As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEA - NR 1 AND 2 TORQUE SURGE 5 PERCENT TO 8 PERCENT ON CLIMB AND 3 PERCENT TO 5 PERCENT AT 65 PERCENT TORQUE. NO SURGE BELOW 60 PERCENT NOTED. CREW REQUESTED A RETURN TO SEA. AIRCRAFT LANDED WITHOUT INCIDENT. AIRCRAFT DOWN FOR MAINTENANCE.