Patent attributes
An aircraft engine includes a core gas path through which a core gas flow flows, an exhaust duct receiving the core gas flow, an air-cooled heat exchanger disposed in a heat exchanger duct having an air inlet providing cooling air to the air-cooled heat exchanger and an air outlet in fluid communication with the exhaust duct, and a cover disposed in the heat exchanger duct downstream of the air-cooled heat exchanger. The cover is movable between an open position, in which the cover allows the cooling air to flow through the air outlet into the exhaust duct, and a closed position, in which the cover substantially blocks the air outlet. The cover is operable to move from the open position to the closed position at a predetermined temperature of the cover.