The table speaks for itself, but we might add that it was based on approximately 100 million flights. Mid-air collisions come as close as anything in aviation to a problem But the danger is not extinct, because air traffic control is not a static entity. In Western Europe, there is strong pressure to replace the numerous national air-traffie systems with a centralized system. In the United States, the present arrangements--under in favor of free flight which would allow planes to travel straight-line routes from d which planes are confined to a network of prescribed flight paths--are slated to be revi origins to destinations. Free flight would ideally lead to shorter flight times and lesser fuel consumption, saving billions of dollars annually Such changes present real safety challenges. Merging dozens of different air traffic control systems which, while similar, are nonetheless not identical in their procedures, is unlikely to be a straightforward process. And the vastly altered flight patterns under free flight could reduce "situational awareness" among air traffic controllers. The moving dots representing planes on controllers screens-which today line up like points on a grid--could in the future more closely resemble gas molecules in random scatter. Barring extremely reliable computer aids, it might be harder for controllers to identify menacing situations before they become critical And, beyond specifics, it is conceivable that any major changes in air traffic control pose dangers. One of the fundamental notions of industrial sociology is the learning curve, " under which new procedures beget errors and difficulties that had not been anticipated. Table 4 shows that innovations in air traffic control cannot diminish the likelihood of midair collisions, for there is literally nothing to reduce. If any change arises in the risk of such collisions, it must necessarily be for the worse On the other hand We have just examined three hazards to First-World aviation that caused almost no deaths in the 1990 s For two of them--sabotage and midair collisions--there is plausible reason to fear that risks could increase in the years ahead. For the third- runway collisions-there is reason to expect that risks should increase in the years ahea Furthermore, recent safety achievements in the first-World have not been matched elsewhere, and there could be sources of future peril that we do not yet recognize Before August 2000, who imagined that a tire blowout alone could cause the destruction of a Concorde SsT?)Against this backdrop, aviation-safety can hardly be viewed as obsolete source of worry 88 The table speaks for itself, but we might add that it was based on approximately 100 million flights. Mid-air collisions come as close as anything in aviation to a problem that is fully resolved. But the danger is not extinct, because air traffic control is not a static entity. In Western Europe, there is strong pressure to replace the numerous national air-traffic systems with a centralized system. In the United States, the present arrangements--under which planes are confined to a network of prescribed flight paths--are slated to be revised in favor of “free flight,” which would allow planes to travel straight-line routes from origins to destinations. Free flight would ideally lead to shorter flight times and lesser fuel consumption, saving billions of dollars annually. Such changes present real safety challenges. Merging dozens of different air traffic control systems which, while similar, are nonetheless not identical in their procedures, is unlikely to be a straightforward process. And the vastly altered flight patterns under free flight could reduce “situational awareness” among air traffic controllers. The moving dots representing planes on controllers’ screens—which today line up like points on a grid—could in the future more closely resemble gas molecules in random scatter. Barring extremely reliable computer aids, it might be harder for controllers to identify menacing situations before they become critical. And, beyond specifics, it is conceivable that any major changes in air traffic control pose dangers. One of the fundamental notions of industrial sociology is the “learning curve,” under which new procedures beget errors and difficulties that had not been anticipated. Table 4 shows that innovations in air traffic control cannot diminish the likelihood of midair collisions, for there is literally nothing to reduce. If any change arises in the risk of such collisions, it must necessarily be for the worse. On the Other Hand… We have just examined three hazards to First-World aviation that caused almost no deaths in the 1990’s. For two of them—sabotage and midair collisions—there is plausible reason to fear that risks could increase in the years ahead. For the third— runway collisions-there is reason to expect that risks should increase in the years ahead. Furthermore, recent safety achievements in the First-World have not been matched elsewhere, and there could be sources of future peril that we do not yet recognize. (Before August 2000, who imagined that a tire blowout alone could cause the destruction of a Concorde SST?) Against this backdrop, aviation-safety can hardly be viewed as an obsolete source of worry