5 ms·
> Well, if the engines were transmitting, can't someone figure out the direction of the plane? Unfortunatley not; the flight-data transmitting systems ( ACARS
by dingaling 13y ago
> Well, if the engines were transmitting, can't someone figure out the direction of the plane?
Unfortunatley not; the flight-data transmitting systems ( ACARS and ADS-B ) that do include position data appear to have been turned-off or disabled deliberately.
The engine telemetry feed is part of Rolls-Royce's 'Power by the Hour' system, which aims to identify faults or under-performance in the engines whilst still in-flight so that an engineer can tune and correct when the aircraft arrives. It doesn't care where the aircraft is.
Though... it might include environmental data such as inlet pressure and temperature, which could help to determine altitude.
- bbosh 13y agoDoes the data include power information? At least you could get some sort of bound on the distance it is likely to have travelled.
- dingaling 13y agoGood thinking; yes, fuel flow and power settings are included: http://www.rolls-royce.com/about/technology/systems_tech/monitoring_systems.jsp http://www.rolls-royce.com/about/technology/systems_tech/mon...
- jwise0 13y agoThat seems to indicate that the data are transmitted via ACARS. Is there another back-channel, if ACARS were unavailable for some reason?
- notthetup 13y agoIf they received the data that means the engines managed to communicate somehow. So that tells you the length of time the transmission unit was powered up. Also, using differential signal strength between successive communications one can generate an approximate trajectory (x km from satellite at y time) etc etc. This would surely narrow down the possible locations.
- melling 13y agoWhat is it transmitting to every 30 minutes (fixed: seconds)? If more than one satellite was involved, that might give direction. traceroute?
- ars 13y agoMinutes, not seconds.
- melling 13y agoSorry about that. Fixed. Wouldn't my question still hold? It's talking to a ground network.
- rdl 13y agoWhy ground? I'd do that as an L-band ORBCOMM type system, since it's going on planes operating over oceans. $0.01/character.
- ars 13y agoSo why don't planes do that that? You need 24 bits for 3 meter GPS accuracy (times 2). Add some extra for altitude and airplane ID (or does a unique ID come built in?) So maybe 80 bits in total. This would be nothing for an airplane - $0.40 per hour? Why don't they do this already?
- userbinator 13y agoAnd since this plane is far larger than 3 meters, it doesn't even need to be that accurate; 50 meter GPS accuracy would be good enough.
- hueving 13y ago>This would be nothing for an airplane - $0.40 per hour? Why don't they do this already? They would likely receive pushback from private jets that don't want all of their flight path transmitted back to RR.