FUEL-LESS FLIGHT; GRAVITY POWERED FLIGHT
The idea that an airplane can fly endlessly carrying heavy loads of passengers and cargo without burning any fuel, can stop and hover in place weightless at any time, and can takeoff and land vertically is a radical departure from accepted thought concerning aviation. This new reality that is made possible by the invention of Robert Hunt's astounding new hybrid aircraft is Hunt Aviation’s vision of the future of aviation. Our aircraft is a rigid glider made of lightweight composite materials. The new hybrid “gravity-powered aircraft” is formed by merging the capabilities of the following devices into a single new aircraft apparatus: (1) an aircraft capable of aerostatic (lighter-than-air) lift to gain altitude; and, (2) a glider aircraft capable of aerodynamic lift, having a high glide ratio to accomplish long range gliding; and, (3) an innovative new extremely low drag vertical axis wind turbine that is capable of harnessing the force of the wind to generate power as the aircraft glides upward via positive buoyancy and glides downward via gravity acceleration.
They have a nice video of it too.
Even as such a system would not allow fuelless motion, it might be very efficient. Jet aircraft go through the trouble of climbing to and flying at 12 kilometers ( and regaining part of that gravity energy on the way down), because flight is more efficient up there. Gliders can fly almost for free by extracting energy from thermal rising winds. Blimps require little power because they can fly slow (not because they use no power to stay afloat). Possibly the Hunt aircraft would open such an 'effiency niche', even if it is not really a fuelless aircraft.
But their website never mentions how this would happen, and more specifically how their aircraft is going to do this better than existing gliders, blimps and autogyros from whch they borrow elements. This suggests to me that they are either frauds or clueless.
