Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain EMBRAER Model EMB-120, -120ER, -120FC, -120QC, and -120RT airplanes. This proposed AD would require replacing the shut-off and crossbleed valves of the bleed air system with new valves having hermetically sealed switches. This proposed AD results from fuel system reviews conducted by the manufacturer. We are proposing this AD to prevent a potential source of ignition near a fuel tank, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.