An emergency wind turbine system for an aircraft comprising an external surface in which an opening is provided, said emergency wind turbine system comprising: - an aircraft structure, - an emergency wind turbine connected to the aircraft structure and configured to move with respect to the aircraft structure between a retracted position in which the emergency wind turbine is housed in the interior of the external surface of the aircraft, and a deployed position, in which the emergency wind turbine extends outside the external surface of the aircraft, through the opening provided in the external surface, the emergency wind turbine comprising: - a mast extending along a longitudinal axis and connected to the aircraft structure, - a turbine comprising a body mounted in rotation on the mast around an axis of rotation, and a single blade or two blades extending radially from the body between a blade root housed in the body and a blade tip, the blade root(s) extending along a same blade root axis, disposed substantially perpendicular to the axis of rotation of the turbine, - a blocking device configured to block the rotation of the body of the turbine around the axis of rotation, when the emergency wind turbine moves between the retracted position and the deployed position, the system being characterized in that the blocking device is configured to block the rotation of the body of the turbine around the axis of rotation, in a position such that the blade root axis forms a blocking angle (a), acute and non-zero, with an orthogonal projection of the longitudinal axis of the mast on a plane substantially perpendicular to the axis of rotation of the turbine and in which the blade root axis extends, so as to reduce the volume swept by the emergency wind turbine when it moves between the retracted position and the deployed position, the blocking angle (a) being an angle comprised between 10 and 45°. - an aircraft structure, - an emergency wind turbine connected to the aircraft structure and configured to move with respect to the aircraft structure between a retracted position in which the emergency wind turbine is housed in the interior of the external surface of the aircraft, and a deployed position, in which the emergency wind turbine extends outside the external surface of the aircraft, through the opening provided in the external surface, the emergency wind turbine comprising: - a mast extending along a longitudinal axis and connected to the aircraft structure, - a turbine comprising a body mounted in rotation on the mast around an axis of rotation, and a single blade or two blades extending radially from the body between a blade root housed in the body and a blade tip, the blade root(s) extending along a same blade root axis, disposed substantially perpendicular to the axis of rotation of the turbine, - a blocking device configured to block the rotation of the body of the turbine around the axis of rotation, when the emergency wind turbine moves between the retracted position and the deployed position, - a mast extending along a longitudinal axis and connected to the aircraft structure, - a turbine comprising a body mounted in rotation on the mast around an axis of rotation, and a single blade or two blades extending radially from the body between a blade root housed in the body and a blade tip, the blade root(s) extending along a same blade root axis, disposed substantially perpendicular to the axis of rotation of the turbine, - a blocking device configured to block the rotation of the body of the turbine around the axis of rotation, when the emergency wind turbine moves between the retracted position and the deployed position,