India's aviation watchdog has issued a stern warning to Air India for violating safety regulations after it was discovered that three of its Airbus aircraft flew despite overdue checks on emergency equipment. The Directorate General of Civil Aviation (DGCA) also criticised the airline for its slow response to the issue, according to government documents.

These warnings and investigation report, which were reviewed by Reuters, are not related to last week's crash of an Air India Boeing 787-8 that killed all but one of the 242 people onboard. They were issued days prior to this incident. In May, spot checks on three Air India Airbus planes revealed that they had been operated despite mandatory inspections being overdue on their "critical emergency equipment" of escape slides. In one instance, the DGCA found that the inspection of an Airbus A320 jet was delayed by over a month before finally being carried out on May 15.

AirNav Radar data indicates that during this delay, the plane flew to international destinations such as Dubai, Riyadh, and Jeddah.

Another case involved an Airbus A319 used on domestic routes, where checks were over three months late, while a third case showed an inspection was two days late.

The DGCA report said: "The above cases indicate that aircraft were operated with expired or unverified emergency equipment, which is a violation of standard airworthiness and safety requirements."

Air India also "failed to submit timely compliance responses" to issues highlighted by the DGCA, "further evidencing weak procedural control and oversight".

The airline, which was acquired by the Tata Group from the government in 2022, has stated that it is "accelerating" the verification of all maintenance records, including those of escape slides, and aims to complete this process in the coming days.

The DGCA reported that any aircraft missing mandatory checks would have their certificates of airworthiness "deemed suspended".

Animesh Garg, a deputy director of airworthiness in the Indian government, sent warning notices and the report to Air India CEO Campbell Wilson, as well as the airline's continuing airworthiness manager, quality manager and head of planning.

The junior aviation minister of India revealed in February that airlines had been warned or fined on 23 occasions for safety violations last year.

Air India and Air India Express were involved in half of these instances - 12 in total, including one case for "unauthorised entry into cockpit". 

The heftiest fine was $127,000 (£94,000) imposed on Air India for "insufficient oxygen on board" during a flight to San Francisco. 

Air India has been approached for comment.