The plane crash in Ethiopia that killed Rep. Mickey Leland (D-Tex.) and 15 others last year probably was caused by pilot error, an Ethiopian government investigation has found.

The Ethiopian Civil Aviation Authority said the pilot may have felt pressured to fly in bad weather because of the "importance of the mission" to inspect relief efforts in the Ethiopian famine.

The report was released yesterday by the U.S. National Transportation Safety Board, which assisted in the investigation. A Canadian safety expert also participated because the plane was built in Canada.

Leland, who was chairman of the House Select Committee on Hunger, was flying from the Ethiopian capital of Addis Ababa to Fugnido, a refugee camp on the Sudanese border. Three congressional staffers also were killed in the crash.

The plane ran into a mountainside more than an hour after takeoff Aug. 7, 1989. The crash destroyed an emergency transmitter on the plane that could have helped rescuers locate the aircraft. The wreckage was not found for a week.

The report said the plane, a 1980 Twin Otter, had no defects. Investigators faulted the pilot and flight crew for not properly studying weather along the route.

The report said the flight schedule was tight, considering the weather. Organizers of the trip, including Leland, and the flight crew discussed delays caused by the weather, the report said.

"The long delay on the one hand and the importance of the mission on the other may have created undue pressure and uneasiness on the flight crew," it said.

The intended route was cloudy and rainy. The plane was plotted to fly at 12,500 feet, and the pilot acknowledged reaching that altitude shortly after takeoff.

But witnesses who saw the plane about 25 miles before it crashed told authorities it was flying below the clouds at a low altitude. The plane burned after crashing into a boulder 800 feet below the summit of a mountain.