Critical update completed on 80% of affected Airbus A320 family planes in India; no major impact on flight ops

As per data shared by the DGCA, a total of 338 Airbus A320 family aircraft of Indian airlines—IndiGo, Air India, and Air India Express—were identified as planes that required rectification action prescribed by Airbus late Friday. The required action, which typically takes around a couple of hours, was completed on 270 of those aircraft as of 5:30 pm Saturday. The required rectification action on the remaining 68 aircraft was likely to be completed on Saturday itself, according to the regulator.

Officials said that there was no need for passengers to panic as the impact on flight operations is not significant. Indian carriers have largely been able to avoid flight cancellations, and managed to limit the disruption to some delays and rescheduling of flights. Apart from four Air India Express flights, DGCA did not report any flight cancellations due to this issue as of Saturday evening. Despite the very short downtime for implementing the fix, some delays were unavoidable as a narrow-body jet typically operates multiple flights in a day and delays can quickly cascade.

The necessary changes had already been carried out on 184 of 200 IndiGo aircraft that required rectification action, as of 5:30 pm Saturday. In the case of Air India, it was completed on 69 of the 113 affected aircraft. As for Air India Express, the required changes were made on17 of the 25 affected planes. In all, IndiGo has around 370 A320 family jets in its fleet, Air India has 127, and its low-cost arm Air India Express operates 40 A320 family aircraft. But not all aircraft required software changes or any hardware realignment.

European aerospace major Airbus on Friday said that a large number of its best-selling narrow-body A320 family aircraft will require an immediate software change, with some requiring hardware modifications as well. The urgent rectification action, required to be taken before the next scheduled flight of each affected aircraft, was mandated for thousands of jets globally and over 300 in India. It was prescribed after Airbus learnt that intense solar radiation could corrupt data critical to flight controls. There are over 11,000 A320 family aircraft in operation globally, and over half of those are estimated to be affected by the issue.

Shortly after the announcement from Airbus, the European Union Aviation Safety Agency (EASA) issued an Emergency Airworthiness Directive (AD) requiring operators of the affected A320 family jets to implement the solutions prescribed by Airbus “before next flight”. The DGCA also issued a mandatory modification circular for Indian airlines to carry out the required changes.

“An Airbus A320 aeroplane recently experienced an uncommanded and limited pitch down event. The autopilot remained engaged throughout the event, with a brief and limited loss of altitude, and the rest of the flight was uneventful. Preliminary technical assessment done by Airbus identified a malfunction of the affected ELAC (elevator aileron computer) as possible contributing factor. This condition, if not corrected, could lead in the worst-case scenario to an uncommanded elevator movement that may result in exceeding the aircraft’s structural capability,” the EASA AD said.

ELAC is a flight control computer that processes pilot input to control the aircraft’s elevators and ailerons, which control the pitch and roll of the aircraft. A specific ELAC hardware and software combination was seen as the vulnerability that made the computer susceptible to data corruption due to solar flares or radiation. The fix prescribed by Airbus for the bulk of the affected aircraft involved a software change in the ELAC. In some older aircraft, the ELAC itself needed replacement.

For IndiGo, the base stations where software upgrade is being undertaken include Delhi, Bengaluru, Mumbai, Chennai, Hyderabad, Ahmedabad, and Kolkata. Air India is carrying out the changes at Delhi, Bengaluru, Mumbai, Hyderabad, Kolkata, and Chennai, while Air India Express is doing it at Delhi, Bengaluru, and Chennai.