As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MGB MAIN SHAFT INSPECTION. TWO SPLINES FOUND CONTAINING ONE INDICATION EACH. INDICATIONS LOCATED ON THE LOAD SIDE OF THE SPLINE AND IN THE ROOT AREA. LENGTH OF INDICATIONS WERE APPROXIMATELY 0.100 INCH LONG. INDICATION DID NOT EXTEND ONTO THE TOOTH FACE OF SPLINE. INDICATIONS WERE FOUND DURING MPI INSPECTION.