Solar Impulse covers two-thirds of way from Japan to Hawaii

Los Angeles

A solar-powered aircraft flying from Japan to Hawaii on the most perilous leg of a round-the-globe bid has passed the two-thirds point, and was under 40 hours from landing, organizers said. 

Solar Impulse 2 had traveled 67 per cent of the way to the tropical US state by 2100 GMT Wednesday, having flown 5,199 kilometers (3,230 miles) with 2,536 km more to go, according to the project. 

By that time the plane and its veteran Swiss pilot Andre Borschberg had logged nearly 75 hours of continuous flight, having already bettered the previous record of 44 hours they had set between China and Japan. 

"Just doing some #yoga exercises on a #solar airplane after 74 hours of flight. That's all. Regular day at the office," organizers tweeted with a picture of Borschberg apparently upside-down in his cockpit.

The Swiss aviator is napping for only 20 minutes at a time to maintain control of the pioneering plane. He is equipped with a parachute and life raft, in case he needs to ditch in the Pacific.

In its latest update, organizers estimated that it had about 40 hours until arriving in Hawaii, if all goes well.

Earlier the plane, on the eighth leg of the global circumnavigation billed as the most difficult part of the adventure, had crossed a potentially problematic cold front, the project said.