India, Feb. 10 -- IndiGo has increased its crew buffer from zero in December to 3% in February and raised its pilot-to-aircraft ratio, improvements that have led government officials to expect minimal disruption when exemptions on pilot rest periods expire on February 10, according to officials aware of the matter.

The build-up in pilot strength comes as the airline prepares to resume full compliance with flight duty time limitation (FDTL) norms that triggered operational collapse in December, when IndiGo cancelled over 5,000 flights and drew a record Rs.22.2 crore penalty from aviation regulators alongside accountability action against its top leadership.

The December crisis forced DGCA to grant temporary exemptions on December 6, allo...