Airworthiness Directives; The Boeing Company Airplanes

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