The solution to the antiquated air traffic control system? Make pilots their own air traffic controllers!
Suppose that sometime this year two US airliners find themselves on a collision course. An air traffic controller relying on rapidly deteriorating 1960s-vintage equipment must distinguish the two planes from others on his radar screen and make a mental calculation about the likelihood of a crash. Though his radar display is two-dimensional, the controller must envision the planes' flight paths in three dimensions, then project the paths through time. He must take into account that, say, one plane is turning sharply and rapidly descending, while the other is slowly climbing. Alarmed, he'll quickly get on his radio to instruct one of the pilots to change course. Only if his message isn't garbled or drowned out or misunderstood will an accident be averted.
Now imagine the same scenario 15 years from now. Both planes carry satellite-based navigational equipment that identifies their positions with a precision far outstripping radar's. Instead of passing information by voice, pilots rely on digital communications gear that automatically transmits a constant flow of data about the planes' location, direction, and speed to controllers and other nearby aircraft. Surveillance and data processing equipment on the ground and aboard the aircraft projects the planes' flight paths over time, instantaneously making the same calculations that the 1996 controller struggled to do in his head. Long before the two aircraft seriously threaten each other, cockpit displays in both planes warn the pilots of the potential conflict and recommend course changes.
Welcome to "free flight," the aviation community's term for changes that constitute the most significant development in air traffic management since the invention of radar 60 years ago. Under free flight, many tasks now carried out by air traffic controllers will be automated, and some of the authority that controllers possess will be shifted to pilots. Not surprisingly, the engine driving free flight is digital technology, which has laid bare the obsolescence of the current air traffic control system.
"It's as though our telephone systems were still operating with manual switchboards, with telephone operators who were pulling the plugs out of one outlet and putting them in another," says James Coyne, president of the National Air Transportation Association, which represents airport businesses such as food vendors and repair services. "All of the information that flows to and from a pilot today in virtually all aircraft is done on a strictly single-voice channel, back and forth, with human beings actually saying all the words live. As anyone can imagine, that is an extremely inefficient way to convey data."
Free flight mirrors the shift from centralized mainframe technology to distributed, networked systems that's occurring in many realms. And, as in those arenas, the shift faces considerable obstacles, most notably cost. The Federal Aviation Administration, which oversees the US air traffic control system, has embraced the concept but may have a hard time persuading Congress to allocate the many billions of dollars that free flight will probably cost. Thanks to past debacles in developing air traffic management technology, the FAA's credibility is notoriously low, to the point that proposals for privatizing the agency are filtering through Congress.
Nevertheless, most discussion of free flight has a tone of inevitability, chiefly because it makes so much sense. Though free flight restores to pilots some of the same freedom to choose routes, altitudes, and speeds that aviators enjoyed before the advent of air traffic control in the mid 1930s, what drives it is not some romantic notion of airborne adventure, but economics. Pilots no longer required to follow rigid routes presumably would fly more direct paths to their destinations, saving fuel and increasing airline productivity. It's not surprising that free flight's strongest advocates are the nation's major air carriers, which maintain that free flight would enable the industry to recoup a significant portion of the US$3.5 billion it claims to lose each year because of limitations in the current air traffic control system. Since the industry only recently returned to minimal profitability after losing as much as $12.8 billion between 1990 and 1994, it's possible that free flight could make the difference for some carriers between lucrative and losing years.
Airlines aren't the only potential beneficiaries. Paul Fiduccia, president of the Small Aircraft Manufacturers Association, thinks that free flight soon could help make flying a small plane almost as simple as driving a car. The result, Fiduccia believes, is that general aviation for personal and business use could enjoy an upsurge in popularity after 15 years of stagnation. "What we're trying to do is feed the fruits of the digital revolution into airplanes," Fiduccia says. "If we do, you'll be able to fly a plane after a couple months of training. You'll have the same operational simplicity that you have in a car with cruise control. You get the plane in the air, you sit there, and you talk with your passengers for a few hours until you get to where you're going."
