Volcanic ash from Mount Anak Krakatau has delayed 2,927 flights and cancelled 584 more across Asia, including at Delhi and Mumbai, since the volcano began erupting on September 4.
What stands out is how far the disruption travelled from its source. Delhi’s Indira Gandhi International Airport logged 177 delays and Mumbai’s Chhatrapati Shivaji Maharaj International Airport logged 245, despite both cities sitting well outside the immediate eruption zone in Indonesia’s Sunda Strait.
That’s the nature of a hub-and-spoke aviation network: a localized hazard at one geographic point doesn’t stay localized. Aircraft, crew and slot schedules are shared across the system, so a closure or diversion at one node propagates delays outward through every route connected to it.
IndiGo (258 delays, 9 cancellations) and Air India (114 delays, 2 cancellations) illustrate the point at the carrier level — neither airline flies anywhere near the volcano, yet both absorbed measurable operational disruption because their networks intersect with affected hubs like Jakarta and connecting Southeast Asian routes.
For any business built on tightly scheduled, interconnected infrastructure — logistics, aviation, even distributed compute — the lesson generalizes: resilience isn’t just about avoiding direct exposure to a hazard, it’s about understanding how deeply your system is coupled to nodes that are exposed, even indirectly.
Volcanic ash poses a direct safety hazard to jet engines, which is why aviation authorities impose ground restrictions and altitude diversions rather than allowing aircraft to fly through affected airspace.
Garuda Indonesia and Batik Air, the two largest carriers based in the affected region, reported the heaviest cancellation rates of any airline tracked in the disruption.
Airlines advised passengers travelling through affected hubs to check flight status directly with carriers before heading to the airport, as ash-related restrictions were being updated through the day.
Mount Anak Krakatau, in Indonesia’s Sunda Strait, began erupting on September 4, triggering a five-day aviation shutdown that closed eight Indonesian airports and stranded more than 270,000 passengers.
Interior of Terminal 3, Indira Gandhi International Airport, Wikimedia Commons, CC0