Why can’t they simply have a computer program which will not allow a pilot to take a plane into a mountain? Or, if such instructions are put into it, the plane could automatically contact the tower for verification.
Seems as though this would be an easy fix. The technology is there, and there is absolutely no need for a plane to even head directly into a mountain (or the sea, or a tower)
Problem is the more systems and warnings you pack into a plane, the more likely one of them will malfunction and work against you. Or the software can be sabotaged/hacked. An insane pilot is extremely extremely rare but computer failure is common.
For that reason every airliner can always revert to full manual mode and each of the hand controls are multiple redundant. Giving the pilot full control to respond to mechanical failure is more important than keeping control from a potentially crazy pilot
Actually, with CAT V capability, modern aircraft do not need a pilot ... They are able to taxi, T/O, land and taxi back to the terminal w/o any human interface.
There really is no reason to have a flight crew, other than to give passengers some illusion of safety and comfort ... Yeah, that worked out really well.
Solution: eliminate human factor. Make all civil airliners fully automated. That ends the terrorist threat completely.