The FAA sees free flight's projected efficiencies as a way of coping with growth in passenger traffic, which the agency projects - perhaps overoptimistically - at 7 percent a year over the next decade. Free flight might reduce congestion at the nation's most crowded airports by enabling planes to land with less spacing between them. The National Air Transportation Association's Coyne thinks free flight could even eliminate the need for air traffic controllers, saving the federal government up to $5 billion a year. While other officials are far less sanguine about the safety of a system shorn of all controllers, some believe free flight would make likely a downsizing from the current workforce of 17,000 controllers. Nevertheless, even that prospect has not led the controllers union, the National Air Traffic Controllers Association, to oppose free flight. Instead, union leaders have expressed tempered enthusiasm.
One charge notably absent is that free flight is unsafe. On the contrary, experts in government and industry are confident that free flight will enhance aviation safety, not jeopardize it. Considering that the current US air traffic control system is regarded as the safest in the world, that's a substantial claim, but one with considerable justification. For starters, free flight will enable planes to spread out over much of US airspace instead of sticking to prescribed routes, thereby reducing the likelihood of conflicts. In addition, the vastly greater precision of digitally based instruments will almost certainly increase safety. Air carriers already have installed an array of digital gear in their planes, and airline cockpits often have data about weather and surrounding aircraft that are more precise and comprehensive than the information controllers must rely on. Unfortunately, pilots can't use their sophisticated equipment to much advantage because the air traffic control system doesn't acknowledge its existence.
Virtually all the technology required for free flight is already in limited use or in development. The crucial navigation equipment is the US Department of Defense's satellite-based Global Positioning System, which provides accurate readings to within 76 meters of a plane's location, far outstripping the two- to four-mile standard that radar now provides. The FAA plans GPS enhancements that initially will bring accuracy down to 7 meters and ultimately to within a meter. A second vital component is data-link technology, which would transmit information to and from controllers and other planes almost instantaneously. One benefit is that it would eliminate the current communications delay - sometimes as long as 20 minutes - that occurs when planes flying oceanic routes cannot communicate directly with controllers. Finally, sophisticated surveillance and data-processing equipment installed on board and on the ground would survey the skies, project each plane's route, and notify pilots and controllers of potential conflicts. Though this equipment will cost several hundred thousand dollars per airliner, the airlines are enthusiastic enough about free flight to accept the expense.
The recognized "father of free flight," a United Airlines systems manager named William Cotton, described key components of free flight back in 1971, but it wasn't until two decades later, after the new technologies were developed, that his ideas took off. Though United's top executives initially were too preoccupied with other issues to pay attention, a May 1994 report co-authored by one` of Cotton's former deputies reached Representative Collin Peterson (D-Minnesota), chair of the House subcommittee with investigative jurisdiction over the FAA. Peterson, a recreational pilot who already used GPS technology in his own plane, was intrigued enough to hold hearings on free flight in August 1994. The hearings, in turn, forced the agency to take notice. After calling upon a committee of representatives from all segments of the aviation community to develop guiding principles for free flight, the FAA's administrator, David Hinson, embraced the concept during April 1995 and organized a task force to draw up detailed plans to implement it.
The task force's report, issued last October, calls for the introduction of free flight in three phases spread over a minimum of five years. In the first phase, extending through 1997, air traffic controllers would yield some of their authority and enter into a more collaborative relationship with airlines and pilots. Rule changes that do not require extensive investments in new technology would be instituted. For example, when a busy airport such as Chicago's O'Hare experiences a storm, controllers typically decide the order in which all of an airline's planes land. Chicago may be the final destination of most passengers in one plane, while half the passengers in another plane may be hoping to make connecting flights. Controllers, however, aren't aware of such passenger configurations, and, in any event, they're trained to sequence landings on a first-come, first-served basis. They may allow the plane filled with passengers bound for Chicago to land while the other plane circles overhead. Under free flight, controllers would simply inform each airline how many landing slots it could use during the storm, and the airline would decide the order in which its planes land. That change alone would save passengers thousands of wasted hours and airlines many millions of dollars.
