A US official says a Malaysia Airlines plane was sending signals to a satellite for four hours after the aircraft went missing, an indication that it was still flying.
The official said the Boeing 777-200 was not transmitting data to the satellite, but sending out a signal to establish contact. Boeing offers a satellite service that can receive a stream of data during flight on how the aircraft is functioning.
The official, who spoke on condition of anonymity because he was not authorised to speak publicly, said Malaysia Airlines did not subscribe to that service, but the system was automatically pinging the satellite anyway.
The official also said some messages involving a different data service were received for a short time after the plane’s transponder went silent.