The Kiteplane is an airplane shaped kite constructed with inflatable beams and canopy surfaces. It features a bridled wing, efficient aerodynamics for a kite, and easy angle of attack control. The combination of lightweight flexible membrane design and favorable control characteristics renders tethered inflatable airplanes an attractive option for high-altitude wind power systems.

The kite power research group currently focusses on the single-kite single-line pumping kite power concept. For such a system to succeed, a kite is required that is not only agile and aerodynamically efficient to maximize power output, but also stable to minimize the control effort. In addition, a low lift mode - in kite terminology called depower - is necessary to implement a swift low power consuming downstroke. Some kite types are naturally stable on a single-line, such as box kites, sled kites, delta kites and some ram-air kites, but neither meets the full set of requirements. The Kiteplane is specifically designed to meet these requirements, but it remains a challenge to enable its full potential.

The theoretical potential of the Kiteplane concept is visualized in the Laddermill cycle simulation and the maximum instantaneous power chart below.

The development of the Kiteplane over the years is visualized in the figure below, with the recent prototype to the right. The Kiteplane has been scaled up significantly, and improved both structurally and aerodynamically.

The main features of the third generation Kiteplane are:

• Effective wing surface area of 9 m²
• Wing span of 7 m
• Aspect ratio of 5.5
• Dihedral angle of 20 degrees
• Mass of 10 kg
• RC controlled elevator and rudder
• Double bubble main wing leading edge tube
• Double skin wing sections

The following figures show a tow tests of the Kitplane 3G at airport Valkenburg. With a wind measurement unit attached to the roof of the van, the wind speed can be controlled by the van velocity to allow for more conditioned testing.

The video footage in the youtube links below give an impression of the performance of the Kiteplane 3G.

The research goals for the near future are:

• Study the aerodynamics of membrane wing sections, the fluid structure interaction plays an important role in the aerodynamic properties of membrane wing sections and this is not well understood and investigated. The open jet facility should be used to gain more knowledge in this area.

• Investigate control methods for the kiteplane: aerodynamic control surfaces on flexible structures, morphing of wing sections, bridle line actuators. The control methods implemented so far do not provide the required control authority to fly Laddermill cycles.

Interested? Visit us at the 10^th floor of the Faculty of Aerospace Engineering or contact Roland Schmehl at This e-mail address is being protected from spambots. You need JavaScript enabled to view it