The FAA has begun investigating potential causes for a faulty GPS that caused delays and changes in flight paths earlier this week at Dallas Fort Worth International Airport.
The GPS disruption even caused one runway to be shut down briefly, later being reopened on Tuesday. The FAA was first alerted to the disturbance on Monday when it issued an Automatic Terminal Information Service announcement to incoming pilots.
The announcement read that all GPS signals within a 40-mile chunk of airspace over DFW Airport were “unreliable.” At the same time, the Air Traffic Control System Command Center reported that DFW Airport and others nearby were “experiencing GPS anomalies that are dramatically impacting” flights.
Some airports were forced to use ground-based radar systems that predate GPS technology.
John Wiseman, who collects data on GPS interference and posts maps on the popular GPSJam.org, says the interference soon spread to other areas such as Waco. Around a day and a half after the mysterious interference started, it suddenly stopped.
“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,” Wiseman wrote. He added that he was almost certain the issues did not arise from a natural phenomenon.
Thankfully, all flights landed without any major difficulties, and all pilots and passengers were safe. Both Southwest Airlines and American Airlines said the GPS issues did not disrupt any operations. The U.S. military also reassured the FAA that they were not conducting any drills that would cause a GPS interruption.
For now, the cause remains unknown.
Despite a reliance on GPS as the main method of tracking and directing flights, airports still use ground-based radar and other fail safes just in case. Hence, the GPS failure earlier this week was more of an annoyance rather than a danger.