Airworthiness Directives; The Boeing Company Airplanes

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737-800, -900, and -900ER series airplanes. This AD was prompted by reports of in-flight failure of the left temperature control valve and control cabin trim air modulating valve. This AD requires replacing the left temperature control valve and control cabin trim air modulating valve. We are issuing this AD to address the unsafe condition on these products.