Background

Human flight has, in more than a century of development not yet achieved the true freedom of flight. An essential limitation lies in the dependence on runways. The Exulans project has embarked on a quest to find a form of fixed wing flight that can do without runways.

Achieving this goal would contribute towards a safer form of human flight by giving a pilot more options if forced to land. It would also provide less expensive alternatives to rotorcraft to access remote areas. Ultimately, man would be able to journey in the ocean of air and explore the world in a way not yet possible for him.

In the first of four self-contained phases the tailless aircraft is being investigated as a suitable configuration to achieve short-field landings. In the next phase short-field landing strategies are to be examined. Essentially working with gliders, which use the energy of the sun in the form of thermals to silently gain their height it would be necessary in the third phase to add a power plant for the take-off. Thereafter the short field take-off is to be challenged.

Of relevance in the shorter term is only the first phase. Exploring a new concept of tailless aircraft at the University of Pretoria, fundamental observations from nature are being implemented. To eliminate the most serious shortcomings of traditional tailless aircraft, the novel design involves a bird-like wing layout and method of control. Intensive theoretical scrutiny has indicated that both aerodynamic efficiency as well as stability stand to benefit by applying these tricks of nature. It seems as if we can still learn from the 85 million years of bird evolution.

To test a theory on aircraft stability and control a scaled-down, radio controlled version of the design was first used. Inspiring results prompted the development of the full-scale glider, an ultra-light craft made from composite materials. Called the Exulans I this first prototype was extensively flown on a vehicle mounted test-rig. Restrained only by safety lines the flight behavior could be established.

The results exceeded the expectations and strongly encourage further development. Exulans II is being developed to take the next step in the evolution of a new species of aircraft in human aviation.