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 TIME AROUND 2 HOURS INTO FLIGHT. NO ABNORMAL INDICATIONS ON FLIGHT DECK.**SUPPLEMENTAL REPORT FOR (AALA202408096403): ACCOMPLISHED CONDITIONAL INSPECTION, PER AMM 05-51-67-280-801 AND PERFORMED HIGH-POWER ENGINE RUN, PER AMM 71-00-00. NO ABNORMAL SOUNDS AND VIBRATION FOUND AT THIS TIME. NO FAULT FOUND**(CLOSED).