As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
INNER AND OUTER RACE OF NR 4 BLADE SHANK BEARING FOUND BROKEN AND SEPARATED INTO NUMEROUS PIECES. HUB RENDERED SCRAP AS A RESULT OF BEARING FAILURE. SUBMITTER SUGGESTS ENGINEERING REVIEW OF LOADS IMPOSED AT BLADE/HUB INTERFACE. UNDER LOW C.F. LOADING, IF THE BLADE IS A MAXIMUM ALLOWABLE TIP MOVEMENT, POST SB A190 CONDITION (.750), THE BEARINGS MAY BE EXPERIENCING CYCLICAL LOADS NOT PRESENT DURING ORIGINAL CERTIFICATION.