What was found
(CAN) THE HOT SECTION WAS GIVEN A SCHEDULED BORESCOPE INSPECTION. A COMPRESSOR TURBINE SHROUD SEGMENT HAD SHIFTED SLIGHTLY. THE RETAINING RING HAD COME OUT OF THE GROOVE. THIS PROBLEM HAS BEEN DOCUMENTED ON OTHER ENGINES. MFG HAS ISSUED P/N 3110741-02 RETAINING RING ON SB 13121 (60A, 61, 62, 65 SERIES) AND SB 3248 (41/42, 45 SERIES) TO PREVENT THE COLLAPSE OF THE RETAINING RING. THE LATTER SB HAS NOT BEEN ISSUED ON SMALLER ENGINE MODELS.