National Airlines Flight 2511 was a United States domestic passenger flight from New York City to Miami, Florida. On January 6, 1960, the Douglas DC-6 serving the flight exploded in midair. The National Airlines aircraft was carrying 5 crew members and 29 passengers, all of whom perished. The Civil Aeronautics Board investigation concluded that the plane was brought down by a bomb made of dynamite. No criminal charges were ever filed, nor was the blame for the bombing ever determined, though a suicide bombing is suspected. The investigation remains open.

One of the victims was retired U.S. Navy Vice Admiral Edward Orrick McDonnell, a Medal of Honor recipient and veteran of both World Wars.