What was found
POST-FLIGHT DAILY INSPECTION REVEALED ENGINE FREEWHEEL AT FLANGE ATTACH BOLT UNSCREWED FROM THE TORQUED AND SAFTIED POSITION. DAMAGED PIECES INCLUDE FREEWHEEL SHAFT, T/R SHORT SHAFT ASSY, AND FLANGES, AFT FREEWHEEL BEARING, AFT MAG SEAL, T/R LONGSHAFT SPLINES, AFT COUPLING BUSH HALVES, AFT COUPLING ATTACH BOLT. NEW SERVICEABLE PARTS INSTALLED. TAIL ROTOR SHORT SHAFT AND BALL ROTOR ASSY, BALANCED BELOW MFG''S SPECIFICATIONS. NOTE: ENGINE HAS NEVER BEEN REMOVED FROM AIRFRAME. ALL TIMES AND COMPONENTS ARE INSTALLED NEW FROM THE FACTORY. POSSIBLE CAUSE; UNKNOWN. RECOMMENDATION TO PREVENT RECURRENCE; ADVISED EUROPCOPTER AND TURBOMECA TECHNICAL SUPPORT TO RESEARCH AND WITNESS THIS OCCURRENCE. (X)