Airworthiness Directive · Amendment 39-11706 · Lockheed Model L-1011-385 Series Airplanes
Lockheed Model L-1011-385 Series Airplanes
Model L-1011-385-1, -1-14, -1-15, and -3 series airplanes, equipped with high pressure bleed valve controller Hamilton Standard part number (P/N) 739084-2 or 739084-3 (Lockheed P/N 672286-103 or 672286-105); certificated in any category.
Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (c) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
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.
To prevent 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, accomplish the following:
(a) Within 14 months after the effective date of this AD, modify the high pressure bleed valve controller of each engine in accordance with Lockheed Service Bulletin 093-36-065, dated February 9, 1999.
Note 2: Lockheed Service Bulletin 093-36-065, dated February 9, 1999, references Hamilton Standard Service Bulletin 36-1060, Revision 1, dated March 1, 1977, as an additional source of service information for the modification of the high pressure bleed valve controller of each engine.
(b) As of the effective date of this AD, no person shall install on any airplane a high pressure bleed valve controller having Hamilton Standard part number (P/N) 739084-2 or 739084-3 (Lockheed P/N 672286-103 or 672286-105), unless it has been modified in accordance with this AD.
