As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF, A STRONG STATIC NOISE TRANSMITTING TO ALL THREE HEADSETS MAKING IT IMPOSSIBLE TO COMMUNICATE WITH ATC. REMOVED AND REPLACED OBSERVER AUDIO CONTROL PANEL IAW AMM 23-51-01.OPERATIONAL CHECK OK IAW AMM 23-51-00. NO STATIC NOTED.