NEW ORLEANS — The Coast Guard is responding to a plane crash approximately 120 miles west of Tampa, Fla., in the Gulf of Mexico, Thursday.

The North American Aerospace Defense Command notified the Coast Guard 8th District watchstanders at 8:30 a.m. CST of an airplane flying erratically over the Gulf of Mexico.

Coast Guard district watchstanders dispatched an HC-144 Ocean Sentry aircrew from Coast Guard Aviation Training Center Mobile in Mobile, Ala., an MH-60 Jayhawk helicopter and crew from Coast Guard Air Station Clearwater, Fla., and the crew aboard the  Coast Guard Cutter Coho, an 87-foot patrol boat homeported in Panama City, Fla.

The Ocean Sentry crew is on scene and monitoring the situation, the Jayhawk crew is en route with an estimated arrival time of 1 p.m., and the Coho is estimated to arrive on scene at approximately 3 p.m.

The airplane crashed at approximately 11:15 a.m. and has been identified as a Cessna 421. The nose of the plane is reported to be submerged.

"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 assests."

The Coast Guard has requested assistance from good Samaritans in the area, but has received no responses.