>
The failure of a system that alerts pilots and other flight personnel to hazards and other key information led to a temporary suspension of all US domestic flights on Wednesday morning.
From approximately 7 a.m. to 9 a.m., the FAA halted all US domestic departures, a disruption that affected at least 4,000 scheduled flights, in the first nationwide ground shutdown since September 11, 2001.
The FAA outage was caused by an outage in the system that alerts pilots to hazards and changes to airport facilities and procedures that had stopped processing updated information.
‘The FAA is still working to fully restore the Notice to Air Missions (NOTAM) system following an outage. While some functions are beginning to come back online, National Airspace System operations remain limited,” the FAA said in a statement.
Travelers wait in the terminal as an Alaska Airlines plane sits at a gate at Los Angeles International Airport in Los Angeles on Wednesday during a nationwide ground stop.
Here is what is known so far about the outage, its origins, and potential impact:
What is the NOTAM system?
The takeoff interruption was due to a failure in what is known as the Notice to Air Missions (NOTAM) system.
A NOTAM is a notice that contains essential information for pilots and other flight personnel, but is not known sufficiently in advance to be published by other means.
Before beginning a flight, pilots should consult NOTAMs, which list potential adverse impacts on flights, from runway construction to the possibility of icing.
The information can be up to 200 pages long for long-haul international flights and can include items such as runway closures, general bird warnings, or low-altitude construction obstacles.
The NOTAM system is seen above, listing notices for New York’s JFK airport. Notices issued before the outage still appeared during the outage on Wednesday.
The system used to be telephone-based, with pilots calling dedicated flight service stations for information, but has now moved online.
In an advisory, the FAA said its NOTAM (Notice to Air Missions) system had “failed.”
There was no immediate estimate of when it would return, the website showed, although NOTAMs issued before the outage could still be seen.
The outage caused widespread outage and led to a nationwide ground shutdown. All aircraft must route through the system, including commercial and military flights.
European flights to the US appeared to be largely unaffected.
Why are all US flights grounded?
With the NOTAM system offline, air traffic controllers cannot risk allowing pilots to take off without potentially key information about hazards on their route.
The FAA ordered all U.S. flights to delay departures until 9 a.m. Eastern time, though the airlines previously said they were aware of the situation and had already begun landing flights.
A screen shows flights, many delayed, at New York’s LaGuardia airport on Wednesday. An FAA computer glitch halted flights in the US.
As of 8:40 a.m., there were more than 4,000 delayed flights within, to, or from the United States, according to flight-tracking website FlightAware, surpassing the number of all flights delayed the previous day.
More than 1,900 flights have been cancelled, and those numbers are likely to rise.
More than 21,000 flights were scheduled to take off in the US today, mostly domestic trips, and some 1,840 international flights were expected to fly to the US, according to aviation data firm Cirium.
Could this be a cyber attack?
The White House said there is no evidence of a cyberattack, but President Joe Biden has ordered the Department of Transportation to investigate the cause of the outage.
President Joe Biden addressed the issue of the FAA on Wednesday before leaving the White House. He said he had just been briefed by Transportation Secretary Pete Buttigieg, who told him they hadn’t yet identified what went wrong.
The planes landed at Washington’s Reagan Airport on Wednesday morning after a failure in FAA systems grounded all flights across the country.
I just spoke with Buttigieg. They don’t know what the cause is. But I was on the phone with him for about 10 minutes,” Biden said. I told him to let me know directly when they found out. Air traffic may still land safely, but not take off at this time. We don’t know what the cause is.
Buttigieg said in a tweet that he is in contact with the FAA and monitoring the situation.
Has this happened before?
The last time a nationwide ground stop was issued, halting all departures from US airports, was immediately after the terrorist attacks of September 11, 2001.
Regional or airport-specific ground stops have been issued since then, mostly for security incidents, though even those are fairly rare.
Tampa: Passengers stranded at the Tampa airport in Florida on Wednesday
For example, on January 10, 2022, the FAA issued a ground stop for the West Coast and Hawaii.
Although officials did not give any explanation for the disruption in the takeoffs, it was believed to be related to a North Korean missile test.
Experienced pilots say the NOTAM system disruption is unprecedented and cannot recall a similar incident with such a widespread impact on flights.