Federal aviation officials said yesterday that faulty ground equipment was probably not responsible for the crash of a Henson Airlines commuter flight Monday that killed 14 persons and said they are investigating whether mechanical failure or pilot error caused the accident.

"He could have crashed while making the approach or by turning the wrong way on an aborted attempt at landing," said Brad Dunbar, a spokesman for the National Transportation Safety Board. "So far, we have no evidence of engine failure."

Among those killed in the crash in the western Virginia mountains was Larry Shue, 38, a highly regarded actor and playwright who performed this summer in Joseph Papp's New York production of "The Mystery of Edwin Drood." He also wrote two plays that had successful runs in London and New York.

Five of the victims were businessmen flying to the Shenandoah Valley to work on a business deal involving a Connecticut-based cosmetics firm.

Rescue workers had cut a path through the rugged wilderness of the Blue Ridge five miles east of the Shenandoah Valley Airport near Weyers Cave, where the Beech 99 from Baltimore-Washington International Airport crashed shortly after 10 a.m. Monday.

The crash site was discovered shortly before dusk Monday and rescue teams, using ropes and litters to aid them on the steep terrain, removed the dead one at a time beginning about noon yesterday.

National Park Service rangers who supervised the effort said the west face of Hall Mountain, where the aircraft smashed into a ridge of trees, before breaking apart and burning, was the most dangerous terrain in the area around the Shenandoah National Park. The peak was partly enveloped in clouds at the time.

"I'm surprised they even found it in that heavily wooded area," said Terry Nyquist, director of marketing for Henson, after he saw the crash site from a helicopter. "You just wouldn't believe it, I've never seen trees like that in my life."

A team from the National Transportation Safety Board said it will be some time before it is known whether the crash was due to the plane's guidance systems, pilot error, weather, or mechanical problem or some combination of problems.

Officials said that if the pilot had aborted his landing, FAA guidelines call for a left turn after climbing to begin another attempt. If Flight 1517 aborted its landing and the pilot mistakenly turned right the plane would have hit the mountain.

Much attention will focus in the days ahead on the localizer beam at Shenandoah Valley, which electronically guides aircraft toward the center of the runway.

Patricia Goldman, vice chairman of the National Transportation Safety Board, reviewing yesterday's examination of the wreckage at a news conference last night, said a safety board employe and a representative of the FAA flew into the field after the crash Monday and yesterday and reported no problems with the localizer.

But she said there were several past reports of "momentary interruptions" in the beam.

She said it appeared the plane's electrical system was functioning when it crashed and that the cockpit instruments were severely damaged, but that the altimeter appeared to have been set correctly, indicating that the crew knew the altitude.

She also said the plane's landing gear apparently had not been lowered and the wing flaps, which slow an aircraft as it descends toward a landing, had not been extended, indicating the crew had not yet prepared for a landing.

The plane was following the proper compass heading -- 38 degrees -- for an approach to the runway from the southwest, she said, but was flying eight to 10 miles parallel to the runway instead of being lined up with it.

First Officer Zilda Spadaro Wolan apparently was at the plane's controls, Goldman said, based on recordings of radio transmission between the plane and ground controllers. Goldman said it is not unusual for a copilot to be flying a plane.

Small commuter airline planes such as the Beech 99 are not required to carry flight recorders, so there are no cockpit tapes to detail what happened to the flight. There were communications between the pilot and the Air Route Traffic Control Center in Leesburg shortly before the crash, but officials said they were routine.

Officials said the pilot was clearly off course, but they could not say why. Among the possible explanations was that the pilot came in for a landing too low to be guided properly by the localizer beam, that there might have been a malfunction of the plane's instruments, or that the pilot had aborted a landing and turned toward the mountain.

A Henson official said that this was the airline's first accident involving loss of life since it began operating in 1931. The line is a subsidiary of Piedmont Airlines.