As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) AFTER TAKEOFF, DURING THE CLIMB PHASE OF FLIGHT, THE MAIN CABIN DOOR BEGAN SQUEALING. THE FLIGHT CREW DECIDED TO RETURN TO THE POINT OF DEPARTURE. AFTER ARRIVING, MAINTENANCE ACTION FOUND THAT THE MCD SEAL WAS RIPPED AT THE LOWER, FORWARD CORNER OF THE DOOR. SEAL WAS REPLACED AND THE AIRCRAFT WAS RETURNED TO SERVICE.