Method of operating an aircraft bypass turbofan engine having variable fan outlet guide vanes

摘要

A method of operating an aircraft bypass turbofan engine having variable fan outlet guide vanes. In a first embodiment, an engine out condition is sensed, fan rotor speed is repeatedly measured, and vane pitch is adjusted to a predetermined value as a function of the fan rotor speed to generally maximize airflow through the vanes during the engine out condition. In a second embodiment, vane pitch is adjusted to a preselected value as a function of fan rotor speed to generally minimize engine noise during a noise reduction mode of engine operation.