(Recasts, adds pilot found dead)
By Ian Simpson
Aug 28 (Reuters) - The pilot of a Massachusetts Air National Guard F-15C fighter that crashed in mountainous western Virginia was found dead on Thursday, officials said.
The plane went down on Wednesday in the George Washington and Jefferson National Forests about 100 miles (160 km) southwest of Washington, sending up a thick plume of smoke.
More than 100 police and rescue personnel searched the rugged area, backed by helicopters and other aircraft, Massachusetts' Barnes Air National Guard Base said in a statement.
The base said on Thursday that the pilot was fatally injured in the crash in the remote mountains near Deerfield Valley, Virginia.
"Our thoughts and prayers are with the family and we are doing all we can to support them during this very difficult time," Col. James Keefe, Commander, 104th Fighter Wing, said in a statement.
The pilot's name was being withheld pending notification of family members and will be released when appropriate, the statement said. The investigation into the crash was ongoing.
A report by a witness of seeing a parachute before the crash proved to be unfounded, it said.
The single-seat, twin-engine plane was part of the 104th Fighter Wing of the Massachusetts Air National Guard, stationed at the Barnes base in Westfield, Massachusetts.
The airplane was being flown to New Orleans to receive a system upgrade and was not carrying munitions, the statement said.
The pilot reported an inflight emergency shortly before contact was lost with the Washington flight controller.
The F-15 is designed by McDonnell Douglas, a unit of Boeing Co. It has been in U.S. service since the 1970s. (Reporting by Ian Simpson in Washington; Additional reporting by Eric M. Johnson in Seattle; Editing by Mohammad Zargham)