An Air India Express aircraft is displayed at Wings India 2024 aviation event at Begumpet airport, Hyderabad. File / Reuters

Passengers protested at airports as Air India Express faced major disruption in services as 86 flights were cancelled and many were delayed after cabin crew called in mass ‘sick leave’ to mark their protest against the ongoing transition in the airline.

In 2023, the Directorate General of Civil Aviation (DGCA) gave its go-ahead to the Tata Group's initiative to merge the budget airline AIX Connect (previously known as AirAsia India) with Air India Express. Sources said the senior employees, including the cabin crew, are unhappy with the changes.

"The disruptions have cascaded across the network, forcing us to curtail the schedules over the next few days," Air India Express Chief Executive Aloke Singh said in a statement, without giving details of the schedule changes.

More than 100 cabin crew had reported sick prior to their rostered flight duty at the last minute, "severely disrupting our operations", Singh said. Air India Express has mobilised all resources and revised its flight schedule, a spokesperson for the budget carrier said in a statement to Reuters, without providing details about the sick leaves.

Many complained that they would lose their jobs for failing to meet the deadline for joining duty. A lady said she was on an urgent trip to visit her husband in the hospital.

The low-cost subsidiary of India's flag carrier, Air India, said: "We sincerely apologise for the inconvenience caused by unprecedented flight delays and cancellations."

"While we are working hard to minimise disruptions, please check your flight status before heading to the airport," it said in a post on X, formerly Twitter. The airline, which has its primary hub in Kochi, asked passengers to contact its office if their flight was impacted to receive a refund and rescheduling support.

Federal aviation authorities have requested a report on Air India Express's sudden cancellations and asked the airline to resolve issues promptly. The aviation ministry also advised the airline to provide facilities for passengers as per India's Directorate General of Civil Aviation norms.

"A section of our cabin crew has reported sick at the last minute, starting last night, resulting in flight delays and cancellations," the budget carrier said in a statement.

The strike hit the AIE hard as it was in the process of merging with AIX Connect (formerly AirAsia India), streamlining operations and catering to increased demand.

Reports said the airline refused to recognise workers' unions opposed to its broader performance appreciation policy aimed at streamlining operations.

The sudden cancellations and delays, caused by 300 senior cabin crew members reporting sick overnight, affected international and domestic flights.

"I was supposed to leave in the morning. But I am now leaving on an IndiGo flight after sitting here for 3-4 hours," former aviation minister Gulam Nabi Azad, stranded at Delhi airport, said.

"If the flights were cancelled, they should have informed us in the morning itself. Why did they fool everyone? Air India should be shut...Air India's basic culture is bad, nothing will become of it."

The principal opposition Congress party asked the civil aviation minister, Jyotiraditya Sicndia, who was busy with the election campaign, to end the stranded passengers' woes.

In a letter, Congress general secretary KC Venugopal, who was formerly a junior aviation minister, asked him to initiate talks with the striking crew members.

"Air India Express is a low-cost airline that is essential to connect our hardworking middle-class workers across the world to their homeland," he said.

"When 80+ flights are cancelled due to employees' strikes, it causes huge agony to our fellow citizens, especially those in the Middle East."