Phoenix – A solar-powered airplane that developers, hope eventually to pilot around the world, landed safely in Phoenix on the first leg of an attempt to fly across the US using only the sun’s energy, project organisers said. The flight from San Fransisco to Phoenix by the plane dubbed the ‘Solar Impulse’ took 18 hours and 18 minutes, completing the first of five legs with planned stops in Dallas, St. Louis and Washington on the way to a final stop in New York, and it didn’t use a drop of fuel. The spindly-looking plane barely hummed as it took off Friday morning from Moffett Field, a joint civil-military airport near San Francisco. It landed in pre-dawn darkness at Sky Harbour International Airport in Phoenix, according to a statement on the Solar Impulse’s website.The flight crew plans pauses at each stop to wait for favourable weather, and hope to reach John F. Kennedy International Airport in New York in about two months.Swiss pilots and co-founders of the project, Bertrand Piccard and Andre Borschberg, will take turns flying the plane, built with a single-seat cockpit. Piccard was at the controls for the first flight to Arizona. The aircraft is propelled by energy collected from 12,000 solar cells built into the wings that simultaneously recharge four large batteries with a storage capacity equivalent to a Tesla electric car that allow it to fly after dark. It was designed for flights of up to 24 hours at a time and is a test model for a more advanced aircraft the team plans to build to circumnavigate the globe in 2015. It made its first intercontinental flight, from Spain to Morocco, last June. The aircraft can climb to 28,000 feet and flies at an average of 69km per hour.The plane project started in 2003 with a 10-year budget of 90m euros (about $112m) and has involved engineers from Swiss escalator maker Schindler and research aid from Belgian chemicals group Solvay.