Solar plane on longest leg of journey
LONDON: The Swiss pilot of a solar-powered plane has embarked on the longest leg of the first attempt to fly around the world without a drop of fuel.
André Borschberg took off from Nanjing, China, on Sunday in the Solar Impulse 2 for a flight across the Pacific Ocean expected to last six days and five nights. If he succeeds, it will also be the longest a solo pilot has ever flown an aircraft.
The plane’s journey started in March in Abu Dhabi, and the solar plane has stopped in Oman, India, Burma and China. The 8 173km flight from Nanjing to Hawaii – almost all over the sea – is the seventh of 12 flights and the most dangerous, as well as six times longer than any single leg so far.
“This is the moment of truth,” Borschberg, 62, said before take-off.
He has been taking it in turns with another Swiss pilot, Bertrand Piccard, to fly the single-seater plane in a journey that will eventually take about five months to complete. After Hawaii, the plan is for Piccard to fly the aircraft on to Phoenix, Arizona.
Borschberg is in no doubt how tough the flight will be.
“It’s more in the end about myself; it’s going to be an inner voyage,” he said before departure. “It’s going to be a discovery about how I feel and how I sustain myself during these five or six days in the air.”
Piccard said: “The pilot needs to do everything on his own. And it’s a very large aeroplane, big wingspans, sensitive to turbulence, flying quite slow… But we have an auto-
The 34 998km journey will span 25 flight days and spread over at least five months, with stops at 12 locations. pilot, we have toilets on board, we have food for days, water reserves and everything, and we are well trained.”
The carbon-fibre aircraft is covered with solar panels which drive the four propeller engines.
During daylight hours, when it is designed to climb to 8.22m, spare energy from the 17 000 solar cells is used to charge lithium batteries. These power the plane at night as it glides down to 1 524m. The two-ton aircraft’s 22m wingspan is longer than that of a Boeing 747 and it has a top speed of 138km/h.
The pilots learned meditation techniques to maintain their concentration throughout the journey and took regular, 20-minute naps. The plane’s departure from China was delayed for a month as the pilots waited for favourable winds to shorten its flying time and clear skies, enabling it to absorb maximum solar energy.