Propulsion unit with foldable propeller blades and method for stopping the propeller in an indexed angular position

A propulsion unit having a propeller for an aircraft comprising:

• a nacelle which is intended to be assembled on a structural element of the aircraft;
• a propeller which is rotatably mounted in the nacelle about a longitudinal axis of rotation by means of a hub, the propeller comprising blades evenly distributed around the hub, the blades being pivotally mounted by a root on the hub between a deployed position in which they extend radially with respect to the axis of rotation and a folded position in which they are received longitudinally against the nacelle;
• propulsion means which drive the propeller in rotation;
• indexing means for stopping the propeller in at least one indexed angular position relative to the nacelle;
• wherein the indexing means are formed by a stepping electric motor which comprises a rotor which is coupled to the hub of the propeller.