As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) LOUD (BANG) HEARD DURING FLIGHT. CLUTCH SUSPECTED. REMOVED TO INSPECT. CLUTCH WAS TORN DOWN IN THE COMPONENT SHOP AND SHAFT WAS FOUND WORN BEYOND LIMITS. SPRAG WAS MOST LIKELY DRAGGING ON THE SHAFT. CLUTCH AND SHAFT ASSY BEING SENT BACK FOR WARRANTY. (TC NR 20070622003)