5 ms·

I don't know for sure, but I think that autorotation of the multiple vertical rotors provide substantial lift even if they're not being actively driven, similar

• Someone1234 9y ago
  Auto rotation converts air speed (i.e. drag) into lift. That may slightly reduce the relative costs of drag (by providing benefit) but it still has to be overcome by forward momentum.
  • fastball 9y ago
    But that's probably more of an issue for max speed than it is for efficiency, which would explain why it's operating speed is only 150kmph.
• syntaxing 9y ago
  I wonder if the auto-rotation is enough to overcome the drag from the huge wake they produce. The wake has to be almost the size of the aircraft with the wings oriented as so.
• mnw21cam 9y ago
  If you look carefully during the video, you can see that while in forward flight the rotors are aligned and locked in a forward position, which presumably reduces drag a fair amount. But yes, I can still imagine them producing a lot of drag.
• jccooper 9y ago
  From the video the rotors seem to park in fixed wing flight. The extra large hubs may be designed for lift generation, however.