IndiGo landed a jet via Gagan, not radio. What is it, and why does it matter for India?
On the afternoon of June 27, 2026, an IndiGo Airbus A320 dropped gently towards the runway at Udaipur. From a window seat, nothing looked unusual
On the afternoon of June 27, 2026, an IndiGo Airbus A320 dropped gently towards the runway at Udaipur. From a window seat, nothing looked unusual. Yet the aircraft was not being guided down by the ground-based radio beams that line most big-city runways. It was being talked down by satellites parked thousands of kilometres above India. A network of 15 ground stations across India measures GPS errors and beams the corrections up to satellites over the equator. (Photo: PTI) Read Full Story Under the watch of the Directorate General of Civil Aviation (DGCA), it became the first jet in India to land using Gagan, the country's homegrown navigation system, media reports said. Small turboprop planes had managed it before. A passenger jet never had. A turboprop is a smaller, slower aircraft powered by a propeller that is spun by a jet engine, the kind used on short regional routes, such as IndiGo's ATR fleet, rather than the larger jets like the A320 that fly busier sectors. WHAT IS GAGAN, AND WHO BUILT IT? Gagan stands for GPS Aided GEO Augmented Navigation. It was built jointly by the Indian Space Research Organisation (Isro) and the Airports Authority of India (AAI). The Gagan Signal-In-Space (SIS) is available through Isro's GSAT-8 and GSAT-10. An IndiGo Airbus A320 on final approach to Udaipur on June 27, 2026, guided down by Gagan, India's own satellite navigation system.
(Representative Photo of an IndiGo Airbus: PTI) It is not a fleet of navigation satellites like GPS. Think of it instead as a helper that sits on top of GPS and quietly checks its homework, correcting the mistakes before they reach the pilot. It is easy to mix Gagan up with NavIC, the other Indian navigation system in the news, but the two do opposite jobs. NavIC, short for Navigation with Indian Constellation, is a standalone positioning network that finds your location on its own, much like GPS. Gagan does not navigate by itself at all. It exists only to sharpen and police the signals that GPS is already sending. WHY IS LANDING A PLANE WITH GPS SO HARD? The GPS in your phone is usually accurate to a few metres. That is fine for finding a coffee shop. It is nowhere near sharp enough to bring a 70-tonne jet down through clouds. Gagan was developed jointly by Isro and the Airports Authority of India to sharpen GPS signals for aviation use. (Representative Photo of an IndiGo Airbus: PTI) As GPS signals travel to Earth, they are slowed and bent by the ionosphere, an electrically charged layer of the upper atmosphere. Over India, which sits beneath a restless band called the equatorial ionisation anomaly, those errors are unusually large and shift from minute to minute.
