As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MIR / DAL - RIGHT ENGINE SURGING AFTER TAKE OFF, RETURNED TO AIRPORT. FOUND COUNTERWEIGHT COLLAR BROKEN. REMOVED PROP AND SENT TO PROP SHOP FOR INSPECTION, EDDY CURRANT INSPECTION AND REPAIR. RETURNED TO SERVICE REINSTALLED ON AIRCRAFT.