As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: INFLIGHT, THE FLIGHT DECK DOOR HANDLE STUCK IN LOCKED POSITION FROM INSIDE. UNABLE TO MOVE IT OR EXIT FLIGHT DECK. MAINTENANCE REPLACED FLIGHT DECK DOOR CONTROL UNIT 24MQ PER AMM 52-51-14-400-001-A AND TASK CARD 26L20052001. A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED.