A fire at an Aurora FAA facility caused all sorts of airport problems in Chicago and across the country:

The FAA said it’s working “closely with the airlines that serve the Chicago-area airports to minimize disruptions for travelers” and expects to “continue to increase the traffic flow at those two airports over the weekend.” FAA officials did not respond Saturday to requests for more information.At least 778 flights had been canceled Saturday out of both airports by just before 3 p.m., according to Flightstats, a website that monitors air traffic.

O’Hare was able to operate at around 60 percent of its usual Saturday capacity, said Doug Church, a spokesman for the National Air Traffic Controllers Association.

Because of the fire at the Aurora facility, O’Hare’s control tower can’t receive or send to other control centers the airlines’ automated flight plans, so airlines are having to fax them to O’Hare. That’s requiring two controllers to staff every position at the main O’Hare tower, and had to close the auxiliary north tower at the airport, Church said.

While this is certainly an unusual accident, it illustrates the fragility of some of our key infrastructure: the behind-the-scenes equipment and people that keep airplanes flying and airports operating. As many have noted, flying has become quite hum-drum in the United States in recent decades and this is partly due to the general efficiency of this system. No one likes delays or lost luggage or maintenance problems but it is still pretty remarkable the number of flights in the air on a daily basis and the relative ease of traveling across long distances.

What we need are some redundancies in these key systems in case something does go wrong. As the article notes, the whole system isn’t shut down because flight plans can be sent by fax. But, there isn’t a quicker way – like digital photos or digital scans – to do this? Can’t this be done with one person? But, building redundant systems might often cost significant money upfront, a luxury many systems don’t have. At the least, this incident in Aurora should lead to some rethinking of what can be done better in the future if a key facility breaks down.