Sunday, April 6, 2014

SO I gotta question:

Question for the Geeks:

Since modern aircraft are apparently connected full time/real time by satellite and other methods of data communication, why aren't the Flight Data Recorders given a channel to transmit data ?

I mean, the actual amount of data is really fairly small. A few Kilobytes a second for flight instrumentation and engine data, a few more for cockpit voice and radio traffic.

Really a fairly small amount f data, considering the connections most modern aricraft have today to send and receive data from their systems.

SO why? Why don't we have a portion of one of these channels set aside? Why don't we have the last moments of cockpit and voice data and radio traffic stored on someone's server where we could get to it to see what the pilots were seeing and hearinf and saying to each other?

Sure, these systems could be disabled, and the Flight Data Recorders (the "Black Boxes" which are actually bright orange) would be the only backup. But if they were disabled, we'd know that something was up....


Borepatch said...

It's a ton of data - so much data that they only store the last 2 hours of cockpit voice recording on the black boxes. Older data gets overwritten because it's too expensive to keep more.

And the comms link between the recorder and the storage media in the black box is 1000+ times the speed of the link to whoever might be listening.

It may be in the future that comms links become fast enough to capture this, but right now they're surprisingly slow.

Not an aircraft guy, but I am a comms guy,

B said...

But do ya need all that data? Throttle position(s), aileron/rudder/elevator, rpms(x2), voice and radio traffic. Airspeed. Heading and altitude and attitude. Maybe GPS coords.

That isn't that much even in alphanumerics. And it'd be a start. You could likely do that over a 56 k modem if you updated every 30 seconds or 1 minute.

And we'd know a lot more about where to look for 370 than we do now....