The Crowded Skies

The color pictures and charts that begin on the opposite page tell the remarkable story of a jetliner's nonstop flight across the U.S. Oddly enough, one of the remarkable things about the flight was that it was not remarkable at all. The TWA 707 took off from Los Angeles International Airport, soared smoothly across the nation, landed at New York's John F. Kennedy Airport. No hitches, no nervous moments, no bother. And therein lies an even more remarkable story--a story that involves 14,000 highly trained and dedicated men who work with some of the most complex and sophisticated electronic apparatus ever devised.

Even before Flight 740 began taxiing toward the runway at Los Angeles, it was under the surveillance and guidance of the Federal Aviation Agency. Careful eyes watched the plane turn at the end of the runway, poise, and then reach for the sky. Flight 740 then became a bright, moving blip on a succession of FAA radarscopes as it was guided along a transcontinental airway.

Golden Triangle. The route taken by Flight 740 is only one segment of the FAA's 350,000-mile network of federal airways, freeways of the sky that are complete with aerial versions of warning signs, access roads, directional guides and even parking places--the holding areas in the vicinity of busy airports. With the help of ground controllers, pilots navigate from point to point along these invisible airways by means of electronic navigational aids that provide course, distance and location information. These "navaids" range from small location-marker beacons on the ground that light a bulb on the aircraft's instrument panel as it passes overhead, to huge, long-range radar systems that track aircraft and are linked to distant air-traffic control centers by microwave.

Like the highways below them, the nation's airways are becoming increasingly congested. At any moment during daylight hours, the FAA estimates, there are between 8,000 and 9,000 planes aloft in the U.S. airspace, as many as 4,000 of them in the "Golden Triangle," formed by lines connecting Chicago, New York and Washington. With 1,000 new planes a month being added to the nation's aircraft population, the traffic jams are becoming increasingly heavy--both in the sky and at airports. Of the 9,500 U.S. airports, only 114 can handle jets. And although the FAA estimates that the number of jet airports will increase to 346 by 1970 and to more than 500 by 1975, their added capacity will not fully relieve the growing pressure or end the flight delays at such busy fields as Chicago's O'Hare, Los Angeles' International and New York's John F. Kennedy airports.

Over the next decade, the agency estimates, landings and takeoffs at airports controlled by FAA towers will triple--from more than 41 million in 1966 to 139 million. During the same interval, the annual number of flights by instrument rules will grow from 5.2 million to 12.4 million. The number of U.S. commercial airliners will increase from 2,124 to 3,500. Airline business will soar from 114 million passengers and 76 billion passenger-miles in 1966 to 352 million passengers and 266 billion passenger-miles in 1977. The general aviation fleet of business and pleasure craft will increase from 95,442 to 180,000.

"Aviation is growing so explosively that we are not even now properly prepared to predict its full measure," says FAA Administrator William ("Bozo") McKee. "This is no exercise in abstract thought. There is an immediacy to the need. The jumbos [Boeing's 490-passenger 747 jets] are coming in 1969, and the supersonic transports will follow. Not only the airways, but the airports must be ready."

Evasive Action. Although today's FAA airways are the most extensive and best-controlled in the world, they are far from foolproof--even with their current traffic load. On two occasions in 1965, for example, airline pilots, confused by optical illusions, took violent evasive maneuvers to avoid airliners that were actually separated from them by 1,000 feet of altitude prescribed by FAA controllers. Such unnecessary evasive maneuvers were cited as the probable cause of the collision over New York's Westchester County between an Eastern Airlines Constellation and a TWA 707 jet. Although both planes were damaged, the 707 limped safely to JFK, and the Constellation managed to crash-land, killing four. In the other accident, the pilot of an Eastern DC-7B approaching JFK maneuvered so violently in order to avoid a Pan American jet that was actually 1,000 feet above him that he lost control and crashed into the Atlantic Ocean, killing all 84 aboard. All four planes were under FAA surveillance, but the pilots chose to believe their eyes, rather than their instruments.

Other problems are posed by the FAA's lack of control over the flights of many of the nation's private aircraft. All commercial airlines and some of the larger and speedier private planes use the airways, operating under instrument flight rules (IFR) even in clear weather to take advantage of the separation and protection afforded by FAA controllers. But many small planes fly by visual flight rules (VFR), permissible when visibility is greater than three miles. Pilots flying VFR are responsible only for seeing and avoiding other aircraft, and are not even prohibited from entering busy FAA control zones.

Earlier this month, a TWA DC-9 on a proper IFR approach to the Dayton airport collided with a twin-engine Beechcraft being flown under VFR on a bright, cloudless day. All 25 aboard the jet and the pilot of the private plane died. A few days later, an American Airlines jet flying IFR toward Newark Airport narrowly missed a small plane flying VFR in the same area.

Potential aerial collisions were uppermost in the minds of a group of air-traffic controllers who last week publicly charged that aviation in the U.S. is reaching a "point of public peril." Speaking for the National Association of Government Employees, which represents some 3,000 of the 14,000 air-traffic controllers employed by the Federal Aviation Agency, ex-Controller Stanley Lyman charged that economies in the FAA had resulted in "seriously underequipped, undermanned, undercompensated and underadministered" traffic-control towers and centers. "We are fortunate that we don't have the collisions now," said Lyman.

