Eastern Air Lines Flight 401: a single chime was the only warning the L-1011 was descending, and 101 people died
Eastern Air Lines Flight 401, a Lockheed L-1011, descended unnoticed into the Florida Everglades on 29 December 1972, killing 101 of the 176 people aboard, after the autopilot stopped holding 2,000 feet with no alert that the mode had changed while the crew worked on a burned-out landing-gear light.
