Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 777-200 and 777-300 series airplanes. This proposal would require application of high-temperature sealant to the strut aft dry bay. This action is necessary to prevent leakage of hydraulic fluid into the strut aft dry bay, where high temperatures associated with the adjacent primary exhaust nozzle may ignite the fluid, resulting in an uncontrolled fire in the strut aft dry bay. This action is intended to address the identified unsafe condition.