Does carbon fiber make an adequate ground plane?

Does anyone have experience using carbon fiber (like a fuselage) as the ground plane for an antenna? My primary interest would be a transponder antenna.

I know carbon fiber can shield the radio signal, but it's not obvious it would be conductive enough to work as a ground plane. If it did, it would simplify installing a transponder antenna, since only a mounting hole would be required.

Why not use a thin piece of scrap aluminum (there's gotta be an RV builder nearby) or foil (copper or aluminum). Since you are dealing with high frequency, a large ground plane isn't required. The antenna mounting hole could even serve as the only mount for the ground plane.

The factory used some self stick aluminum foil in my Stemme, and the fuselage is CF. If you don't have any self stick aluminum foil handy (McMaster-Carr) then 3M spray adhesive (77 or 90) and some heavy duty aluminum foil should do nicely.

Without test data on carbon fiber at UHF frequencies, I can only guess, but I suspect that the laminate is rather lossy at UHF and up. It may not make a nromal ground plane, but the antenna will probably work fine if you just cut a hole and stick it out. I suggest behind the wheel is a good place; my HP 11 VHF antenna worked well there; I got 60 miles air to ground ona 1/2 W transmitter. John Firth C-FAJS