Now why I did the range reduction instead of a modifier. The range in hexes don't really represent range. They represent increasing and decreasing target size as you get closer or further from the target. When you get above or below an aircraft you can see more of it, but you also create deflection since you are now out of the plane of movement of the target. Actually you would see more of the enemy from and angle that depends on the stagger of his wings and the size of them, instead of directly overhead or from directly below.

Next headache will be how to handle the 2 seater blind spot. Thinking on that one.

By the way, I'm answering this just before I have to leave for a meeting with a friend. Couldn't be as longwinded as usual. Lucky you are my friends.