Airworthiness Directives; Boeing Model 777 Airplanes

The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 777 airplanes. This AD requires repetitive inspections for corrosion or missing corrosion inhibiting compound of the fuselage skin under the forward and aft wing-to-body fairings for certain airplanes, or the fuselage skin under the forward wing-to-body fairings only for other airplanes; and corrective action if necessary. The AD also provides an optional preventive modification of the fairing areas, which terminates the repetitive inspections. This AD results from several reports indicating that significant levels of corrosion were found on the external surface of the fuselage skin under the forward and aft wing-to-body fairings. We are issuing this AD to detect and correct corrosion, and prevent subsequent fatigue cracks, on the fuselage skin under the forward and aft wing-to-body fairings, which could result in rapid decompression of the airplane.