What is XA0000 in ACARS?

[eorange]

I collect acars data using acarsdec, and I've been noticing a flight number of XA0000 appears quite often with varying tail numbers. Is that an actual flight number, or just some default acars value? flightaware last shows XA0000 flew to Spain in 2018.

 

[ATCTech]

XA (and GS) has historically been used by bizjets, the 0000 of course reflecting no flight number entered into the ADSB box in the cockpit.

 

[eorange]

Awesome, thank you. And yes, I've been seeing the GS prefix many times as well. I live very close to a county airport with lots of bizjets. Mystery solved!

 

[ATCTech]

Glad to help! I had exactly the same question when I first dove into ACARS decoding years ago. I should have said "FMS box" instead of ADSB in my reply, it's been a long time since I paid much mind to ACARS/VDL2 from a hobby perspective. My bad!

 

[eorange]

No problem; I knew what you meant. I monitored VDL2 a little while ago but it didn't seem as interesting. A number of years ago on ACARS I remember seeing messages that contained detailed engine telemetry, like maybe pressures and temperatures and a bunch of other data. I haven't seen that since. Is that data still sent via ACARS?

 

[ATCTech]

VDL2 can be thought of as much-enhanced old ACARS in terms of data speed, complexity and ultimately the type of messages that can be exchanged. I'm not able to say one-for-one what preformatted message types are identical between the two but I have no reason to think anything you saw on conventional ACARS wouldn't be on VDL2, likely containing loads more data in an enhanced format that might prove more difficult to decode or see in plain text on your screen. Aircraft will fall back to ACARS in areas not covered by VDL2 so there has to be a lot of commonality for the original message set.