Delays hit major carriers after Airbus issued an alert on Friday that as many as 6,000 active A320 aircraft might need immediate software updates, a directive that created severe pressure on airlines during one of the busiest travel weekends of the year.

Many airlines in the US felt the impact within hours of the order, which forced rapid checks and unexpected groundings across multiple regions.

The scale of the action appears to be one of the biggest recalls in Airbus’s 55-year history and arrived weeks after the A320 overtook the Boeing 737 as the most-delivered aircraft model.

The directive, among the largest ever undertaken by Airbus, spilled into the US holiday travel and reached as far as Australia. The disruption, which analysts linked to solar flares that interfered with the software, hit Asia with particular force.

The A320 family anchors dense short-haul networks from India to Japan, where passenger demand has climbed rapidly.

Asian airlines scrambled to fix the software glitch on their Airbus A320 fleets.

India’s aviation regulator DGCA (Directorate General of Civil Aviation) said 338 Airbus jets in the country were affected but insisted the software reset would be completed by Sunday.

Air India, which has 113 impacted aircraft, completed the reset on 42. IndiGo, the country’s largest airline, completed the software reset on 143 out of 200 aircraft, the DGCA said.

Both airlines warned of delays on Saturday. “There isn’t any major impact on schedule integrity across our network,” Air India wrote on X. “However, some of our flights may be slightly delayed or rescheduled.”

Taiwan’s Civil Aviation Administration instructed airlines to conduct inspections and maintenance and estimated that nearly two-thirds of the 67 A320 and A321 aircraft operated by the island’s carriers were affected.

Japan’s ANA Holdings (9202.T), the country’s largest airline, cancelled 65 flights on Saturday and warned of more disruption on Sunday. ANA and its affiliates, including Peach Aviation, operate Japan’s largest Airbus narrow-body fleet, while Japan Airlines relies primarily on Boeing aircraft.

American Airlines notified travelers on Friday that it expected some operational delays due to the software change. The carrier initially said about 340 aircraft were affected, but after it received clarification from Airbus, American said 209 A320 family aircraft needed updates — far fewer than first believed. It expected most of the remaining work to finish overnight, with only a small number of planes left to update for Saturday.

United Airlines said only six aircraft in its fleet were affected and expected limited disruption to a few flights.

Alaska Air said it was not experiencing any disruption from the Airbus software fix and that its operations would continue normally unless further notice was issued.

Globally, about 11,300 single-aisle jets are in service, including 6,440 from the core A320 line.

The fix involves reverting to earlier software. Engineers across multiple continents described the procedure as simple but non-negotiable: no aircraft could return to the skies until the reset was complete.

Airbus did not provide a timeline for full normalisation but said it was coordinating with carriers to clear backlogs as soon as possible.