IndiGo told the DGCA its mass flight cancellations were caused by a “compounding effect” of technical issues, weather, congestion and new crew rules.
The airline said no single factor triggered the disruption and sought more time for a full root-cause analysis.
DGCA is reviewing the response and may take regulatory action.
IndiGo has informed the Directorate General of Civil Aviation (DGCA) that its recent wave of flight cancellations stemmed from a “compounding effect” of multiple operational challenges rather than a single trigger. In its detailed response, signed by the airline’s CEO and COO, IndiGo cited technical issues, winter-schedule transitions, adverse weather, air-traffic congestion and new FDTL Phase II crew-rostering norms as simultaneous pressures that disrupted services.
The airline said the convergence of these factors in early December led to crew shortages and declining on-time performance, prompting the large-scale cancellations on December 5 to stabilise operations and reposition aircraft and staff. IndiGo maintained that it is “not realistically possible” to isolate one cause and has sought the full 15-day window to submit a comprehensive root-cause analysis.
IndiGo added that refunds and passenger support were provided as per norms and said performance indicators have since improved. The DGCA is examining the reply and may take enforcement action if required.
The airline has attributed the mass cancellations to adjustments required under the revised Flight Duty Time Limitations (FDTL) norms, introduced nationwide in two stages on 1 July and 1 November. The updated rules mandate 48 hours of weekly rest, extend overnight duty periods, and cap night landings at two instead of six.
Domestic carriers, including IndiGo and Air India, had earlier opposed parts of the framework, but the DGCA rolled them out on the direction of the Delhi High Court, albeit a year later than planned and with some variations for IndiGo and Air India.
