Delhi Airport Chaos Explained: How ‘Fake GPS Signals’ Led To Massive Flight Delays
All airline operations at the Indira Gandhi International Airport were impacted due to a technical issue in the Automatic Message Switching System (AMSS), which supports air traffic control data.
At least 20 flights were cancelled and around 800 domestic and international flights were delayed on Friday after a technical problem disrupted operations at Delhi’s Indira Gandhi International Airport, the country’s busiest aviation hub.
The issue, which created widespread delays and diversions, was linked to a failure in the air traffic control system’s Automatic Message Switching System (AMSS) and interference from fake satellite navigation signals, also known as “GPS spoofing.”
What Is GPS Spoofing
Several aircraft approaching Delhi this week reported receiving corrupted satellite navigation data. This phenomenon, called GPS spoofing, occurs when a transmitter imitates genuine satellite signals and sends false position or timing information to aircraft systems. The misleading data affected onboard navigation, forcing pilots to abandon precision approaches and, in several cases, divert to nearby airports such as Jaipur.
Modern aircraft rely heavily on global navigation satellite systems (GNSS) for precise approaches and route management. Spoofing interferes with these signals, making it difficult for pilots and air traffic controllers to maintain accuracy and consistency in flight paths.
How Conditions Made It Worse
Delhi’s main runway, 10/28, has been undergoing an Instrument Landing System (ILS) upgrade. With full Category-III ILS unavailable on both ends, pilots had to depend more on satellite-based procedures, making operations more sensitive to spoofing.
Weather conditions also played a role. When easterly winds required runway use in certain directions, the area affected by spoofing overlapped with regular arrival routes. Reports suggested the interference extended up to about 60 nautical miles from the airport.
As navigation data appeared unreliable, pilots discontinued automated approaches and requested radar assistance or conventional navigation aids. Some aircraft diverted to alternate airports, which reduced runway capacity and caused cascading delays across the network.
Was Safety At Risk
GPS spoofing does not allow external control of an aircraft, but it can distort critical data. Pilots, air traffic controllers, and onboard systems cross-check data using radar and inertial systems to identify inconsistencies. While these procedures maintain safety, they take time to complete, which slows traffic and increases delays.
What Authorities Did
The Airports Authority of India (AAI) said in a post on X that the “technical issue in the Automatic Message Switching System (AMSS)” was identified and resolved by 8:56 pm on November 6. The problem, detected in the IP-based AMSS that handles flight plan messages, required assistance from engineers of the Electronics Corporation of India Ltd in Hyderabad.
AAI deployed additional staff to manually process flight plans during the outage to keep operations running safely. The authority said the system has since been restored and flight schedules are returning to normal as backlogs clear.
The Directorate General of Civil Aviation (DGCA) and airport operators have accelerated ILS upgrades on runway 10/28 to reduce dependence on satellite-based systems, especially during the winter season. National agencies have also begun mapping interference patterns around Delhi to identify sources of spoofing and strengthen air navigation resilience.
