Nano is mainly used in aviation to make airplanes much lighter and stronger, by creating new materials which can replace the heavier parts that are used more commonly.
While this may sound inconsequential, it is really important to the airline industry. If a composite made out of nanoparticles can be just as strong as a metal alloy but save 10- 15% in weight, the fuel savings can be enormous.
Nanotechnologies may not only lighten the aircraft to produce fuel savings, but also do so by adding nanoparticles of aluminum to the fuel of a conventional jet, significantly increasing its fuel mileage