Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Dornier Model 328-100 and -300 series airplanes. This proposed AD would require a pressure test and detailed inspection of each fuselage drain line to determine if there is a blockage, and related investigative/corrective actions if necessary. This proposed AD is prompted by a report of leakage at one of the drain lines in the fuselage. We are proposing this AD to prevent blockage within the drain lines, causing fluids to collect. These fluids may freeze and expand, damaging the drain lines, and allowing fuel to leak into the cabin and fuel vapors to come into contact with ignition sources, which could result in consequent fire in the cabin.