By DAVID WARREN
Associated Press

DALLAS (AP) -- The pilot of a small plane that failed to land at its Central Texas destination and was later tracked by fighter jets flying over the Gulf of Mexico appeared unresponsive and may have been suffering from a lack of oxygen, authorities said Thursday.

A dog rescue group says the pilot was flying to Central Texas to collect a disabled dog and deliver it to a foster home in Oklahoma.

The pilot of the Cirrus SR-22, identified as Dr. Bill Kinsinger, took off from Wiley Post Airport in Oklahoma City Wednesday afternoon after filing a flight plan to land in Georgetown, Texas, about 25 miles (40 kilometers) north of Austin.

It's unclear why the plane never landed in Georgetown. Federal Aviation Administration spokesman Lynn Lunsford said the plane kept flying and was last observed on radar 219 miles (352 kilometers) northwest of Cancun, Mexico, flying at 15,000 feet (4,600 meters).


A small plane that left Oklahoma City diverted from its flight plan to a route over the Gulf of Mexico. (FlightAware.com)

Coast Guard spokeswoman Lexie Preston in New Orleans said Thursday that Coast Guard aircraft are searching for the plane in a broad area off the Yucatan Peninsula in Mexico.

The executive director of the Oklahoma Medical Board, Lyle Kelsey, said Kinsinger serves on the board and lives in Edmond, Oklahoma. Kinsinger is an anesthesiologist.

Monica Marshall coordinates flights for the nonprofit group Pilots N Paws and says she was tracking Kinsinger's plane Wednesday when radar showed it veered off course by hundreds of miles.
    
Marshall says she has been unable to reach him by text and phone.
    
She says Kinsinger didn't collect the disabled dog in suburban Austin, Texas.

After Kinsinger stopped responding to air traffic controllers, the North American Aerospace Defense Command, or NORAD, launched two F-16 fighters from a base in Houston and made contact with the plane, NORAD spokesman Michael Kucharek said. The fighters flew in front of the plane, dropped flares and performed other military maneuvers in an effort to gain the pilot's attention, but the pilot, who was the only person on board, appeared to be unresponsive, he said.

The F-16s became low on fuel and were replaced by two F-15 fighters from New Orleans. The F-15s stayed with the plane for a time but later returned to base because of darkness and their proximity to Mexican air space.

"We didn't deem the plane to be a threat and that's normally what we're looking for," Kucharek said.

The Eighth Coast Guard District, referencing a NORAD report, said Kinsinger appeared to be suffering from hypoxia, in which the brain is deprived of adequate oxygen. The condition can cause confusion, nausea, breathlessness and hallucinations. If left untreated, it can be fatal.

According to FAA regulations , a civil aircraft pilot flying solo must use supplemental oxygen if flying for longer than 30 minutes above 12,500 feet (3,800 meters), and for an entire flight if flying above 14,000 feet (4,300 meters).

The plane is registered to Oklahoma-based Abide Aviation. A public phone listing for Abide could not be found.

Karen Carney, a spokeswoman for Oklahoma City's department of airports, said Abide Aviation doesn't appear to be a tenant of the airport but that it might have been subleasing hangar space. She didn't have any additional information available.

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