WASHINGTON — Recently a federal government report noted with alarm that "congestion of the airways" has become a menace to air travel safety. How recently? The year 1957.
It's not that the skies themselves are crowded. The three-dimensional U.S. sky volume, where a few thousand planes are present at one time, is immense compared to the two-dimensional area of U.S. highways, prowled by many millions of vehicles simultaneously.
Congestion is a problem not so much of the sky as of what we'll call the "undersky." The comparatively tiny regions that aircraft pass through at the beginning and end of their journeys--the runways, ground-servicing facilities and the "terminal control areas" (TCAs) proximate to the descent lanes into major airports--can easily become congested relative to traffic volume. So can the air-traffic control system that directs airplanes. From a safety standpoint this is significant because almost all aircraft accidents occur in the undersky, either on the ground (the worst aviation disaster ever was a 1977 collision between two 747s on a runway in the Canary Islands) or near the ground as airplanes are taking off or landing.
Congestion hit in 1957 because the Boeing 707 had just been introduced, commercial jetliner travel was about to grow rapidly and several of today's major airfields did not yet exist. It has hit again in 1987, because lower air fares brought on by deregulation have dramatically increased public demand. In 1987, U.S. airlines are expected to board nearly 460 million passengers, about twice as many as 1976; total departures of commercial airliners, the main index of strain on the system, will be about 25% higher than before deregulation.
Meanwhile the number of traffic controllers has declined relative to air activity. A variety of statistical somersaults can be performed regarding how many air controllers is the right number, but the compelling figure is this: 287 departures per controller in 1981, 411 per controller in 1986. And there hasn't been a large new airport added to the U.S. aviation system since Dallas-Fort Worth, 13 years ago.
"One of the things we misjudged was airport growth," explains Elizabeth E. Bailey who was vice-chairman of the Civil Aviation Board when deregulation took place in 1979. "We assumed that state and regional authorities would have incentives to build airports in order to bring in business, trade and tourism. We never anticipated how effectively local groups would organize to oppose airport construction." Only one major city, Denver, has plans to build a large new airport. Everybody wants cheap flights to their favorite destination; nobody wants to live near a noisy airport.
Congestion of the undersky has not made air travel more deadly--at least not yet. In fact, statistically it has become safer. During the eight years prior to deregulation, 1,455 people lost their lives in fatal accidents involving scheduled U.S. airlines. During the almost nine years since, 960 have been killed, even as the total number of flights and passengers has grown substantially. But warning signs that this trend may reverse--particularly, new incidence of what ought to be an avoidable problem, aircraft collisions-- now frighten the public and the aviation Establishment.
Amid all the recent concern about reports of near collisions, it seems to have escaped public attention that the majority of such incidents involve not two commercial jetliners but one jetliner and one private plane. Only one midair collision between jetliners occurred worldwide in the past decade, a 1979 incident involving two Aeroflot transports over the Ukraine. But of the seven major commercial crashes in U.S. airspace during the past decade, two, the San Diego crash in 1978, and Los Angeles crash last year, involved airliners hitting private aircraft. No cause was common to the other five crashes; that makes private aircraft the biggest current peril in U.S. commercial aviation.
Here are a few other statistics about private planes to chew on: While no wrecks of major U.S. airliners occurred during 1986 (the Los Angeles crash involved an Aeromexico jet), 958 people were killed in general aviation accidents. During the first six months of 1987, there have been almost 150 reports of near collisions from commercial airline pilots and about 460 reports of near collisions from private pilots. Adjusting for flight lengths and other factors, a private aircraft ride is about 40 times more likely to end in death than a commercial flight. A recent Federal Aviation Administration study of one major airport TCA found 21 unauthorized private aircraft cutting through during a two-hour period, each one a collision waiting to happen.