The Indian Air Force, which first detected the signal, has submitted a report indicating that the false alarm was likely the result of a technical error
India’s aviation regulator, the Directorate General of Civil Aviation (DGCA), suspects that a technical fault in the transponder system may have triggered a false hijack alarm on an Air India flight last month, prompting emergency responses at two major airports.
The incident occurred on 27 January when Air India flight AI 2957, carrying 126 passengers from New Delhi to Mumbai, transmitted a “squawk 7500” code shortly after take-off. The four-digit code specifically signals a hijack attempt and remained active for three minutes before being deactivated. Despite the pilot’s immediate clarification that the signal was accidental, authorities were bound to follow full emergency protocols.
The Indian Air Force, which first detected the signal, has submitted a report indicating that the false alarm was likely the result of a technical error. “As of now, it’s appearing to be an error in codes,” a Ministry of Civil Aviation official confirmed.
Transponders in aircraft use codes between 0000 and 7777 to convey different emergency situations to air traffic control. While code 7500 denotes a hijack attempt, 7600 signals radio failure, and 7700 indicates a general emergency. Aviation experts suggest that overlapping or accidental entry of these codes is highly uncommon, warranting a thorough investigation.
Following the alarm, a central emergency committee comprising the police, the Central Industrial Security Force, the Airports Authority of India (AAI), the Bureau of Civil Aviation Security, and the Air Force was formed in Delhi. In Mumbai, where the flight landed at 9.47 pm, authorities declared a full emergency, deploying the National Security Guard, local police, and other security agencies.
The aircraft was directed to an isolation bay, where passengers were only allowed to disembark after an hour-long security verification. “The pilot repeatedly insisted that the plane had not been hijacked and that it had been a regular flight,” a Mumbai airport official said.
Aviation experts have called for a deeper probe into the incident. “The incident can be possible either when someone accidentally entered the code wrong or if there is a technical issue with the transponder of the aircraft. The code in the ATC system will only reflect what the aircraft sends,” said aviation expert Mohan Ranganathan.
Another former AAI official added, “The pilots seem void of folly as the airline would have evaluated the Flight Data Recorder (FDR). However, a technical glitch or a malfunction seems like a remote possibility. The incident needs a thorough study.”
Air India has not officially commented on the matter. The DGCA has requested a detailed report from the AAI and is continuing its investigation into the cause of the alarm. The outcome of the inquiry will be crucial in determining whether further regulatory changes are required to prevent such incidents in the future.
