Most of the thousands of airplanes that fly around the world each day use their main engines to move around on the ground when they are landed at airports. That's kind of like using your car to go pay a visit to your neighbor who lives across the street.
We've written about the Solar Impulse solar plane a few times. It's not only a great feat of engineering, but it's also a project that follows in the footsteps of a long tradition of pioneers and explorers who attempted things that nobody else had done be
Airplanes waste a lot of fuel on the ground. To taxi around airports, from passenger gates to runways, planes are powered by their main engines which simply aren't optimized for that task. This creates a lot of unnecessary CO2 emissions, air pollution, an