I don't know why, but today I decided to attach the Comm Antennas (temporarily so I could get the doublers figured out.).. Not much information about how to mount these, but basically they go through the skin; need to be about 3 feet apart; and since they are out in the wind will need to have doublers so that they don't consistently flex the skin and eventually start to pull and or tear at the skin. Also, they need to have a metal ground plane, which is no problem here since the airplane is all metal. ;-)
A lot of people, just add a second layer of .032 or .040 where the antenna penetrates and move on. For me I was still concerned about the amount of flex in the skin, at least with these bent whip antennas. So I decided to tie the doubler into one of the seat ribs. According to the aircraft handbook, this is the way you are supposed to do it anyway. I decided to mount them under the seat pans, on each outside bay. The actual center post is exactly 9 inches aft of the main spar web, which is as far back as I could get them. Since the skin at this point in the fuse has a slight fore/aft curve, I decided to cut the angle so that I did't have a straight edge the length of the doubler. This allows for the slight curve with no problems. Happy the way this turned out, now I just need to prime or alodine these parts and get Bekah to help me rivet them in..
A lot of people, just add a second layer of .032 or .040 where the antenna penetrates and move on. For me I was still concerned about the amount of flex in the skin, at least with these bent whip antennas. So I decided to tie the doubler into one of the seat ribs. According to the aircraft handbook, this is the way you are supposed to do it anyway. I decided to mount them under the seat pans, on each outside bay. The actual center post is exactly 9 inches aft of the main spar web, which is as far back as I could get them. Since the skin at this point in the fuse has a slight fore/aft curve, I decided to cut the angle so that I did't have a straight edge the length of the doubler. This allows for the slight curve with no problems. Happy the way this turned out, now I just need to prime or alodine these parts and get Bekah to help me rivet them in.. 
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