NEW DELHI, Dec 4: India’s aviation regulator, the Directorate General of Civil Aviation (DGCA), has launched an investigation into the widespread disruptions affecting flight operations of IndiGo, the country’s largest airline. The regulator has demanded a detailed explanation for the unusually high number of delays and cancellations, and has directed the carrier to present a concrete plan to stabilise operations.

On Wednesday alone, more than 150 IndiGo flights were estimated to have been cancelled, while numerous others experienced prolonged delays at major airports across the country. The airline has been grappling with operational turbulence over the past few days due to a combination of factors—most notably, an acute crew shortage triggered by the implementation of new crew duty and rest norms. IndiGo has also attributed the disruptions to certain technology-related problems and airport congestion, which have compounded the cascading delays.

In a statement issued on Wednesday night, the DGCA confirmed that it is monitoring the situation closely. “The Directorate General of Civil Aviation is evaluating corrective measures with the airline to reduce cancellations and delays and minimise inconvenience to passengers. IndiGo has been asked to appear before DGCA Headquarters to present facts regarding the current disruptions and submit its mitigation plan,” the regulator said.

With operations deteriorating on Tuesday and Wednesday, and cancellations increasing across its network, IndiGo has initiated what it describes as “calibrated adjustments” to its schedule over the next 48 hours. While the airline has not specified the changes, sources indicated that the measures could include additional rescheduling and targeted cancellations to align flight schedules with available crew resources.

According to the DGCA, IndiGo has begun reinforcing crew planning and rostering, ensuring full compliance with the new FDTL (Flight Duty Time Limitations) requirements. The airline is also strengthening coordination with air traffic control (ATC) and airport operators to better manage capacity constraints, while improving turnaround processes and disruption-management systems.

The revised FDTL norms—whose second phase came into effect last month—appear to be at the heart of IndiGo’s operational strain. As per IndiGo’s submission to DGCA, the airline recorded 1,232 flight cancellations in November, of which:

The airline’s on-time performance (OTP) has deteriorated sharply, slipping to 67.7% in November from 84.1% in October. The decline has accelerated this week: only 35% of IndiGo flights operated on time on Tuesday, with Monday performing marginally better at around 50%.

The revised FDTL rules have imposed new restrictions, including an increase in weekly pilot rest requirements from 36 hours to 48 hours, a reduction in permitted night landings from six to two, and an expanded definition of night hours. These changes have significantly affected IndiGo’s crew rostering, especially given its extensive late-night operations.

As India’s dominant low-cost carrier, IndiGo traditionally operates with higher aircraft and crew utilisation levels than most Indian airlines. Its large fleet, dense schedule, and heavy reliance on night-time flights—key to maintaining cost efficiencies—have made the airline particularly vulnerable to FDTL-related challenges. Combined with its massive scale, these factors have amplified the impact of the new norms on IndiGo more than on any other carrier in the country.