I guess you mean the Blackbird:I remember reading about a windmill sort of contraption that used wind power to drive the wheels mechanically. I don't recall the details, but think this moment that its claim to fame was its ability to exceed windspeed directly upwind.
A conventional sail craft can neither go directly upwind (at any speed), nor directly downwind faster than wind. Using rotors, like the Blackbird, you can do both.(In all cases, the apparent wind is the issue. Dead downwind, you can never exceed windspeed. Upwind, though, the v-squared relationship is beneficial, although aero drag also increases at that same rate.)