AD FAA-2012-0597

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 777-200, -200LR, -300, and -300ER series airplanes. This AD was prompted by reports of in-service events related to electrical power system malfunctions resulting in damage to electrical load management system (ELMS) P200 and P300 power panels and the surrounding area. This AD requires installing enclosure trays to contain debris in certain ELMS panels, and replacing certain ELMS contactors. We are issuing this AD to prevent contactor failures, which could result in uncontained hot debris flow due to ELMS contactor breakdown, consequent smoke and heat damage to airplane structure and equipment during ground operations, and possible injuries to passengers and crew.