What was found
(CAN) PILOT CONDUCTED TAKE-OFF SCHEDULED TO CONDUCT LONGLINE OPERATIONS. APPROX 2 MINS AFTER TAKE-OFF THE PILOT HEARD A LOUD BANG FOLLOWED BY TORQUE YAWING. THE PILOT ENTERED AN AUTOROTATION AND LANDED THE ACFT ON A LOGGING ROAD. THE ACFT SUSTAINED MINOR DAMAGE DUE TO HARD LANDING. SUBSEQUENT INVESTIGATION REVEALED APPROX 3 INCHES EXIT HOLE IN THE COMBUSTOR ASSY FROM TURBINE BLADE/DISC FAILURE. INSPECTION OF THE LT ACFT COWLING REVEALED APPROX 2 FT OF ENGINE INTERNAL PART SCATTER DAMAGE. INSPECTION OF THE TAILPIPE AREA REVEALED EXTENSIVE DAMAGE TO ALL WHEEL AND DISC ASSEMBLIES. ACFT INSPECTED AS UN-AIRWORTHY.