Yoga, Hypnosis Prop Up Solar-Powered Plane Pilots

The power of yoga and self-hypnosis are being harnessed to prop up the endurance of the pilots of the solar plane which set off Monday on a first round-the-world tour.

The Solar Impulse 2 left Abu Dhabi for the first leg of its epic journey, which will test not only the environment-friendly technology but also human endurance as pilots will fly solo across oceans with minimum sleep in a non-pressurised cockpit.

Swiss pilots Bertrand Piccard, 57, and Andre Borschberg, 63, will take turns flying the plane through 12 stops on the historic 35,000-kilometre (22,000-mile) journey which aims to take them around the world in 25 days spread out over five months.

The pilots have undergone intensive training in preparation for the trip, including in yoga and self-hypnosis, allowing them to sleep for periods as short as 20 minutes but to wake up feeling refreshed, organisers said.

"You have to make the cockpit like your own house... you go to the toilet, you wash yourself with wet wipes, you eat, you drink, you recline the seat to have some rest, you turn on the auto-pilot," Piccard told reporters.

"But meanwhile you still have to control the plane, stay in touch with air traffic controllers, navigate, (and) have the Monaco centre giving you the latest update with the weather," he added.

Should a problem occur while sleeping, support staff based in Monaco can wake up the pilot.

The two pilots "will be required to demonstrate extraordinary endurance under extreme conditions, living in a... non-pressurised cockpit, unheated, with external temperatures ranging from -40 to +40 degrees Celsius (-40 to 104 Fahrenheit)," organisers said.

Another uneasy prospect has been how the pilot relieves himself during flight, since there is no bathroom and he cannot get up and walk around.

The team made a YouTube video called "Solar Impulse Behind The Scenes: Bathroom", which says the pair have found no solution but to use "bottles".

"I think the human factor is the more challenging in this trip, as the plane is sustainable energy-wise," said Borschberg, who took the first turn in flying the airplane from Abu Dhabi towards Muscat in a 12-hour trip.

"The question is how the pilot could be made sustainable," he told AFP before departing.

The longest single leg of the endeavour will see a lone pilot fly non-stop for five days and nights across the Pacific Ocean between Nanjing, in China, and Hawaii, a distance of 8,500 kilometres (5,270 miles).

"This is an attempt, and only time will tell if we can overcome the numerous weather, technical, human and administrative issues," the pair of pilots said in a statement.