WASHINGTON -- The flight simulator and hard drives that the pilots of Flight 370 had at their homes appear to be a dead end, yielding few clues that shed any light on whether they deliberately diverted the missing jet, according to two people briefed on the investigation.
The Malaysian authorities seized the devices early in their investigation and, after initially keeping U.S. officials at a distance, turned to the FBI last week for help in analyzing them. The Malaysians were particularly interested in learning what it was that the captain of the flight apparently deleted from the simulator in the days before the plane disappeared; the FBI has extensive expertise in recovering deleted computer files.
The FBI's spokesman, Michael Kortan, said the bureau would not discuss what it had found on the hard drives because the investigation was continuing.
Though investigators are continuing to focus on the pilot's role in the plane's disappearance on March 8, no concrete evidence has come to light to indicate that they sabotaged the flight.
Nor has any physical trace of the plane been recovered from the Indian Ocean southwest of Australia, where officials have concluded that the flight must have ended in a crash. Growing numbers of floating objects have been spotted in satellite photos of the area in recent days, but search planes were unable to hunt for them Thursday because of bad weather, the second time this week that storms have forced a suspension of the search effort.
James B. Comey, the FBI director, testified before the House Appropriations Committee on Wednesday that the bureau was close to completing its analysis of the pilots' simulator and hard drives.
"I have teams working really around the clock to exploit that," Mr. Comey said.
One former senior law enforcement official briefed on the investigation cautioned that although the FBI had found little on the pilots' hard drives and simulator, there could be information on them that will be helpful to the Malaysians as they continue to investigate.
"Something on the drive which does not seem important today could be, when viewed with additional data obtained from the background of the individual, his other activity, interviews and data from the flight recorded," the former official said. "Then, something that seemed like nothing may be something."
The official and the two people briefed on the investigation spoke on the condition of anonymity because they did not want to jeopardize their access to sensitive information.
Officials leading the search for wreckage continue to hope that one of the floating objects spotted by satellites will turn out to be part of the plane, allowing them to considerably narrow the search zone. But little progress could be made Thursday because storms made flying to the area too risky for search crews.
Lt. Cmdr. Adam Schantz, the head of a U.S. team flying a Navy surveillance plane, said the search zone was afflicted by "severe turbulence, severe icing and basically zero visibility."
"Anyone who is out there is coming home," he said at the airport in Perth where search planes from several nations have been operating. "And all additional sorties are canceled."
The latest satellite sightings came from a Thai government agency, which said Thursday that one of its satellites had detected what appeared to be a relatively compact field of floating debris near the search zone. The images were taken Monday, one day after a European satellite photographed 122 floating objects.
The head of the Thai agency, the Geo-Informatics and Space Technology Development Agency, told reporters in Bangkok that his country's images showed around 300 objects spread over an area of about 170 square miles. The agency said it could not describe the objects in any detail because the images were of a relatively low resolution.
Anond Snidvongs, the agency's executive director, said the objects seen by the Thai satellite were 120 miles southwest of the European satellite sighting.
The probable area of impact of the aircraft, calculated from signals emitted by the plane before it went down, is more than 620,000 square miles, or roughly three times the size of mainland France. Search aircraft have been able to search only roughly 5 percent of that area each day.