As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PASSING THROUGH APPROX. 7000FT, THE NR 1 ENGINE SURGED THROUGH APPROX. 95%. CREW ELECTED TO RETURN TO ANC, NO EMERGENCY DECLARED. LANDED WITHOUT INCIDENT. CORRECTIVE ACTION: COULD NOT DUPLICATE DURING ENGINE RUNS. OCF PERFORMED TO MONITOR ALL ENGINE PARAMETERS. NR 1 & 2 ENGINES SURGED IN VARIOUS PHASES OF FLIGHT. REPLACED NR 1 ADC. OPS CHECKED GOOD. SECOND OCF PERFORMED. OCF SUCCESSFUL, NO TORQUE SURGE. AIRCRAFT RETURNED TO SERVICE.