AD FAA-2009-1074

The FAA is revising an existing airworthiness directive (AD), which applies to all 328 Support Services GmbH (Dornier) Model 328-100 airplanes. That AD currently requires modifying the electrical wiring of the fuel pumps; installing insulation at the hand flow control and shut-off valves, and other components of the environmental control system; and installing markings at fuel wiring harnesses. That AD also requires revising the Airworthiness Limitations section of the Instructions for Continued Airworthiness to incorporate new inspections of the fuel tank system. This AD clarifies the intended effect of the AD on spare and on-airplane fuel tank system components. This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to reduce the potential of ignition sources inside fuel tanks, which, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the airplane.