If hydraulic propeller feathering systems are used for stopping the engine, the hydraulic feathering lines or hoses must be fire resistant.
(hydraulic propeller feathering systems; are used; for stopping the engine) (the hydraulic feathering lines or hoses; must be; fire resistant)
hydraulic propeller feathering systems the hydraulic feathering lines or hoses
are used must be
for stopping the engine
fire resistant