Cubana de Aviación Flight 493, registration CU-T188, was a Douglas DC-4 en route from Miami, Florida, United States, to Havana, Cuba, on April 25, 1951. A US Navy Beechcraft SNB-1 Kansan, BuNo 39939, was on an instrument training flight in the vicinity of Naval Air Station Key West at Key West, Florida, at the same time. The two aircraft collided in mid-air over Key West, killing all 43 aboard both aircraft.