I don't know if anyone else uses here the open source sim FlightGear, but I spent some time messing around getting it to work with SD so I thought I'd share the details here in case it is of use.
You need to copy the XML file attached in your flightgear/Protocol directory, then in advanced settings create a new IO-

Protocol - generic
Medium - socket
Direction - out
Hz - 1
Hostname - (your SD device IP)
Port - 49002
TCP/UDP - UPD
Generic - skydemon

Fire up SD in X-plane mode and off you go.
K