Action
Final rule.
Summary
We are adopting a new airworthiness directive (AD) for certain Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Model 188 series airplanes. This AD was prompted by an evaluation by the design approval holder (DAH) indicating that the upper and lower wing skin planks at the attachment of the main landing gear (MLG) ribs at certain wing-stations are subject to widespread fatigue damage (WFD). This AD requires an inspection (for cracking) and modification of the chordwise fastener rows of the upper and lower wing planks at the attachments to the MLG ribs at certain wing-stations. We are issuing this AD to prevent fatigue cracking of the upper and lower wing skin planks at the attachment of the MLG ribs, which could result in failure of the wing.