Airworthiness Directives; Boeing Model 737-600, -700, -700C, -800, and -900 Series Airplanes

This amendment adopts a new airworthiness directive (AD) that is applicable to all Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes. This action requires reviewing the airplane maintenance records to determine whether an engine has been removed from the airplane since the airplane was manufactured. For airplanes on which an engine has been removed, this action requires an inspection of the aft engine mount to determine if the center link assembly is correctly installed, and follow-on actions if necessary. This action also prohibits installation of an engine unless the aft engine mount is inspected and the center link assembly is found to be installed correctly. This action is necessary to prevent increased structural loads on the aft engine mount, which could result in failure of the aft engine mount and consequent separation of the engine from the airplane. This action is intended to address the identified unsafe condition.