Two F-15 pilots Thursday morning discovered that the pilot of a plane flying aimlessly over the Gulf of Mexico was apparently unconscious.
Coast Guard aircraft from Alabama and Florida were also responding for a rescue operation.
The twin-engine Cessna 421 (N48DL) was flying from Slidell, Louisiana to Sarasota, Florida.
A FlightAware map showed the plane was over the Gulf of Mexico about halfway to its destination when it began circling uncontrollably.
UPDATE: 12:19 PM ET: The plane may have gone down into the Gulf in the past few minutes, as the last four blips from FlightAware have shown the plane at the same location, about 170 miles west of Sarasota, Fla.
UPDATE 12:47 PM ET: FAA records show the Cessna 421 that crashed was registered to an LLC in Delaware, a practice frequently used by aircraft owners for tax advantages. The identity of the pilot was not yet known.
While not always 100% accurate, the FlightAware track indicated that the plane entered a steep spiral in its final few minutes.
UPDATE 4:07 PM ET: The Times-Picayune has identified the pilot as Dr. Peter Hertzak, a physician from Slidell, Louisiana.
ALSO SEE: Gulf of Mexico Plane Crash May Have Been Caused by Pressurization Problems, Early Evidence Indicates