AD FAA-2018-0588

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 777-200LR series airplanes. This AD requires revising certain documents to provide revised operating limitations. For certain airplanes, modification of the water and fuel scavenge systems in the fuel tanks, electrical changes in the main equipment center, and installation of new electrical load management system (ELMS2) software is an acceptable alternative to the documents revision. This AD was prompted by reports of unreliable performance of the water and fuel scavenge systems. We are issuing this AD to address the unsafe condition on these products.