What was found
(CAN) IN CLIMB, NR 2 ENG REQD 5 PERCENT HIGHER RPM TO MAINTAIN SAME THRUST AS NR 1 ENG. ON LEVELING OFF, CREW DECIDED TO TREND BOTH ENGS TO ASSIST MAINT IN T/S OF LOWER POWER PROBLEM. 100 MILES OUT, A THUD FOLLOWED BY A CONTINUOUS SHUDDER FELT ACCOMPANIED BY 20-30 PERCENT LOSS OF THRUST ON NR 2 ENG. ALL OTHER NR 2 ENG PARAMETERS UNCHANGED, BUT A SLIGHT VIBRATION FELT AT NR 2 HP FUEL LEVER. WITH POWER REDUCTION ON NR 2 ENG, SHUDDER DECREASED, BUT ENG DID NOT SOUND NORMAL. ENG SHUT DOWN. POST-FLIGHT INSP REVEALED 2 EACH NR 2 ENG COWLINGS MISSING AND FRONT BYPASS DUCT FOUND RUPTURED AT FWD FLANGE ALONG UPPER CIRCUMFERENCE. NO SECONDARY DAMAGE NOTED. ENG REPLACED. FURTHER REPORT WILL FOLLOW.