A small plane whose pilot either passed out or died flew in circles for several hours before running out of fuel and spiraling into the Gulf of Mexico Thursday afternoon as F-15s circled above.

The Cessna 421 is in the water about 120 miles west of Tampa, Fla., and is completely submerged, the U.S. Coast Guard said. The plane made a soft landing and was fully intact before sinking.

It is unclear how many people were on board the aircraft and a MH 60 helicopter is en route to the location with rescue swimmers.

Earlier, it was believed the pilot was the only one aboard the Cessna 421, which was en route from Louisiana to Brandenton, Fla. His identity was not immediately known. But Bill Huete, a mechanic who has worked in the past on the downed aircraft at Slidell Airport, identified him as Dr. Peter Hertzak, an OB-GYN who worked in the Slidell community just northeast of New Orleans.

“This is a joint response with the Coast Guard and Air Force,” said Kevin Robb, the command duty officer for the 8th District command center. “We’re saturating the scene, responding with multiple air and surface assets.”

Two F-15s had been scrambled after it appeared its pilot, flying about 150 miles off Florida, either passed out or died, a law enforcement official told Fox News. The jets’ pilots reported that the Cessna’s windshield was iced over and that the plane was fluctuating between 25,000 and 35,000 feet.

North American Aerospace Defense Command (NORAD) said two F-15s were scrambled to follow the Cessna 421 plane at approximately 8:45 a.m. to monitor the flight after the Federal Aviation Administration lost radio contact with the pilot.

NBC-2 reports that the plane began making a corkscrew pattern about half way through the trip.

(Source: Fox News)