As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: FLIGHT ATTENDANTS REPORTED VIBRATION IN FLOOR AND BUZZING SOUNDAROUND ROW 11 AND 12. MORE PRONOUNCED ON INITIAL CLIMB OUT ANDCRUISE. SUBSIDED SOME AROUND 2 HOURS INTO FLIGHT. NO ABNORMALINDICATIONS ON FLIGHT DECK.**SUPPLEMENTAL REPORT WILL BE SUBMITTED**(OPEN).