NATIONAL AND DULLES INTERNATIONAL AIRPORTS are expanding. The scenes are of dust, steel, and heavy machinery. But stunning things are emerging from the disarray, offering a thrilling prelude of what’s to come. If for some reason all work were to stop on the airports tomorrow, they would still be very cool to look at, marvelously incomplete as they are.

National’s new terminal is without the four acres of faceted glass walls that will serve as its skin—hence its exposed bones serve as a three-dimensional study in proportion. It’s been going up, bay by bay, for several months. The excitement for spectators has been building since the first corrugated metal domes were erected earlier this year. Now Cesar Pelli’s massive, domed pavilion stretches 1,600 feet, a procession of bays that stands two deep and 27 long. A new control tower juts up near the northern end like a giant pestle.

The sight of it all is enough to dizzy Metro riders who ascend the escalator to the platform. Huge craters lie on either side of the tracks—the Metro has never been this dramatic. The skeleton of the new terminal fills the entire foreground. It’s a forest of steel columns—an intensely vertical arrangement sliced through by the decks for the floors.

The structure’s up and down lines run together and fall apart constantly as pedestrians move before it. Pelli’s steel columns appear to hang from the domes almost like strings from a parachute, and the ensemble of silvery domes—abstractions of the Capitol—form a lyrical profile undergirded by yellow steel trusses. A long steel canopy out in front undulates a bit more softly, like a sine wave. Near the middle of the building are two tall, floorless bays that will likely serve as major entrances. For now, the tire tracks underneath the open bays give them the appearance of gates to an ancient walled city.

From the temporary terminal to the north, the view into the spine of Pelli’s building is vaguely industrial; with so much exposed steel, it seems as if the hopper cars are about to roll in with the pig iron. The light leans in, striated, through the columns.

Pelli’s new National terminal departs sharply from the original complex, a stripped-down classic built by the Works Progress Administration and opened in 1941. At Dulles, though, there is a master plan that accounts for expansion. Architect Eero Saarinen specified where every last lamp on the airport’s 10,000 acres would go, and there are few deviations. (It so happens that Pelli worked in Saarinen’s office 35 years ago, doing the working drawings for Dulles.) Today the building, one of the 20th century’s greatest works of architecture, is being enlarged by the Skidmore, Owings & Merrill and Leo A. Daly firms to twice its current size, in strict accordance with Saarinen’s original vision. There are, interestingly, no new technologies that make the structure any easier to build today than in 1959, the year when Saarinen’s secrets were put in action. It could be the ’50s all over again.

From the bone yards on either side of the Dulles terminal, new columns are beginning to thrust upward. The roof will be suspended from the columns like a giant hammock. The oblique columns resemble steel allosaurs, surfacing six or seven abreast.

Some of the columns are more defined than others; the steel assemblies of several are completely mocked up and ready for concrete. Down the row, other columns are sketchily formed by the first shoots of 2-inch rebar. There is a vague suggestion of how they will recreate the compound curves at the bases of Saarinen’s columns, which are drawn forward and up with great force. They embody all the tension of takeoff, like talons springing from the building’s podium, launching the roof into space.

The swooping curve of the roof recalls that tentative moment when the wheels of a plane leave the ground. “We felt a jet airport should be nonstatic,” Saarinen remarked in 1961, explaining that building an airport “is really placing something between earth and sky.”

Art accompanying story in the printed newspaper is not available in this archive: Darrow Montgomery.