Flydubai Boeing 737 MAX 8 flying Dubai to Tel Aviv on September 30 nosedived from roughly 34,000 feet to about 17,000 after the Omani co-pilot allegedly stabbed Indian captain Smit Machchhar
Machchhar, bleeding on the cockpit floor, managed to hit the door release, letting Israeli passenger Yaniv Hayun a plumber to enter and subdue the attacker and pull back on the controls before off duty pilots took over. The flight landed safely at Tabuk, Saudi Arabia with roughly 174-180 aboard, mostly Israelis; the co-pilot is in Saudi custody, Israeli officials call it a jihadist terror attack, and Netanyahu met Hayun and told him "without you it could have been another 9/11."
Everything aviation security built after 2001 was designed to keep a threat from getting into the cockpit. It just happened to be protecting the wrong man, clear loophole that allowed pilot to take knife with him.