Television footage showed Mexican army soldiers removing bodies from thick jungle near Chetumal, 180 miles south of Cancun.
The rare, twin-engine Grumman Albatross was owned and piloted by Rob Carlson, 51, of East Walpole, Mass., according to Frank Hoff, Carlson's executive assistant.
An American woman also was killed but her name was being withheld until relatives could be notified.
A man identified as Ulrich Schuller of Cancun and another woman whose identity wasn't released were also killed, according to Hoff and to Quintana Roo officials.
Spokesmen for the coastal state of Quintana Roo confirmed that the crash had occurred and that four people had died.
``It appears the plane took off from Cancun or Tulum,'' a nearby beach town, said state spokesman Victoriano Robles.
``As it fell, the plane caught fire,'' Robles said, describing the crash scene near the village of Subteniente Lopez, about 6 miles outside Chetumal, the state capital.
Officials haven't determined what caused the crash.
The 10-seat Albatross, manufactured between the 1940s and the 1970s, was used by the U.S. Navy.
