What was found
THE ORANGE FRESH AIR DUCT IN THE TAILCONE IS CHAFING AGAINST THE SPEED BRAKE LINES. THIS RESULTED IN A FAILURE IN THE SPEED BRAKE LINE. THE CREW AND PASSENGERS OF THE AIRCRAFT REPORTED A HYD FLUID MIST COMING OUT OF THE WEMACS IN THE CABIN. REPLACED DUCT AND SPEED BRAKE LINE WITH NEW. FOLLOWED BY THE APPLICATION OF ANTI-CHAFE MATERIAL TO THE SPEED BRAKE LINES. ALSO REPLACED VENTILATION JUNCTION BOX, REPLACED CABIN FRESH AIR DUCTS AND REMOVED ATOMIZED HYD FLUID IN THE AFFECTED AREAS.