Prinair Flight 277 was a regular passenger flight by Puerto Rican airline Prinair, between Harry S. Truman Airport in Charlotte Amalie, U.S. Virgin Islands, and Isla Verde International Airport in Carolina, Puerto Rico, a suburb of San Juan.

On March 5, 1969, the flight, operated by de Havilland Heron 2D N563PR, crashed into a mountain near Fajardo, killing all 19 occupants on board.

This was the point in which the airplane's pilot contacted San Juan's approach control, letting them know that they were flying at 4,000 feet (1,200 m) and maintaining that flight level.

The approach controller, who was a trainee on the fateful afternoon, mistakenly thought that Prinair Flight 277 was near San Juan, but it was instead near Luquillo at what is described as the "Fajardo intersection".

The plane's pilots, trusting that the information given to them was correct, followed the instructions and prepared for landing, soon finding themselves in front of an unavoidable mountain instead.