What was found
NR 1 PROPELLER WILL NOT COME OUT OF FEATHER AFTER ENGINE START. INTERROGATED CDS. NO FAULTS. PERFORMED FUNCTIONAL TEST OF PROPELLER TIME TO UNFEATHER IAW AMM 61-20-00-720-801 AND OPS TEST OF PROPELLER OVERSPEED GOVERNOR IAW AMM 61-20-00-710-803. BOTH OPS & FUNCTIONAL TEST GOOD. PROP NR 1 UNFEATHERS AND FEATHERS WITHOUT FAIL NUMEROUS TIMES. PROPELLER ALSO UNFEATHERS NORMALLY WITH MANUAL UNFEATHER. COULD NOT DUPLICATE PROBLEM. AS PRECAUTIONARY MEASURE REMOVED OSG IAW AMM 61-20-26-000-801. INSTALLED SERVICEABLE OSG IAW AMM 61-20-26-400-801 AND HS 61-0038. OPS TEST GOOD. NO FAULT CODES NOTED. RETURNED TO SERVICE.