Is that really taken with Reala 100? I thought it was digital at first! So sharp! What equipment are you using?
I am using Reala 100 too, but never get these kind of results in the aspect of sharpness...
I thnk your biggest problem is errored color. Use Color Balance and slide the bar away from the green a littl bit until you think it's just right. I'd bet an adjustment of about 15 would do the trick. Just do it until the gray on the bottom of the plane is at a nice true gray, and then youll notice that the white stripe and the blue also look fuller.
SOME people would also mask the sky and adjust the color and/or brightness. Just some people, not that I condone that. hehe. lol