Out in the Swiss countryside last week the Solar Impulse made its virgin voyage, where it cruised for 87 minutes at an altitude of 1,200 metres, demonstrating conclusive proof that an airplane can fly without any emissions. This solar-powered airplane is designed to fly day and night without fuel or emissions as it relies solely on the energy absorbed from 12,000 solar cells, built into its wings of the aircraft. The energy absorbed is saved in high-performance batteries and is used to power the four electric engines the plane runs on. Key to the design of this zero-emission aircraft is its weight – the body is made from carbon fibre meaning in total it weighs just 1,600 kilograms- that’s about the same as a mid-sized car!

The objective of this particular mission was to verify that the plane’s flight behaviour is in line with the calculations and simulations done using the flight simulator. Given that such a large and light plane had never been flown before, the behavior of the plane under real flying conditions remained unexplored, yet the test showed extremely positive results. The test pilot, Markus Scherdel, reported a stable and controllable ride from the outset and project leaders confirmed that all objectives had been reached. The Solar Impulse project, initiated by Bertrand Piccard in 2004, had been designed as a prototype for an aircraft intended to fly around the world without fuel in 2012. Of course this plane is not the passenger-carrying type, yet the model has proved very useful for testing new technologies that could potentially be used for driving some aircraft systems in the future.

Last week was also witness to two successful test flights coordinated by AIRE (the Atlantic, Interoperability Initiative to Reduce Emissions). The door to door flights were undertaken by Air France and American Airlines on the Paris – Miami route, and represented the first ever transatlantic flights whose objective was focused entirely around the reduction of greenhouse gas emission and noise pollution. The flights involved the cooperation of the air traffic control centres of France (DSNA), the UK (NATS), Portugal (Nav-Portugal) and the USA (FAA) along the route. Procedures adopted by Air France included shorter taxiing times at both airports, continuous climb, optimum altitude and speed during the cruise phase, and a continuous descent approach on arrival into Miami. The American Airlines’ flight included single-engine taxiing, continuous climb-out and descent, optimized routing over water and a tailored arrival. The results announced showed CO2 emissions reductions of 6-9 metric tons and fuel savings of 2-3 metric tons!