[Svartalfiar]

The other method would be for planes to be programmed not to crash, and to stop taking manual instructions if they are headed for a crash collision. This would present its own problems, like hacking.

So how do you land then? A landing is, essentially, just a controlled crash that keeps the plane in one piece. A gradual descent into the side of a mountain isn't gonna look much different from landing to the computer.

[Defiant]

Presumably, it would have to be guided by gps to land at an airport with beacons that help with the landing. It's not ideal, and of course experts would have to design it, but it is an option. Better than having a nutball crash it into a mountain.

When the plane descends for its piloted landing in an ordinary landing, the plane's gps and computer won't take over because the pilot's actions will not be out of the ordinary.