'Ghost plane' crashes into Gulf of Mexico

A SMALL private plane with only an "unresponsive" pilot on board has crashed into the Gulf of Mexico after circling for more than two hours, US officials said.

The US Air Force had scrambled two F-15 fighter jets to intercept and monitor the Cessna 421 aircraft, which was headed from the southern state of Louisiana to Florida.

North American Aerospace Defence Command said the jets "intercepted and monitored an unresponsive general aviation aircraft over the Gulf of Mexico at approximately 9:30 am" (2330 AEST).

"The NORAD fighters remained on station and monitored the aircraft until it crashed in the Gulf of Mexico at approximately 12:15 pm. The fighters stayed on station to assist partner agencies in further efforts before returning to base," it added in a statement.



The light, twin-engine aircraft's "windows were iced over... They were unable to see the pilot," US Coast Guard spokesman Petty Officer Bill Colclough told AFP.

Its nose appeared to be submerged after the crash, according to the Coast Guard.

The plane departed from Slidell, Louisiana, and was headed to Sarasota, Florida. But it began flying in circles at about 8500m about midway through the trip, according to flight tracker FlightAware.

Colclough said the plane had been flying "erratically" about 320km south of Panama city, Florida.

"The pilot was the only person on board the plane," Coast Guard Captain Steve Lehman said.

The Coast Guard, which has requested assistance, has deployed an MH-60 Jayhawk helicopter, along with the US Coast Guard Cutter Coho patrol boat and an HC-144 Ocean Sentry maritime patrol airplane.

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

The plane is registered to Lee H Aviation Inc in Wilmington, Delaware.

One aviation expert told CNN a loss of cabin pressure could have caused the pilot to lose consciousness.

[theaustrailian.com.au]