The Federal Aviation Administration said the pilot told air traffic controllers the passenger fell from the Piper PA-46 aircraft about 1:30 p.m. EST, 8 miles southeast of Tamiami Airport.
The plane proceeded to land safely at the airport. But a subsequent search for the victim, concentrated on an area in the Atlantic Ocean off Key Biscayne, found no one, authorities said. It was not clear if the fall was deliberate or accidental.
Coast Guard spokesman Jon-Paul Rios said the search was still underway. The pilot and missing passenger were not immediately identified.
But in a recording of his "Mayday" call to air traffic controllers, the pilot can be heard blaming the incident on his passenger.
"You said you've got a passenger that fell out of your plane?" an air traffic controller asked.
"That's correct, sir," the pilot responded.
"He opened the backdoor and he just fell out the plane."
