A major glitch in the passenger service system (PSS) of Air India and its subsidiaries, Alliance Air and Air India Express, led to at least 155 flights getting delayed and an unspecified number cancelled on Saturday. This happened due to the shutdown of Air India’s check-in software for more than five hours early in the morning.

Ail India Chairman and Managing Director Ashwani Lohani said the PSS software, which looks after check-in, baggage and reservation, did not work from 3.30 am to 8.45 am. During the period, thousands of Air India passengers were stranded at airports globally as the airline staff were unable to issue boarding passes to them.

An Air India press statement said senior officials, including the CMD, board directors, station heads and executive directors, rushed to the airports to take control of the situation and also facilitate the harried passengers.

Air India’s PSS is owned and managed by Atlanta-based SITA. Lohani said total 85 flights were delayed till 10 am because of PSS shutdown.

#FlyAI: Our server system SITA, which faced a temporary glitch, this morning was restored at 0845hrs. Air India senior executives, including CMD, Directors, Station Heads rushed to airports to take control of situation & facilitate pax. Flts rescheduled to minimise inconvenience. pic.twitter.com/Np0DgRbQIV

— Air India (@airindiain) April 27, 2019

“Because of the 85 flights that have been delayed a ripple effect will take place throughout the day,” he said in the morning, adding that a few flights would also be cancelled because of this delay.

The average number of flights that Air India group, including subsidiaries Alliance Air and Air India Express, run daily is at least 674. It is mostly the domestic flights that have been affected the most due to the software shutdown, Lohani clarified.

“International departures will not be facing much problem. There will be delay in one or two international flights. One Delhi-Shanghai flight is getting delayed by about 1.5 hrs. The flights that are departing for Europe are largely running on time,” he said.

About affected passengers, the CMD said the airline was trying its best to inform through social media and its call centre. “But as the magnitude is so big, it is possible that our call centre is not able to handle the volume,” he said.

“The passengers who will miss their flights will be given hotel accommodation or they will be rescheduled in a different flight of Air India or of an another airline,” he said. Compensation will be paid to passengers whose flights get cancelled.

Lohani said SITA was currently looking into what caused the shutdown. “They are checking if it was because of virus or for any other reason. They are still searching for the root cause,” Lohani said.

No other airline apart from Air India uses SITA’s PSS software. When asked if SITA would be compensating the airline for disruption in the operation , the CMD replied: “We will have to take a look into it.”

SITA regretted the inconvenience caused and said it had experienced a complex system issue during server maintenance early morning which resulted in operational disruption of flights.

“We have now fully restored services at all airports where Air India was affected. Our priority remains as always to ensure a stable system where customers can conduct business efficiently and we are undertaking a full investigation to understand the root cause and prevent a recurrence,” SITA said in a statement.

When asked why passengers were not informed about flight delays through SMS or social media during shutdown, Lohani said, “Whenever any other system does not function properly we use PSS to get contact information of passengers and then contact them. But when our PSS itself has stopped working there is no way we can inform them.”

A similar incident took place on 23 June last year when there was a technical glitch in the airline’s check-in software.

Passengers took to social media to express their anger as thousands were stranded globally across airports because of the system glitch.