Malaysia Airliner Communications Shut Down Separately: US Officials Say

[uppityperson]

22. Mix of data adds to MH370 confusion

http://www.ft.com/cms/s/0/41a77c50-ab00-11e3-83a2-00144feab7de.html#axzz2vtrBVpsi

Amid the continuing mystery of the disappearance early on Saturday of Malaysia Airlines flight 370, some of the few clues as to what happened to the doomed flight appear to have come from satellite tracking of the aircraft.
However, there have been substantial misunderstandings over the exact nature of the data received and who could access it.

The confusion arrives from the proliferation of different communication systems sending different sets of data to the ground about the health of different aircraft systems.

One system sends information to Rolls-Royce, the British maker of the aircraft’s engines, about the state of the engines. Rolls-Royce, however, appears to have received only two sets of information during the flight about the engines’ health and to have received no information after 1.07am local time last Saturday, 26 minutes into the flight and around 14 minutes before the aircraft disappeared from the main civilian radar system.

The aircraft also carries transponders which communicate with the “secondary radar” system – the system that tells air traffic controllers the aircraft’s identity, altitude and other critical information. It is the switching off – or failure in a crash or other mishap – at 1.21am last Saturday that provided the widely-watched dramatic images of the aircraft’s disappearing from radar over the South China Sea...