As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING SHUTDOWN WITH NR1 CONDITION LEVER IN START/FEATHER. NR 1 ENGING TORQUE SURGED TO 90 PERCENT AND PROPELLER RPM STAYED AT 600 FOR 7 SECONDS. ALL OTHER PARAMETERS NORMAL. R & R ECU. PERFORMED RUN UP OPS CHECK IAW MX RUN UP MANUAL FOR COMPONENT CHANGED. OPS CHECKED GOOD FOR SERVICE.