On the edge of risk
Airspace in the Middle East has undergone substantial change after the attack by the Islamic Resistance Movement (Hamas) on 7 October, which restricted air traffic around Israel. Even before that, cases of misdirected planes around Iran had increased.
Shortly after Ukraine International Airlines’ flight 752 took off from Tehran on 8 January 2020 it was shot down by two Iranian anti-aircraft missiles. All of the 176 people on board the Boeing B737-800 died. Iran later officially attributed this to a miscalculation by its air defence forces.
There have been several cases since mid-September in which civilian aircraft have been in similar danger, on account of wrong GPS data leading them to unintentionally approaching Iranian airspace. The main scene of these episodes is the UM688 airway, which runs parallel to the Iranian border in Iraqi airspace.
According to the OPS Group, a private association specialising in flight operations information for pilots, GPS interference is ‘spoofing’, which means that the on-board electronics systems are fooled into registering false data, until all on-board systems lose their correct reference values and eventually fail.
What’s new about this type of disruption is that the aircraft suffer a failure of their internal navigation systems (IRS), which are supposed to be impossible to manipulate, and could only follow their route with support from the outside, that is to say from air traffic control.
The commercial aeroplanes affected can be of various sizes and types, including Boeing B747s, B777s, B737s and Embraer 190s, as well as a number of business jets. An affected B777 crew sounded particularly irritated when addressing two questions to air traffic control in Baghdad. “What time is it? Where are we?”
A warning from the FAA
According to the OPS Group the interference can only be combatted if the spoofing is detected very early and the GPS receiver signal is immediately disconnected from the IRS. Only then will it keep its unadulterated data.
Most crews aren’t aware of the dimension of the impending consequential disruptions and the networking of the IRS, according to the OPS Group, which advises airlines to discuss system design, imminent dangers and countermeasures with their aircraft manufacturers. The association, headquartered in New York, has called on operators to inform their crews about these new dangers.
The Federal Aviation Administration (FAA) has pointed out safety risks for civil aviation in the Baghdad and Baku flight information regions (FIR). It recommends that aviation operators passing through these FIRs monitor the regional data situation and be prepared for operations without GPS navigation.