[WalterBright]

Airliners are simply not designed to fly inverted. In Tex Johnson's famous barrel roll of a 707, he kept positive g on the airframe at all times.

One problem with flying inverted is the bottom of the airplane tends to accumulate junk - nuts, bolts, dropped tools, lunch boxes, dead mice, etc. Turning the airplane over means all that junk falls into the machinery, potentially jamming it.

[ipython]

Right- in the FedEx case it was a last ditch effort to literally knock the suicidal flight crew member off his balance and regain control of the aircraft. If you have a 'nanny' computer telling you that you're unable to do that, those crewmembers may have ended up dead instead.

Point being, in an unforeseen emergency, allowing crews to override the normal safety mechanisms may in fact save lives.

[askvictor]

I guess the question is what's the likelihood of such a situation, vs the likelihood of the situation where a 'nanny' computer prevents the crew doing something dangerous?

[ithinkso]

And then we have 'nanny' computers of 737 MAX that caused crashes (more than one) against the pilots actions to save it

[WalterBright]

The MAX crews had the option to turn off the stab trim. Of the 3 MAX incidents, only one of them turned it off, which is why you only hear about the other 2.

[WalterBright]

The crews can do whatever they need to do to save the airplane.