Suicide by pilot
U.S. regulations require at least two flight crew members to be in the cockpit at all times for safety reasons, to be able to help in any medical or other emergency, including intervening if a crew member tries to crash the plane. Following the deliberate crash of Germanwings Flight 9525 on March 24, 2015, some European, Canadian and Japanese airlines adopted a two-in-cockpit policy as did all Australian airlines for aircraft with 50 or more passenger seats.