Last week, Manjuri carried her husband's coffin from one town to another in India's northeast region, hoping to catch a flight that would take her hundreds of miles away - to Kolkata city - for his final farewell.

But the difficult journey turned unbearable when delays by IndiGo, the country's largest airline, left her stranded for hours before the flight was finally cancelled.

Manjuri was one of hundreds of thousands of passengers whose plans were upended as IndiGo's sudden wave of cancellations pushed India's aviation sector into one of its worst crises in years.

A trickle of delays suddenly became more than 1,000 cancellations on 5 December, stranding families and causing people to miss weddings, funerals and vital exams.

Once the poster child of India's low-cost aviation boom - commanding a 60% market share and 2,000 daily flights - IndiGo now risks losing its hard-won reputation as the country's reliable, no-frills carrier, experts say.