As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON TAKE OFF OUT OF NRT THE RIGHT EXPERIENCED 4 TO 6 STALLS WITH FLAMES FROM TAILPIPE. A/C RTB TO NRT. ENGINE WAS NOT SHUTDOWN. FURTHER INSPECTION REVEALED METAL ON THE MCD AND IN THE TAILPIPE. MAX TGT OF 946 AND 940 FOR 8 SECONDS. PER AMM ENGINE CHANGE REQUIRED. PERFORMED BORO INSP PER AMM. FOUND SEVERAL BLADES BENT/DAMAGED HPC BORO PLUG HP5S. PERFORMED POWERPLANT AFTER SURGE INSP PER AMM. REPLACED NR 2 E PER TRANS 11T003. ETOPS CATEGORY 'C': UNCOMMANDED PWR CHANGES, SURGES, OR STALLS