What was found
DURING CLIMBOUT, EN-ROUTE, AT APPROX 15,000 FT MSL, CREW OBSERVED THE RT ENGINE HORSEPOWER DECREASE TO APPROXIMATELY 600 ACCOMPANIED BY A CORRESPONDING DECREASE IN FUEL FLOW AND TIT. NO IMMEDIATE CHANGE IN RPM. CAPTAIN UNABLE TO MAKE ANY CHANGES IN ENGINE HORSEPOWER WITH POWER LEVER MOVEMENT. ENGINE WAS E-HANDLED IAW PROCEDURES IN QRH, ACFT RETURNED & LANDED UNEVENTFULLY. CREW DID NOT DECLARE AN EMERGENCY. ENGINE INSPECTED FOR FOD. NONE FOUND. ALL FUEL FILTERS INSPECTED & FOUND CLEAN EXCEPT LOW PRESSURE FILTER WHICH HAD A SMALL AMOUNT OF MATERIAL IN IT. LOW PRESSURE FUEL FILTER REPLACED. MX CREW PERFORMED A LOW & HIGH POWER ENGINE RUN & COULD NOT DUPLICATE DISCREPANCY. ALL ENGINE PARAMETERS NORMAL. A