The Growth of Airports

Early airfields and airports grew from the use of airplanes for military, agricultural, airmail, and aerial observation purposes. Equipped with grass or dirt runways, they were not pleasant places for the early passengers that flew once U.S. scheduled airline service began in 1926. Arriving and departing aircraft blasted dirt, pebbles, and grit into the passengers' faces as they walked exposed through all types of weather and climbed open stairways into their plane. Eventually, procedures changed so that aircraft could warm up away from the passengers, then be pushed to the boarding area by hand with the engine off, boarded, and restarted with the doors closed.

Many of these airfields originated as a result of the airmail system created in the United States just after World War I. As postal officials laid plans for a transcontinental airmail system between New York and San Francisco via Chicago in 1921, they persuaded many local communities to build the necessary facilities for the service in what became a “triumphal procession” across the country. The business communities and ordinary citizens of Cheyenne, Wyoming; Salt Lake City, Utah; and Reno Nevada, for example, all contributed thousands of dollars to build airfields, hangars, and repair, office, and storage buildings. James Clark Edgerton, an employee of the Air Mail Service, found that "each success induced others" to support the development of airfields. Only through these efforts was the linkage of the route to San Francisco complete before the end of 1920.

Airlines also built facilities in city centers. Before a flight, passengers would wait downtown at airline lounges, then take an airline bus to the field just before departure. Universal Air Lines System, an airline of the late 1920s, built a downtown Chicago terminal with wicker furniture, a fireplace, and restaurant service. Since weight was important on early aircraft because engines had only a small margin of lifting power, after lunch, passengers stepped onto scales for weighing just before boarding an airline bus to the airport. 

While magazine articles and city boosters struggled to point out the value of air travel and airports, it was Charles Lindbergh's solo flight across the Atlantic in 1927 that not only electrified the public but also encouraged the development of airports. Local officials and business leaders recognized the increased visibility and the new businesses and tourists that could result from modern airport facilities and airline traffic. As an example, before Lindbergh's flight, Los Angeles leaders debated long and hard the necessity of building an airport. After his flight, they began constructing a truly outstanding airport, Vail Field.

As aircraft grew larger, equipment was built to connect the terminal with the aircraft. Early planes had their own built-in steps at the side or rear door or could be reached by small stairways pushed up to the plane on wheels. The first movable stairways connecting passengers on the surface to the side of an aircraft were built for the Ford Trimotor and a German Junkers model. Airports introduced rollup, ground-level canopies to make the connection more pleasant in bad weather. The larger airliners had doorways more than a full story above ground, so enclosed airbridges were introduced to connect elevated terminals directly with the aircraft. 

In 1936, airlines began using new planes that made planners rethink runway length, passenger-handling capacity, and ground-support needs. The new Douglas DC-3 and its sleeper-equipped variant, the Douglas Sleeper Transport (DST) airliners, made long-distance flight less tiring and more common, adding to airport demand. With regular day and night service, the use of the DC-3 led the national airport system to increase its hours; build larger terminals; and add more support vehicles to fuel these “huge” aircraft, refill their galleys (kitchens), and even to supply new bed linens and magazines.

By the 1930s it was clear that grass runways had become inadequate as aircraft became heavier and their landing gear more rigid, requiring a smooth and predictable paved surface. Runways were oriented based on local conditions such as the prevailing wind direction and the size, height, and position of obstructions in the area. New York's new municipal airport, LaGuardia, was opened on December 2, 1939, with a paved 6,000-foot (1,820-meter) runway, the nation's longest. Still, in 1940, the U.S. Civil Aeronautics Board specified only a minimum 3,000-foot (910-meter) runway for scheduled operations of passenger transport aircraft.

After World War II, airports needed longer runways for heavier and faster aircraft, more runways and taxiways to handle more aircraft, and larger passenger terminals. But new housing right at the airports' edges built to accommodate the post-war “baby boom” often prevented airport expansion. New York City's LaGuardia Airport, for example, had to reclaim marshland to extend its runway into the bay. Berlin Tempelhof Airport, locked in by suburbs, lost air traffic steadily in favor of the new Berlin Tegel Airport built twice as far from the city in October 1974. Airports worldwide began to limit flights to city centers in favor of new airports 10 to 40 miles (16 to 64 kilometers) from the nearest large city.

