Airworthiness Directives; Boeing Model 777-200 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 777-200 series airplanes, that requires inspections for cracking of the web of the horizontal and sloping pressure decks of the fuselage and certain stiffener splice angles and stiffener end fittings, and repair, if necessary. This amendment also provides an optional preventative modification, which ends the repetitive inspections. The actions specified by this AD are intended to find and fix cracking of the web of the horizontal and sloping pressure decks, which could result in rapid in-flight decompression of the airplane. This action is intended to address the identified unsafe condition.