Computers entered the cockpit and began taking a role in every aspect of flight. So-called fly-by-wire control systems, for example, replaced weighty and complicated hydraulic and mechanical connections and actuators with electric motors and wire-borne electrical signals. The smaller, lighter electrical components made it easier to build redundant systems, a significant safety feature. Other innovations also aimed at improving safety. Special collision avoidance warning systems onboard aircraft reduce the risk of midair collisions, and Doppler weather radar on the ground warns of deadly downdrafts known as wind shear, protecting planes at the most vulnerable moments of takeoff and landing.
Another area of flying advanced alongside commercial and military aviation in the last few decades of the century. General aviation, the thousands of private planes and business aircraft flown by more than 650,000 pilots in the United States alone, actually grew to dwarf commercial flight. Of the 19,000 airports registered in the United States, fewer than 500 serve commercial craft. In 1999 general aviation pilots flew 31 million hours compared with 2.7 million for their commercial colleagues. Among the noteworthy developments in this sphere was Bill Lear's Model 23 Learjet, introduced in 1963. It brought the speed and comfort of regular passenger aircraft to business executives, flew them to more airports, and could readily adapt to their schedules instead of the other way around. General aviation is also the stomping ground of innovators such as Burt Rutan, who took full advantage of developments in composite materials (see High Performance Materials) to design the sleek Voyager, so lightweight and aerodynamic that it became the first aircraft to fly nonstop around the world without refueling.
In today's world, air travel may have lost some of the original glamour that once prompted passengers to dress their best for any flight. But the miracle of flying through the air is still there to be seen, perhaps best in the eyes of a child looking down for the first time on a field of clouds. The dream of flight, a dream turned into reality by the precise work of engineers, continues to enchant.