TWA Flight 529 was a Lockheed Constellation L-049 propliner, registration N86511, operating as a scheduled passenger service from Boston, Massachusetts to San Francisco, California. On September 1, 1961, at 02:05 CDT, the flight crashed shortly after takeoff from Midway Airport (ICAO: KMDW) in Chicago, killing all 73 passengers and five crew on board; it was at the time the deadliest single plane disaster in U.S.