One of the add-ons I used with FSX was the IGC Flight Replay. Through various machinations you could get a FSX flight log into IGC format.
While the application provided analysis of soaring performance the part I used the most was the ability to view your flight in Google Earth.
Unfortunately due to a deprecation of the Google Earth API the application ceased to be functional several years ago.
As an experiment I started looking to see how much of the IGC Flight Replay display functionality could be
replicated though just KML.
I created a small Java app that captures Aerofly FS 2 broadcast data and formats it as a KML linestring.
The resulting display is not too far off the basic flight path display functionality of IGC Flight Replay.
The screen capture shows a short soaring flight at LOWI