aircraft". As shown by the fact that over 100,000 hours of accumulated training didn't help.

Saying the "737 Max is an inherently stable aircraft without MCAS" is like saying its stable if it never leaves the ground. It has (well had) MCAS by default.

Minimising the size of this mistake is what is detrimental to the discussion. Boeing should go out of business. They are responsible for hundreds of deaths. If this were a person, this wouldn't even be a discussion. But corporations some how get a free pass on man-slaughter.

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PuffinBlue's problem seems to be one of terminology and I'd agree with them. "Unstable" is not a good term for what you're trying to describe.

It's like if I started to describe your app's database as "unstable" because your website's down due to cloudflare configuration.

(With that said it's all just petty semantics; we all understand what the post is trying to convey)

> With that said it's all just petty semantics

Ordinarily I would agree with you, but this issue of stability is clouding the truly detestable course of action Boeing took.

Boeing was trying to save money. They wanted to keep the same type rating, so they added MCAS to an inherently stable and flyable aircraft for purposes of retaining the same type rating.

The system they added included optional safety measures that airlines had to pay more to install [0]. Boeing new that MCAS would be safer with these features and charged more for them!

The true outrage here should be directed at this underlying cause and the erroneous discussion over stability should be put by the wayside.

[0] https://www.theguardian.com/business/2019/mar/21/doomed-boei...

Sorry to say but you’re the one doing what you accuse others of doing.

"With that said it's all just petty semantics..."

Semantics is what words mean.

No amount of "stability" is going to correct for a system constantly adjusting your nose to point into the floor.

All mcas does is adjust the offset on the elevator.

it is a failure of UX and oversight. Pilots weren't trained, Alarms weren't installed. Its as simple as that.

Yet four highly trained pilots plowed this "inherently stable aircraft" into the ground.

This had nothing to do with the aircraft being unstable, but that MCAS had introduced a huge downwards trim as consequence of the sensor malfunction. Had MCAS not been active, none of the accidents had happened.

This is not what inherently stable means

Any aircraft will make a hole in the ground if its nose is pushed down, which is what mcas was doing.

But the airframe is not mcas. The pitch up movement happens in the NG as well, to a lesser degree.

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