Fake Satellite Signals Cause Major Flight Disruptions At Delhi Airport

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 happens when counterfeit satellite signals are transmitted to mislead navigation systems, causing aircraft to compute false position or altitude readings. Unlike GPS jamming which blocks signals, spoofing actively feeds incorrect coordinates, tricking systems into showing false routes or approach paths.

The fake satellite signals are stronger than authentic GPS signals, causing aircraft systems to miscalculate their position. These false readings can sometimes be off by hundreds or even thousands of kilometres.

For example, a plane flying over Delhi could appear on cockpit instruments to be over Nepal. If not detected promptly, such distortions can cause major route deviations and pose safety risks during critical phases like approach or landing.

What happened at Delhi airport?

Over the past few days, several aircraft approaching IGI Airport experienced navigation issues linked to manipulated GPS signals. On Tuesday evening, at least seven flights, including those operated by IndiGo and Air India, were forced to divert to Jaipur after their onboard systems displayed incorrect location data.

According to flight-tracking website Flightradar24, IGI ranked second globally that night in terms of airport disruptions, behind Kathmandu. The situation worsened when winds shifted eastward, forcing a reversal of runway operations and intensifying congestion across the airport despite all four runways being fully functional.

The compounding factors: Runway upgrade and wind shift

The issue occurs as IGI's main runway (10/28) remains partially closed for an Instrument Landing System (ILS) upgrade to Category III standards, which will eventually allow aircraft to land safely during dense winter fog.

Until the upgrade is complete, planes have to rely on Required Navigation Performance (RNP), a GPS-based guidance system now vulnerable to spoofing interference. With signals reportedly affected up to 60 nautical miles from Delhi, aircraft faced serious navigation errors on approach, forcing several to abort landings or divert.

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

Passenger impact and airline response

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

Air India also reported delays, citing a "third-party connectivity network issue" that had temporarily affected its 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 said, advising passengers to check their flight statuses before heading to the airport.

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

In a statement, IndiGo acknowledged the impact on passengers, 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 a growing menace 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 all major automated flight systems, including autopilot and flight director, forcing 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 marks 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 working with regulators and technology experts to safeguard navigation reliability and flight safety in the Indian airspace.