As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT FL 350 NR 2 HAD A SUDDEN POWER LOSS OF AROUND 15 PERCENT, N1 CAME BACK TO NORMAL FEW SECONDS LATER. TROUBLESHOOT RT ENGINE AND FOUND FAULTY FADEC 2B. REMOVED AND REPLACED THE FADEC 2B IAW AMM 73-22-01. RESET FADECS AND INSPECTED LABELS IAW AMM 73-22-01-700-801-A AND OPERATED ENGINES IAW ROLLS ROYCE MM 72-00-00. NO DEFECTS NOTED.