Early Friday morning, a faulty software update from security firm CrowdStrike knocked out Windows computers around the world. For the aviation industry, the service disruption created the kind of chaos usually reserved for sudden, catastrophic weather events — except all over the world, and at the same time.
The service disruption highlighted an assumed but sometimes hidden fact about the aviation industry: The systems that enable entry and exit from airports are complex and optimized for efficiency and profit. For passengers, the advantage of this system is that ticket prices are lower, but the downside is that if one part of the system fails, the industry can grind to a halt.
That happened in real time on Friday. In the United States, the three major airlines (Delta, American and United) suspended their flights for several hours. A handful of airports around the world, including Hong Kong International AirportBengaluru’s Kempegowda International Airport in India and Liverpool’s John Lennon Airport resorted to checking passengers into flights by hand and urged passengers to show up well before takeoff time. By Friday afternoon, more than 4,000 flights had been canceled and 35,500 delayed worldwide. according flight tracking company FlightAware.
“Today, a CrowdStrike update caused multiple computer systems to go down globally,” a Microsoft spokesperson said in a statement. “We are actively supporting customers to assist with their recovery.”
Delta, American, and United may have experienced more cancellations than other airlines (including easyJet, Allegiant Air, and Southwest) because of their “hub-and-spoke” model. This strategy concentrates flights and crews at a few major airports (the hubs) and increases the likelihood that passengers traveling outside the hubs will have to connect through them. This centralization allows airlines to offer passengers more flight options, even if only through connections, and to concentrate their maintenance and ground support services in fewer locations, saving them money.
“Because the hub-and-spoke system is so dependent on how quickly flights leave hub airports, airlines have come to rely on a variety of automated systems to check in passengers, inform them of boardings or delays, get baggage handlers to the right place at the right time, and so on,” said Michael McCormick, a professor and coordinator of the Air Traffic Management program at Embry-Riddle Aeronautical University. “Automation is critical to airline operations,” he says.
But automation requires computers. When those computers fail at a given airport, the effects can multiply and delays pile up. But when they fail at operations centers, the entire aviation system is constrained. This happens even if the technologies used to fly and direct the planes while they are in the air are not affected. For example: The U.S. Federal Aviation Administration wrote Friday morning that it was “not affected by the global IT issue.”
The complexity of the airline industry also goes far beyond computers. Airports are sometimes compared to small towns, and rightly so: While airlines are the “brands” that passengers interact with most often, many different companies help get planes off the ground. And it turns out that some of them rely on CrowdStrike.
