A two-seat solar powered aircraft has been undergoing test flights in Italy over the past few months.
The Sunseeker Duo from Solar Flight is thought to be one of the world's first practical solar-powered aircraft because of its ability to carry two people and baggage.
The first flight of the Sunseeker Duo occured on 17 December from Solar Flight’s headquarters in Voghera, Italy.
“We are working very hard to have the airplane tested and ready for passenger flights by this summer," said Irena Raymond, one of the project leaders. "No sight is more captivating than Earth from above. It will be even more beautiful from the cockpit of a solar powered airplane.”
Previously, most solar-powered aircraft have been developed to win prizes or break records, without much thought to capability as a practical aircraft.
Over the past two months, Solar Flight has been exploring the flying qualities of the aeroplane as well as the performance of the battery system, motor, propeller, folding hub mechanism, and landing gear retraction systems.
Pitch instability was observed during the unpowered test flights, and corrected with more area and additional solar cells being added to the horizontal stabilizer.
The Sunseeker Duo has a wingspan of 22 m, an empty weight of 280 kg and 1510 solar cells with 23% efficiency. The motor has a maximum output of 25 kW. The aircraft is able to cruise directly on solar power with two people on board and has an endurance in excess of 12 hours.
It uses a battery pack located in the fuselage to store energy harvested from the solar cells which line its wings and tail surfaces.
Designer Eric Raymond has a long history in successful solar flight, with the Sunseeker 1 becoming the first solar aircraft to cross the USA in 1990, and Sunseeker II completing the first solar crossing of the European Alps in 2009.
Sunseeker pilot Eric Lentz-Gauthier said a practical solar aircraft would add a completely new experience to flight.
“Flying a solar powered airplane really can’t be compared to anything else, it’s totally unique.
"In sailplanes you are usually stuck under the clouds and in conventional airplanes you have terribly noisy cockpits. In both you have a sense of urgency about energy that detracts from the experience.
"In a solar powered airplane, you fly on top of the clouds. The horizon looks a little different when you’re flying with an unlimited supply of free energy. That’s what I’m most excited about with the new airplane - sharing this experience, it changes you."
Find out more about the Sunseeker Duo on the Solar Flight website.