April 2010: launch of a new campaign
After 7 years of development and a fly hop at the end of 2009, the season starts for the prototype HB-SIA of Solar Impulse. The first flight on the 7th of April is a success: the test pilot Markus Scherdel flew during one hour, reaching 1000 meters height and landing with better results than expected. The season keeps on with several flights to test different plane parameters: maneuverability, speed, controllability… Each flight allows understanding better and adjusting this nonstandard plane.
Spring flights are marked by André Borschberg first flight on May 24th: a new pilot for Solar Impulse. After years of training, the project co-founder can finally pilot the HB-SIA.
July, 8th 2010: first night flight
At seven in the morning, the Solar Impulse heads to the sunrise hopping to stay as long as possible in the air without moving far away from the Payerne air basis.
During the first part of the flight, the aim is to gain altitude and to gradually charge batteries. Around 6:00 p.m., the aircraft reaches its maximum altitude of 28 000 feet (8 500 meters) and its batteries are fully charged by the 11 628 solar cells on its wings.
Sunset coming, the Solar Impulse begins the second part of the flight by using its potential energy, meaning without direct energy from the sun or energy from the batteries, but by sliding during a long way down such as a glider.
The third part of the flight starts around midnight: André Borschberg reaches 4 500 feet altitude (1 370 meters) and begins using electric energy from the batteries by 10% per hour. At sunrise, enough energy remains in the batteries to start a new day/night cycle. The principle of “perpetual flight” now confirmed, the plane lands after 26 hours of flight for its pilot, after having been through 10 hours with -20°c, could take back strengths.
“This is just a start!” he said, exhausted but enthusiast. This extraordinary day marks a new step ahead to world flight without fossil energy.
September, 21st and 22nd 2010: Swiss flights
To perfectly end this season, Solar Impulse team gives to Swiss spectators a series of national flights. The aim is to make long straight lines above Switzerland and to land on international airports which requires stopping the traffic during almost one hour.
During the first day, the plane lands in Geneva International Airport to parade among commercial planes. On the way back to Payerne, the HB-SIA flies above Leman Lake and Lausanne. During the second day, the aircraft flies above Switzerland until Zurich where many spectators came to admire it.