A solar-powered plane nearing the finale of a cross-continental journey landed at Dulles International Airport outside the nation's capital early Sunday, with only a last leg to New York remaining.
Solar Impulse's website said the aircraft with its massive wings and thousands of photovoltaic cells "gracefully touched down" at 12:15 a.m. EDT after 14 hours and four minutes of flight from Cincinnati to Dulles in Washington's northern Virginia suburbs.
Pilot Bertrand Piccard was at the controls for the last time on the multi-leg journey that began in California in May. His colleague, Andre Borschberg, is expected to fly the last leg from Washington to New York City's John F. Kennedy International Airport in early July, the website added.
It's the first bid by a solar plane capable of being airborne day and night without fuel to fly across the U.S. at speeds reaching about 40 mph. The plane began May 3 in San Francisco, flying via Arizona, Texas, Missouri and Ohio on to Dulles.
Organizers said in a blog post early Sunday that Piccard hopscotched over the Appalachian mountain chain on a 435-mile course from Cincinnati to the Washington area, averaging 31 mph. It was the second stint of a final leg that began in St. Louis.
The plane, considered the world's most advanced sun-powered aircraft, is powered by about 12,000 photovoltaic cells that cover its enormous wings and charge its batteries during the day.
The single-seat Solar Impulse flies around 40 mph and can't go through clouds; weighing about as much as a car, the aircraft also took longer than a car to complete the journey from Ohio to the East Coast.
The plane also is vulnerable to bad weather. Organizers said fog at Cincinnati Municipal Lunken Airport was a concern that required the ground crew's attention before takeoff just after 10 a.m. Saturday. The crew gave the plane a gentle wipe-down with cloths because of condensation that had formed on the wings.
"The solar airplane was in great shape despite the quasi-shower it experienced" before takeoff from Cincinnati, the website said.
Washington was the first East Coast stop before the final leg to New York expected in early July.
Organizers said the leg to the nation's capital was an emotional one for Piccard as it was his last on the cross-country flying mission he shared with Borschberg.
At each stop along the way, the plane has stayed several days, wowing visitors. Organizers said a public viewing of the aircraft would be held for several hours Sunday afternoon at Dulles.
As the plane's creators, Piccard and Borschberg, have said their trip is the first attempt by a solar airplane capable of flying day and night without fuel to fly across America. They also called it another aviation milestone in hopes that the journey would whet greater interest in clean technologies and renewable energy.
Piccard and Borschberg have said the project's ultimate goal is to fly a sun-powered aircraft around the world with a second-generation plane now in development. They say they are aiming for such a mission in 2015.