The Pull Up callout comes from the Ground Proximity Warning System fitted to commercial airliners including Concorde, the supersonic passenger jet that operated from 1976 to 2003. GPWS was introduced in the 1970s to prevent controlled flight into terrain, using radar altitude to trigger synthetic voice warnings when an aircraft gets too low or descends too quickly. Recordings and recreations from flight simulators spread the Concorde version online, where its distinctive delivery became a shorthand for aviation emergencies in videos and memes.