FanWing

This backward flow over the upper surfaces also creates a net circulation of air around the rotor-wing combination, resulting in vertical lift.

The flow sets up a trapped vortex within the rotor, which can rotate faster than the airspeed and greatly enhances both lift and thrust.

[1] Twisting the fan blades into a slight spiral, in a manner similar to a cylinder mower, helps to reduce rotor noise and make it inherently quieter in operation.

[4][5][6] Besides the added weight and complexity of the fan system, it has some limitations compared with a conventional fixed wing: Although the cross-flow fan has been known since the late nineteenth century, its use as a rotary aircraft wing was not studied until 1997 when Patrick Peebles, an American based in Europe, conceived of it as a STOL device and subsequently formed the FanWing Co. Wind tunnel tests and powered model flights were supported by UK government funding, winning SMART grant awards in 2002 and 2003.

[3] By 2014, support for wind tunnel tests of a 1.5 meter wing section was being provided through EU sources including €783,000 through the German Aerospace Center.