As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT MIC CONTROL STUCK IN CURRENT POSITION. UNABLE TO TRANSMIT OR RECEIVE ON ANY RADIO AFTER AIRBORNE. AIR TURN BACK TO KILN WITH EMERGENCY DECLARATION. NO ADDITIONAL PRECAUTIONARY ACTIONS NOTED. ON ARRIVAL, AIRCRAFT GROUNDED FOR UNSCHEDULED MAINTENANCE. WORK IN PROGRESS.