Summary
We are revising an earlier proposed airworthiness directive (AD) for certain The Boeing Company Model 767-200, -300, and -400ER series airplanes. The NPRM proposed an inspection for plastic couplings, corrective actions if necessary, and installation of new spray shrouds. The NPRM was prompted by a report of the engine indication and crew alerting system (EICAS) display system malfunctioning during flight. This action revises the NPRM by adding, for certain airplanes, a general visual inspection of the spray shield and related investigative and corrective actions if necessary. We are proposing this supplemental NPRM (SNPRM) to prevent an uncontrolled water leak from a defective potable water system coupling, which could cause the main equipment center (MEC) line replaceable units (LRUs) to become wet, resulting in an electrical short and potential loss of several functions essential for safe flight. Since these actions impose an additional burden over that proposed in the NPRM, we are reopening the comment period to allow the public the chance to comment on these proposed changes.