Airworthiness Directives; Boeing Model 777-200, -200LR, -300, and -300ER Series Airplanes Approved for Extended-Range Twin-Engine Operational Performance Standards (ETOPS)

We are adopting a new airworthiness directive (AD) for certain Boeing Model 777-200, -200LR, -300, and -300ER series airplanes. This AD requires a one-time inspection to determine the part number of the cargo compartment fire suppression filter/regulator. This AD also requires, for certain airplanes, a revision of the "Maximum Diversion Time in Minutes" for ETOPS operation specified in the Operations Specifications. For certain airplanes, this AD also provides for optional replacement of the cargo compartment fire suppression filter/ regulator, which would allow revision of the "Maximum Diversion Time in Minutes" for ETOPS operation specified in the Operations Specifications to restore the airplane's full ETOPS capability. This AD results from a report that the filter/regulator installed in the cargo fire suppression system did not meter the Halon for the certified duration during ETOPS flight tests. We are issuing this AD to prevent ETOPS operation with insufficient cargo fire suppression capability, which could result in an uncontained fire in the cargo compartment.