India's biggest airline IndiGo faced a growing crisis, with more than 300 flights cancelled since Tuesday, leaving thousands of passengers stranded nationwide.
Delhi, Mumbai, Hyderabad and Bengaluru - among India's busiest airports - were worst hit.
The airline blamed technical glitches, weather and new crew rostering rules for the disruption.
The budget airline, one of India's largest with over 60% domestic market share, links major metros and smaller cities.
IndiGo said it had made "calibrated adjustments" to its schedule until Friday to stabilise operations.
