Production of the main structures, such as: wing spar, fuselage, cockpit, tail structure and more.

With its huge wingspan equal to that of an Airbus A340, and its proportionally tiny weight – that of an average car - the HB-SIA prototype presents physical and aerodynamic features never seen before. These place it in a yet unexplored flight envelope. 

Carbon fiber structure, propulsion chain, flight instrumentation, everything has been designed to save energy, to resist the hostile conditions facing airplane and pilot at high altitudes and to marry weight restraints with the required strength. 

It was not built to fly round the world. Its purpose was rather to demonstrate the feasibility of the program by making the first ever whole day-and-night flight without fuel, a task that it accomplished brilliantly in July 2010. The lessons learned by the team are now being applied to the construction of Solar Impulse HB-SIB, which is due to circumnavigate the Earth in 2015.

 Source: Solar Impulse

Video of the construction