This is a quite fine shot as it is Kevin, however I would turn on AA to get rid of those jaggies. That's the only main improvement, as everything esle.....works! The clouds acting as a border between building and sky, the beautiful sky colour itself, the trees serving as another visible border, the scenery for the airfield and the aircraft. Talking of the aircraft, to improve this shot again you could use the recorder tool (assuming this is FS9) to get a similar angle to this one but from a different view (i.e. you still have everything in the shot like the clouds, trees etc but you take it from a different place, like lower to the ground, or slightly more left or right etc).
Another suggestion (might not improve this shot at all) would be that if you took this shot at dawn so that the light is reflecting off of the aircraft and making it the main focal point of the shot, as it would be lighter against the darker background. However, the sun in the background of this picture is fantastic and adds to the shot greatly.

Hope you can find some help in the above

The tires dont seem to touch the ground, seems like the plane is floating...maybe add some weight? 

I would move the plane to the right, so then the plane would contrast against the brilliant sky. Other than that, great shot.