[whoknowsidont]

>Most aircraft outside of fighter jets are aerodynamically stable.

Sure, but there is significant overlap between being stable and throwing around passengers, unfortunately.

Dropping 500 feet is perfectly okay for the aircraft and it will largely continue to not simply fall out of the sky past that.

[alistairSH]

That's not what aerodynamically stables means. Anything external that would cause a 787 to drop 500 feet is probably going to do that with or without the flight computers working.

In the case of military aircraft, they quite literally can't glide or maintain stable flight without the flight computer actively managing the control surfaces.

A 787 is perfectly capable of flying in steady state should the computer glitch.