What was found
HIGH ENGINE VIBRATION ON NR 1. ENGINE CONDITION MONITORING DETECTED HIGH N1 FREQUENCY VIBRATION ON ALL 3 ACCELEROMETERS, ACCOMPANIED BY DOWNWARD SHIFT IN EGT MARGIN. CONSEQUENTLY, IMPENDING ENGINE FAILURE WAS SUSPECTED. THE EGT LOSS WAS SUBSEQUENTLY DETERMINED TO BE THE 2.5 BLEED NOT CLOSING FIRMLY & CONSISTENTLY ON TAKEOFF. THE VIBRATION WAS DETERMINED TO BE THE RESULT OF AN UNEVEN DISTRIBUTION OF DEICING FLUID AROUND FAN BLADE ROOTS. THIS PATTERN OF SHARP VIBRATION INCREASE, AND SUBSEQUENT RECOVERY, HAS BEEN SEEN BEFORE AFTER TAKEOFFS IN ICING CONDITIONS, BUT NEVER BEFORE AT SUCH HIGH VALUES.