Green

Bad weather forces solar plane to make unplanned landing in Japan

May 31, 2015: Crew members push the aircraft Solar Impulse 2 piloted by Swiss Andre Borschberg out of a hangar before taking off at Nanjing Lukou International Airport in Nanjing in eastern China's Jiangsu province. (Chinatopix via AP)

May 31, 2015: Crew members push the aircraft Solar Impulse 2 piloted by Swiss Andre Borschberg out of a hangar before taking off at Nanjing Lukou International Airport in Nanjing in eastern China's Jiangsu province. (Chinatopix via AP)

A solar plane attempting to fly around the world without a drop of fuel plans to make an unscheduled stop Monday night in Nagoya, Japan, because of bad weather.

Swiss pilot Andre Borschberg took off from Nanjing, China, on Sunday on what was to be the longest leg of the journey, a five-day, 5,079-mile flight to Hawaii.

Instead, the Solar Impulse 2 will land in Nagoya in central Japan, according to the website and Twitter feed for the plane.

Japanese Transport Ministry and Nagoya airport officials confirmed that they are making arrangements for an unanticipated landing at Nagoya Airport in central Japan.

Elke Neumann, a spokeswoman for the Solar Impulse project, said from Nanjing that the teams had noticed the bad weather pattern about 36 hours ago.

"We thought we might go through it," she said. "But between Japan and Hawaii there's no place to stop ... so we said, for us, the pilot's safety and the plane's safety are really a priority right now. So we said, let's wait the weather out a bit in Japan."

The plane is to land sometime after 10 p.m., after scheduled flights at the airport end.

Solar Impulse 2 needs room to land, so it generally avoids times when commercial flights are operating, Neuman said. The plane also usually lands at night, because the winds tend to be lower. It needs wind to be no more than 10 knots, she said.

"We are a little bit sad, because everything's functioning perfectly: The batteries are charging, there's enough sun, the pilot is in good health, he's in good condition -- it's all working well," Neumann said.

The journey started in March in Abu Dhabi, and the plane has stopped in Oman, India, Myanmar and China. The flight from Nanjing to Hawaii is the seventh of 12 flights and the riskiest.