Travel: New Directions

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The idea first occurred to Navy Pilot James R. Conrey in 1960, while he was jockeying his plane through a tricky crosswind landing at Lincoln, Neb. The field—like many military and small private airports—had only one runway, leaving him little choice in the direction of his approach and landing. As he struggled with the controls, Conrey longed for a landing strip that would always allow him to approach into the wind—no matter what its direction. Why not a circular runway? he asked himself. With great single-mindedness, he polished his idea, found an ideal test site—the banked, circular General Motors test track at Mesa, Ariz.—and persuaded the Navy to get G.M.'s permission for landing and takeoff tests.

In 1963, before his concept was tried, Conrey was killed in an aircraft-carrier landing accident. But now he has won post-mortem recognition. In a report on tests made at Mesa in 1964, the Navy has predicted "a definite and vital place in future aviation" for the circular runway.

Inside a Bowl. Because it would slope upward in a graduated bank from its inner edge to its raised outer edge—much like the inside of a shallow bowl —the circular runway would provide great directional stability to a plane landing at high speed. It would prevent the plane from veering out of control to the right or left. Pulled outward by centrifugal force and downward by gravity, a fast-rolling plane would be confined to a circular path high against the outer, steeply sloping part of the runway. As its speed decreased, centrifugal force would lessen, and gravity would pull it in a slowly descending spiral toward the lower, more horizontal section.

There would be other considerable advantages. Planes would never run out of landing room, as they often do at conventional airports; they could simply continue to circle until they slowed sufficiently to use a banked turn-off ramp that would lead them to a centrally located terminal, conveniently spotted for passengers or freight. A circular runway would also be able to handle more traffic than straight runways. With a diameter of 10,500 ft.—about the length of most jet runways—it would have a circumference of more than 32,000 ft., allowing the simultaneous takeoff or landing of several planes spaced at safe distances around the circle, and directed by an elaborate ground-control system.

Into a Hole. Little additional pilot training would be required. Navy pilots who landed at G.M.'s Mesa track felt at first that they were "flying down into a hole"; they were uneasy about touching down at an angle on the sloping surface on the runway. But they became oriented after only one or two landings, and reported that the runway tended to correct some of their errors in landing speed, degree of bank and point of touchdown.