[DVSNCYNIKL]

Good to know you have an airbrush. One technique that I used to use to paint B-17 bombers and stuff was to angle the direction of the spray towards the color of the paint and work back. I'm assuming that you are painting the bottom part and the fade starts from the front and becomes more solid to the back of the wing. Let's say you've painted the green already on the wing. With the wing upside down now and the front of the wing towards you, aim the airbrush at about 45 degree angle. Starting from the back of the wing to the front. I tend to use left to right strokes or vice versa depending on your preference. Gradually working to the front of the wing and as I do this I am also decreasing the amount of spray coming out, thus producing the fading effect. You need to have a steady hand at this though. If you need additional help, let me know.