This July, PC Aero’s single-seater solar-electric Elektra One Solar airplane got some media attention by flying across the Alps in both directions within one trip. Starting in 2009, however, Solar Flight president Eric Raymond took his solar-electric Sunseeker II over the mountain range a number of times. This August, he did his own over-and-back trip … although this time he flew his two-seater Sunseeker Duo, which allowed him to bring his wife Irena along as a second pilot.

The Raymonds started out from their base in Voghera, Italy on August 2nd, flying to the Torino Aeritalia airport in Turin. On the following day, they proceeded from there to their turn-around point, the Swiss mountain of Mönch, then went on to land at Switzerland’s Munster-Geschinen airfield.

Inclement weather including low clouds and strong downdrafts added a challenge to that leg of the journey.

On August 7th, they took off from that same airport and flew back to Voghera via the Matterhorn and the city of Genoa. The return trip took just four hours, with the couple reaching a maximum altitude of 4,545 meters (14,911 ft) – they say that they could have gone higher, were it not for the fact that the plane didn’t have a dual oxygen system.

The Sunseeker Duo has a wingspan of 22 meters (72 ft) and weight of 280 kg (617.3 lb). A total of 1,510 solar cells line the wings and tail surfaces, gathering the sun's energy to be stored in the lithium-polymer battery pack located in the fuselage. The plane's motor has a maximum output of 25 kW.

It was the first solar-electric aircraft to ever carry two people … and is now also the first one to carry two people across the Alps and back.

Source: Solar Flight

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