Airworthiness Directives; Lockheed Model L-1011-385 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain Lockheed Model L-1011-385 series airplanes, that requires modification of the high pressure bleed valve controller of each engine. This amendment is prompted by reports of failure of the bleed air system components such as the thermal compensators and bleed air ducts. The actions specified by this AD are intended to prevent such failures of the bleed air system components, which could result in high temperature air leaking into the cabin and/or cargo areas and could possibly require an emergency landing and evacuation.