In the Boston-Washington air corridor alone, he said, there were between five and nine reported "incidents" per week--situations in which the separation between two aircraft was less than the FAA minimum. If all incidents were logged, Lyman said, there would be from 20 to 25 per week; many go unreported because controllers do not want to take time off from their work or get themselves or flight crews in trouble.

Need for Expansion. Calling the union's charges "exaggerated," the FAA pointed out that there were no mid-air collisions of airliners in 1966 and that most of the 25 mid-air collisions involving private aircraft occurred near small fields that were not under the agency's control. The number of reported near misses declined from 565 in 1965 to 463 in 1966, despite a 19% increase in flight operations. But the growing numbers and speeds of aircraft clearly call for more sophisticated devices to ensure safety in the skies.

Many aviation experts believe that an essential device for preventing high-speed collisions is a collision avoidance system (CAS) that warns the pilot early enough for him to take corrective measures. FAA authorities are hopeful that a CAS device acceptable for airline use may evolve from a system devised by the McDonnell Co. (see cover story) called EROS (for Eliminate Range Zero System). It has already been successfully used by McDonnell in high-altitude testing areas near St. Louis. When an EROS-equipped aircraft is on a collision course with another plane, a beeping sound is produced in the pilot's earphones. Glancing at his instrument panel, the pilot sees a lighted arrow pointed either up or down, in the direction that EROS calculates he should take to avoid a collision. EROS provides a 60-second advance warning at closing speeds as high as 3,000 m.p.h., adequate for even supersonic transports.

Category II Landings. Equally important for effective air-traffic control is the ability of aircraft to land at their destination in any kind of weather. "If aviation is to reach its full potential," says FAA Deputy Administrator David Thomas, "we shall need to have in daily operation a true, dependable, all-weather landing system. One socked-in airport, even today, disrupts an entire area. Think of the problems that would arise from a zero ceiling and visibility at JFK in the era of 500-passenger planes and SSTs."

Using automatic systems, several U.S. airlines have already been cleared for "Category II" landings at some airports. These permit properly equipped planes to be guided electronically and automatically toward a landing when the ceiling is as low as 100 ft. and visibility is as little as 1,200 ft. At an altitude of 100 ft., the pilot takes over and completes the landing if he can see the lights and markings--or he uses full throttle to climb away if he cannot see them. The FAA is also considering such aids to blind-landing systems as Bendix Microvision, which uses microwave radio signals beamed to the plane by ground transmitters from the sides of the landing strips. The signals form an image of the runway on a display in front of the pilot, enabling him to find it in zero visibility.

In computer-controlled blind landings, the U.S. is somewhat behind British aviation, which has already made 15,000 fully automatic test landings with six different kinds of planes. British pilots keep their hands entirely off the controls as the plane descends, while electronic devices operate the control surfaces and throttle all the way to touchdown. British aviation authorities may certify the VC-10 and other aircraft for fully automatic landings in zero-visibility conditions on regular passenger flights as early as 1969. But U.S. landing systems are also being perfected. Last month a Pan Am jet made a fully automatic landing at New York using a system developed jointly by Boeing and the Sperry Phoenix Co.

Back to the Shrimp Boats. Even while it evaluates these and other advanced air-traffic devices, the FAA has begun to install advanced radar traffic-control systems. Computerized alphanumeric systems are already in operation in air-traffic control centers in Atlanta, Jacksonville and New York, electronically printing the flight number, course and altitude next to the appropriate airliner blip on the radarscope. Eventually, FAA hopes to blanket U.S. airspace with alphanumeric coverage, providing a three-dimensional radar picture of all air traffic equipped with the necessary transponders.

Although the system was designed to take some of the pressure off harried FAA controllers, they themselves have found that alpha numerics poses a few problems of its own. To feed information about a flight into the radarscope and attach that information to the appropriate blip, for example, the controller must turn away from the screen to punch buttons on a computer input box, leaving his flights unattended for several vital seconds. In addition, as the alphanumeric data blocks move with their appropriate blips across the screen, they occasionally merge with data blocks from other flights, making both sets of data illegible. During heavy traffic, when the screen is crowded with blips and data, controllers switch off the alphanumeric system and go back to the traditional system of manually moving "shrimp boats"--plastic identification markers--across the screen with their appropriate blips.

Sheer necessity will no doubt soon mother the invention of improved alphanumeric systems. Necessity will also spur the development of fully automatic landing techniques, of collision warning systems, of more effective ways to control aircraft flying under visual flight rules. In the meantime, the bulk of the burden must be borne by the 14,000 controllers in towers and control centers. By intensive training and concentration, these highly trained men have learned to control as many as 21 radar blips--each representing an airplane--at a time. They have learned to steel themselves against confusion and panic, no matter how extreme the emergency. They have developed an intense but quiet pride in their talents, their responsibility and their record.

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