Colombia’s Transport Minister María Fernanda Rojas said on Monday that Avianca is close to completing mandatory software updates on its Airbus A320 fleet, with only 19 aircraft still pending intervention after a week of global disruptions triggered by what aviation experts describe as the largest recall in Airbus’s 55-year history.

The grounding forced airlines across several continents to halt operations, rebook thousands of passengers, and reconfigure flight schedules during one of the busiest travel periods of the year.

According to Aerocivil, Colombia’s Civil Aviation Authority, 102 of Avianca’s 124 grounded A320 aircraft are now back in service following an accelerated technical effort led in coordination with Airbus technicians. The remaining aircraft are expected to be updated within three days at Avianca’s main maintenance base at Rionegro, Antioquia. Authorities fast-tracked the import of 10 additional software units from France after Colombian regulators, the Ministry of Transport, and the tax agency DIAN jointly cleared an emergency customs process over the weekend.

Latam Airlines and JetSMART, the two other carriers in Colombia operating affected A320s  have already completed updates on their six combined jets. The minister said the rapid turnaround reflects “an unprecedented level of coordination” between airlines, regulators and Airbus engineers, who were deployed across several countries to help implement the corrective measures.

Globally, airlines said operations were returning to normal on Monday, after the grounding struck at a sensitive time for the global aviation industry. The Airbus A320, which only weeks ago overtook the Boeing 737 as history’s most-delivered jetliner, also faces long-term maintenance bottlenecks that have left hundreds of aircraft parked and waiting for parts under the pressure of post-pandemic demand.

The crisis also hit Airbus at a moment when the European manufacturer was stepping up efforts to meet its year-end delivery targets. Signals of lower-than-expected deliveries for November have already rattled investors, and the grounding added further uncertainty to an already tight production schedule. Shares of major Airbus customers — including Lufthansa and easyJet — fell on Monday amid concerns that delivery timelines could slip further. According to Reuters several deliveries have already been impacted, though the extent and duration remain unclear; one industry insider estimated around 50 aircraft could face delays.

Adding to Airbus’s challenges, the company on Monday confirmed a separate quality issue involving metal fuselage panels on a “limited number” of A320 aircraft. While the defect does not pose an immediate safety risk, Airbus said it is taking a “conservative approach” by inspecting all aircraft that could potentially be affected. The announcement sent Airbus shares tumbling as much as 6% during early trading, heightening market anxiety already fueled by the software crisis and flight disruptions.

The initial software alert was triggered after Airbus analyzed data from a recent in-flight incident and concluded that intense solar radiation under certain conditions could corrupt data linked to the aircraft’s flight-control computers. The disruptions rippled across major hubs in Latin America and the United States, coinciding with the U.S. Thanksgiving travel weekend, one of the busiest periods of the year.

Delta and American Airlines were forced to delay or cancel flights as dozens of A320 jets were pulled from service for urgent inspections. “Airbus apologises for any challenges and delays caused to passengers and airlines by this event,” the manufacturer said in a statement.

For Colombia’s flagship carrier and one of the world’s largest A320 operators, the near-completion of the updates marks a significant recovery after days of cancellations, rebookings and schedule reshuffling. The airline will reopen ticket sales on December 5 as its domestic and international network returns to full capacity and the remaining 19 jets are certified to fly.

Colombia’s flagship carrier, Avianca, announced Friday it has grounded more than 70% of its Airbus A320 fleet after the European manufacturer issued an urgent global bulletin ordering operators to carry out immediate software updates to prevent potential flight-control failures.

The disruption, one of the most severe to hit the airline in years, comes as Airbus launched one of the largest fleet-wide recalls in its history, affecting some 6,000 A320 commercial aircraft worldwide — more than half of the global fleet. The A320 is the world’s most widely used single-aisle airliner and the backbone of Avianca’s operations across Latin America and to U.S and Canadian hubs.

There are around 11,300 A320 jets in operation in total.

In a statement, Avianca said Airbus notified operators on November 28 that a significant portion of A320 require a mandatory software modification. The update, which Airbus described as reverting to an earlier software version, must be applied before affected aircraft can resume flights, except for ferry operations to maintenance bases.

“As soon as the aircraft reach their maintenance bases, they must remain on the ground until the updates are completed,” Avianca said. “This order affects more than 70% of Avianca’s fleet.”

The airline warned that the grounding will trigger significant operational disruptions over the next 10 days as engineers work to install the update across its aircraft. To limit further complications and manage passenger flow, Avianca has temporarily closed ticket sales for travel dates through December 8 — an extraordinary measure taken to “reorganize its capacity and re-accommodate passengers on available flights.”

Customers with upcoming reservations will receive direct notifications from the airline detailing their travel options.

The update requirement has already led to cascading delays and cancellations across several regions. Reuters reported that, at the time Airbus issued its notice to more than 350 operators, roughly 3,000 A320 aircraft were airborne. Airlines in the United States, Europe, South America, India and New Zealand said the repairs could trigger operational disruption during one of the busiest travel weeks of the year.

American Airlines, the world’s largest operator of the A320 family, said about 340 of its 480 aircraft require the fix. The carrier expects the majority of updates to be completed by Saturday, estimating about two hours of work per jet. Delta Airlines said updates to a small portion of its Airbus A320 planes will likely be completed by Saturday morning, a spokesperson said.

Avianca, however, expects the impact to last longer given the scale of its grounded fleet in Latin America and the limited availability of maintenance slots at Bogotá’s El Dorado International Airport.

The airline said its priority is passenger and crew safety and that it is working “as quickly as possible” to complete the mandatory modifications and restore normal operations.

To mitigate the fallout, Avianca is offering several options to affected passengers:

• Rebooking on the nearest available Avianca flight or on partner airlines with which it has commercial agreements.

• Flexible changes, allowing travelers to reschedule without penalty fees or fare differences, subject to availability, for up to 180 days after the original travel date.

• Refunds for unused flight segments through the airline’s website, call center, sales offices or travel agencies.

Avianca urged customers not to go to the airport unless their flight has been confirmed and to closely monitor email notifications associated with their reservation, as well as updates on its official channels.

Despite the scale of the disruption, the airline said the swift grounding demonstrates its commitment to safety while complying with Airbus’ unprecedented directive.

“The priority of Avianca is to ensure the safety of our passengers and crew,” the company said, adding that it aims to complete the required modifications as soon as possible to “minimize service disruptions.”