As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON FLIGHT 4455 THE CREW REPORTED THEY WERE UNABLE TO OPEN MAIN CABIN DOOR FROM INSIDE. (GATE AGENT WAS ABLE TO OPEN IT FROM OUTSIDE). THE AIRCRAFT WAS REMOVED FROM SERVICE. FOUND THE INTERNAL HANDLE LOOSE. RE-SECURED THE MAIN PASSENGER DOOR INTERNAL HANDLE IAW EMB AMM 52-18-05. ALL CHECKS WERE NORMAL. THE OPERATIONAL CHECK WAS GOOD. THE AIRCRAFT WAS RETURNED TO SERVICE.