A private plane went down 170 miles off the Florida coast after the pilot reportedly lost consciousness.

NBC affiliate WBBH-TV reported the plane was circling over the Gulf of Mexico before running out of fuel and splashing down.

The Cessna 421 was due to land in Sarasota at 10:45 a.m. after leaving Slidell, La. at 6:43 a.m., WBBH reported. A tracking chart for the plane showed it making a "corkscrew pattern headed toward Florida" at 9 a.m., halfway through the flight.

According to CNN, the Air Force noticed the Cessna flying "erratically" and dispatched planes to check it out. The jet's windows had either fogged or iced over and the pilot did not respond to radio calls.

Authorities believe the pilot was the only person on board.

Update: The Associated Press reported the plane landed intact and was floating right side up. A Coast Guard helicopter and patrol boat was responding. The pilot's condition was unknown.

This post has been updated since it was first posted.