Airworthiness Directives; Boeing Model 777-200 and -300 Series Airplanes Equipped With Rolls-Royce Model RB211-TRENT 800 Series Engines

The FAA is superseding an existing airworthiness directive (AD) that applies to certain Boeing Model 777-200 and -300 series airplanes. The existing AD currently requires revising the airplane flight manual (AFM) to include in-flight procedures for pilots to follow in certain cold weather conditions and requires fuel circulation procedures on the ground when certain conditions exist. This new AD retains the fuel circulation procedures. This new AD also revises the AFM procedures required by the existing AD. This AD results from a report of a single-engine rollback as a result of ice blocking the fuel oil heat exchanger. We are issuing this AD to prevent ice from accumulating in the main tank fuel feed system, which, when released, could result in a restriction in the engine fuel system. Such a restriction could result in failure to achieve a commanded thrust, and consequent forced landing of the airplane.