Airworthiness Directives; The Boeing Company Airplanes

The FAA is adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737-8, 737-9, and 737-8200 airplanes. This AD was prompted by a determination that new airworthiness limitations are necessary to require periodic replacement; or testing, and replacement if necessary; of the oxygen sensor of the nitrogen generation system (NGS). This AD requires revising the existing maintenance or inspection program, as applicable, to incorporate the new airworthiness limitations. The FAA is issuing this AD to address the unsafe condition on these products.