GPS interference caused the FAA to reroute Texas air traffic. Experts stumped

A runway at the Dallas-Fort Worth International Airport has been closed over the past few days due to interference with the gps signal.

On Monday, the FAA issued an advisory over ATIS. It warned flight personnel and air traffic controllers of the possibility of interference with their navigation systems. There is an advisory that says "attn all aircraft."

A dramatic impact

The Air Traffic Control System Command Center issued an advisory around the same time that said the region was experiencing "GPS anomalies that are dramatically impacting" flights in and out of Dallas-Fort Worth. Some of the airports were using navigation systems that were pre-GPS, according to the report.

The map was published by Gpsjam.org, a website that monitors gps interference in real time.

The operator of gpsjam.org said that the interference began at 1 pm and continued for several hours. A time-lapse video shows what he was talking about.

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GPS interference around DFW seems to have started around 1900Z - 2000Z/12 PM - 1 PM local time. The ATCSCC advisory was signed t 2151Z/2:51 PM local time if I did my math right. The interference is still going. pic.twitter.com/fjVcZS8iEF

— John Wiseman (@lemonodor) October 18, 2022

The interference continued and aircraft on the ground in the affected region were not able to get reliable gps readings. Military operations, the most common source of interference, weren't playing a role. The unexplained problems not only continued but had spread to other areas.

High resolution map of GPS interference around Dallas Fort Worth/DFW with sectional chart, including data from 2022-10-18 0000Z through 1600Z. It can be tricky to interpret a higher res map because you might start to see effects of individual aircraft, flight routes and altitudes pic.twitter.com/iSVE7nNlu5

— John Wiseman (@lemonodor) October 18, 2022

As mysteriously as it began, it stops

The interference ended around 11pm Dallas time. It had stopped as soon as it began. Wiseman wrote in an online interview.

This GPS interference stood out because it was significant, covered a relatively large area, and didn't look like the typical interference I see in the United States which is almost always clearly associated with military testing or training in a military operating area. My understanding is that lack of GPS isn't an emergency for aircraft, but it can definitely be annoying and lead to delays and even canceled flights. I don't know what caused this interference or whether it was intentional, but it almost certainly came from a piece of electronic equipment and not a natural phenomenon. GPS is kind of a weird piece of the world's infrastructure in that it's so important, but also very easy to break through intentional or accidental jamming. I hope it continues to stay usable!

The L band is used by civilian radio sources, including 5G mobile devices, as well as low power satellite signals. This next-generation technology can cause interference to the gps device. Military bases use equipment that is frequently causes.

Authorities can determine the cause of interference within a few hours. FAA officials said in a statement that they are looking into reports of problems with approaches for one of the runways. There was no evidence of interference and the agency is trying to find the cause. The aircraft can land on other runways.

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Experts can only theorize.

Josh Lospinoso, co- founder and CEO of aircraft and transportation security company Shift5 and a former US Cyber Command official, said in an interview that they don't know if there are malicious actors behind the incident. It's a timely issue for airports and airlines. There was a big push by wireless carriers to roll out 5G in airports a few months ago that was a terrible idea from the perspective of how manylegacy devices in aircraft rely on the wireless bands that are impeded by 5G.

Lospinoso pointed out the susceptibility of the civilian gps to spoofing. The gps jamming was done by North Korea. Three years ago, the Center for Advanced Defense Studies reported that Russia had spoofed signals from the Global navigation satellite systems in Syria and other combat zones.

Other forms of aircraft navigation are similarly vulnerable. In 2012, for instance, researcher Brad Haines reported that he was able to spoof the ADS-B signals a surveillance technology aircraft rely on to determine their position via satellite navigation. The researcher demonstrated how attackers could use these spoofed signals to create “ghost planes” that would appear on air traffic controllers' screens. Researchers have also devised a low-cost hack that spoofs the instrument landing systems that planes rely on to safely land.

The event that played out in Denver last January seems to have played out in this week's event. In the January episode, there was a report of unreliable gps for more than 33 hours.

Readers should be aware that the interference with the gps is not life threatening. These episodes cause delays and cancelations. They show the weakness of a system that the world is growing more dependent on. There is a mystery as to what caused it.