The Indian aviation authorities have issued a Notice to Air Missions (NOTAM) warning airlines about possible GPS interference near Kolkata from November 13 to 17, 2025.
This is the third major air corridor affected in recent weeks, following similar GPS anomalies near Delhi and Mumbai.
Defence analysts say the pattern is worrying, raising concerns in both civil aviation and defence circles.
A Widening Pattern Across Major Metro Routes
The GPS disruptions in Delhi, Mumbai, and Kolkata indicate a larger trend, not isolated incidents.
These cities are among India’s busiest aviation hubs and are strategically important politically, economically, and militarily.
Experts suggest that these GPS anomalies resemble grey-zone tactics—where adversaries test a nation’s response capability without engaging in open conflict.
The interference near command centres, coastlines, and key trade routes increases the potential strategic impact.
DGCA Tightens Reporting Rules
The Directorate General of Civil Aviation (DGCA) has instructed airlines, pilots, and air traffic controllers to report GPS anomalies within 10 minutes of detection.
The advisory covers:
Position deviations
Loss of satellite integrity
Suspected GPS spoofing
This comes after multiple anomalies near New Delhi raised questions about the reliability of GNSS navigation, which is critical for both civilian and military flights.
What Is GPS Spoofing and Why It Matters
GPS spoofing occurs when false satellite signals are broadcast to mislead navigation systems.
Unlike jamming, spoofing provides realistic but incorrect location data.
It is often used in geopolitical hotspots to:
Hide movements
Distort surveillance data
Test an adversary’s electronic defence
For aviation, spoofing can cause navigation errors, autopilot disruptions, and route deviations.
During poor visibility, pilots may have to rely on manual controls, increasing operational risk.
False coordinates can also affect surveillance systems, impacting situational awareness for both civil and defence operations.
The Road Ahead: Strengthening GNSS and Aviation Safety
With recurring GPS anomalies across three major metros, the issue is no longer just a technical problem.
India now faces an urgent need to:
Enhance GNSS resilience
Improve electronic warfare preparedness
Safeguard aviation safety and national security
The government and aviation authorities are monitoring the situation closely, ensuring pilots and airlines are alert and ready for any further interference.
