Airworthiness Directives; McDonnell Douglas Model DC-9, DC-9-80, and C-9 (Military) Series Airplanes, and Model MD-88 Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9, DC-9-80, and C-9 (military) series airplanes, and Model MD-88 airplanes, that requires modification of certain non-regulating shutoff valves on the engine starter, or installation of a pressure relief valve in the pneumatic supply line to the starter air shutoff valve on engines 1 and 2. This amendment is prompted by reports of uncontained failures of engine starters during flight and maintenance, which resulted from the application of excessive pressure on the engine starter that was associated with the installation of non-regulating shutoff valves on the starter. The actions specified by this AD are intended to prevent such uncontained failures of the engine starters, which could create a fire hazard in the engine nacelle.