Solar plane reaches height of one mile on first flight

PAYERNE, Switzerland — At the pace of a fast bicycle, a solar-powered plane took to the skies for its maiden flight Wednesday, passing an important test on the way to a historic voyage around the world — a journey that would not use a drop of fuel.

The Solar Impulse lifted off from a military airport at a speed no faster than 28 mph after briefly accelerating down the runway. It slowly gained altitude and eventually faded into the horizon as villagers watched from the nearest hills.

"There has never been an airplane of that kind that could fly — never an airplane so big, so light, using so little energy. So there were huge question marks for us," said Bertrand Piccard, who is leading the project. In 1999, he co-piloted the first nonstop round-the-world balloon flight.

During Wednesday's 90-minute flight, the plane completed a series of turns by gently tilting its black-and-white wings, which are as wide as those of a 747 jumbo jet. It climbed nearly a mile above the Swiss countryside. The weather was sunny, and there was little wind — obvious advantages for a plane so light and dependent on the sun.

Engineers on the $93.5 million project have been conducting short tests since December, taking the plane no higher than 2 feet and flying no more than 1,000 feet. A night flight is planned before July, and then a second plane will be built based on the results of those tests.

That plane will be the one to attempt the round-the-world flight planned for 2012.