LISA Airplanes' amphibious skiplane completes test runs, nears production

French firm LISA Airplanes, manufacturer of the amphibious skiplane AKOYA, says it has tested the composites-intensive two-seater on a standard runway and on water. The company is also freezing design and materials for the plane.

LISA Airplanes (Le Bourget du Lac, France), manufacturer of the amphibious skiplane AKOYA, reported on March 23 that it has followed up its flight tests from both the airport runway and the Bourget Lake. The company says that intensive taxiing tests on the lake proved the stability of the seafoils and maneuverability of the AKOYA at low speed. LISA also is finalizing choice of composite materials to be used to manufacture the plane.

"The AKOYA flows easily upon contact with water at a speed up to 90km/h (49 knots), widening even more AKOYA’s capabilities. We’re thrilled with the seafoils' performance and with the maneuverability and stability they provide. We’ve broken the seaplane rules but the result of our work is now acknowledged by the most renowned aviation experts," explains Jean-François Clavreul, research and development manager.

Flying every week, the first production AKOYA allows the validation of most of the announced performance. Recently, test pilot Gérald Ducoin completed stall tests with several weight and balance configurations and different flap positions in which the aircraft showed a safe behavior. The AKOYA does not have a “nose-down” tendency, which means that at 45 knots, the airplane tends to go down but the nose of the aircraft always stays above the skyline. The airplane keeps its lateral and longitudinal stability; the pilot just needs to push the stick to restore the speed and reverse the stall. This behavior results from four years of experimentation in wind tunnel and in flight that enhanced our design choices related to pilot safety.

Meanwhile, LISA’s engineers are completing the AKOYA’s production preparation. All structural components and materials choices are now frozen. The fuselage, wings and many small parts are made of composite materials: fiberglass, Kevlar, and mostly light-weight sandwich structures made of polymer foam core material and carbon fiber prepreg supplied by Umeco. The mechanical parts are made of aluminum and titanium.

The craft weighs 410kg/903lb when empty and features emergency airframe parachute, folding wings, electrically operated canopy, retractable landing gear equipped with skis, pearl painting and leather interior .

The AKOYA is a two-seater amphibious airplane that can land on or take off from ground, water or snow. It has a range of 1600 km/1000 miles and can reach speeds of 250 kmh/135 knots. Its wings can be folded so that the craft can be parked in a garage. The landing gear system consists of two hydrofoils and retractable landing gear. The AKOYA is designed to fulfill the LSA (Light Sport Aircraft) regulation – the new American standard that is to become an international standard such as in Europe with the CS-LSA implementation.