Under the second phase, projected from1998 to 2000, airliners no longer would be limited to the rigid flight paths now prescribed by the FAA. Instead, they could choose the routes that best fit their needs. A cargo plane might choose a route that maximizes speed or fuel efficiency, even if that means flying through a storm. A passenger plane flying between the same two airports might choose to ensure passenger comfort by avoiding the storm at a sacrifice in speed. While controllers would continue to have responsibility for keeping aircraft from colliding, they would be instructed to approve all proposed routes as long as the planes maintain "separation" - the aviation term for collision avoidance. To do this, controllers would need digital "conflict probe" technology that tracks planes' projected courses and warns of potential conflicts.
It's in the third phase, optimistically projected to begin in 2000 and end perhaps a decade later, that free flight's full potential could be realized. Pilots no longer would need to ask controllers for permission to make route changes, and they'd even take on some responsibility for separation. Each plane would be considered to be surrounded by two hockey-puck shaped volumes of space, one inside the other. When conflict probe technology detects an intruder entering a plane's larger volume, known as the "alert zone," the two pilots and the ground controller would be warned to consider evasive action, while the smaller volume, called the "protected zone," would be considered inviolate. The size of a plane's zones would depend on the accuracy of its technology and its performance capacity: the more advanced the plane, the smaller the zones.
Though it's too early to predict the size of the zones, they almost certainly would be much smaller than the five miles of horizontal separation that the FAA now mandates for planes in midflight. Planes would be free to fly at speeds and altitudes that maximize their performance, instead of being hung up behind slower planes on prescribed air routes. Today controllers often begin shunting aircraft into line for landing at busy airports when the planes are as far as 600 miles from their destination, but digital sequencing tools would enable planes to fly at higher, more fuel-efficient altitudes until as close as 90 miles before landing.
The current system requires wide separation standards because controllers need large margins of error when making four-dimensional calculations in their heads. Airliners usually are required to stay on rigid flight paths because it's easier for controllers to keep track of them. Computers, however, can project the paths with relative ease. They can allow separation standards to be based not on controllers' mental capacities but on each plane's performance capability.
Most objections to free flight focus on cost. While many owners of small planes are enthusiastic about what they'd gain through free flight, such as access to many more airports in bad weather, they are worried about the expense of the equipment they'd need to install. Estimates are frustratingly vague, ranging from several thousand dollars upward. To allay such fears, the FAA has endorsed the principle that free flight should not penalize airplanes that don't carry the new technology. This pledge complicates an already labyrinthine transition to free flight, requiring that elements of the current system remain in place long after the new one is fully functional. One result is that the transition is likely to take 10 or 15 years, not the currently projected five.
An even bigger obstacle maybe the FAA itself, which is notorious for procurement fiascos. Air traffic controllers still use 1960s-generation computers because state-of-the-art replacements that were supposed to be installed starting in 1993 were never built, even though the agency spent billions of dollars on them. Many controllers still stare at radar screens in dimly lit rooms evocative of an earlier era, flipping toggle switches that date as far back as 1943. Now the FAA plans a more modest upgrade, but it will not be in place until late 1996 at the earliest, and it will not be compatible with free-flight technology.
All this, combined with the federal government's current budget constraints, means that Congress's willingness to allocate billions of dollars for free flight is uncertain at best. J. Roger Fleming, senior vice president of operations and safety at the Air Transport Association, which represents major US air carriers, worries that if Congress sticks to its 1995 budget resolution, "free flight, in my judgment, is highly improbable."
Still another formidable barrier is the US military, which would have to upgrade its fleet of 10,000 aircraft to accommodate free flight. To make even the slightest change in those planes, says Frank Colson, executive director of the Defense Department's Policy Board on Federal Aviation, would cost $1 billion; installing the sophisticated technology that free flight entails would cost many billions and take at least 10 years. Asked whether this expense poses a substantial obstacle to free flight, Colson only says, "I hope not," and professes to pin his hopes on a long transition.
It is an intriguing role reversal. After all, one justification given for airline deregulation back in 1978 was that it would spawn innovation in an industry long accustomed to applying technological advances developed by the military. Now the airlines have proposed a major innovation of their own, and the military's response is: Maybe we can't afford it.
