Dave, i've always supported your high speed intermeshing concept.
Kaman apparently offered an intermeshing solution at the same time as Seasprite, but the Navy chose conventional. This may have held back counterrotating helicopter development. I suspect the reason was more to do with head clearance on deck than performance. Unfortunately development of X2 seems to have ground to a halt, which is a great shame.
The modified S-61 was part of the competition that lead to the AAFSS, for which Cheyenne was designed. The competitors were all compounded machines with Bell getting 274kts and Lockheed getting 263kts. This gives an idea of maximum achievable speed with a pusher prop compounded helicopter. I am suggesting an adaptation to compounding which would alleviate the retreating blade stall, while minimising hover download and parasitic mass.
The asym-wing is very much a compromise, with the objective being the minimum solution for the specific problem of retreating blade stall. A movable tail rotor may well be part of that solution. The single wing would produce anti-torque at speed, so tail rotor could become a pusher. Part of me recoils from the concept, but i'm sure it would be viable. Basically it has the lowest parts count.
