A simulated crew door “NOT LOCKED” light is illuminated on the C-5M left-hand forward loadmaster control panel trainer Jan. 28, 2020, at the 373rd Training Squadron, Detachment 3 on Dover Air Force Base, Del. During a recent mission dubbed Reach 190, an aircrew from the 9th Airlift Squadron had this light illuminate, causing a “PRESS DOOR OPEN” warning to appear on the pilot’s, copilot’s and flight engineer’s Multifunction Display Units. (U.S. Air Force photo by Roland Balik)