As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON FLIGHT 4070 THE CREW REPORTED THE CABIN DOOR WAS DIFFICULT TO OPERATE. THE AIRCRAFT WAS REMOVED FROM SERVICE. DURING PHASE CHECK 1A/3A PERFORMED W/C 52-600-00 SIDE HINGED MAIN DOOR ACTUATING AND LOCKING MECHANISM LUBRICATE. THE OPERATIONAL CHECK WAS GOOD. THE AIRCRAFT WAS RETURNED TO SERVICE.