In case anybody comes this way - I've written a simulator for R/C planes , mostly gliders since that's what I tend to fly. It's completely free on Windows and mostly free on iOS/Android (limited sceneries/planes in the free version). You may be able to get it to run under linux (wine) and/or OSX (PlayOnMac).

http://rowlhouse.co.uk/PicaSim/

It's not under active development at the moment for a couple of reasons:

* I needed to concentrate on writing software for my own business
* Technical reasons which mean future development would require as significant re-write of the platform layers.

Nevertheless, I hope it's still useful and fun. I've met a lot of people (online and in real life) through it, discovered DLGs (thanks Jenne!), and improved my own flying!