What was found
CREW REPORTS VIBRATION IN CONTROL YOKE AFTER TAKEOFF PASSING THRU 250KTS. ALSO EXPERIENCED VIBES ON NR 1 ENG THAT VARIED FROM 1.7-3.5 WITH A PEAK OF 5.0.ENGINE THROTTLES PULLED AND ENG VIBE DROPPED TO .8 BUT YOKE VIBRATION REMAINED. C/W BOROSCOPE OF NR 1 ENG BORO PLUGS B1-1/B1-12/B1-5, NO DAMAGE FOUND. CKED NR 1 COMPONENTS FOR SECURITY SHAKE CKED NO FAULTS FOUND. INSP CHIP DETECTORS. NO DEBRIS FOUND, DL ID 448555. REMOVED ENG OIL FILTER IN. INSPECTED SAME NO METAL FOUND INSTALLED NEW FILTER LEAK CK OK. INSPECTED AND LUBED ROTOR BLADES. FOUND ALL OK PER AMM.