Quote:
Originally Posted by Philip Argy
I was not aware of the engine data satellite comms/pinging independent of ACARS and transponder - can anyone on here who knows what they're talking about explain how this works, assuming the basic proposition is accurate?
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Forget the engine data, it's been confirmed no ACARS transmissions have been made before handover. What they have done is looked at the handshake ping that occurs once every hour from the Immarsat to clients. Presumably the return ping also provides the satellite with elevation data, that is where the aircraft is seeing the sat on the horizon, if you look at the image there are clear angle rings, starting from 90 at the sat, which of course is what the antenna angle would be at underneath the sat.
Whoever took the aircraft was not across the fact a satcom pings, despite all the devices connected to it being shutdown. Had the aircraft been newer it would probably have the irridium package which are low orbit sats, and would have been able to narrow down the location to a much smaller area. The foot print on each Immarsat takes up 1/3 of each part of the world at the equator, but is non existent / unusable once you get past + or - 70 degrees of latitude heading for the poles.