What was found
ENGINE VIBRATION NOTED IN CRUISE FLIGHT. CLIMB WAS NORMAL. AS POWER WAS REDUCED AT TOP OF CLIMB, VIBRATION WAS NOTED AND DETERMINED TO BE ENGINE NR1. VIBRATION WAS MOST PROMINENT AT APPROX 95 PERCENT NI. AT LOW POWER SETTINGS VIBRATION WAS LESS AND NO VIBRATION NOTED DURING DESCENT. INSPECTED NR 1 ENGINE THROUGHLY, LOOKING AT EACH ACCESSORY COMPONENTS, GEARBOX MOUNT BRACKETS, AS WELL AS REVERSER, CORE AND FAN COWL ATTACHMENT FITTINGS WITH NO VISIBLE SIGNS OF BROKEN OR MISSING HARDWARE . INSPECTED ALL FAN BLADES FOR SHINGLING OR EXCESSIVE RUB, ALL OK. RAN NR 1 ENGINE IAW MD10 JRH CH 5 TO 96 PERCENT N1 FOR 5 MINUTES WITH NO VIBRATIONS FELT THROUGH THROTTLES OR YOKE. ALSO INSPECTED ALL FLAPS, AILERON AND ELEVATORS, ALL CHECKED GOOD. ALL 3 PACK INLET & EXHAUST DOORS GOOD. UNABLE TO DUPLICATE DISCREPANCY ON GROUND AS WAS DISCRIBED IN FLIGHT. OK FOR SERVICE.