New Delhi, Dec. 4 -- IndiGo, India's largest airline, was plunged into deeper chaos on Thursday after new pilot rest-period norms crippled its rostering system, forcing the cancellation of over 180 flights from major airports across the country.

The cascading delays - now entering their third day - have stranded thousands of passengers across major airports and triggered renewed scrutiny of the airline's planning and preparedness.

The turmoil stems from stringent flight duty time limitations (FDTL) introduced by India's aviation regulator to combat pilot fatigue.

IndiGo has acknowledged that these updated safety norms have had a significant impact on operations, saying earlier this week that cancellations were driven by "various factor...