Why can't airlines seize control of doomed jets from the ground?

Manufacturers in Europe and America have worked on ways of creating a ‘hijack-proof’ aircraft. In 2006, Boeing was awarded a US patent for an ‘uninterruptible autopilot system’.

This would allow pilots, ground controllers or security agencies such as the CIA to activate an automatic flight mode that cannot be turned off by anyone on board.

The system could also switch itself on if terrorists tried to fight their way into the cockpit, with pressure sensors on the door responding to excessive force.

The aircraft’s flight path could be radioed to it by ground control, and it would be brought safely down at a nearby airport using existing automatic landing aids.