Marine Radio Installation P337

[Dave Underwood]

For the extra antenna, and more importantly, the hole required, you will need a DER sign off on an 8110-3 on a P-series.

The science behind the mod is a doubler of sufficient thickness and enough rivets of enough strength. The big FAA/DER concern is hoop stress & thus strength around the hole. The smaller the hole the better.

You might want to call Ray Torres from RT Aerospace as he is a DER and perhaps less expensive than others as well as being one of us.

I have had to do this twice now on the roof area of my P and in the end it is a doubler of the same thickness as the skin and about 12 AD rivets for a 3/4" hole. If anyone is interested in the calculation please let me know. Regardless you still need the DER to sign the 8110-3.

My only advice is to plan the position out carefully and work with the DER.

Regards - Dave