This was so stupid.
A hijacking happens when passengers overflow into the cockpit from the cabin.
Oh no! A little kid has been invited to have a look! Passenger overflow! Hijacking!
His attempt at solution isn’t as cringe worthy, if one overlooks the reasoning. Separating the cabin from the pilots is a way of preventing hijacking that has been attempted, but it has problems. Notably if the pilots get acute medical emergency or indeed if the pilot steer the plane into the ground.
Some ten years ago a french pilot locked out his second and ran the plane into the ground. For increased safety the after 911 the door to the cabin could only be opened from the inside.
That’s the one, thank you.
German pilot, and crash in France, not French pilot. Second pilot locking out the captain, not the other way around. Otherwise my memory seem to have served.