Airlines around the world have rushed to roll back software that powers Airbus A320 planes after the aviation giant discovered a recent update could put the aircraft in danger.
This story starts on October 30th, when flight 1230 operated by US airline JetBlue made an unplanned diversion to Florida’s Tampa International Airport, interrupting its journey from Cancun to Newark. According to a US Federal Aviation Administration statement, “the crew experienced a flight control issue.”
At the time, CNN reported the plane experienced “a sudden drop in altitude” that caused injuries to around 15 passengers. ABC News reported “up to 20” injuries.
In the following days and weeks, the incident seemingly faded into history – until November 28th when Airbus published a press release that opened “Analysis of a recent event involving an A320 Family aircraft has revealed that intense solar radiation may corrupt data critical to the functioning of flight controls.”
The same day, the European Union Aviation Safety Agency (EASA) published an Emergency Airworthiness Directive to address “an issue which manifested itself in an event on JetBlue flight 1230 on October 30, 2025.”
The Directive [PDF] explained the incident as follows:
The “ELAC” mentioned above is the elevator and aileron computer that drives the elevator, a hinged flap on the trailing edge of the horizontal stabilizer – the aerodynamic surfaces that look like little wings at the back of a plane.
Horizontal stabilizers are effectively upside-down wings because they create downward pressure to balance the lift created by the main wings. Elevators vary the amount of downward force to help push a plane’s nose up or down
Whatever was wrong with the ELAC meant the elevators pushed Flight 1230’s nose down, sharply and suddenly.
Remember the phrase “exceeding the aircraft’s structural capability” above? That means Airbus found the ELAC could move the elevators in ways that could break the A320.
Which is why Airbus, EASA, and other aviation authorities ordered a fix of all A320s with the problem, ASAP.
“These measures may cause short-term disruption to flight schedules and therefore inconvenience to passengers,” the EASA stated.
That’s an understatement because Airbus identified around 6,000 planes that need the fix.
Fixing an ELAC
Fixing the ELAC required rollback of a recent Airbus software update.
Industry sources tell The Register that the procedure required about three hours of work.
Airlines around the world scrambled to make the fix, but many couldn’t avoid delays to their schedules. One reason for those delays was that the equipment to install the software wasn’t available at every airport, a situation the EASA acknowledged by allowing airlines to fly planes without passengers to a location where they could do the necessary work.
A320 pilot Arjun Singh has identified the problematic software release as “L104” and said the rollback was to version “L103+”.
Left unexplained, for now, is exactly how intense solar radiation corrupts data.
That radiation can impact comms is not in dispute: Solar flares disrupt communication on Earth and in orbit. The Register has seen theories suggesting that L104 may not have recognized data corrupted by solar radiation and the ELAC therefore acted on bad data and issued erroneous and dangerous instructions.
Airbus CEO Guillaume Faury has apologized for the mess.
“The fix required on some A320 aircraft has been causing significant logistical challenges and delays since yesterday,” he wrote on Sunday. “But we consider that nothing is more important than safety when people fly on one of our Airbus aircraft – like millions do every day,” he added.
Faury also surely realized that this incident shared many characteristics with the 2018 and 2019 crashes involving Boeing 737 Max aircraft, in which faulty software was found to have caused hundreds of deaths. Boeing’s reputation remains stained by that incident, as does its balance sheet and share price.
At the time of writing, FlightRadar24 reports major delays in some parts of the northeast USA. Things may yet worsen as The Register finished this story at around 05:15 UTC on December 1st, a quiet time for commercial aviation. ®
