What was found
DURING DESCENT, PASSING THROUGH FL180 A SUDDEN AND PRONOUNCED CHANGE IN AIRCRAFT SOUND (A RUMBLE) WITH AIRFRAME VIBRATION IN THE FLOOR AND POWER LEVER QUADRANT. FA'S REPORTED THE RUMBLE AND VIBRATION IN THE CABIN STRONGEST AFT OF THE ENGINES. SELECTED THE ANVS TO PAUSE WITH NO EFFECT. NO POWER LEVER CHANGE WAS ASSOCIATED WITH THE ONSET OF RUMBLE/VIBRATION. RUMBLE/VIBRATION REDUCED AT LOWER ALTITUDES AND BARELY NOTICEABLE BELOW 10,000' AND TAXI IN. NEGATIVE ICING IN THE DESCENT. TORQUE APPROXIMATELY 40%. NO ABNORMAL ENGINE INDICATIONS. REMOVED FROM SERVICE. MAJOR CAUSE OF VIBRATION WAS RH WING TRAILING EDGE FAIRING DAMAGE. REPLACED FAIRING. RETURNED TO SERVICE.