I tried using the Windows 7 telnet client to connect to flightgear, and it mostly works, but I can't get 'subscribe' to do what I expect (to send new data whenever the subscribed property changes). Is this what it's supposed to do? Do I need to set something on the terminal to get it to work? When I type 'subscribe <property>' it returns a message saying it's subscribed, but no data streams to the terminal. I tried setting 'mode stream' before connecting, and that didn't help.
EDIT: You have to issue a 'data' command first, dummy.