Airworthiness Directives; The Boeing Company Airplanes

We are adopting a new airworthiness directive (AD) for all The Boeing Company Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) airplanes, and Model MD-88 airplanes. This AD requires repetitive eddy current high frequency (ETHF) inspections for any cracking in the left and right side center wing lower skin, and corrective actions if necessary. This AD was prompted by reports of cracking at certain stringers, associated end fittings, and skins in the center wing fuel tank where the stringers meet the end fittings. We are issuing this AD to detect and correct cracking in the center wing lower skin. Such cracking could cause structural failure of the wings.