Airports began expanding by digging underground. Many started using light underground rail trains or moving walkways between terminals to allow full use of the airport surface for aircraft movement. Other services, like aircraft fueling, also moved underground. Before World War II, most aircraft fuel was hand-pumped into wingtanks by linemen standing on the wings. The new hydrant-dispenser tanker pumped from underground lines through a vent in the concrete apron. Airport fuel is now kept on a “farm” some distance from the passengers and aircraft in case of accident or fire, requiring large new tracts of land for airport construction. 

The growing power of aircraft also required new types of ground support near passenger terminals. Jets do not operate safely or efficiently at low speeds under their own power, so when taxiing close to terminal buildings, they rely on a system of “tugs” that connect to the aircraft's front landing gear. Aircraft are pushed safely away from the terminal before engines are brought to higher power, or pulled into a gate area after landing.

Until the late 1940s, most passenger bags were moved by hand, but with new volume, airport ground vehicles were redesigned to connect baggage carts pulled by tractor or tug directly to the aircraft cargo area. These mechanisms consist of a conveyor belt on a platform that can be raised to connect the baggage loaders with the workers standing just inside the aircraft cargo bay.

The year 1959 was the first full year of U.S. commercial jet travel, and the first airport built specifically for the longer takeoff distances of jets was Washington Dulles outside of Washington, D.C., which opened in 1962. Its runways were about two miles (3.2 kilometers) long and 150 feet (46 meters) wide.

Powerful new engines required new airport flight patterns to prevent noise from bothering suburban homeowners. New airports were built farther still from major cities and the main consideration in building new airports became their ability to expand. Cities began building new trains and roads exclusively for airport passengers.

By 1975, the world's busiest airport was Chicago O'Hare with 666,600 aircraft movements and more than 37 million passengers per year, and an average 2,000 daily takeoffs and landings. In 1978, the Airline Deregulation Act relaxed the Federal Government's control of airline routes and fares. Many new airlines offering discount fares set up shop, and airports needed still larger terminals and more runways.

Some airport design requirements came from government regulations. For example, though jet aircraft are technically able to use shorter runways, the Federal Aviation Administration established minimum safety requirements that often result in longer runways. This is because an aircraft carrying passengers must be able to land and come to a full stop within 60 percent of its runway length. Today's longest runways can reach nearly 16,000 feet (4,877 meters). Three such runways, though somewhat shorter at 12,000 feet (3,658 meters), run parallel to each other at Denver International Airport, which opened on February 28, 1995, replacing the older Stapleton Airport.

In 1926, all of the scheduled passenger airlines in the United States together used only 28 aircraft, and if they all were in the air at the same time, only 112 passengers would be flying. Today, a typical jumbo jet carries three times that number. In 2000, the 422 primary airports in the United States boarded nearly 683 million passengers. Today's hub airports may employ tens of thousands of workers, in addition to boarding 50,000 or more passengers daily, creating vast support needs but also contributing greatly in taxes and benefits to the local economy.

The next decades are likely to see new demands on airport terminals and runway length. Airbus Industries, for example, has committed to building a double-decker airliner carrying nearly 600 people, which will require boarding from a height of at least three stories; the longest runways; and new ideas in passenger facilities, support vehicles, and apron design and construction. Boeing may present its own design.

--Roger Mola

Bibliography

Greif, Martin. The Airport Book, From Landing Field to Modern Terminal. New York: Main Street Press, Mayflower Books, 1979.

Horonjeff, Robert and McKelvey, Francis. Planning & Design of Airports. New York: McGraw-Hill Book Company, 1983.

Sullivan, George. How an Airport Really Works. New York: Dutton, Lodestar Books, 1993.

Wells, Alexander T. Airport Planning & Management. Blue Ridge Summit, Pa.: Tab Books, 1992.

Zukowsky, John, editor. Building for Air Travel - Architecture and Design for Commercial Aviation. Munich and New York: The Art Institute of Chicago, 1996.

“U.S. Airport Emplanement Activity by Rank, Order.” http://www.faa.gov/arp/pdf/vpd.pdf.

“Denver International Airport Factsheet.” http://www.flydenver.com/z401-3.html