PRODUCT: Certain The Boeing Company Model 757 airplanes SUBJECT: Airworthiness Directive 2012-06-06 ACTION: Final Rule
SUMMARY: This AD requires replacing the power control relays for the fuel boost pumps and override pumps with new relays having a ground fault interrupter (GFI) feature. This AD also requires an electrical bonding resistance measurement for certain GFI relays to verify that certain bonding requirements are met. This AD also requires, for certain airplanes, an inspection to ensure that certain screws are properly installed, and installing longer screws if necessary.
This AD was prompted by fuel system reviews conducted by the manufacturer. The FAA is issuing this AD to prevent damage to the fuel pumps caused by electrical arcing that could introduce an ignition source in the fuel tank, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and
consequent loss of the airplane.