This article is part of our special report Greening aviation.
The solar-powered Solar Impulse plane landed in Brussels late on Friday on its first international flight, 13 hours after leaving Payerne airport in western Switzerland.
The landing was delayed by about 40 minutes by strong winds. Take-off on Friday morning had already been delayed by fog.
Bertrand Piccard, the man behind the Solar Impulse idea, described the flight as a "historic moment", and stressed its symbolic importance for flight using renewable energy.
Air traffic controllers in Brussels said bring the plane in to land was a "unique challenge." The plane behaved "like a pedestrian on the motorway round Brussels". Since it is so light and sensitive to turbulence, it had to keep three times the normal distance from other planes.
The pilot André Borschberg was reported to be "tired" after the flight.
The plane left Swiss air space at about 10.30, and flew for six hours over France, before reaching Luxembourg. It entered Belgian air space at about 17.30.
From Brussels, it will attempt to fly to Paris le Bourget airport in France where it will be shown at the Paris International Airshow in June.
Last July Solar Impulse made aviation history by flying through the night on solar power alone.