How airlines try to make sure pilots are safe to fly

Paris, France —The apparent attack by the co-pilot on a flydubai flight to Israel, in which he stabbed his captain and tried to crash the plane, is a reminder that the cockpit is an extremely sensitive place in terms of aviation safety.
What can be done to stop an airline pilot from deliberately crashing a plane?
READ : UAE probes possible ‘terror’ link in mid-air attack on Israel-bound flight
As the flydubai Boeing 737 flew over northwestern Saudi Arabia en route from Dubai to Tel Aviv, the co-pilot suddenly attacked his captain, according to Israeli officials.
“During the flight, as they approached the country, one of the pilots stabbed the other pilot, and apparently tried to crash the plane with everyone on board,” Prime Minister Benjamin Netanyahu said in a video message.
Officials have not said what was used as a weapon in the attack.
Some reports have suggested the plane’s “crash axe” could have been used. This is a small axe kept in every plane coc