A Swiss-made solar powered aircraft has landed in western India, completing the second leg - and its first sea crossing - of its historic round-the-world trip.

The Solar Impulse 2 touched down at Ahmadabad airport in Gujarat state about 16 hours after it took off from Muscat, Oman, for the 1,465-kilometre flight without a drop of fuel.

The world's first aircraft powered by solar energy was to remain in Ahmadabad for two days before flying to the holy city of Varanasi in northern India on Saturday.

The Swiss pilots, Bertrand Piccard and Andre Boschberg, will take turns at the controls of the aircraft during their 35,000-kilometre journey.

The aircraft's wings are covered by more than 17,000 solar cells that recharge the plane's batteries. It flies ideally at around 25 knots, or 45 kph.

Yesterday, Borschberg, who co-founded the Solar Impulse company that built the plane, flew the Si2 from Abu Dhabi, the capital of United Arab Emirates, to nearby Oman in the first leg of the epic journey.

The Swiss explorers say their aim is to highlight the importance of renewable energy and the spirit of innovation. They say the visionary journey is a "strong message for clean technologies".

Si2 is slated to make 12 stops during its 35,000-kilometre journey, including in China and Myanmar, before it crosses over the Pacific Ocean. It will then land in Hawaii and the US Midwest and East Coast before flying over the Atlantic Ocean. It may also stop in southern Europe or North Africa, depending on weather conditions.

Some legs of the trip, such as over the Pacific and Atlantic oceans, will mean five days and five nights of flying solo. Both pilots have been training hard for this journey, which will span 25 flight days over five months.

The Si2 aircraft has a wingspan of 72 metres, spanning larger than a Boeing 747 jumbo jet. At around 2,300 kilos, the Si2 weighs about as much as a minivan or mid-sized truck. An empty Boeing 747, in comparison, weighs some 180,000 kilos.