(CNN) -- A small plane crashed outside Muncie, Indiana, as military F-16s trailed it Wednesday after its pilot failed to respond to radio calls, the North American Aerospace Defense Command said.

The plane crashed into a farm field in Randolph County, Indiana, officials said. There were no reports that anyone on the ground was hurt.

The pilot was the only one on board the single-propeller, four-seater plane. His fate was not immediately known.

The incident was not believed to be terrorism-related and may be a medical situation, officials said.

The F-16s, from the Indiana Air National Guard, began escorting the plane about 10 a.m. ET after the pilot was "unresponsive," failing to respond to radio calls, NORAD said in a statement.

Randolph County is about 25 miles east of Muncie.

Footage taken by CNN affiliate WTHR over the crash site showed police and fire officials surrounding the charred wreckage, in what appeared to be tall rows of corn.

The plane, registered out of Michigan, departed Gerald Ford International Airport in Grand Rapids, Michigan, at 9:43 a.m. ET, according to flight records

http://www.cnn.com/2009/US/09/30/ind...ponsive.pilot/