One of the world’s largest airplane makers said Friday that intense solar radiation may corrupt data critical to flight controls on a “significant number” of its most popular aircraft, prompting a swift response from several airlines. Airbus attributed the revelation to a recent analysis involving its A320 family of aircraft.

Airbus has decided to ground more than 6,000 A320 jets to implement an urgent software update nearly a month after a JetBlue flight suddenly lost altitude mid-flight and sent at least 15 passengers to the hospital.

After Airbus ordered software fixes to 6,000 A320-family jets on Friday, Fort Worth-based American Airlines says all of theirs have been repaired.

Here are real, documented impacts of high-energy radiation on aircraft systems: GPS receivers can lose accuracy or momentarily glitch. Flight-control computers (like Airbus ELAC or FAC units) may register incorrect data. Pilots may see warnings, frozen screens, or incorrect data.

The incident that sparked the recall happened on Oct. 30. The European Union Aviation Safety Agency issued a directive on Friday reporting that a JetBlue flight experienced an “uncommanded and limited pitch down event.” Airbus later determined “intense solar radiation” was likely responsible for corrupting data vital to flight controls.

European jet-maker Airbus on Friday said that a “significant number” of its A320 aircraft could be affected by a technical issue stemming from solar radiation, raising the risk of flight disruptions during the busy holiday-travel season, although major U.S. carriers tried to downplay the impact.

Travelers heading home from Thanksgiving break could see delays this weekend as airlines race to patch a software vulnerability linked to intense solar radiation. Airbus and European safety regulators confirmed Friday that the issue,