What was found
DIVERTED EMER DUE TO UNCONTROLLABLE EXCESSIVE NR 1 ENG VIBRATION AT 17000, NR 1 1.5%, NR 2 .3%, ABOVE FL 250 NR 1 1.8 - 2.0. PULLED NR 1 THRUST LEVER BACK TO KEEP IN GREEN. AT FL 340 UNABLE TO MAINTAIN AIRSPEED & ALT WITH NR 1 THRUST LEVER & NR 2 NEEDED TO BE IN MCT. NO PRECAUTIONARY ENG SHUTDOWN, WAS ABLE TO MAINTAIN VIBRATION ON DESCENT & THROUGH LANDING PHASE. PERFORMED INSPECTION FOR STIFF FAN BLADES IAW AMM 72-21-02. PERFORMED OPERATIONS CHECK IAW AMM 72-00-00. OPERATIONS CHECKED GOOD. VIBRATION WORK SCOPE REQUIRED WITHIN 50 FLIGHT CYCLES, REF LOG PAGE 3898273 ITEM 1.