Solar-powered plane completes first leg of global record attempt

March 09, 2015 // By Paul Buckley
Swiss solar-powered plane Solar Impulse-2 (Si2) has completed the first leg of the aircraft's attempt to be the first plane to fly around the world without a drop of fuel.

The flight, which will take months to complete, took off this morning from Abu Dhabi, heading east to Muscat in Oman where the solar-powered aircraft touched down after a 13-hour flight.  On the first leg the plane rose to a maximum altitude of 5791 meters.

Solar Impulse founder André Borschberg was at the controls of the single-seat aircraft when it took to the air at the Al Bateen Executive Airport in Abu Dhabi, United Arab Emirates. Borschberg will swap piloting duties with Solar Impulse co-founder Bertrand Piccard during layovers on the 35,000-kilometer journey.

As the solar-powered aircraft passes over the Pacific and Atlantic oceans the pilots will require to fly solo for as many as five days and five nights. The journey will span 25 flight days over five months before the plane returns to Abu Dhabi in late July or August.

The Solar Impulse 2 aircraft has a wingspan of 72 meters which is larger than that of the Boeing 747. As many as 17,248 ultra-efficient solar cells have been built into the aircraft's wing design and they will transfer solar energy to four electrical motors that power the plane's propellers. The solar cells will be used to recharge four 21 kWh lithium polymer batteries which provided 7.5 kW (10 HP) each.  

The Si2 weighs 2,300 kilograms compared to an empty Boeing 747 that weighs some 180,000 kilograms.  Top speed for the carbon-fiber-based Si2 is about 45 kph.