IndiGo, India's largest airline, is currently grappling with significant operational disruptions, leading to widespread flight delays and cancellations across the country. The situation has caused chaos at airports, with passengers facing long queues and last-minute schedule changes. The Directorate General of Civil Aviation (DGCA) has taken notice of the situation, requesting an explanation from IndiGo and asking for a mitigation plan to address the ongoing issues.

Here are 10 things to know about the factors contributing to the disruptions:

1. New Flight Duty Time Limitation (FDTL) Rules: A primary cause of the disruptions is the recent implementation of new FDTL rules in November. These rules, designed to combat pilot fatigue, mandate increased weekly rest periods of 48 hours and limit night landings for pilots. While intended to improve safety, the new regulations have significantly impacted pilot availability and scheduling, leading to crew shortages.
2. Crew Shortages: The FDTL rules have exacerbated existing crew shortage issues within IndiGo. The airline has struggled to adjust pilot rosters to comply with the new regulations, resulting in a crunch in available crew members.
3. DGCA Investigation: The DGCA is actively investigating the situation and is evaluating measures with IndiGo to mitigate delays and cancellations. The aviation regulator has asked IndiGo to provide a detailed report explaining the causes of the disruptions and outlining a plan for restoring normalcy.
4. Airline Apology and Schedule Adjustments: IndiGo has acknowledged the disruptions and issued an apology to customers for the inconvenience caused. The airline has initiated "calibrated adjustments" to its schedules, effectively cancelling some flights to stabilize operations over the next few days.
5. November Flight Cancellations: Data from the DGCA reveals that IndiGo cancelled 1,232 flights in November, with a significant portion attributed to FDTL issues. Almost 62% of these cancellations were due to crew constraints.
6. Technical Glitches: IndiGo has cited technology issues as another contributing factor to the delays and cancellations. These glitches have reportedly affected passenger boarding processes and overall operational efficiency.
7. Adverse Weather Conditions and Airport Congestion: Adverse weather conditions, particularly during the winter season, and increased congestion at airports have further compounded IndiGo's operational challenges.
8. Impact on On-Time Performance: IndiGo's on-time performance has been severely affected by the disruptions. On December 2nd, the airline's on-time performance plummeted to 35%, the lowest among all scheduled airlines in India. In November, punctuality dropped to 67.7% from 84.1% in October.
9. Pilot Concerns and Operational Planning: Some sources suggest that poor planning and insufficient hiring may have contributed to the severity of the disruptions. Concerns have been raised regarding pilot utilization and the airline's preparedness for the implementation of the new FDTL rules.
10. Airbus A320 Software Patch: An urgent Airbus A320 software patch, implemented at the end of November, further disrupted IndiGo's operations, which were already strained by the new FDTL rules. This mandatory software fix followed an incident involving a JetBlue flight and affected a significant portion of the A320 fleet.