Solar Impulse 2 has landed in Abu Dhabi, completing the final leg of its journey and finishing the world’s first ever round the world flight in a solar powered plane.
The 26,000 mile, 17 stage journey, which began in Abu Dhabi back in March 2015, was designed to demonstrate the viability of solar power and renewable energy generally. It was described to the Guardian by Bertrand Piccard, one of the pilots, as “not just a first in the history of aviation, but also a first in the history of energy.”
The plane itself has a wingspan just wider than that of a Boeing 747 but weighs just 2.3 tonnes, about as much as an average car. It’s top speed is also more in line with a small motor vehicle than a traditional passenger plane, at just 87mph, although in practise it was kept at an average speed close to 30mph during its round the world journey.
No fossil fuels whatsoever are used to power the plane. Instead, it is equipped with around 17,000 solar panels on its wings, which charge up the plane’s engine during the day. Because of this, the only real barrier to more or less perpetual flight is the limitations placed on the pilot flying it, who must spend the entire time in a small cockpit about the size of the drivers compartment in an F1 car.
Two pilots flew alternate legs on the journey – Piccard and André Borschberg, both of whom said that conditions in the plane’s cockpit made for most of the difficulties throughout the trip.
The pilots had to remain seated in the cramped compartment throughout each leg, occasionally taking short, 20 minute naps, and going to the toilet without moving using the specially designed seat.
All in all, 19 world records were broken by the journey, including the record for the longest ever uninterrupted flight made by any kind of plane. This leg, the 4,000 mile journey from Japan to Hawaii, was piloted by Borschberg.
Piccard flew the final leg, from Cairo to Abu Dhabi, which he described as particularly tough because of persistent turbulence caused by the hot desert winds which, he said, prevented him from sleeping at all during the night.
“It is so turbulent, there were moments in the last night that I could not rest at all,” he said, “I just had to fight with my flight controls.”
The rest of the journey was not without its hiccups; as well as some legs being delayed due to weather problems, the leg leaving from Hawaii had to be pushed back by 10 months due to problems with the plane’s battery, described by Piccard as “a human mistake”.
The idea for the journey was born in 2002, when Piccard first conceived it. Borschberg was brought on board in 2003. Both pilots are seasoned adventurers, with Piccard also holding the record for the first ever non-stop round the world trip in a hot air balloon, competed in 1999.
Despite experience in adventuring though, Piccard had no experience flying a plane when he first came up with the idea – indeed the six years he had to spend learning how to fly represented one of the biggest challenges for him.
As the journey was completed, UN secretary general Ban Ki Moon praised the pilots and the ground team, saying: “Solar Impulse has flown more than 40,000 kilometers without fuel, but with an inexhaustible supply of energy and inspiration. This is a historic day for Captain Piccard and the Solar Impulse team, but it is also a historic day for humanity.
“You may be ending your around the world flight today, but the journey to a more sustainable world is just beginning. The Solar Impulse team is helping to pilot us to that future.”
