EVERETT, Wash. -- Where Amelia Earhart found adventure in the 1930s, big business saw opportunities for profit and started to focus on how to move more people more efficiently through the air.
A breakthrough in commercial aviation came in the late 1930s, when Douglas Aircraft's DC-3, with a cruising speed of 190 mph and a range of 800 miles, showed for the first time that an airplane could carry passengers and make money.
America's involvement in World War II began and ended with the airplane. In December 1941, Japanese warplanes attacking Pearl Harbor shook the United States out of its isolationism. Four years later, a Boeing B-29 SuperFortress called the Enola Gay dropped an atomic bomb on Hiroshima. In between, the United States produced nearly 300,000 military aircraft, including the first practical helicopters.
After the war, jet and rocket engines took aircraft faster, farther and higher. Test pilot Chuck Yeager became the first man to travel faster than sound, hitting nearly 700 mph in a rocket-powered Bell X-1 during a flight in October 1947. Jet fighters proved themselves in combat during the Korean War. The Boeing 707, introduced in 1958, established jet airliners as a dominant force in passenger aviation.
In the 1960s, the X-15 rocket-propelled plane flew higher and faster than any other airplane in tests done by the Air Force and NASA. It hit 4,520 mph and soared high enough to earn its pilots astronaut's wings.
By then, however, the greatest glory in the skies was going to the space program. As the rocket race to the moon captured the public's attention, advances in air-breathing aircraft down below started to focus on less flashy but no less significant achievements -- making flight cleaner, cheaper and safer.
The Boeing 747, the world's largest commercial jetliner, is a prime example. It can carry more than 400 passengers and fly them 8,300 miles without refueling. More than 1,230 of the jumbo jets have been made since 1969, and they have carried 2.2 billion passengers.
"The 747 made intercontinental travel possible for the masses," says Boeing spokesman Gary Lesser.
Thirty years later, the enormous plane still impresses. The Boeing Co. assembles the jetliners in Everett, 30 miles north of Seattle, in a factory that the company claims is the world's largest building -- 98 acres under one roof. Painted on the concrete floor are roadways, regulated by stop signs and traveled by electric buggies, trucks and three-wheeled bicycles.
One recent day, Mr. Lesser was driving a visitor around the factory. He referred his guest to a fact sheet explaining that a 747 has six million parts, 171 miles of wiring and five miles of tubing. It contains 147,000 pounds of aluminum and has a tail that reaches 63 feet high, the equivalent of a six-story building.
The jetliner's normal operating weight is ... well, Mr. Lesser hesitated on that statistic.
"I don't know exactly," he confessed. "But whatever it is, it's big. When it comes to the 747, I like the word big. It's all big, big, big."
For Boeing or any airplane maker, today's digitized blueprints, computer simulations and fastidious engineering have eliminated the old seat-of-the-pants drama of early aircraft designs.
Yet there is still room for amazement. You can see it in the eyes of a child who presses her nose to the glass at the airport, watching jetliners dash down the runway and tilt skyward -- the impossible made routine.
You can hear it from old hands such as Bill Sweetman, an aerospace writer who tracks the latest developments in secret aircraft.
What's the latest in aeronautical technology? Only a few privileged people know, Mr. Sweetman says. Many observers, including Mr. Sweetman, believe a supersonic aircraft known as Aurora is being tested at the U.S. government's top-secret Area 51 in Nevada.
Whether or not this cutting-edge aircraft is streaking across the cloudless desert sky -- and the government isn't saying anything -- it doesn't take "black budget" secrets to impress. Mr. Sweetman advises simply looking skyward, wherever you happen to be.
"I think what would most amaze somebody from 1903, if they were around today, would be that there are so many airplanes," he says, referring to the pioneering Wright brothers. "They're as routine as trains were in the 19th century. They're flying everywhere."