One of my friends makes Yagi's. He currently has the desighn for military air, but VHF will be out soon. He has picked up (DX'ed) ground stations from over 175 miles away. They have a 9.8db gain. Scroll down to watch the video. This guy has the best milair setup I have ever seen. He is the best milair antenna maker by far.
Also, if you live in a less populated area, you may want to try a preamp. This is the same company that makes it for NASA
www.AngleLinear.comYagi's are great for ATC, and air. They will do the BEST job.
73s
Caleb