NOTAM outage: How one corrupt file halted all US flights
The usually bustling skies above the United States of America were engulfed in a sense of eeriness on Wednesday. Birds had the usually busy air routes all for themselves. All because of an unprecedented outage of a relatively obscure system dubbed Notice to Air Missions (NOTAM), thousands of flights were affected. Let's dig a little deep into the catastrophic system failure in the US.
Millions of flyers were affected by NOTAM failure
We have seen and heard of relics of the past becoming modern problem-creators. However, not many can boast about the commotion NOTAM created. The outage resulted in the delay of over 9,700 flights, while more than 2,800 flights were canceled, per CBS. The NOTAM outage affected millions of flyers as well. This is bound to make one wonder about the importance of NOTAM.
What is NOTAM?
To understand the importance of NOTAM, we first have to understand what it is. NOTAM's history can be traced back to 1947. What it does is alert pilots about conditions that could affect the safety of their flights. The system was known as "Notice to Airmen" until December 2021. Authorities changed the name to remove the gender reference and reflect its wide-ranging uses.
What kind of messages does NOTAM send pilots?
You must have heard about air traffic control that keeps planes at a safe distance. NOTAM is different from that. The Federal Aviation Administration (FAA) website describes NOTAM messages as "notice stating the abnormal status of a component of the National Airspace System." In other words, they are a compilation of pre-flight information such as bad weather, faulty runways, enclosed airspace, or distracting birds.
Pilots cannot take off until they receive NOTAM messages
Now that we've seen the kind of information that NOTAM disseminates to pilots, it is easy to understand why it is critical for flight safety. These messages are provided to every plane, big or small, before they take off. Legally, a pilot can't take off until they receive NOTAMs. To pack all the information, it uses specialized abbreviations that can be decoded by computers.
NOTAM failed on Tuesday
The FAA said that issues began creeping up in the system around 3 pm ET on Tuesday (1:30 am IST on Wednesday). This meant that new messages couldn't be processed. At 8:28 pm ET (6:58 am IST), the system completely failed. Later that night, FAA officials decided to shut down the system and reboot it. They decided to perform the reboot early Wednesday.
Why did FAA issue a ground stop?
The reboot of NOTAM takes 90 minutes. The FAA chose early Wednesday to perform this to minimize the disruption. The system came back up after the process, but it wasn't pushing out pertinent information as expected. This led FAA to issue a ground stop at around 7:30 am ET, Wednesday (6 pm IST). It was lifted just before 9 am ET (7:30 pm IST).
What led to the failure of NOTAM?
Since information about NOTAM's issues began coming out, people have been asking questions about what led to the failure. The possibility of a cyberattack was eliminated early on. From what we know so far, it seems that a corrupt file in the central database for all NOTAMs nationwide led to the failure. The same file was found in the backup as well.
FAA investigating how corrupted file got into database
One wonders how did a bad file enter such a critical system. The FAA is investigating whether any person or routine entry into the database is responsible for the corrupted file, which caused the NOTAM system outage.
NOTAM is in dire need of upgradation
What this episode brought to light is a glaring hole in the system. The NOTAM system is an example of an aging infrastructure in dire need of an overhaul. Washington has been delaying the tech upgrade due to budgetary constraints. Well, now we can assume that they are going to do it.
