Clues From Flight 447

American and French officials say there is no doubt that the Air France Airbus 330 that is believed to have gone down in the South Atlantic encountered severe thunderstorms before it apparently fell out of the sky. But they say at this point they have no clear evidence pointing to what might have brought down the plane.

Both American and French officials said that no cause for the accident can be determined until significant evidence is gathered—a process that investigators on both sides of the Atlantic say is only beginning and could take a long time because of the remote location where the plane apparently went down.

U.S. and French officials say that at present there is no evidence, or even credible intelligence reporting, indicating that the flight was attacked by terrorists. The Associated Press reported today an Air France office in Argentina received some kind of threat against a flight from Buenos Aires to Paris on May 27. An Air France spokesman said the warning was false; in any case, the plane that disappeared was flying to Paris from Brazil, not Argentina. Late last month, media in Brazil reported that, following a tipoff from the FBI, authorities there had arrested a man of Lebanese extraction on suspicion of operating a pro-terrorist Web site. However, prosecutors later reportedly released the man after an investigation determined he was not connected to terrorism. (Story continued below...)

American government and aviation-industry experts say that Air France itself may be one of the only sources of significant evidence about the fate of Flight 447, which disappeared overnight Sunday while flying to Paris from Rio de Janeiro. The industry and government officials said that air-traffic-control systems have very limited ability to monitor remote ocean areas; as a result, they said, it is likely that very little official information was collected that could give clues about how and why the plane might have gotten into trouble.

According to several U.S. government and industry officials, who asked for anonymity when discussing an ongoing investigation, at the time that it appears to have gone down, Flight 447 was flying over a sufficiently remote ocean location that it would not have appeared on the screens of any government air-traffic-control system, whose tracking systems are generally fed with signals from land-based radars. Moreover, while flying over distant quadrants of both the Atlantic and Pacific oceans, airliners can only communicate with land-based air-traffic controllers through relatively primitive—and sometimes unreliable—high-frequency radio links. When the planes are on or near land, by contrast, they communicate with air-traffic control via much more reliable VHF radio channels. (While over the ocean, aircraft can communicate with other planes on nearby routings via VHF radio to share weather information, for example; so far no information has surfaced to indicate the crew of Air France 447 made any distress-related calls to other nearby aircraft.)

In contrast to the primitive wireless technology used by the international air-traffic-control system, airlines normally equip planes like the Airbus 330 with sophisticated satellite-communications systems, allowing crews to keep in touch with company dispatchers even while traveling along ocean routings hundreds of miles from land and well away from government air-traffic-control coverage.

In one of its first official statements issued after the plane disappeared, Air France disclosed that it had received a message about three hours after the flight took off signaling a possible electrical problem aboard. "An automatic message was sent … indicating a fault in an electrical circuit in a zone distant from the coast," the airline's statement said. If the plane was capable of transmitting automatic fault messages to Air France, then theoretically the pilots could have also been in voice contact via satellite with Air France dispatchers, maintenance personnel or emergency services. No such communications have been publicly revealed, however.

When NEWSWEEK asked an Air France spokesperson whether there had been any voice communications between the Flight 447 crew and Air France personnel before the plane disappeared, the official said the company had been instructed by French government investigators not to answer any such questions. A spokeswoman for the Bureau Enquête Accidents—the official French air-accident investigations authority—also declined to answer any questions about possible communications between Flight 447 and Air France. She did confirm that the accident-investigation office believes the plane went down in a very "stormy zone" where there was a lot of turbulence. The investigations-bureau spokeswoman said that her agency hoped to be able to publish an initial report on the plane's disappearance by the end of June.