The Swiss team flying the aircraft in a campaign to build support for clean energy technologies hopes eventually to complete its circumnavigation in Abu Dhabi, where the journey began in March 2015.
The spindly, single-seat experimental aircraft, dubbed Solar Impulse 2, arrived in Phoenix shortly before 9 p.m., following a flight from San Francisco that took it over the Mojave Desert.
The flight would have taken a conventional airplane just two hours, but the solar craft’s cruising speed, akin to that of a car, required pilots to take up meditation and hypnosis in training to stay alert for long periods.
Occupying the tiny cockpit for the trip was project co-founder Andre Borschberg, who alternates with fellow pilot Bertrand Piccard at the controls for each segment of what they hope will be the first round-the-world solar-powered flight.
“I made it to Phoenix, what an amazing flight over the Mojave desert,” Borschberg said in a Twitter post.
Borschberg was the pilot for the Japan-to-Hawaii trip over the Pacific last July, staying airborne for nearly 118 hours.
That shattered the 76-hour world duration record for a non-stop, solo flight set in 2006 by the late American adventurer Steve Fossett in his Virgin Atlantic Global Flyer. It also set new duration and distance records for solar-powered flight.The feat, however, dealt a setback to the Solar Impulse, which suffered severe battery damage, requiring repairs and testing that grounded it in Hawaii for nine months.
Piccard completed the trans-Pacific crossing last month, reaching San Francisco after a flight of nearly three days, more than three times the 18 hours Amelia Earhart took to fly solo from Hawaii to California in the 1930s.
The biggest difference is that the propeller-driven Solar Impulse flies without a drop of fuel, its four engines powered solely by energy collected from more than 17,000 solar cells built into its wings.
Surplus power is stored in four batteries during the day, to keep the plane aloft on extreme long-distance flights.
The carbon-fiber plane, with a wingspan exceeding that of a Boeing 747 and the weight of a family car, is unlikely to set speed or altitude records. It can climb to 28,000 feet (8,500 m), and cruise at 34 to 62 mph (55 to 100 kph).
In a precursor of their globe-circling quest, the two men completed a multi-flight crossing of the United States with an earlier version of the solar plane in 2013.