What was found
(CAN) DURING TEST FLIGHT, AFTER INSTALLATION OF THE FRESHLY O/H P/S, DURING AN AUTO-ROTATION MANEUVER, THE PILOT HEARD A LOUD NOISE AND RECEIVED A CHIP DETECTOR WARNING. HE WAS ABLE TO SAFELY LAND THE ACFT. POST FLIGHT INSPECTION FOUND THE P/S GAS GENERATOR CASE SPLIT OPEN WITH FRAGMENTS HAVING EXITED THE ENGINE AND DAMAGING THE ENGINE DECK. THE ENGINE WILL BE REMOVED AND FORWARDED TO MFG FOR INVESTIGATION.