The United B777 Pratt & Whitney engine that failed on Flight 328 had flown les than half the flights allowed between fan blade inspections several reports have indicated. The blades are supposed to be inspected every 6500 cycles – a cycle being one take-off and landing – and this aircraft had only 3000.
Japan and South Korea have ground B777s in those countries pending fan blade inspections. FAA says they had discussed requiring inspections sooner after a Japan Airlines incident involving a PW4000 in December. Subsequent to the United incident, the FAA issued an Emergency AD for inspections.