Airworthiness Directive · Amendment 39-17377 · Electrical power
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 777-200, -200LR, -300, and -300ER series airplanes; certificated in any category; as identified in Boeing Special Attention Service Bulletin 777-24-0106, dated July 20, 2007; and Boeing Special Attention Service Bulletin 777-24-0112, Revision 2, dated December 14, 2011.
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.
For airplanes identified in Boeing Special Attention Service Bulletin 777-24-0106, dated July 20, 2007: Within 36 months after the effective date of this AD, install enclosure trays to contain debris in the ELMS panels, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 777-24-0106, dated July 20, 2007.
For airplanes identified in Boeing Special Attention Service Bulletin 777-24-0112, Revision 2, dated December 14, 2011: Within 60 months after the effective date of this AD, replace specified electrical power contactors in the ELMS P200 and P300 power panels with new contactors, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 777-24-0112, Revision 2, dated December 14, 2011, except as provided by paragraph (j)(2) of this AD.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Aircraft
