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 737s and 777s.
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 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. But how did this occur?
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:
As a result of the navigation system failure, pilots are forced to seek help from ATC to know the exact aircraft location.
GPS jamming, a more common occurrence, especially on long-haul flights, is not as dangerous as spoofing, and pilots have learned how to recognize it and cope with it.
Flickering readings instantly reveal that the GPS signal is being jammed, 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.
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.
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.
Source » simpleflying