Robots weren't a specific requirement for the VTOL X-Plane, but DARPA says that the best proposals ended up being unmanned. Pictured here is Boeing's
. It shouldn't be a surprise that this is the case; in a contest based on speed, efficiency, and payload, including a human pilot would be a significant disadvantage: humans are fragile and require a lot of maintenance, and it's becoming increasingly arguable that a human in an aircraft has the potential to be more of a liability than an asset, at least in some cases, which may include (say) cargo delivery into dangerous areas.
Specifically, DARPA is looking for an aircraft capable of demonstrating the following:
• Achieving a top sustained flight speed of 300-400 knots (555-740 km/h)
• Raising aircraft hover efficiency from 60 percent to at least 75 percent
• Presenting a more favorable cruise lift-to-drag ratio of at least 10, up from 5-6
• Carrying a useful load of at least 40 percent of the vehicle’s projected gross weight of 10,000-12,000 pounds (4.5-5.4 metric tons)
“We were looking for different approaches to solve this extremely challenging problem, and we got them,” said Ashish Bagai, DARPA program manager. “The proposals we’ve chosen aim to create new technologies and incorporate existing ones that VTOL designs so far have not succeeded in developing. We’re eager to see if the performers can integrate their ideas into designs that could potentially achieve the performance goals we’ve set.”