What was found
ON CLIMBOUT PASSING 20,000 FT, A/C YAWED RIGHT AND GRINDING NOISE WAS FELT THROUGH CONTROLS. NR 2 N1 + N2 FLUCTUATED APPROX 5 PERCENT WITH GRINDING NOISE. POWER AT CLIMB (APPROX 90 PERCENT) EGT + FUEL FLOW NORMAL. AFT F/A REPORTED BANGING NOISE IN CABIN. NR 2 ENG PARAMETERS NORMAL ON APPROACH. FOUND EVIDENCE OF SHINGLED BLADES. INSP'D INLET, EXHAUST VBV, VSV, OIL FILTER AND CHIP DETECTORS; NO FAULTS NOTED. RAN ENG, PARAMETERS WITHIN M/M LIMITS. ENG OPS CHECK GOOD.