Communications satellites picked up faint electronic pulses from Malaysian Airlines Flight 370 after it went missing on Saturday, but the signals gave no indication about where the stray jet was heading nor its technical condition, a source close to the investigation said on Thursday.
The "pings" equated to an indication that the aircraft's maintenance troubleshooting systems were ready to communicate with satellites if needed, but no links were opened because Malaysia Airlines and others had not subscribed to the full troubleshooting service, the source said.
Two sources familiar with the investigation into the disappearance of the jet five days ago also confirmed that manufacturers Boeing and Rolls-Royce did not receive any maintenance data from the jet after the point at which its pilots last made contact. Only one engine maintenance update was received during the normal phase of flight, they said, speaking on condition on anonymity.
Boeing and Rolls-Royce declined comment.