Airworthiness Directives; Boeing Model 777 Series Airplanes

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Boeing Model 777 series airplanes. This action requires inspections of the outboard leading edge slats on the wings for installation of seal assemblies with undersized seal inserts and missing or gapped inserts, and follow-on and corrective actions if necessary. This action also provides for an optional replacement of the seal assembly in lieu of the inspections. This action is necessary to find and fix such discrepancies, which could result in cracking of the slats, subsequent separation of the cove skin, structural damage or loss of the trailing edge wedge, and consequent reduced controllability of the airplane. This action is intended to address the identified unsafe condition.