An application is as a sustaining motor or even a self-launching motor for gliders. The most common system is the front electric sustainer, which is used in over 240 gliders. The short range is not a problem as the motor is used only briefly, either to launch or to avoid an outlanding (an unplanned landing while soaring). The first commercially available, non-certified production electric aircraft, the Alisport Silent Club self-launching glider, flew in 1997. It is optionally driven by a DC electric motor running on of batteries that store of energy. The first certificate of airworthiness for an electric powered aircraft was granted to the Lange Antares 20E in 2003. Also an electric, self-launching glider/sailplane, with a DC/DC brushless motor and lithium-ion batteries, it can climb up to with fully charged cells. The first flight was in 2003. In 2011 the aircraft won the 2011 Berblinger competition. In late 2000s Chinese manufacturer of radio-controlled models Yuneec International developed and tested several battery-powered manned fixed-wing aircraft, including E430, the first electric aircraft designed to be serially produced, but failed to commercialize them (only prototypes were built) and in mid-2010s turned to the lucrative consumer drone market. The Taurus Electro was the first two-seat electric aircraft to have ever flown, while the Taurus Electro G2 is the production version, that was introduced in 2011. Powered by a electric motor and lithium batteries for self-launching to an altitude of , after which the engine is retracted and the aircraft then soars as a sailplane. It is the first two-seat electric aircraft to have achieved series production. As pilot training emphasises short flights, several companies make, or have demonstrated, light aircraft suitable for initial flight training. The Airbus E-Fan was aimed at flight training but the project was cancelled. Pipistrel makes light sport electric aircraft such as the Pipistrel WATTsUP, a prototype of the Pipistrel Alpha Electro. The advantage of electric aircraft for flight training is the lower cost of electrical energy compared to aviation fuel. Noise and exhaust emissions are also reduced compared with combustion engines. The Bye Aerospace eFlyer 2 (formerly the Sun Flyer 2) is a light electric aircraft designed and under development by Bye Aerospace of Denver, Colorado. The aircraft was first publicly introduced on 11 May 2016, and first flew on 10 April 2018. On 10 June 2020, the Velis Electro variant of the two-seat Pipistrel Virus was the