India, Dec. 3 -- IndiGo, India's largest airline, is grappling with one of its most severe operational crises in recent years, with widespread flight delays and cancellations disrupting travel across the country for a second consecutive day.

According to the airline's website, IndiGo operates more than 2,200 flights daily. Government data from Tuesday shows its on-time performance plunging to 35%, implying that over 1,400 flights were delayed in a single day, a dramatic fall for a carrier known for its punctuality.

A major reason behind the operational collapse is a shortage of pilots and cabin crew following the implementation of revised Flight Duty Time Limitation (FDTL) norms last month.

Several flights were grounded due to a shorta...