As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IN DESCENT THROUGH APPROX 16,000 FEET AND AROUND 300 KTS, THERE WAS A NOTICABLE AIRFRAME VIBRATION THAT LASTED UNTIL WE SLOWED THROUGH ABOUT 270 KTS. ENGINE/POWER CHANGES HAD NOT NOTICABLE EFFECT ON THE VIBRATION. NO INDICATION OF ANY ENGINES PROBLEMS WERE NOTED. SEE LINE MAINTENANCE WORK ORDER NR 600213176 AND NR 2004971 FOR WORK ACCOMPLISHED. A FUNCTIONALY CHECK FLIGHT WAS PERFORMED WITH NO VIBRATION NOTED.