Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Dornier Model 328-300 series airplanes. This proposed AD would require modifying the electrical wiring of the fuel pumps; installing insulation at the flow control and shut-off valves, and other components of the environmental control system; installing markings at fuel wiring harnesses; replacing the wiring harness of the auxiliary fuel system with a new wiring harness; and installing insulated couplings in the fuel system; as applicable. This proposed AD also would require revising the Airworthiness Limitations section of the Instructions for Continued Airworthiness to incorporate new inspections of the fuel tank system. This proposed AD is prompted by the results of fuel system reviews conducted by the airplane manufacturer. We are proposing 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.