Little fresh light

The new information shed little light on the mystery of what happened to the plane, whether there was a technical failure, a hijacking or another kind of incident on board after it took off from Kuala Lumpur en route to Beijing.

While the troubleshooting systems were functioning, no data links were opened, the sources said, because the companies involved had not subscribed to that level of service from the satellite operator, the sources said.

Boeing Co, which made the missing 777 airliner, and Rolls-Royce, which supplied its Trent engines, declined to comment.

Earlier Malaysian officials denied reports that the aircraft had continued to send technical data and said there was no evidence that it flew for hours after losing contact with air traffic controllers early Saturday.

The Wall Street Journal had reported that US aviation investigators and national security officials believed the Boeing 777 flew for a total of five hours, based on data automatically downloaded and sent to the ground from its engines as part of a standard monitoring program.

Malaysian authorities have said the last civilian contact occurred as the Boeing 777-200ER flew north into the Gulf of Thailand. They said military radar sightings indicated the plane may have turned sharply to the west and crossed the Malay Peninsula toward the Andaman Sea.

It is one of the most baffling mysteries in the history of modern aviation - there has been no trace of the plane since nor any sign of wreckage despite a search by the navies and military aircraft of over a dozen countries across Southeast Asia.

"It's extraordinary that with all the (satellite and telecommunication) technology that we've got that an aircraft can disappear like this," Tony Tyler, the head of the International Air Transport Association that links over 90 percent of the world's airlines, told reporters in London.