If you have taken a relatively recent flight inside the U.S., chances are pretty strong it was either on board a Boeing 737 or an Airbus A320, the two best-selling commercial airplanes in the world.

The Airbus A380 made its first commercial flight in 2007. When it debuted, it overtook the long-reigning Boeing 747 as the world's biggest passenger plane. It has four engines and is a full ...