Searchers near Hemphill, Tex., have found a flight data recorder, intact and on dry land, that could yield significant clues to what caused the space shuttle Columbia to disintegrate in midair last month, investigators said late yesterday.

If the data are recovered, they could provide vital information on the aerodynamic pressures, temperatures and vibrations aboard the orbiter during its final moments Feb. 1, said Laura Brown, spokeswoman for the Columbia Accident Investigation Board. "This could be very important," she said.

The device, about the size of a breadbox, is the near-equivalent of a "black box" carried by many aircraft. It potentially contains data from dozens of sensor locations on the orbiter.

This information was not part of the detailed telemetry that was constantly relayed to flight controllers as the flight progressed, which was studied intensely by investigators trying to determine what caused the vehicle to disintegrate, killing the crew of seven astronauts.

The flight recorder was being taken to NASA's Johnson Space Center in Houston for analysis. Engineers plan to clean the instrument, but rather than playing it back normally -- running it over the tape heads -- they intend to develop a special testing protocol.

"They want to come up with a plan where, if it has damage, they'll still be able to recover the data," Brown said. "There could be heat damage. . . . We don't know if it's in a condition where any of the data can be recovered, but we're very hopeful."

Called the Orbital Experiment Support System recorder, the device was part of the experimental instrumentation installed aboard Columbia when it became the first reusable space plane flown, in 1981.

The recorder was turned on 10 ten minutes before the orbiting Columbia began its reentry process. It may have run through some or all of the reentry, depending on the sequence of the breakup.

The accident most likely was triggered, investigators have said, when a breach on or near the leading edge of the left wing enabled superheated gases to penetrate to the interior of the structure, setting up a chain of events that led to the disaster. The damage may have been caused, or aggravated, by debris that came off the shuttle's external tank and struck the area of the left wing during the Jan. 16 liftoff.

Since the accident, thousands of workers daily have scoured the terrain beneath the orbiter's flight path, recovering about 30,000 pieces of wreckage. They have focused with increasing intensity on an area near Caliente, Nev., where one of the first pieces shed by the descending shuttle is believed to have fallen.

In Bay St. Louis, Miss., yesterday, NASA Administrator Sean O'Keefe told reporters he expects the investigation will turn up a combination of factors that led to the accident, rather than a single cause.

Those contributors could include hardware failure, failures of processes and procedures during the flight or bad judgment calls, O'Keefe told the NASA Advisory Council at Stennis Space Center, the Associated Press reported.

"I bet it's going to be a combination of all three," O'Keefe said during an address to the council, which comprises private professionals who advise NASA on various issues.

O'Keefe said he does expect answers that will enable NASA to return the shuttle to flight. "My personal sense is that the problem is definable and the problem is fixable," he said.