As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF FAS CALLED WITH VERY LOUD AIR NOISE FROM AFT RT LAV. VERIFIED FLUSH VALVE ON RT AFT LAV IS STUCK OPEN. REMOVED AFT RT TOILET ASSY REF MM 38-32-01-000-838-002 INSTALLED SERVICEABLE AFT RT TOILET ASSY REF MM 38-32-01-400-838-002.