A physical disconnection of the satellite communications system would require extremely detailed knowledge of the aircraft, its internal structure and its systems.
The satellite data system is spread across the aircraft and disabling it would require physical access to key components.
Disconnecting the satellite data system from the jet's central computer, known as AIMS, would disable its transmission. The central computer can be reached from inside the jet while it is flying, but its whereabouts would have to be known by someone deeply familiar with the 777.
Getting into the area housing the 777's computers would "not take a lot" of knowledge, said an aviation professional who has worked with the 777.
However, this person added, "to know what to do there to disable" systems would require considerable understanding of the jet's inner workings.
Some airlines outfit the access hatch to the area below the floor with a special screw to prevent unauthorized intrusion, the person added.
Orbiting satellites are designed to check in with the aircraft's satellite-communication system hourly if no data is received during that time.
The pings from the aircraft became a subject of scrutiny earlier this week, said a person familiar with the matter, several days after the plane first went missing.
Because the pings between the satellite and the aircraft registered that the aircraft's satellite communications system was healthy and able to transmit, the data did not immediately raise any red flags in the hours after the jet's disappearance.
At first, the origin of the final ping from the Malaysia Airlines jet seemed like an anomaly to investigators, according to a person familiar with the matter, given that the plane was believed to have crashed off the coast of Vietnam, hundreds if not thousands of miles from the location of the final ping.
Until just a few years ago, the satellite communication system used by jetliners didn't include data on an aircraft's location in the pings, the electronic equivalent of handshakes used to establish initial contact.
