AD FAA-2017-0503

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 was prompted by reports of cracking of various structures in the bulkhead. This AD requires an inspection for cracking in these structures, and corrective actions if necessary. We are issuing this AD to address the unsafe condition on these products.