An exhaust duct for an engine includes an outer exhaust duct and a nested exhaust duct capable of having at least two configurations. The nested exhaust duct is circumferentially surrounded by the outer exhaust duct for a first length of the nested exhaust duct in a first configuration. The nested exhaust duct is circumferentially surrounded by the outer exhaust duct for a second length of the nested exhaust duct in a second configuration, which is less than the first length.