A noise suppressor for attachment to the aft end of an existing turbojet engine. The noise suppressor includes a free-running turbofan wheel which includes a turbine section mounted for reaction to the exhaust gas from the jet engine, and a concentric outer fan section extending within an air duct concentric with the turbofan wheel. The jet exhaust from normal operation of the jet engine spins the free-running turbofan wheel, and the fan section of that wheel produces a flow of compressed air through the duct to surround and mix with the jet exhaust, thereby reducing the noise emission of the jet engine. A thrust reverser and an afterburner are optional for use with the noise suppressor.