New Delhi, Dec. 8 -- The week-long disruption at IndiGo-India's largest airline-resulted in more than 1,500 flight cancellations and widespread delays across major airports, prompting the Directorate General of Civil Aviation (DGCA) to issue a show-cause notices to chief executive officer (CEO) Pieter Elbers and other executives for failing to ensure reliable operations.

The crisis has deeper roots in a decade-long legal dispute over the rights of pilots to regulated work hours and strict enforcement of fatigue-mitigation norms.

Before IndiGo went into chaos, a contempt plea was already pending in the Delhi High Court alleging that the DGCA had failed to implement the new pilot Flight Duty Time Limitations (FDTL), contrary to its undert...