As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT VIBRATES AT 280 KIAS OR .73 MACH AND GREATER VIBRATION FELT ON COCKPIT FLOOR, CABIN FLOOR TO AFT GALLEY. INSPECTED ELEVATOR AND ELEVATOR TAB AND FOUND THE LEFT HAND ELEVATOR TAB CONTROL ROD FITTING LOOSE. RETORQUED THE LEFT HAND ELEVATOR TAB CONTROL ROD FITTING PER BOEING MM 27-31-31.