OTTAWA (AP) _ One engine of an Arrow Air DC-8 was delivering less power than the three others when the plane crashed in Newfoundland last month killing 248 U.S. servicemen, the head of the Canadian investigation said.

But the investigator, Peter Boag of the Canadian Aviation Safety Board, told a news conference Monday he has not concluded that the lower rate of revolutions per minute of the right outboard engine contributed to the crash.

''It is more than apparent at this time that this investigation is not going to reach any quick answers,'' he said.

The safety board's chairman, Bernard Deschenes, said he and four other board members will conduct public hearings in Ottawa beginning April 8 to present results of the investigation and hear witnesses. The board also plans to visit the crash site in Gander, Newfoundland, on March 24-25 to prepare for the inquiry.

The Arrow Air flight, carrying 248 soldiers of the U.S. Army's 101st Airborne Division home from peacekeeping duties in Egypt's Sinai desert, crashed just after takeoff from Gander Dec. 12. All passengers and the eight crew members were killed.

With the Canadian investigation and U.S. efforts to identify the bodies both running into difficulties, a renewed search of the crash site began last week.

Boag said two bodies discovered by the searchers were returned to the United States on Monday, and that about 40 percent of what is left of the plane has been retrieved.

The key parts, some of which were picked up in the days following the crash, are being examined at safety board laboratories in Ottawa.

''We have observed a different damage impact in the fourth engine, which is consistent with a lower rpm (revolutions per minute) at ground impact, lower than the other three engines,'' Boag said.

''It is quite possible that this lower rpm was a result of ingestion of debris from trees, as the wing cut through trees in the accident.''

In response to questions, Boag said even a complete loss of power in one engine should not cause a crash in normal conditions, but that investigators are looking at the possibility a combination of circumstances prevented the plane from making a successful takeoff.

The flight data recorder revealed that the plane reached a good speed for takeoff, but then lost power suddenly and veered about 20 degrees to the right in the seconds before impact.

Canadian investigators have visited West Germany, where the Arrow Air crew had a rest stop before taking over the flight from another crew, and are now in Egypt looking into maintenance and loading procedures, Boag said.

Army experts in Dover, Del., had identified just 137 of the bodies by late last week, Boag said.