Aerial vehicles are equipped with propellers having clutch mechanisms that contract around a shaft when the propellers are not rotating, or are rotating at low angular velocities, and expand around the shaft when the propellers are rotating at sufficiently high angular velocities. The clutch mechanisms surround one or more fixed posts within an opening or window defined therein. When the clutch mechanisms contract into a closed position, components of the clutch mechanisms come into contact with the posts, and the propellers are forced to remain in an alignment defined by the posts. When the clutch mechanisms expand into an open position, such components may rotate freely without contacting the posts. The clutch mechanisms cause propellers to remain aligned in desired orientations when the propellers are not required for operation, thereby reducing drag or adverse acoustic effects.