MANUFACTURER: The Boeing Company Model DC-9-81
(MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and
MD-88 Airplanes SUBJECT: Airworthiness Directive 2011-17-11 ACTION: Final rule
SUMMARY: This AD requires repetitive
inspections for cracking of the lower rear spar caps of the wings,
and related investigative and corrective actions if necessary. This
AD also requires repetitive inspections of certain repaired areas.
This AD was prompted by reports of cracking of the wing rear spar
lower cap at the outboard flap and inboard drive hinge at station
Xrs=164.000; the cracking is due to material fatigue from normal
flap operating loads. The FAA is issuing this AD to detect and
correct such fatigue cracking, which could result in fuel leaks,
damage to the wing skin or other structure, and consequent reduced
structural integrity of the wing.