I've fabricated 4 doubler plates - to go under the 4 antenna's. The two small one are made from 0.025" aluminum and will be for the transponder and ADS-B antennas - both of which are about 3" long. The two larger doubler plates are made from 0.032" aluminum and are for the com and ELT antennas - both of which are about 21" long and will create significantly more stress to the fuselage skin.