EASA updates advisory on navigation interference

Photo: GPS IIIF

The European Union Aviation Safety Agency (EASA) has updated its Safety Information Bulletin (SIB) to address the growing number of GNSS outages and disruptions.  

This updated advisory, SIB No. 2022-02R3, highlights the increasing sophistication and impact of GNSS jamming and spoofing, which have become significant concerns for aviation safety. 

The bulletin is directed at competent authorities, Air Traffic Management/Air Navigation Services (ATM/ANS) providers, air operators, aircraft and equipment manufacturers and organizations involved in the design or production of ATM/ANS equipment. It aims to inform these stakeholders about the risks and necessary precautions related to GNSS interference. 

Since February 2022, there has been a notable increase in GNSS jamming and spoofing, particularly in regions surrounding conflict zones and other sensitive areas such as the Mediterranean, Black Sea, Middle East, Baltic Sea and the Arctic, reports the EASA. These interferences can disrupt the accurate reception of GNSS signals, leading to various operational challenges for aircraft and ground systems. 

Tackling jamming and spoofing  

The bulletin addresses jamming and spoofing. Jamming involves intentional radio frequency interference that prevents GNSS receivers from receiving satellite signals, rendering the system ineffective or degraded, while spoofing involves broadcasting counterfeit satellite signals to deceive GNSS receivers, resulting in incorrect positioning, navigation and timing (PNT) data. Jamming typically results in immediate and noticeable effects, whereas spoofing is more difficult to detect and poses a higher safety risk. 

Some symptoms of suspected GNSS spoofing include incoherence in navigation position, abnormal differences between ground speed and true airspeed, time and date shifts and spurious Terrain Awareness and Warning System (TAWS) alerts. These disruptions can lead to significant operational issues, such as re-routing or diversions, loss of Airborne Collision Avoidance System (ACAS) and misleading surveillance data. 

EASA recommends several measures to reduce the risks associated with GNSS interference. These measures include establishing coordinated procedures between authorities, ATM/ANS providers and airspace users. The agency also suggests utilizing complementary PNT infrastructure and encourages users to implement a process to collect and report information on GNSS degradation. 

Specific recommendations 

For air operators:  

• Train flight crews to recognize and respond to GNSS interferences. 
• Promptly report any GNSS anomalies. 
• Assess operational risks and maintain alternative navigation procedures. 

 For ATM/ANS providers:  

• Establish monitoring and reporting processes for GNSS degradations. 
• Ensure ground navigation infrastructure supports non-GNSS procedures. 
• Provide navigation assistance and maintain communication coverage in case of GNSS jamming or spoofing. 

For manufacturers:  

• Assess the impact of GNSS interference on products and guide users. 
• Support operators with instructions for managing GNSS-related issues. 

 Stakeholders are urged to implement the recommended measures to mitigate the impact of GNSS jamming and spoofing on aviation safety. 

For further details, read the full EASA Safety Information Bulletin and visit the EASA website for updated information on affected regions.