Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all Lockheed Model L-1011-385 series airplanes. This proposal would require modifications of the engine turbine cooling air panel at the flight engineer/second officer's console, pilot's caution and warning light panel on the main instrument panel, and monitoring system for the engine turbine air temperature. This proposal is prompted by reports of an undetected fire breaching the high speed gearbox (HSGB) case on certain Rolls Royce engines installed on in-service airplanes due to lack of an internal fire detection system within the HSGB. The actions specified by the proposed AD are intended to prevent undetected fires originating within the HSGB from breaching the HSGB case, which could result in engine damage and increased difficulty in extinguishing a fire.