FlyDubai attacker reportedly targeted Tel Aviv Airport: How did he get into the cockpit?

Flight FZ1073 took off from Dubai for Tel Aviv with 182 people on board, including eight crew members. The flight appeared routine at first. Then violence reportedly erupted in the cockpit. UAE Attorney General Hamad Saif Al Shamsi said the co-pilot attacked Captain Smit Machchhar with a crash axe. He then allegedly attempted to take control of the aircraft.