As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) THE AIRCRAFT LOST ALL COMMUNICATIONS FOR A PERIOD OF 20 MINUTES. A PUSH-TO-TALK SWITCH ON THE RT CONTROL COLUMN WAS FOUND STUCK IN THE TRANSMIT POSITION BLOCKING ALL TRANSMIT & RECIEVE COMMUNICATIONS. SWITCH REPLACED. SUBMITTER STATES THIS HAS BEEN A RECURRING DEFECT.