How NOTAM caused widespread flight disruptions

Dallas: Until Wednesday, few travelers had ever 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.

As they arrived at airports in the morning, they quickly found out.

The Federal Aviation Administration computer system that compiles and distributes essential safety information for pilots went kaput. That temporarily grounded all flights nationwide and touched off a cascading air traffic jam that will take at least a day to unclog. More than 1,300 flights were canceled and 9,000 delayed by early evening on the East Coast because of the outage, according to flight-tracking website FlightAware.

What are NOTAMs? 

They are compilations of essential preflight information for pilots, airline dispatchers and others that include details about things such as potential bad weather on the route, runway and taxiway changes at airports and closed airspace that must be avoided. The notices began in 1947 and were modeled after a system used to warn ship captains of hazards on the seas.

A pilot can’t legally take off until he or she has reviewed the information. Airline dispatch centers relay it to pilots. In this case, the services couldn’t get the information because the FAA system malfunctioned, he said.

What Went Wrong? 

The FAA said preliminary indications “traced the outage to a damaged database file.” The agency said it would take steps to avoid another similar disruption.

The system stopped working at 8:28 p.m. Eastern time on Tuesday, but because there weren’t many departures at that hour, pilots were able to get the information verbally. At daybreak in the East, the system was still out, and there were too many flights leaving to brief pilots individually.

Image courtesy of (Image: ToI)

Share this post