Updated

Coast Guard crews saw no signs Thursday that the pilot of a small plane survived when his Cessna went down in the Gulf of Mexico about three hours after two F-15 fighter jets tried to make contact with him.

Coast Guard Chief John Edwards said the plane landed right-side up on the ocean surface and had been floating right after the crash. Planes did not see a life raft deploy or anything to indicate the pilot — the lone person aboard — was alive, the Coast Guard said.

The Cessna 421C later sank into the Gulf about 120 miles west of Tampa, Fla., in about 1,500 feet of water. A C130 and a helicopter were looking for debris from the submerged plane, said Petty Officer Elizabeth Borderland. A Coast Guard cutter would remain in the area all night, she said.

Federal Aviation Administration spokeswoman Kathleen Bergen said the plane was flying from Slidell, La., to Sarasota, Fla. She said controllers lost contact with the pilot at 9 a.m. and the Coast Guard said it went down about 12:10 p.m.

Authorities have not identified the pilot. But Bill Huete, a mechanic at the Slidell Airport, said Dr. Peter Hertzak, an OB-GYN who worked in the community just northeast of New Orleans, was the only person who piloted the plane. Huete said the doctor's wife told him her husband was flying the plane that morning.

Huete had worked on the plane for Hertzak and knew the doctor and his family for years.

"I met him years ago when he was looking to start flying again and bought this plane," said Huete.

Huete described Hertzak as an excellent pilot. "He flew by the book and he didn't scrimp on maintenance," Huete said.

No one answered the door at an address listed for Hertzak and calls to the home rang unanswered. Hertzak's office said any statement would have to come from his family and the Coast Guard said it wouldn't release the name for 24 hours according to its policy.

Two F-15 fighter jets tried to make contact with the plane at 8:45 EDT and were flying with it and monitoring it, but weren't able to hail the pilot, said North American Aerospace Defense Command spokesman John Cornelio. 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.

A computer-generated image provided by FlightAware, a private aviation flight path service, shows the plane traveling in several circles over the Gulf for hours before going down.

The two F-15s from the New Orleans National Guard were already on a mission over the Gulf, Coast Guard Chief John Edwards said in a news release. The Jacksonville Air Traffic Control Center asked the military if jets could check on the plane that was orbiting near one of Eglin Air Force Base's warning areas over the Gulf, Edwards said. Eglin is located on Florida's Panhandle.

___

Associated Press writers Kevin McGill in Slidell, La., Colleen Slevin in Denver and Randall Chase in Dover, Del., contributed to this report