What was found
DURING CLIMB, OIL FILTER BYPASS LIGHT ILLUMINATED. RETARDING THROTTLE DID NOT EXTINGUISH. PERFORMED PRECAUTIONARY ENGINE SHUTDOWN IAW ABNORMAL PORCEDURES. NOTE: THE ENGINE WAS WINDMILLING FOR ABOUT 15-20 MIN AND OIL PRESSURE WAS ABOUT 20-25 PSI. FLIGHT RETURNED TO MSP WHERE A LANDING WAS MADE WITHOUT INCIDENT. INSPECTED MAIN OIL FILTER ON NR 3 ENGINE, FOUND NO CONTAMINATION. INSTALLED NEW OIL FILTER. RAN ENGINE. RE-INSPECTED OIL FILTER NO CONTAMINATION NOTED. RE-INSTALLED NEW FILTER. RAN ENGINE. NO OIL FILTER BYPASS LIGHT NOTED. OK FOR CONTINUED SERVICE. RAN ENGINE NO LEAKS NOTED. RESERVICED OIL TANK. AIRCRAFT WAS RETURNED TO SERVICE. (K)