Abstract: The invention is a shroud for a reversible thrust fan, the shroud having a inlet duct and an exhaust nozzle with the fan located there between. In general terms, the shroud includes a system for increasing the efficiency of the exhaust nozzle when acting as an inlet duct when the fan is providing reverse thrust. The system comprising a plurality of auxiliary inlet duct systems spaced about the circumference of the exhaust nozzle in proximity to the rear end thereof, the auxiliary inlet duct systems extending from the exterior surface of the exhaust nozzle to the interior surface thereof. The auxiliary inlet duct systems are movable from a closed position to an open position wherein air can be drawn from the exterior surface of the exhaust nozzle to the interior thereof when the fan is providing reversed thrust.