What was found
DURING OVERNIGHT CHECK, IN BORESCOPE INSPECTION OF THE LEFT ENGINE WAS DETECTED A THE PISTON RING OUT OF POSITION ON TWO DIFFERENT ZONES BETWEEN THE OGV`S AND BLADES OF 10TH STAGE OF HIGH PRESSURE COMPRESSOR, DUE TO THIS CONDITION THE ENGINE IS OUT OF LIMITS IAW AMM DMC B787-A-G71-00-00-10B-520A-A/720A-A AND SB 72-0348 AND THERE WERE FOUND SEVERAL BLADES AND OGV`S OF HPC 10TH STAGE WITH MISSING MATERIAL, NICKS AND DENTS ON TRAILING EDGES; SO THE LEFT ENGINE P/N GENX1B70CP2G01 WITH S/N 956321 WAS REPLACED IAW AMM DMC B787-A-G71-00-00-10B-520A-A/720A-A, TESTED CORRECT.