The airline industry prepares for chaos. But that doesn’t make responding to it any less complicated.

Carriers were working frantically on Friday to reroute flights after a power outage at Heathrow Airport in London, a global hub, left tens of thousands of passengers stranded. But the aviation system is deeply interconnected, and responding to such severe disruptions is a delicate balancing act. For airlines, moving even a small number of flights can have cascading effects.

“They’re thinking not just in terms of a single day, but recovery,” said Dr. Michael McCormick, a professor of air traffic management at Embry‑Riddle Aeronautical University, who managed the federal airspace over New York during the Sept. 11 terrorist attacks. “They have to look at where passengers with bags, aircraft and aircrews need to be tomorrow, the next day, and the next day.”

When crises occur, airlines’ network operation centers jump into overdrive. They are the nerve centers of the business — typically large, quiet, secure rooms with power backups and protections against severe weather and disasters.

At large airlines, the operations centers are staffed around the clock with teams that monitor the weather, manage planes and flights, communicate with air traffic control, schedule crews and much more.

Small disruptions can be handled surgically — a sick pilot can be replaced with an alternate on call nearby or a broken plane swapped out for another. But bigger disruptions like the one at Heathrow can require scrapping and reworking intricate plans while taking into account a wide range of limitations.

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