Although it is not a fault that can cause an aircraft to crash on its own, it can be a bad experience for pilots who have to manually correct or operate the aircraft while the GPS system is out of alignment.
Over the past three months, there has been a 400% increase in cases of GPS spoofing, according to aviation consultancy OPSGROUP. GPS spoofing, which is often used in war-torn or geopolitically tense territories, is a technique by which a homemade GPS device can interfere with the signals of aircraft, including commercial aircraft, and affect them in various ways, including altering their flight path.
While the number of reported cases was around 200 a day from January to March this year, between April and June the number has risen to 900 a day, affecting up to 1,350 flights in a single day. The number of locations where a flight could encounter this phenomenon has also increased from three to ten. While in September last year cases of GPS manipulation were detected in northern Iraq near Baghdad, in Egypt near Cairo and in Israel, cases are now also being reported in the Black Sea, Cyprus, the border with North Korea and near Russia.
One of the reasons why this technique can be carried out is to hide the trajectories or launches of drones or missiles.
According to cybersecurity researchers, GPS spoofing is becoming a major problem, highlighted by the ease of making these homemade devices that interfere with commercial aircraft instruments. In reality, GPS spoofing usually interferes, above all, with the time setting of aircraft, for example, by making the system believe that they are several years ahead. This seemingly harmless alteration of aircraft clocks can, for example, cause the loss of access to the encrypted communications system.
An aircraft that suffered this alteration in its clocks had to remain on the ground for weeks while a group of engineers manually corrected the time adjustment.
But, according to OPSGROUPThe risk also extends to navigation. The autopilot may be affected, causing a sudden change of trajectory, as well as increasing the error rate in runway approaches, among others.
One example is Finnish airline Finnair’s decision last April to temporarily pause all flights through the eastern Estonian city of Tartu due to GPS spoofing that the country’s capital said was being caused by neighbouring Russia.
Risk of confusion among pilots
GPS manipulation is by no means enough to cause a plane to crash, but it is a cause for concern because of the confusion it can cause among pilots. This confusion can lead to a dreaded ‘cascade effect’, whereby a small problem can lead to a longer series of pilot errors that lead to a more serious problem. It can also increase the likelihood of having to do a go-around, which is a detour where the plane aborts the landing in order to try again.
Go-arounds increase crew stress, and increase the risk with each new round that is undertaken.
