What was found
AIRCRAFT WAS GROUNDED: EVALUATION COMMAND HORN SOUNDED CONTINUOUSLY IN THE COCKPIT AND CABIN. COULDN'T COMMUNICATE WITH CABIN USING THE INTERPHONE SYSTEM. REMOVED AND REPLACED DECODER UNIT, REF AMM 23-73-00.
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
AIRCRAFT WAS GROUNDED: EVALUATION COMMAND HORN SOUNDED CONTINUOUSLY IN THE COCKPIT AND CABIN. COULDN'T COMMUNICATE WITH CABIN USING THE INTERPHONE SYSTEM. REMOVED AND REPLACED DECODER UNIT, REF AMM 23-73-00.