AD FAA-2018-0393

We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. This AD was prompted by reports of loose, worn, or missing attachment bolts for the main landing gear (MLG) center door assemblies. This AD requires repetitive detailed inspections of the forward and aft MLG center door assembly attachments for loose, missing, damaged, or bottomed-out attachment bolts, and any wear to the retention clip assemblies as applicable; and applicable on-condition actions. This AD also provides an optional terminating action for the repetitive inspections. We are issuing this AD to address the unsafe condition on these products.