Anatomy of an Airliner
Our maxim: The airlines giveth, and the airlines taketh away.
- Air & Space magazine, September 2009
Inventions large and small have combined over the years to create the modern experience of air travel. And you don’t have to be a frequent flier to know that today’s airliner is still a work in progress: What you see today may not be there tomorrow.
Debuting on Pan American Airways’ trans-Pacific flying boats in the 1930s, flight engineers were charged with coaxing maximum range from the fuel supply. In the mid-1950s, as airliner systems grew more complex, the Airline Pilots Association mandated three-man crews. In the early 1970s, computers in cockpits replaced flight engineers, who currently fly only on 1970s-era airliners, like the Lockheed L-1011.
The world’s first jet airliner, the British-built de Havilland Comet, was a streamlined beauty with large, square cabin windows. But after two fatal accidents in early 1954, investigators found that repeated cycles of cabin pressurization fatigued the Comet’s thin, aluminum alloy skin where it met the window corners. Oval or rounded-corner windows help prevent metal fatigue by better distributing the stresses of pressurization.
In the 1920s, passengers flying Transcontinental Air Transport placed their hats and other small, lightweight items in open overhead racks — located above the rear seats only — made of aluminum and netting. With the 1969 arrival of the Boeing 747, closeable overhead storage bins became standard equipment on airliners, and passengers have been overstuffing them ever since.
Duralumin, an alloy made up largely of aluminum, a handful of copper, and just a dash of magnesium and manganese, was developed in 1903 by German metallurgist Alfred Wilm. Its first use was in airship frames, but by the early 1930s, its lightness and strength led to widespread use in aircraft. If the mostly composite Boeing 787 is as successful as its builders hope, duralumin will likely be eclipsed by even lighter and stronger carbon composites.
Almost as soon as the turbojet emerged in the 1940s, engineers began looking for ways to hush the engine and increase its efficiency. The solution, which first appeared in engines on the Douglas DC-8, was a large fan, driven by the turbine, that heaved masses of cold air rearward, bypassing the combustion chamber and mixing with its hot exhaust.
Airplanes with ’em can fly farther than airplanes without ’em. They have the effect of increasing the wing’s span, and therefore its lift, without increasing its length. The first airliner to use them was the 747-400 in 1988, and you’ll see them on almost all Boeing airliners (Airbus uses wing fences for the same benefits).
For seven other inventions that have made air travel what it is today, see the photo gallery at right. - the editors.