Boeing 737-200, United Flight 533
Boeing 737-222, N9031U "City of Lincoln", c. 1972

United Air Lines Flight 553 was a scheduled flight from Washington National Airport to Omaha, Nebraska, via Chicago Midway International Airport. On December 8, 1972, the Boeing 737-222 serving the flight, City of Lincoln, registration N9031U, crashed during an aborted landing and go around while approaching Midway Airport.