What was found
(CAN) DURING DAILY INSPECTION PILOT NOTICED AN UNUSUAL WHINING NOISE COMING FROM THE NR 1 HYDRAULIC PUMP WHILE HE WAS TURNING THE MAIN ROTOR BLADES. THE HYDRAULIC PUMPS ARE DRIVEN BY THE MAIN TRANSMISSION AND WILL BE DRIVEN WHENEVER THE ROTOR SYSTEM IS TURNED. THE PILOT CONTACTED ENGINEERING AND THE AIRCRAFT WAS GROUNDED. RESEARCH SHOWED THAT THIS PUMP WAS ONLY 78.4 HRS, 8 CALENDAR MONTHS TIME SINCE REPAIR BY VENDOR. A REPLACEMENT PUMP WAS ORDERED AND THE FAULTY PUMP SENT BACK FOR INSPECTION/REPAIR. AWAITING EVALUATION.