Air traffic nationwide has been snarled since a fire erupted in the basement telecommunications room of an air traffic control center outside Chicago early Friday. Things won't get better anytime soon, and you can blame an air traffic control system that hasn't changed in any meaningful way since the 1950s.

The problem started with a fire that authorities said was part of a suicide plot by an FAA contractor. Beyond canceling thousands of flights over the weekend and raising troubling questions about the security of these facilities, the incident calls into question the efficacy of an air traffic system that manages 87,000 flights daily and won't fully recover for another two weeks.

First, a quick lesson on air traffic control. In the course of a flight, an aircraft is guided by a series of air traffic controllers, each handling a specific portion of the flight. Take-off is run by the airport control tower. Once a plane reaches 3,000 feet or so, it’s passed off to one of 160 terminal radar control facilities (TRACON) nationwide that monitor airspace up to about 10,000 feet. Beyond that, aircraft are managed by one of 22 air route traffic control centers (ARTCC). These centers ensure aircraft are properly spaced and following their flight plans, tracking them using a national network of more than 400 ground-based radars.

Friday's fire occurred at an air route traffic control center in the Chicago suburb of Aurora. After evacuating the facility, the FAA issued a ground stop—allowing any aircraft already en route to Chicago to complete the flight, but halting any Chicago-bound flights that had not taken off. It went through its contingency plan, transferring air traffic control to neighboring centers and establishing direct communication between all of the centers called upon to help out. By all accounts, the FAA did a top-notch job, and at no point was anyone in danger. That’s how the system is supposed to work, says retired air traffic controller Jim Swenberger: Efficiency is readily sacrificed for safety.

And make no mistake: Efficiency was sacrificed. The disruption to air traffic was serious, and immediate. The Aurora ARTCC is responsible for 91,000 square miles, an area that covers five states and hundreds of airports. On Friday, 66 percent of flights to and from O’Hare and Midway airports were canceled, according to FlightAware.com. That number dropped to 40 percent on Saturday and was still at 38 percent on Monday. All told, thousands of flights have been cancelled, creating headaches nationwide because O’Hare is a major hub and among the world’s busiest airports.

Our air traffic control system takes a lot of criticism because of its age, but it generally works—until it doesn't. And when it goes down at a major hub like Chicago, or New York, or Atlanta, it creates a cascade of problems that underscore just how fragile things truly are. Technicians are busy replacing damaged equipment at the Aurora center, but despite what FAA Director Michael Huerta calls an “extraordinarily accelerated timeline,” the center won’t be operational until October 13. Huerta has called for a review of security procedures and the FAA’s contingency plans, but the slow pace of the resolution reveals the bigger problem: This is an old system, based on old technology.

An Aging System

The ground radar network dates back to the 1950s, when air traffic finally got busy enough that officials needed a new way to track aircraft on the move. Since then, the network has greatly expanded, and the radars have been upgraded, though small air traffic facilities didn't upgrade from vacuum tube to solid state radar systems until the 2000s. But the basic technology is the same.

The FAA is quick to use this situation as an argument in favor of NextGen, its $37 billion project to modernize management of US airspace by 2030. A key component of the program is replacing ground based radars with satellite-based surveillance and navigation using automatic dependent surveillance-broadcast (ADS-B) technology. Under the new system, planes will figure out their position using satellite and periodically broadcast it to stations on the ground. The change would allow planes to broadcast and receive more information.

Programs are underway to modernize the ARTCCs, allowing them to work with aircraft well beyond their geographical purview. Combined with the ADS-B network, Huerta says, “we will have the ability to configure any single facility to view any part of our nation’s airspace.” With that capability, after the Aurora ARTCC was shut down, “we would be able to have each of the neighboring en route centers reach into Chicago’s airspace and take control of all of the radios used to control aircraft there,” Huerta says. “We would have been able to rapidly establish ground-to-ground connections between these en route centers and the TRACONS that normally connect to Chicago center.” In other words, the NextGen systems promise more flexibility to work around a problem like this one, so safety could be maintained without giving up so much efficiency.

>"Do we need to upgrade the equipment? Absolutely."

That change has been a long time coming, and it's been a troubled implementation. For the satellite-based system, the FAA has laid the necessary new ground infrastructure, but it hasn't yet updated its systems to incorporate that data. Part of the problem is that for this to work, airlines need to cooperate and spend the money to equip their planes with the technology that allows them to be tracked. The shift from radar to satellite will be as significant as the move to the radar system in the 1950s, Swenberger says.

Cost overruns and delays aren't helping: The program is now expected to cost $4.5 billion through 2035, $400 million more than originally anticipated, according to a recent report from the Office of the Inspector General. Fiscal fights in Congress haven't helped: The FAA's budget is pretty set through 2015, Huerta says, but it "remain[s] in a difficult situation when it comes to long term planning and budgeting."

If the FAA ever fully implements these changes, says former air traffic controller Paul Fagras, it would have a more secure and efficient system. “NextGen will be a great thing if they can pull it off.” But the program is hugely expensive, has been imperfectly implemented so far, and is perennially subject to budget cuts handed down by Congress. And in the meantime, “everything still works,” Fagras says. Arson aside, the system still functions as it’s meant to.

“Do we need to upgrade the equipment? Absolutely,” Swenberger says. “Striving for more technology will only enhance safety.” The move from radars to satellite-based tracking will improve flight planning efficiency in normal circumstances and make emergencies easier to handle. But the need isn’t dire just yet. If a fire hit a different en route center tomorrow, we’d be able to handle it. “There are so many different ways that we can communicate and work airports on a temporary basis to get out of a crisis and ensure safety,” says Swenberger. Air traffic controllers can always fall back to the ways things were done in the 1950s, assigning each aircraft a zone and an altitude and not letting them move into a new area until another plane had reported it had cleared out. “It’s agonizingly slow." But everyone’s safe.