ok not the Microsoft one but i found in the latest google earth if you press Ctrl+Alt+A you get a free flight sim it looks ok but you do not get any diles but you do get a gighter ryle hud it has no sound but looks amazing for what I assume is a work in progress oh also Once you are in the air you can use a joystick I alos found this
http://flightprosim.com/
that also uses the google earth senary aparently so check it out what do you think?