EXPLAINER: How NOTAM caused widespread flight disruptions

By TOM KRISHER and DAVID KOENIG
Associated Press

DALLAS (AP) — Until Wednesday, few travelers had heard of a Notice to Air Missions, or NOTAM. Nor did they know that the system used to generate those notices could cause widespread travel misery. But they found out fast. The Federal Aviation Administration computer system that compiles and distributes essential safety information for pilots went kaput, leading to flights being temporarily grounded nationwide and touching off a cascading air traffic jam. About 1,200 flight were canceled and more than 7,800 delayed by early afternoon on the East Coast, according to FlightAware. NOTAM has been around for more than a half century and it has evolved from paper to computers. It’s in the process of being updated. But it failed in the meantime, along with its backup system.