Rick Cavallaro and his merry band of enthusiasts recently improved the upwind and downwind speeds of their Blackbird, their DDWFTTW (directly downwind, faster than the wind) vehicle, according to Wired.
Using New Jerusalem Airport in Tracy, CA as the testing ground, the vehicle hit an upwind velocity of 2.01 times wind speed, which is counterintuitive until you consider the vehicle's design of having two large turbine blades catching that wind and propelling the wheels. Better yet, Wired reported that the Blackbird reached downwind speeds of 2.86 times wind velocity. Going downwind, the process is reversed, in that the rolling wheels spin the propeller, which further drive the vehicle.
Cavallaro and his cohorts have been at this for at least a couple of years, claiming as far back as June 2010 that the Blackbird's downwind speed could hit three times wind velocity. They're getting close to that mark. Remember, this isn't a direct sail thing, and no perpetual motion is being claimed. Still, there are plenty who doubt the veracity of the DDWFTTW claims. Discuss.