As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER ROTATION NR 2 ENGINE STARTED TO SURGE. PROP RPM'S WERE AROUND 960 TORQUE FLUCTUATED + OR - 30 PERCENT. STARTED TO RUN THE ENGINE FAILURE CHECKLIST. RETURNED TO FIELD UNEVENTFULLY. REMOVED AND REPLACED NR 2 PROPELLER CONTROL UNIT. NO SURGES NOTED. AIRCRAFT RETURNED TO SERVICE.