GPS Spoofing Causes Major Flight Disruptions at Delhi's Indira Gandhi International Airport

Over the past few days, several aircraft approaching IGI Airport experienced navigation issues.

Flight operations at Delhi's Indira Gandhi International Airport (IGIA) faced major disruptions this week after suspected GPS spoofing incidents - the first known cases at the airport interfered with aircraft navigation systems, forcing several flights to divert and causing severe air traffic congestion.

What is GPS spoofing?

GPS spoofing occurs when counterfeit satellite signals are transmitted to deceive navigation systems, causing aircraft to calculate incorrect position or altitude readings. Unlike GPS jamming that blocks signals entirely, spoofing actively transmits false coordinates, misleading systems into displaying inaccurate routes or approach paths.

The counterfeit satellite signals typically overpower legitimate GPS signals, leading aircraft systems to miscalculate their position. These erroneous readings can sometimes be inaccurate by hundreds or even thousands of kilometers.

For instance, an aircraft flying over Delhi might appear on cockpit instruments to be over Nepal. When not identified quickly, such distortions can lead to significant route deviations and create safety hazards during critical flight phases such as approach or landing.

What happened at Delhi airport?

During recent days, multiple aircraft approaching IGI Airport encountered navigation problems connected to manipulated GPS signals. On Tuesday evening, at least seven flights, including those from IndiGo and Air India, were diverted to Jaipur after their onboard systems showed incorrect location information.

According to Flightradar24, IGI ranked second globally that night for airport disruptions, following only Kathmandu. The situation deteriorated when winds shifted eastward, necessitating a reversal of runway operations and increasing congestion throughout the airport despite all four runways being operational.

The compounding factors: Runway upgrade and wind shift

This issue coincides with IGI's main runway (10/28) being partially closed for an Instrument Landing System (ILS) upgrade to Category III standards, which will ultimately enable aircraft to land safely during heavy winter fog.

Until this upgrade completes, aircraft must depend on Required Navigation Performance (RNP), a GPS-based guidance system now susceptible to spoofing interference. With signals reportedly affected up to 60 nautical miles from Delhi, aircraft experienced serious navigation errors during approach, compelling several to abort landings or divert.

A sudden wind direction change further complicated airspace management, requiring aircraft to land from the Dwarka side and take off toward Vasant Kunj - a reversal that heightened congestion and operational pressure.

Passenger impact and airline response

The combination of GPS spoofing and air traffic congestion resulted in extended delays across airlines. Passengers faced longer wait times both on the ground and onboard as air traffic controllers managed diversions and sequencing.

Air India also reported delays, citing a "third-party connectivity network issue" that temporarily affected check-in systems at multiple airports. "The system has since been restored, though some flights may continue to be delayed as operations normalise," the airline stated, advising passengers to verify flight status before departing for the airport.

The Delhi International Airport Limited (DIAL) confirmed that some airlines experienced technical difficulties with check-in processes and mentioned it was "actively coordinating with all stakeholders to minimise delays and restore normal operations as quickly as possible."

IndiGo acknowledged the passenger impact in a statement, saying, "Due to air traffic congestion in Delhi, flight operations are currently impacted. We understand that extended wait times, both on the ground and onboard, may cause inconvenience, and we sincerely appreciate your patience."

Global pattern: Spoofing extends beyond conflict zones

GPS interference has become an increasing threat for international airlines. In October, an Air India flight from Vienna to Delhi was forced to divert to Dubai after spoofed signals over the Middle East disrupted major automated flight systems, including autopilot and flight director, requiring pilots to manually control the aircraft.

Historically, such incidents have been concentrated in military conflict zones like the Black Sea and West Asia. Their appearance over India's busiest airport signals a concerning expansion of this global aviation threat into civilian airspace.

With Delhi Airport handling nearly 1,550 aircraft movements daily, authorities are investigating the source of the spoofing signals and collaborating with regulators and technology experts to ensure navigation reliability and flight safety in Indian airspace.