Just as the Nation is recovering from the SouthWest Airlines meltdown, the U. S. aviation system experience a full “ground stop” on Wednesday. Unlike the previous debacle which only affected Southwest, this meltdown covered all airlines and general aviation flights. If you missed my analysis of the Southwest Airlines meltdown, you can read it here.
The Ground Stop
A ground stop is the full stop ordered for all aircraft to cease operations both airline and general aviation. The exceptions to a ground stop are:
- Air ambulance service and
- Military flights.
This order was in effect from coast to coast for a ninety-minute period of time but it took hours and some cases the next day for the airlines to get their aircraft and flight crews in the positions that they are needed.
The most significant ground stop in U. S. history was immediately after the terrorist attack on September 11, 2001. In this emergency declaration, no aircraft took off and aircraft in flight were ordered to land at the nearest suitable airport. This ground stop was so chaotic, that it took about a week to get all of the aircraft and flight crews to their proper positions.
What Triggered The Ground Stop
The Federal Aviation Administration (FAA) is the government agency that is responsible for aviation safety. The FAA Command Center maintains computer systems whose information is critical to air traffic control and assists flight crews in creating their flight plans. Airline crews must create a flight plan and upload that plan to the FAA. It was a computer system in the Command Center that was the fault that forced the FAA to declare a ground stop.
The system that failed was the computer which pilots obtain NOTAM information from. Flight crews need to determine if their flight will be impacted by conditions that they must be aware of.
NOTAM stands for Notice To Air Missions. It was previously known as Notice To Airmen. These advisories detail specific issues either a an airport or in the air. Some of the common NOTAMs are:
- Runway and taxiway closures,
- Airport obstructions such as a construction crane within the airport perimeter,
- Navigation aids that are offline and
- Airspace restrictions.
One of the most important notifications is the Temporary Flight Restriction (TFR). Temporary flight restrictions are classified into four types:
- VIP and
- Space operations.
For the upcoming Superbowl football game, there will be a security TFR. When pilots check the NOTAM system for flights during the SuperBowl, they will be informed of the active hours and airspace closure for the Superbowl TFR.
Pilots should anticipate a Temporary Flight Restriction (TFR) in the Phoenix area on Sunday, February 12, 2023. Typical TFRs limit the availability of certain operations, including glider operations, flight training, and unmanned aerial system (UAS) operations. Specific procedures described on this website and/or contained in an associated Notices To Air Missions (NOTAMs) may be revised or unavailable at the time of the event, and access to some airports may be restricted. Pilots are encouraged to check NOTAMs frequently to confirm they have the most current information.
TFR information is published by FDC NOTAMs, normally 3 to 5 days prior to the event. TFR NOTAMs and graphics are available at the FAA TFR website.
The President of the United States will have a VIP TFR around Air Force One. When the president leaves his aircraft, a moving VIP TFR will follow his motorcade to its destination.
As you can see, pilots have to review any applicable NOTAMs at the originating airport, en route airspace and arrival airport. Failing to obtain and follow a NOTAM could result in a serious violation.
The Cause Of The Problem
The good news is that the computer failure was not the result of hackers or a cyber attack. The NOTAM system began failing Tuesday afternoon. In the early morning hours of Wednesday, technicians rebooted the computer that handles NOTAMs. The reboot of the system failed to correct the problem and the ground stop was ordered beginning at 7:30 am EST.
The cause of the problem was determined to be a corrupt file in the NOTAM system. As it turns out, the backup NOTAM database also had the same corrupted file. A technician that was uploading a revised NOTAM database to the Command Center computer failed to follow instructions. The resulting data upload failed which also corrupted the backup copy. The fix required repairing the corrupted data set and rebooting the computer.
In addition to human error, the FAA Command Center runs older, legacy hardware and software. This system is scheduled to be updated in 2026. I suspect that the schedule may be changed to update this critical computer system sooner.
As you can imagine, this debacle had a major impact on the aviation sector. There will be an investigation into the cause and to identify mitigation efforts to prevent an incident like this from happening.
President Joe Biden called for a “full investigation”, the White House press secretary said on Wednesday.
Transportation Secretary Pete Buttigieg ordered an after-action review and also said there was “no direct evidence or indication” that the issue was a cyberattack.
The source said the NOTAM system is an example of aging infrastructure due for an overhaul. “Because of budgetary concerns and flexibility of budget, this tech refresh has been pushed off,” the source said. “I assume now they’re going to actually find money to do it.”
Hear Airline Pilots Being Told Of The Ground Stop
The video below has actual radio traffic between airliners waiting to take off and the control tower. Note that the times mentioned in these ATC communications are in 24-hour format in Zulu (Z) time. Zulu time is currently Greenwich Mean Time (London, UK). 13:30 Z is 8:30 am EST.
As inconvenient as this was for the flying public, the Federal Aviation Administration made the correct decision to ensure safety. The good news is that the computer failure was not the result of a hacker or cyber attack. It does show the vulnerability of sophisticated systems being impacted by human error.
You can bet that this situation will be thoroughly investigated and prevention measures will be put in place. Hopefully, this incident will speed up the hardware and software that the aviation sector depends on.