"Fifteen years ago nobody could afford to fly constantly. Today people can fly," said Ingrid Joerg, a senior vice president for Cleveland-based Aleris, which rolls out aluminum skins for major aircraft manufacturers. "The global mobility that has happened to a large extent has been because prices have dropped for passengers."The company recently opened a plant in China to serve the growing Asian market and is constantly adjusting its alloys for lighter weight, but few passengers â¿¿ or even pilots â¿¿ are going to pick up on the subtleties between one aluminum hull and another. A few more might notice the potential in a new way for airplanes to taxi to and from their gate, developed by engineering conglomerate Honeywell and aerospace and defense company Safran. Currently, jet engines are used â¿¿ making taxiing noisy and fuel-guzzling, and preventing airplanes from backing up. That's why they are often towed. The Electric Green Taxiing System instead uses the plane's auxiliary engine, which provides a plane with electricity while the main engines are off, to power the wheels. Taxiing is quieter and more fuel efficient and makes the plane much more maneuverable. For passengers, it means no more waiting for a tow. Some of the technologies developed to put fighter jets at the vanguard are now coming to private jets and may eventually make their way onto commercial flights. Flying in a Gulfstream is about as far from the commercial travel experience as possible. Windows are bigger. Beds, couch and wireless network come standard, as does the ability to use a single mobile app to control the lights, shades, temperature and televisions. The latest model from the Savannah, Ga., company flies at Mach .9 â¿¿ just shy of the speed of sound â¿¿ and is the fastest civilian plane approved for travel, according to Steve Cass, the company's vice president for communications.