Airbus has warned that passengers may face travel disruptions ahead of the festive period, after it requested immediate repairs to thousands of its planes.
Around 6,000 planes, roughly half of the European aerospace giant’s global fleet, have been recalled, after it was discovered that strong solar radiation can corrupt data used by aircraft flight-control systems.
It is understood that most of the planes can be fixed with a simple software update, though flight delays and cancellations are expected.
Airbus said the problem was discovered following a recent "incident" in the US involving an A320 family aircraft and apologised for disruption to passengers.
The setback appears to be among the largest recalls affecting Airbus in its 55-year history and comes weeks after the A320 overtook the Boeing 737 as the most-delivered model.
At the time Airbus issued its directive, some 3,000 A320-family jets were in the air.
The world's largest A320 operator, American Airlines, said some 340 of its 480 A320 aircraft would need the fix. It said it mostly expected these to be completed by Saturday with about two hours required for each plane.
Other airlines said they would take planes briefly out of service to do the repairs, including Germany's Lufthansa, India's IndiGo, and UK-based easyJet.
Colombian carrier Avianca said the recall affected more than 70% of its fleet, around 100 jets, causing significant disruption over the next 10 days and prompting the airline to close ticket sales for travel dates through December 8.
There are around 11,300 A320-family jets in operation, including 6,440 of the core A320 model, which first flew in 1987. Four of the world's 10 biggest A320-family operators are major US airlines: American Airlines, Delta Air Lines, JetBlue and United Airlines.
For about two-thirds of the affected jets, the recall will theoretically result in a brief grounding as airlines revert to a previous software version, industry sources said.
But it comes at a time when airline repair shops are already overrun by maintenance work, as hundreds of Airbus jets have been grounded due to long waiting times for separate engine repairs or inspections.
Airbus said a recent incident involving an A320-family aircraft had revealed that solar flares may corrupt data critical to the functioning of flight controls.
Industry sources said the incident that triggered the unexpected repair action involved a JetBlue flight from Cancun, Mexico, to Newark, New Jersey, on October 30, in which several passengers were hurt following a sharp loss of altitude.
That flight made an emergency landing at Tampa, Florida, after a flight control problem and a sudden uncommanded drop in altitude, prompting a Federal Aviation Administration investigation.
JetBlue and the FAA had no comment.
The European Union Aviation Safety Agency late on Friday issued an emergency directive mandating the fix, and the FAA was expected to follow suit.
An Airbus spokesperson estimated the repairs would affect some 6,000 jets in total, mixed between several variants.
The temporary groundings for repairs for some airlines could be much longer since more than 1,000 of the affected jets may also have to have hardware changed, the sources said.
© The Standard Ltd