High-risk airspace list: India issues third GPS spoofing warning as Kolkata joins Delhi, Mumbai
The pattern resembles GPS-jamming techniques observed in global grey-zone conflicts, where adversaries test a country’s response thresholds without crossing into open hostility.
- Nov 14, 2025,
- Updated Nov 14, 2025 3:43 PM IST
After Delhi and Mumbai, India has issued a Notice to Air Missions (NOTAM) warning of possible GPS interference or signal loss along air traffic routes near Kolkata, according to defence analyst Damien Symon.
The NOTAM, valid from November 13 to 17, 2025, alerts airlines and pilots to remain vigilant against disruptions to satellite-based navigation systems. The development was confirmed by Symon, a geo-intelligence researcher at The Intel Lab, in a post on X.
This marks the third high-density airspace in India to report such anomalies in recent weeks, intensifying concerns within civil aviation and national security circles.
Four strategic concerns
1. Three critical zones affected: Delhi, Mumbai and now Kolkata — all politically, economically, and militarily sensitive corridors — have reported interference, pointing to possible coordinated probing.
2. Possible external probing: The pattern resembles GPS-jamming techniques observed in global grey-zone conflicts, where adversaries test a country’s response thresholds without crossing into open hostility.
3. Aviation & defense impact: Navigation signal disruptions can challenge both commercial aviation safety and military readiness, especially during high-traffic or high-alert periods.
4. High-value targets: Interference around metros connected to command centres, coastlines, and trade routes raises additional strategic red flags.
DGCA tightens reporting protocols
This advisory comes shortly after the Directorate General of Civil Aviation (DGCA) directed airlines, pilots, and air traffic controllers to report GPS spoofing incidents within 10 minutes of detection.
In its circular, the DGCA said: “Any pilot, ATC controller, or technical unit detecting abnormal GPS behaviour (e.g., position anomalies, navigation errors, loss of GNSS signal integrity, or spoofed location data) shall initiate real-time reporting (within 10 minutes of occurrence).”
A similar cluster of anomalies was recently observed around New Delhi, sparking concerns about the safety and reliability of Global Navigation Satellite System (GNSS) data used in both civil aviation and defence operations.
What Is GPS spoofing?
GPS spoofing is a deliberate act of transmitting false GPS signals to mislead navigation systems. Aircraft, ships, drones, and even telecom networks that rely on GNSS can be tricked into showing incorrect coordinates, altitude, or heading.
Spoofing is more sophisticated than jamming:
- Jamming blocks or degrades the signal.
- Spoofing imitates the signal to create believable but false navigation data.
State and non-state actors have used spoofing to mask locations, redirect vessels, or create confusion in contested airspaces.
How GPS spoofing impacts aviation
1. Navigation errors: Aircraft may drift off assigned routes, complicating air traffic control operations—especially around busy airports like Delhi, Mumbai, or Kolkata.
2. Autopilot disruption: Autopilot systems relying on GNSS could receive incorrect position inputs, forcing pilots into manual overrides.
3. Safety risks during low visibility: Approaches and landings that depend on satellite-aided navigation (like RNP approaches) can become unreliable, increasing operational risk.
4. Communication & surveillance challenges: Modern aviation surveillance systems, including ADS-B, can relay false location data if spoofed — impacting both civilian and military situational awareness.
5. Escalatory strategic risk: Repeated spoofing attempts may be aimed at stress-testing a country’s cyber-electronic defence posture, or signalling capability in grey-zone conflict environments.
After Delhi and Mumbai, India has issued a Notice to Air Missions (NOTAM) warning of possible GPS interference or signal loss along air traffic routes near Kolkata, according to defence analyst Damien Symon.
The NOTAM, valid from November 13 to 17, 2025, alerts airlines and pilots to remain vigilant against disruptions to satellite-based navigation systems. The development was confirmed by Symon, a geo-intelligence researcher at The Intel Lab, in a post on X.
This marks the third high-density airspace in India to report such anomalies in recent weeks, intensifying concerns within civil aviation and national security circles.
Four strategic concerns
1. Three critical zones affected: Delhi, Mumbai and now Kolkata — all politically, economically, and militarily sensitive corridors — have reported interference, pointing to possible coordinated probing.
2. Possible external probing: The pattern resembles GPS-jamming techniques observed in global grey-zone conflicts, where adversaries test a country’s response thresholds without crossing into open hostility.
3. Aviation & defense impact: Navigation signal disruptions can challenge both commercial aviation safety and military readiness, especially during high-traffic or high-alert periods.
4. High-value targets: Interference around metros connected to command centres, coastlines, and trade routes raises additional strategic red flags.
DGCA tightens reporting protocols
This advisory comes shortly after the Directorate General of Civil Aviation (DGCA) directed airlines, pilots, and air traffic controllers to report GPS spoofing incidents within 10 minutes of detection.
In its circular, the DGCA said: “Any pilot, ATC controller, or technical unit detecting abnormal GPS behaviour (e.g., position anomalies, navigation errors, loss of GNSS signal integrity, or spoofed location data) shall initiate real-time reporting (within 10 minutes of occurrence).”
A similar cluster of anomalies was recently observed around New Delhi, sparking concerns about the safety and reliability of Global Navigation Satellite System (GNSS) data used in both civil aviation and defence operations.
What Is GPS spoofing?
GPS spoofing is a deliberate act of transmitting false GPS signals to mislead navigation systems. Aircraft, ships, drones, and even telecom networks that rely on GNSS can be tricked into showing incorrect coordinates, altitude, or heading.
Spoofing is more sophisticated than jamming:
- Jamming blocks or degrades the signal.
- Spoofing imitates the signal to create believable but false navigation data.
State and non-state actors have used spoofing to mask locations, redirect vessels, or create confusion in contested airspaces.
How GPS spoofing impacts aviation
1. Navigation errors: Aircraft may drift off assigned routes, complicating air traffic control operations—especially around busy airports like Delhi, Mumbai, or Kolkata.
2. Autopilot disruption: Autopilot systems relying on GNSS could receive incorrect position inputs, forcing pilots into manual overrides.
3. Safety risks during low visibility: Approaches and landings that depend on satellite-aided navigation (like RNP approaches) can become unreliable, increasing operational risk.
4. Communication & surveillance challenges: Modern aviation surveillance systems, including ADS-B, can relay false location data if spoofed — impacting both civilian and military situational awareness.
5. Escalatory strategic risk: Repeated spoofing attempts may be aimed at stress-testing a country’s cyber-electronic defence posture, or signalling capability in grey-zone conflict environments.