(R = Рекордный = Recordnyy = Record)
One production Mi-10 coded "81 Red" modified for setting records. Its weight had been reduced and the original quad undercarriage was replaced by a tricycle undercarriage taken from the Mi-6, with fairings and spats on the main struts, plus the addition of a tailwheel.
First flew on January 14, 1965. It has held seven (or eight?) world records, but are no longer current.