There was a crash some years ago when a commercial airliner had some fairly minor malfunction (I think it was a landing gear down and locked light not lit) at night. They got so engrossed in troubleshooting that damn lightbulb that they allowed the plane to fly into the swamp. No survivors. The voice recorder had them yakking about that light until impact.
The "down and locked light" for nose landing gear was burned out. Instead of switching bulbs the crew got engrossed in trouble shooting and knocked the auto pilot off. The "flight engineer" didn't know how to visually check the nose gear to confirm it was down and locked. The FAA suggested hiring professional flight engineers.
Eastern Air Lines Flight 401 was a scheduled flight from New York JFK to Miami. Shortly before midnight on December 29, 1972, the Lockheed L-1011-1 TriStar crashed into the Florida Everglades, causing 101 fatalities. The pilots and the flight engineer, two of 10 flight attendants, and 96 of 163 passengers died; 75 passengers and crew survived.
