WASHINGTON -- Senior U.S. officials focused yesterday on the likelihood that a horrific storm and inadequate instruments forced a jet carrying Commerce Secretary Ronald H. Brown to veer off course Wednesday before crashing into a Croatian hillside, killing Mr. Brown and 34 others.
In advance of a formal investigation, Peter Galbraith, the U.S. ambassador to Croatia, indicated that foul weather was one probable cause of the crash.
"The weather yesterday as the plane flew in was terrible," Mr. Galbraith said at a news conference televised from Dubrovnik. "People in Dubrovnik say that this was the worst storm in a decade."
The envoy said "the plane was not where it should have been, and it seems to have flown up not along the coast, but along a valley one ridge over," nearly two miles away. He did not indicate whether human error or another cause might be to blame.
Speaking to reporters on a flight back from Egypt, Defense Secretary William J. Perry said of the crash: "It was a classic sort of an accident that good instrumentation should be able to prevent."
In recent weeks, Mr. Perry flew on the same plane while visiting the Balkans. The aircraft was the only Air Force plane based in Europe used to carry large official delegations.
Other questions raised in the aftermath of the crash include whether the airport in Dubrovnik had adequate equipment to aid in a difficult landing and whether the delay of more than three hours in finding the crash site might have doomed any survivors. Of the 35 people on board, one person, a crew member, was found alive but died en route to a hospital.
Military helicopters and ships searched the Adriatic Sea before a Croatian villager alerted authorities to the crash site 2,600 feet up a hill outside Dubrovnik.
"I think everything that you can come up with is going to be considered in trying to determine what caused this accident," Air Force Lt. Gen. Howell Estes III told reporters at the Defense Department.
As workers began removing bodies from the rugged hillside near the Adriatic to a makeshift morgue, four investigators from the National Transportation Safety Board were on their way to join a team headed by Brig. Gen. Charles Coolidge of the Air Force to find the cause of the crash.
But investigators lack a crucial tool employed in most air crash investigations: cockpit voice and data recorders, known as "black boxes," that record communications and flight maneuvers.
Air Force officials said the devices were not installed on the T-43, the military version of the Boeing 737, when it was outfitted as a navigational training aircraft. The recorders are not required on training planes.
The Air Force could have installed black boxes in 1988, when the plane was converted to a government passenger jet but chose not to because of tight budgets.
A senior Air Force official, who declined to be identified, told reporters yesterday that officials instead chose to spend the money on upgrading equipment that affects plane safety. Flight recorders don't prevent crashes; they assist investigators after the fact.
Without black boxes, investigators might be unable to determine whether there were signs of trouble before the crash. But the lack of flight recorders will not necessarily prevent a successful search for a cause.
General Estes said investigators will have access to recordings of conversations between ground controllers and the pilot. Officials also might get data from tapes taken from Air Force AWACS radar planes in the Balkans.
Sen. Arlen Specter, a Pennsylvania Republican who also visited the former Yugoslavia this week, said Wednesday that he had canceled plans to fly from Belgrade, the capital of Serbia, to Bosnia because of bad weather.
Croatia's prime minister, Zlatko Matesa, who appeared at the news conference with Mr. Galbraith, said five planes had landed at the airport at Dubrovnik on Wednesday, suggesting that the storm should not have prevented a safe landing.
"The professionals who fly take that under consideration," said Tech. Sgt. Michael Land, a spokesman for the U.S. Air Force Base at Ramstein, Germany, where the plane was based. "If they believed there was any danger, I'm confident they would not have flown that mission."
At the Pentagon, General Estes dismissed one theory suggested by Mr. Galbraith's remarks: that the pilots, Capts. Ashley Davis and Tim Schafer, had stopped flying an "instrument landing approach" -- one that relies on navigational equipment and predeter- mined maneuvers rather than on visual references -- and became lost.
"It doesn't seem plausible to me as a pilot," General Estes said. "When you're flying an instrument approach, you fly an instrument approach until you have complete contact with the runway and are safe to land, then you transition from your instruments to a visual approach."
He said the equipment at the airport outside Dubrovnik offered a "very valid" method of helping planes land.
Passengers and crew aboard the plane that crashed outside Dubrovnik, Croatia, according to the State Department:
Ron Brown, Commerce secretary
Kathryn Hoffman, senior adviser for strategic scheduling and special initiatives
Duane Christian, security officer
Carol Hamilton, press secretary
Bill Morton, deputy assistant secretary for international economic development
Chuck Meissner, assistant secretary for international trade
Gail Dobert, deputy director, office of business liaison
Lawrence Payne, special assistant for U.S. and foreign commercial service
Adam Darling, confidential assistant
Steve Kaminski, commercial counselor for U.S. and foreign commercial service
Naomi Warbasse, international trade specialist
Kathy Kellogg, confidential assistant, office of business liaison
Barry Conrad, chairman and chief executive officer, Barrington Corp.
Paul Cushman, chairman and chief executive officer, Riggs International Banking Corp.
Robert Donovan, president and chief executive officer, ABB Inc.
Claudio Elia, chairman and chief executive officer, Air and Water Technologies
Leonard Pieroni, chairman and chief executive officer, Parsons Corp.
John Scoville, chairman, Harza Engineering Co.
Donald Terner, president, Bridge Housing Corp.
Stuart Tholan, president, Bechtel Corp.
David Ford, president and chief executive officer, Interguard Corp.
Frank Maier, president, Enserch International Corp.
Walter Murphy, senior vice president, AT&T; Submarine Systems Inc.
Robert Whittaker, chairman and chief executive officer, Foster Wheeler Energy International
Jim Lewek, analyst, Central Intelligence Agency
Lee Jackson, U.S. executive director, European Bank for Reconstruction and Development, Treasury Department
Dragica Lendic Bebek, interpreter
Niksa Antonini, photographer
Nathaniel Nash, New York Times reporter
Capt. Ashley Davis, pilot
Capt. Tim Schafer, pilot
Staff Sgt. Gerald Aldrich, flight mechanic
Staff Sgt. Robert Farrington Jr., steward
Tech. Sgt. Cheryl Turnage, steward
Tech. Sgt. Shelly Kelly, steward