Action
Final rule.
Summary
We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 777 airplanes. This AD was prompted by a new revision to the airworthiness limitations of the maintenance planning document. This AD requires revising the maintenance program to update inspection requirements to detect fatigue cracking of principal structural elements (PSEs). We are issuing this AD to ensure that fatigue cracking of various PSEs is detected and corrected; such fatigue cracking could adversely affect the structural integrity of these airplanes.