Expressways in the Sky

The seat-belt sign has flashed on, and the engines begin to whine as the big California-bound jet prepares to lumber out for takeoff at New York's John F. Kennedy Airport. Suddenly the pilot announces that there will be a half-hour delay. Reason: traffic is backed up on the runways. Later, flying over the Rockies, the passengers have more reason to gripe. The plane is being tossed by turbulence, but the pilot cannot avoid it because ground controllers have refused to let him change course in the jammed air corridors. Finally, as San Francisco Bay comes into view, there is another exasperating delay; the jet is ordered into a holding pattern, and has to circle for 25 minutes before being permitted to land.

Although this particular cross-country trip is fictional, the inconveniences experienced by the passengers and crew are all too real. In an age when man can rendezvous and dock spacecraft high above the earth, travel to the moon with pinpoint accuracy and send payloads to much more distant targets in the solar system, the control of air traffic closer to home is still crude and imprecise in comparison. As a result, runways are overcrowded on the ground, air lanes are jammed aloft. Particularly near airports, spacing between aircraft is often so hard to control that near-misses are dangerously familiar. Is there any solution in sight for the growing air-traffic snarl?

Great Leap. Many aviation men are convinced that there is. For the past few years, they have fought vigorously--and lately with increasing success--for a new system of flight control that may answer many, if not all the problems: area navigation or R-Nav (short for random navigation). In the opinion of many aviation experts, widespread use of R-Nav would be the greatest leap forward in aerial navigation since the early 1950s, when the U.S. first set up its present air corridors by crisscrossing the country with radio beacons or VORs (for very-high-frequency omnidirectional range).

R-Nav's new equipment will be added not on the ground but in the plane. Built around small onboard computers and other complex electronic gear, it will give the pilot instant access to information that until now has been relayed from the ground or has required time-consuming computations in the cockpit. R-Nav will provide continuous bearings pointing toward any predetermined destination; it will supply the plane's exact position throughout the trip and immediate corrections whenever the plane veers off course. If the pilot should make a mistake in punching out his route on the keyboard of R-Nav's computer, "error" or "confirm" will be flashed by a cathode-ray tube on his instrument panel. The equipment, in fact, is so versatile that its proponents promise an extraordinary list of payoffs, ranging from increased air safety to greater traffic capacity at existing airports to the reduction of noisy descents over crowded residential areas.

The beauty of the system is its inherent simplicity. No longer will pilots have to zigzag their way along radio beams from one VOR station to another until they finally reach their destination. Instead, the R-Nav computer will enable them to use the signals from existing stations to set up their own straight-line "phantom" path with waystations that will guide them directly from one airport to another. (Ground controllers will still have to approve the route and monitor the flight to avoid conflict with other planes.) Furthermore, R-Nav will relieve bottlenecks near airports. Aircraft will be able to approach the landing runway from a number of different directions; under existing controls, they must all be funneled into the same approach track. Indeed, area navigation should be so efficient that Eastern Airlines Board Chairman Floyd Hall likens its introduction to converting "an old-fashioned horse-and-bug-gy country road into the equivalent of a superhighway with an almost unlimited number of express lanes."

Those express lanes should be extremely useful, especially along heavily traveled short-haul routes --between New York and Washington, say, where a combination of delays on the ground and in the air often slows jet travel to a train's pace. In addition, since the plane will be constantly guided by its own instruments, R-Nav will relieve already overburdened airtraffic controllers who are now kept busy constantly giving pilots new navigation directions. Equally important, R-Nav will permit planes to make bad-weather landings at airports that do not have approach radar or instrument landing systems; it will also speed up traffic at airports that now have the most modern controls. "It's unbelievable that Chicago's O'Hare Airport goes to about one-half capacity when IFR [instrument-flight-rules] weather moves in," says Dr. Charles Fenwick, an engineering executive at Collins Radio, a leading manufacturer of R-Nav equipment. "And that's in a world that can land men on the moon."

Advanced Systems. Though still a relatively new development, R-Nav gear already is available in varying degrees of complexity and cost. For small craft, there is relatively inexpensive (about $2,000) gear, like Narco's Freeflight courseline computer, that makes continuous calculations of distance and direction to the next waystation. On a higher level, there are systems like Omnitrac, made by Britain's Decca Navigator Co. and tested successfully on Eastern's Washington-New York-Boston shuttle. It not only gives the pilot the required altitude for his flight path but also displays his plane's position on a moving map or TV-type cathode-ray tube throughout the trip. Finally, there are more sophisticated systems like the Arma-Decca Mona system (for modular navigation) and Collins' ANS-70, which can store and read out voluminous information, including navigational data on an airline's entire route structure. These advanced systems are also adaptable to such future navigation aids as satellite systems and the Navy's low-frequency, long-range Omega network.

Last week TIME Correspondent Jerry Hannifin, a licensed pilot, flew aboard a Grumman turboprop executive transport equipped with the Collins ANS-70 on a 350-mile test flight into Chicago. On arrival at O'Hare International Airport, Hannifin was astonished to find that the plane, guided all the way by its automatic pilot, which in turn was controlled by R-Nav, was right on course as it turned into its final approach. He is not the only one who is impressed. McDonnell Douglas has ordered the system for its new trijet DC-10, and the Russians offer it for their Yak-40, a three-engine, workhorse jet that they are ambitiously marketing in the West.

With all its advantages, area navigation has clearly earned its place in the airliner's cockpit. It has strong support from FAA Administrator John Schaffer, who has set aside 16 high-altitude corridors for R-Nav flights, despite the opposition of some FAA controllers who feel that it would rob them of authority and perhaps eventually their jobs. Commercial pilots, almost to a man, are fully convinced that R-Nav has the potential of making air travel faster, safer and more dependable than ever before.

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