KUALA LUMPUR/WASHINGTON - Satellites picked up faint electronic pulses from Malaysia Airlines (MAS) flight MH370 after it went missing on Saturday, but the signals gave no information about where the stray jet was heading and little else about its fate, two sources close to the investigation said on Thursday.
But the "pings" indicated its maintenance troubleshooting systems were switched on and ready to communicate with satellites, showing the aircraft, with 239 people on board, was at least capable of communicating after losing touch with air traffic controllers.
The system transmits such pings about once an hour, according to the sources, who said five or six were heard. However, the pings alone are not proof that the plane was in the air or on the ground, the sources said.
An international search for the Boeing 777, which left Kuala Lumpur early Saturday bound for Beijing, involves at least a dozen countries. Ships and aircraft are now combing a vast area that has been widened to cover the Gulf of Thailand, the Andaman Sea and on both sides of Peninsula Malaysia.
The United States, which has sent ships and planes, said the search area may soon expand into the Indian Ocean, consistent with the theory that the plane may have detoured to the west about an hour after take-off from the Malaysian capital.
"It's my understanding that based on some new information that's not necessarily conclusive - but new information - an additional search area may be opened in the Indian Ocean," White House spokesman Jay Carney told reporters in Washington.
India's defence ministry has already ordered the deployment of ships, aircraft and helicopters from the remote Andaman and Nicobar Islands, 1,190 km east of Chennai, at the juncture of the Bay of Bengal and Andaman Sea.
The Indian armed forces will hold a meeting to decide how to coordinate their search efforts with other countries that are participating, a senior command officer said.
An Indian P8I Poseidon surveillance plane was sent to the Andaman islands on Thursday, ready to join the search once cleared, the head of India's Andaman and Nicobar air force command, Air Marshal P.K Roy, said on Thursday.
The US Navy was sending an advanced P-8A Poseidon to help search the Strait of Malacca, separating the Malay Peninsula from the Indonesian Island of Sumatra. It had already deployed a Navy P-3 Orion aircraft to those waters.
US defence officials later told Reuters that the US Navy guided-missile destroyer, USS Kidd, was en route to the Straits of Malacca, answering a request from the Malaysian government. The Kidd had been searching the areas south of the Gulf of Thailand, along with the destroyer USS Pinckney.
The new information about signals heard by satellites shed little light on the mystery of what happened to the plane, whether it was a technical failure, a hijacking or another kind of incident on board.
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 programme.