Solar Impulse touches down on unscheduled Japan stop

NAGOYA, Japan (2nd UPDATE) – The record-breaking Solar Impulse 2 landed in Japan Monday, June 1, on an unscheduled stop after mission controllers decided the weather was not right for the sun-powered plane to cross the vast Pacific Ocean.

The high-tech aircraft touched down at an airport in Nagoya, central Japan, at around 1450 GMT, an Agence France-Presse correspondent at the scene said.

Pilot Andre Borschberg told reporters in Nagoya that the unplanned diversion was no problem for the mission.

"I would say it has no impact," he said, shortly after climbing out of the cramped cockpit.

"Practically I think it gives us the possibility to be in Japan, which is great. I lived here 30 years ago so it is a great pleasure to be back.

"We learned a lot during last night after 40 hours non stop, and demonstrated that the airplane is really doing great."

The landing had been live streamed on the Solar Impulse website, with viewers treated to scenes of jubilation and relief from the Monaco mission control room when the plane glided to the tarmac in central Japan.

"We are very grateful to everyone in Japan for helping us," @solarimpulse, the venture's main feed, Tweeted in Japanese.

"Without the co-operation of everyone here, this landing wouldn't have been possible."

Borschberg had set off at the controls of Solar Impulse from Nanjing in China more than 40 hours earlier, bound for Hawaii, a distance of some 8,500 kilometers (5,250 miles) that it was expected to cover in a 6-day, 6-night non-stop flight.

But flight managers determined earlier Monday that weather the plane would encounter as it neared Hawaii made the flight too risky and diverted it to Japan.

The 62-year-old pilot, who had spent much of the day in a holding pattern over the Sea of Japan (East Sea), headed south towards Nagoya, where he was met by a skeleton support crew.

Bertrand Piccard, the initiator of the mission, said great conditions at take-off had deteriorated.

"When we left China, the weather conditions as far as Hawaii were okay," he told Agence France-Presse in Monaco.

"Then they got worse. We didn't expect to fly through an active weather front, with ice, rain and turbulence. It's a plane that flies slowly and is sensitive to turbulence, and it needs sun to be able to recharge its batteries."

He admitted the setback was disappointing, but said speed was never the most important thing.

"This world tour is maybe not going as fast as we would like, but this is not a race. The goal is to get there," he said.

Despite having been cut short by several days, the flight from China notched up at least one first – Solar Impulse 2 became the first plane to fly day and night powered only by sunshine.

A small ground crew was waiting in Japan to deal with the unplanned landing, with the bulk of the technicians expected to arrive on Tuesday from Nanjing.

The aircraft will have to be tied down overnight to ensure it does not get buffeted by any wind.

The support team will be bringing an inflatable hangar to protect Solar Impulse as it awaits a weather window to make the journey across the Pacific to Hawaii.

Promote green energy

The flight from Nanjing to Hawaii was scheduled to be the longest section of the maiden solar-powered global circumnavigation of the globe, which is an attempt to promote green energy.

The journey began in Abu Dhabi in March and was originally intended to be for 12 legs, with a total flight time of around 25 days.

But the mission team had always had back-up plans in case the Nanjing-Hawaii flight did not go smoothly, with five airfields in Japan identified.

Japan was the point of no return on the way to Hawaii, and the last place to land. After that, failure could mean a parachute descent into the ocean, hundreds of kilometers from rescue.

No ship is trailing the plane since it travels too fast for a maritime vessel to keep up, even though its maximum speed of 140 kilometers an hour is much slower than jet aircraft.

Solar Impulse 2 is powered by more than 17,000 solar cells built into wings that, at 72 meters (236 feet), are longer than those of a Boeing 747 and approaching those of an Airbus A380 superjumbo.

The plane is the successor to Solar Impulse, which managed a 26-hour flight in 2010, proving its ability to store enough power in lithium batteries during the day to keep flying at night.

Ridiculed by the aviation industry when it was first unveiled, the venture has since been hailed around the world, including by UN chief Ban Ki-moon. – Harumi Ozawa, AFP / Rappler.com