As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT BEGAN A LOUD VIBRATION PASSING 15000 FT/305KNTS. LOUDEST ON LEFT SIDE OF AIRCRAFT AT ROW 12, OVERWING AREA. FOUND LEFT RAM AIR DOOR ACTUATOR CONTROL LINKS HAD SHEARED AND SEPARATED. REPLACED LT PACK RAM AIR DOOR AND MECHANISMS. RAN OPERATION CHECK, DOOR OPS NORMAL.