Europe’s Airbus said on Friday it was ordering an immediate software change on a significant number of its best-selling A320 family of jets in a move that industry sources said would involve some 6,000 jets, or over half the global fleet.

Airbus said in a statement a recent incident involving an A320-family aircraft had revealed that intense solar radiation may corrupt data critical to the functioning of flight controls.

“Airbus acknowledges these recommendations will lead to operational disruptions to passengers and customers,” the company said.

The European Union Aviation Safety Agency will issue an emergency airworthiness directive, Airbus said.

For about two-thirds of the affected jets, the recall will result in a relatively brief grounding as airlines revert to a previous software version, industry sources said.

But the scale of the operation is expected to cause significant disruption, emerging just ahead of the busiest travel weekend of the year in the United States.

Hundreds of jets may also have to have hardware changed, leading to weeks out of service.

The incident that triggered the sweeping repair action involved a JetBlue flight from Cancun, Mexico, to Newark, New Jersey, on October 30, industry sources said.

Flight 1230 made an emergency landing at Tampa, Florida, and several people were taken to hospital after a flight control problem and a sudden uncommanded drop in altitude.

According to Airbus data, there are around 11,300 A320-family aircraft in operation, including 6,440 of the core A320 model.