An aircraft fuselage intake duct seal dampens vibration in a compression seal member of an engine case inlet. The intake duct seal includes an inner leg that engages a stationary portion of the compression seal member and comprises a plurality of plenums for allowing inlet air to pass through the inner leg. The intake duct seal also includes an outer leg that engages a movable portion of the compression seal member and comprises a plurality of deflectors and a plurality of ligaments. The deflectors disengage the movable portion of the compression seal member at a threshold pressure such that inlet air bypasses entry into the engine case inlet. The ligaments remain in contact with and dampen vibration of the movable portion of the compression seal member at or above the threshold pressure.