When hand-winding the movement, the 138
link SS is louder, and the feedback
link makes it easy to visualize the mechanical bits interacting because the audible crunch is so distinct. Wearing the 138 SS Models is akin to piloting something like a Boeing Stearman, a rugged airframe that requires a "by the seat of your pants" approach to flying, and the micro-rotor movements are closer to the operating the Sud Aviation Caravelle, SAS's first jet airliner,
link full of automated systems.