As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LOSS OF ALL RADIO COMMUNICATIONS OCCURRED WITH AIR TRAFFIC CONTROL AFTER TAKEOFF. FLIGHT WAS RETURNED TO STL AND LANDED WITHOUT INCIDENT. MAINTENANCE REPLACED NR 1 VHF COMM TRANSCEIVER, NR 2 MICROPHONE, AND AUDIO CONTROL PANEL. OPERATIONAL CHECK NORMAL.