|Nymbus and eVader 6D on display at Ottawa's Aviation and Space Museum, 2012
Only two rigid propellers are required for hover if they are
treated as CMGs (control moment gyroscopes) and momentum
wheels. Gyroscopic moments arising from the propellers'
forced precession are an order of magnitude larger and faster
than the conventional thrust vectoring moments they
These new, dynamic moments are independent of distances to
the aircraft center of mass, and, of course, are independent of
the atmosphere. Yes, they can fully control an aircraft about
the three axes in outer space, which translates to exceptional
maneuverability and gust resistance here on earth.