What was found
WHILE CRUSING AT 26,000 FEET, PILOT OBSERVED AN INCREASE IN OIL PRESSURE FOLLOWED BY A DROP IN PRESSURE. AS OIL PRESSURE CONTINUED TO DECREASE TO 25 PSI, THE PILOT COMMANDED AN IN-FLIGHT SHUTDOWN. N1 SPEED WAS REPORTED TO BE AS HIGH AS 101.5 PERCENT. FAILURE OF THE FAN PLANETARY GEAR ASSEMBLY CAUSED BY A SEPARATION OF A SECTION OF THE PINION GEAR DAMPER RING. THE SEPARATED SECTION OF THE DAMPER RING BECAME ENMESHED IN THE PLANETARY GEAR TRAIN AND DAMAGED IT EXTENSIVELY CAUSING THE LP SPOOL AND FAN ASSEMBLY TO BECOME DECOUPLED.