Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 757 series airplanes. This proposed AD would require sealing the fasteners on the front and rear spars inside the left and right main fuel tanks and on the lower panel of the center fuel tank. This proposed AD would also require inspections of the wire bundle support installations to verify if certain clamps are installed and if Teflon sleeving covers the wire bundles inside the left and right equipment cooling system bays, on the left and right rear spars, and on the left and right front spars; and corrective actions if necessary. This proposed AD results from a fuel system review conducted by the manufacturer. We are proposing this AD to prevent improperly sealed fasteners in the main and center fuel tanks from becoming an ignition source, in the event of a fault current, which could result in a fuel tank explosion and consequent loss of the airplane.