What was found
ENGINE PROBLEM FIRST ENCOUNTERED DURING RUNWAY PREPARATIONS FOR TAKEOFF WHEN THE HP ROTOR SPOOLED DOWN OF ITS OWN ACCORD. NO SERVICE PROBLEMS OF ANY DESCRIPTION HAD BEEN ENCOUNTERED. SUBSEQUENT CHECKS ON THE ENGINE REVEALED THE HP ROTOR WOULD NOT ROTATE WHEN HAND CRANKED THROUGH THE RT GEARBOX DRIVE. SAME CHECK REVEALED A LOUD GRINDING/ROUGH RUNNING OF THE ASSOCIATED GEAR TRAIN. DETAIL STRIP OF HS GEARBOX DRIVING BEVEL GEAR ASSY REVEALED PROBLEM TO BE SEVERE WEAR OF THE LOCATION SPLINES BETWEEN THE SHAFT AND THE GEARWHEEL. ENGINE REPLACED AND SHIPPED FOR INVESTIGATION. (X)