Air travel across India was in turmoil for a fourth day after IndiGo cancelled around 500 flights on Friday, including all from the capital New Delhi, after failing to plan for new pilot flying time regulations.
Some relief may be in the offing, however, after authorities granted the country's biggest airline a temporary exemption from stricter night duty rules for pilots.
At major airports across the country, crowds of long-stranded passengers could not hold back their frustration, aggressively arguing with staff.
IndiGo, which commands 60 per cent of India's aviation market, has flagged that it does not expect to fully restore operations until February 10. It has not said when it expects an end to the daily mass cancellations.
New Indian pilot duty rules, announced last year and which went into effect on November 1, increased the amount of mandatory rest per week for pilots by 12 hours to 48 hours. In addition, pilots are now only allowed to make two night-time landings per week, down from six under the old rules.
Friday's exemption allows IndiGo to be exempt from the night-duty rule until February 10.
IndiGo in a statement said the disruptions have arisen primarily from "misjudgment and planning gaps".
Other Indian airlines have not had to cancel flights due to the new rules.
On Friday, Delhi airport announced all IndiGo departures were cancelled for the day, a number that a source put at 235 flights. Chennai airport also announced all departure flight from the airline to other major metro airports were cancelled up to 6 pm on Friday.
IndiGo will also cancel 104 flights in Mumbai, 102 in Bengaluru, 92 in Hyderabad, airport sources familiar with the developments said.
The sources declined to be named as they were not authorised to share the information. IndiGo did not respond to Reuters queries.
Shares of IndiGo dropped nearly 3 per cent on Friday, taking their weekly slump to 10.3 per cent.
India's main opposition party has demanded a discussion on the issue in parliament.
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