Deputies and firefighters started searching for the aircraft after the Federal Aviation Administration called about 2:15 a.m. to notify them that a plane had reported mechanical problems, Wilkes County Sheriff Mark Moore said.
Searchers located the crash site and the pilot's body about two hours later in woodlands off U.S. Highway 78, Moore said. The burning wreckage had ignited some of the surrounding brush, he said.
"This aircraft was totally destroyed when it hit some pine trees in a wooded area," he said.
The plane, a six-passenger Piper Saratoga, crashed about three miles east of the airport, just outside the Washington city limit, Moore said.
Moore expects to release the pilot's identity today after investigators complete an analysis of dental records, he said.
The plane was heading from Madison County Executive Airport in Huntsville, Ala., to Mount Pleasant Regional Airport in Mount Pleasant, S.C., according to a flight plan filed with the FAA.
Air-traffic controllers south of Atlanta were monitoring the pilot's progress during the flight and got a report from the pilot about possible engine trouble, said Kathleen Bergen, a communications manager for the FAA's Southern Region.
Investigators from federal and state agencies traveled to Wilkes County on Tuesday to inspect the site, Moore said.