Small plane with unresponsive pilot crashes into Gulf of Mexico

(CNN) -- A small plane with an unresponsive pilot crashed in the central Gulf of Mexico Thursday after circling above the ocean for several hours, a Coast Guard spokesman said.

The Air Force, which had dispatched fighter jets to monitor the twin-engine Cessna 421, reported it crashed about 12:10 p.m., said Lt. Cmdr. Christopher O'Neil, a Coast Guard spokesman. The aircraft had been circling over the Gulf about 200 miles south of Panama City, Florida, another spokesman, Chief Petty Officer John Edwards, told CNN.

The plane took off from Slidell, Louisiana, en route to Sarasota, Florida, with a single pilot on board, a Federal Aviation Administration source told CNN. It had been circling at an altitude of about 28,000 feet.

Mike Maddox, a manager at the Slidell airfield where the plane took off, confirmed there was a situation with a plane and said family members had been notified, but had no further comment.

The Air Force noticed the plane flying erratically over the Gulf of Mexico on Thursday morning and dispatched planes to check it out, Edwards said. They found the Cessna's windows were either iced or fogged over, and the pilot was not responding to radio calls, Edwards said. The Coast Guard was notified about 9:30 a.m. ET, he said.

Fighter jets from the North American Aerospace Defense Command intercepted the aircraft Thursday morning and were watching the plane from the air before it crashed, NORAD spokeswoman Stacey Knott said.

The Coast Guard warned ships in the area to keep a lookout for the plane. Edwards said a Coast Guard plane from Mobile, Alabama, was dispatched to assist with a possible rescue, and the Florida-based cutter Coho is en route to the area. A helicopter in Clearwater, Florida, was also standing by to assist, he said.

- CNN