AD FAA-2011-0652

We are adopting a new airworthiness directive (AD) for all The Boeing Company Model MD-90-30 airplanes. This AD was prompted by reports of cracks of the wing rear spar lower cap at the outboard flap, inboard drive hinge at station Xrs=164.000. This AD requires repetitive eddy current high frequency (ETHF) inspections for cracking on the aft side of the left and right wing rear spar lower caps at station Xrs=164.000, further ETHF inspections if cracks are found, and repair if necessary; and repetitive post-repair inspections, and repair if necessary. We are issuing this AD to detect and correct cracking of the left and right rear spar lower caps, which could result in fuel leaks and damage to the wing skin or other structure, and consequent loss of the structural integrity of the wing.