lights. Kite traction Kites can be used to pull people and vehicles downwind. Efficient foil-type kites such as power kites can also be used to sail upwind under the same principles as used by other sailing craft, provided that lateral forces on the ground or in the water are redirected as with the keels, center boards, wheels and ice blades of traditional sailing craft. In the last two decades, several kite sailing sports have become popular, such as kite buggying, kite landboarding, kite boating and kite surfing. Snow kiting has also become popular. Kite sailing opens several possibilities not available in traditional sailing: Wind speeds are greater at higher altitudes Kites may be manoeuvered dynamically, which dramatically increases the available force There is no need for mechanical structures to withstand bending forces; vehicles or hulls can be very light or dispensed with altogether Power generation Conceptual research and development projects are being undertaken by over a hundred participants to investigate the use of kites in harnessing high altitude wind currents for electricity generation. Cultural uses Kite festivals are a popular form of entertainment throughout the world. They include local events, traditional festivals and major international festivals. Designs Bermuda kite Bowed kite, e.g. Rokkaku Cellular or box kite Chapi-chapi Delta kite Foil, parafoil or bow kite Malay kite see also wau bulan Tetrahedral kite Types Expanded polystyrene kite Fighter kite Indoor kite Inflatable single-line kite Kytoon Man-lifting kite Rogallo parawing kite Stunt (sport) kite Water kite Characteristics Airframe The structural parts of a fixed-wing aircraft are called the airframe. The parts present can vary according to the aircraft's type and purpose. Early types were usually made of wood with fabric wing surfaces, When engines became available for a powered flight around a hundred years ago, their mounts were made of metal. Then as speeds increased more and more parts became metal until by the end of World War II all-metal aircraft were common. In modern times, increasing use of composite materials has been made. Typical structural parts include: One or more large horizontal wings, often with an airfoil cross-section shape. The wing deflects air downward as the aircraft moves forward, generating lifting force to support it in flight. The wing also provides stability in roll to stop the aircraft from rolling to the left or right in steady flight. A fuselage, a long, thin body, usually with tapered or rounded ends