What was found
IN DESCENT, LEVELED OFF AT 300 KIAS, INCURRED VIBRATION, SLOWED TO 290 KIAS, VIBRATION WENT AWAY THEN CAME BACK AGAIN WHEN ACCELERATING THROUGH 295 KIAS. INSPECTED FOR GENERAL CONDITION & SECURITY OF THE FOLLOWING ITEMS: NOSE GEAR AREA, FUSELAGE, FLAPS, SLATS, AILERONS, SPOILER PANELS, RUDDER & TRIM, HORIZONTAL STABILIZER, VERTICAL STABILIZER AND ELEVATOR. FOUND NO DEFECTS. RAN BOTH ENGINES AT IDLE & POWER SETTINGS WITH CSD'S & GENERATOR ON & OFF. NO VIBRATION NOTED.