Mandalay, March 19  The Solar Impulse 2 (Si2), a solar-powered aircraft on a mission to fly around the globe without a drop of fuel, has landed here on Thursday, completing the fourth leg of its historic flight, according to media reports.

The aircraft, piloted by the Swiss project chairman Bertrand Piccard, had taken off from the Indian city of Varanasi early on Thursday, and reached Myanmar after crossing the Bay of Bengal and a tall mountain range, covering a distance of about 1,400 km, according to a BBC report.

Capable of flying over oceans for several days and nights in a row, the single-seater Si2, which started its journey from Abu Dhabi in the United Arab Emirates (UAE) on March 9, will travel 35,000 km around the world in 25 days.

It will likely be another five months before the aircraft returns to the UAE, after it crosses both the Pacific and Atlantic oceans.

Piccard takes turns with project CEO Andre Borschberg to guide the Si2 on its circumnavigation of the globe.

So far, the pair has covered about 4,500 km since the start of their adventure.

The Si2 project has already set plenty of world records, including the greatest distance covered in a single solar-powered flight.

This was the 1,468 km achieved on the second leg of the flight from Muscat in Oman to Ahmedabad in India.

The wingspan of the aircraft is 72 metres, which exceeds that of a 747 jumbo jet airliner. It, however, weighs only 2.3 tonnes, which is equivalent to that of a small car.

The light weight of the Si2 will be critical to its success over the coming months.

So too would the performance of the 17,000 solar cells that line the top of the aircraft’s wings, and the energy-dense lithium-ion batteries that it would use to sustain night-time flying, the report said.

The Pacific and Atlantic crossings will require the Si2 to fly non-stop for several days at a time.

This will put tremendous stress on the pilots, Borschberg and Piccard, who will be permitted only short naps on these long legs of flight.

The Si2 venture is reminiscent of other great circumnavigation feats in the history of aviation, albeit fuelled ones.

In 1986, the Voyager aircraft became the first to fly around the world without stopping or refuelling. The propeller-driven vehicle took nine days to complete its journey.

Then, in 2005, the time set by Voyager was beaten by the Virgin Atlantic GlobalFlyer, a jet-powered plane, which completed its non-stop circumnavigation in just under three days.