As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB OUT OF OAK EN ROUTE FOR PHX A VERY LOUD SQUEALING SOUND WAS OBSERVED COMING FROM THE L-1 DOOR LOWER FORWARD HINGE SEAL, PRESSURIZATION WAS NORMAL, TURNED BACK TO OAK DUE TO LOUD NOISE. MAINTENANCE FOUND THE LOWER HINGE COVER DAMAGED. REMOVED AND REPLACED L-1 DOOR LOWER FORWARD HINGE COVER IAW BMM 25-21-331, PRESSURIZATION CHECK WAS GOOD, NO LEAKS NOTED.