GENEVA: An experimental solar-powered aeroplane took off from Switzerland on its first transcontinental flight on Thursday, aiming to reach North Africa next week.

Pilot Andre Borschberg planned to take the jumbo jet-size Solar Impulse plane on its first leg to Madrid, Spain, by Friday. His colleague Bertrand Piccard will take the helm of the aircraft for the second stretch of its 2,500-kilometer journey to the Moroccan capital Rabat.

Fog on the runaway at its home base in Payerne, Switzerland, delayed the take off by two hours, demonstrating how susceptible the prototype single-seater aircraft is to adverse weather.

''We can't fly into clouds because it was not designed for that,” Borschberg said as he piloted the lumbering plane with its 63-meter wingspan toward the eastern French city of Lyon at a cruising speed of just 70 kilometers an hour.

Before landing in Madrid in the early hours of Friday, Borschberg will face other challenges, including having to overfly the Pyrenees mountains that separate France and Spain.

Just in case things go disastrously wrong, Borschberg has a parachute inside his tiny cabin that he hopes never to use. “When you take an umbrella it never rains,” he joked in a satellite call with AP.

Piccard — the son of undersea explorer Jacques Piccard and grandson of balloonist Auguste Piccard — will have to cross the windy Straits of Gibraltar from Europe to Africa.

The team has been invited to Morocco by the country's King Mohammed VI to showcase the cutting edge of solar technology.

Morocco is about to start construction on a massive solar energy plant at Ouarzazate. The plant will form part of a country-wide solar energy grid with a capacity of 2000 megawatts by 2020.

The mission is described as the final dress rehearsal for a round-the-world flight with a new and improved aircraft in 2014. That trip will include stops in the United States, said Borschberg.

In 2010, the Swiss flew non-stop for 26-hour to demonstrate that the 12,000 solar cells attached to the aircraft can soak up enough sunlight to keep the plane airborne through the night. A year later, he took Solar Impulse on its first international flight to Belgium and France.

The project began in 2003 and is estimated to cost about $100 million over 10 years.—AP