What was found
DURING CLIMB-OUT FROM MHZ FLIGHT 507, NR 1 ENGINE RPM WENT TO 104 PERCENT NO CHANGE IN MECHANICAL GOVERNING, NR 1 PROP PITCH LOCKED, FEATHERED NR 1 PROP AND FOUND PROP FAILED TO COMPLETELY FEATHERED, MAINTAINED 50 PERCENT RPM SHUT DOWN NR 1 ENGINE ACCOMPLISHED AIR TURN BACK TO MHZ. FOUND NR 1 PROP BLADE BOOT SEALS LEAKING. REPLACED NR 1 PROP ASSEMBLY IAW SAT J/C 6101, 6101-1, 6102, 6103. PERFORMED ENGINE RUN UP IAW J/C 7101 AND 7101-2. ALL OPS CHECKED GOOD.