Eero Saarinen's TWA Flight Center turns the shell structure from a purely engineering solution into an emotional, narrative architectural language. In Candela's Los Manantiales the shell was the pure logic of geometry; in Saarinen the same technology becomes the means of expressing a feeling — the thrill of flight.

The terminal's roof is made of four wing-shaped curved surfaces touching the ground at only four points, joined between by thin reinforced-concrete shells. These shells are separated by thin slits of light at their middles; light filtering from the sky makes the vast concrete masses seem to float and gives them the silhouette of a bird or aircraft about to take wing. Inside there is no sharp corner and no straight line: stairs, information desks, waiting areas, and passages are moulded in the same fluid concrete language, as if from a single dough. The passenger moves not in a flat hall but in a continuously flowing space that rises and falls.

Saarinen exploits to the full the plastic nature of reinforced concrete, cast into formwork to take any shape, and turns architecture into a symbol: the building is the formal equivalent of the act that takes place within it — flying. The TWA Flight Center is an iconic building uniting shell engineering with architectural expressionism and incising the optimism of the jet age into stone (concrete); it is a forerunner of contemporary 'experience-driven', sculptural airport architecture.