As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ROUTINE 100 HOUR INSPECTION REVEALED THAT HAMMER BLADE HAD CRACKED. AS THIS BLADE IS NORMALLY UNDER A 1200 FLEX PER MINUTE OPERATION IT IS EXPECTED TO WORK HARDEN OR FATIGUE OVER TIME. SUSPECT A METAL DEFECT OF SOME NATURE AS MOST OF THESE BLADES LAST MUCH LONGER IN SERVICE. (K)