As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
HIGH ENGINE VIB LEFT ENGINE. CONTROLLABLE AT FIRST BUT FA REPORTED SCRAPPING NOISE AND WE FELT EXCESSIVE AIRFRAME VIBRATIONS. (FLIGHT 4974 FILED CLOSED)THIS DISCREPANCY WAS TRANSFERRED TO CAMP ITEM 26341744 WITH THE FOLLOWING CORRECTIVE ACTION: "REMOVED AND REPLACED THE LEFT ENGINE BLADE PINS IN REFERENCE TO AMM 72-21-02 OPS CHECK GOOD PER AMM 71-00-00 AT 0.1 MILS PEAK."