Summary
- Commercial and private jets flying over Iran have been affected by GPS signal spoofing, causing them to veer off course. This is the first time passenger flights have been targeted to such a sophisticated degree.
- GPS signal spoofing occurs when counterfeit radio signals override legitimate GPS signals, leading to navigation system failures and pilots relying on ATC for help in identifying their exact location.
- While GPS jamming is more common and easily recognized by pilots, spoofing is harder to detect as the aircraft’s GPS receiver accepts the false signals and redirects the plane accordingly. The FAA has issued a warning for flights over Baghdad due to these incidents.
Over the past two weeks, more than 20 commercial and private jets flying over Iran have strayed off course after being led off route by deceptive GPS signals sent from the ground. These signals overpowered the jet’s navigation systems and affected multiple aircraft, including Boeing 777s, 737s, and 747s.
Veering off course
In a report by the OPS Group, which focuses on flight safety, a targeted 777 was so off course that the crew asked Baghdad Air Traffic Control, “What time is it, and where are we?” The site, which claims to have a membership of 8,000 flight dispatchers, controllers, pilots, and shoulders, began reporting incidents of GPS navigation signal spoofing on September 25th.
According to the OPS Group report, most of these 20 instances occurred in flights flying along airway UMB688 in northern Iraq, a significant airway between the Middle East and Europe. One business jet almost entered Iranian airspace without clearance.
Photo: Skycolors/Shutterstock
The cause of this is GPS signal spoofing, a type of cyber attack created to steer people or goods off course. Although GPS signal interference has been around for a long time, this is the first time commercial passenger flights have been targeted to such a sophisticated degree. GPS signal spoofing occurs when a counterfeit radio signal is sent to a receiver antenna to override a legitimate GPS satellite signal. A report by the OPS Group stated:
“OPSGROUP has now received [Multiple] separate reports, and in most cases, the [Inertial Reference System] becomes unusable, VOR/DME sensor inputs fail, the aircraft UTC clock fails, and the crew has been forced to request vectors from ATC to navigate.”
As a result of the navigation system failure, pilots are forced to seek help from ATC to know the exact aircraft location.
New interference
Although this type of GPS signal interference has been around for a long time, this is the first time passenger flights have been targeted to such a large degree. GPS jamming, a more common occurrence, especially on long-haul flights, is not a dangerous spoofing, and pilots have learned how to recognize it and cope with it.
When flickering readings instantly reveal that the GPS signal is being jammed, it has become commonplace on long-haul flights, especially on flights over Russia heading East. Pilots have multiple checklists and have undergone training on how to handle jamming. For one, they rely on the plane’s navigation system, which does not take any data from the GPS.
Photo: Paparacy/Shutterstock
However, spoofing is much harder to spot as the aircraft’s GPS receiver is unaware that it is reading false GPS signals. The aircraft’s flight management system will accept the fake GPS signal and redirect the plane to the intended flight plan.
Warning issued
In response to the incidents, the Federal Aviation Administration issued a NOTAM (Notice to Air Men) for flights flying over Baghdad, Iraq, as these airway routes are considered to be sensitive areas by Iran.
Iran has two large military bases just off the airway route, one in the western city of Kermanshah with dedicated anti-aircraft weapons and another in the central city of Khorramabad. For context, in 2020, Iran mistakenly shot down Ukraine International Airlines Boeing 737, killing the nine crew and 167 passengers aboard, and in September, threatened to shoot down an aircraft entering Iranian airspace without clearance.