First Flapping, Two-Winged Aircraft Takes Flight

July 24, 2009 -- The world's first successful flight of a self-powered, rudderless, flapping aircraft has been achieved by engineers from AeroVironment.

The NAV, or nano air vehicle, operates by using two flapping wings, which also function as the rudder, elevators, ailerons and engine. With its two wings, the NAV is able to hover, move forward and backwards, and change its elevation. In flight, the NAV almost appears to replicate the movements of a hummingbird.

Simplified, most airplanes and helicopters today fly using the same principle: Air rushing over a shaped and immovable wing (or helicopter blade) produces an area of high pressure below the wing and an area of low pressure. The difference pushes the wing up in the direction of low pressure, creating lift.

An airplane is steered using adjustable flaps on the ends of the wings and at the tail, which also help steady the aircraft.

"It's extremely complicated and technically challenging to come up with ways to control an aircraft with two flapping wings,"said Matt Keennon of AeroVironment, "but this is the closest anyone has come to a rudderless, flapping aircraft."