Action
Notice of proposed rulemaking (NPRM).
Summary
We propose to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 777-200 and -300 series airplanes. This proposed AD was prompted by reports of fatigue cracks in the lap joints, which initiated at scribe lines that were made during production when maskant was removed from the affected skin panels. This proposed AD would require repetitive external phased-array ultrasonic inspections to detect cracks of the affected fuselage skin lap splices in Sections 41, 43, and 44, as applicable, and repair if necessary. We are proposing this AD to detect and correct such fatigue cracking, which, if not detected and corrected, could grow large and cause sudden decompression and the inability to sustain limit flight and pressure loads.