The pull up alert comes from the Ground Proximity Warning System fitted to commercial aircraft including the McDonnell Douglas MD-11, a wide body trijet introduced in 1990. The system monitors altitude and descent rate and issues voice warnings when terrain closure becomes dangerous. Recordings and simulator recreations of cockpit alerts later circulated among aviation fans, flight simulation communities and editors looking for authentic alarms. Its clear wording and recognisable cadence have kept it in use for plane videos, parody crashes and reaction edits long after the MD-11 left most passenger service.