Daves link contains the statement "Mil recognized, however, that vertical take off characteristics in a side by side rotor configuration are not as good as with a tandem due to greater loss of lift from rotor wash." I would have thought the losses in a tandem set up with the fuselage fully immersed in the wash (and over lapping blades) would have been greater. As Pauline Hanson wouldd say, "please explain".
