EASA Orders Immediate Airbus A320 Flight Control Software Changes

Operators of some 6,000 Airbus A320-family aircraft scrambled over the weekend to undertake software modifications to mitigate the risk of uncommanded flight control inputs from what the manufacturer terms "intense" solar radiation.

A European Union Aviation Safety Agency (EASA) emergency airworthiness directive (EAD) issued Nov. 28 and effective Nov. 29 orders operators to ensure their aircraft have "serviceable" elevator aileron computers (ELACs) before further flights. The EAD is based on a Nov. 28 Airbus message to all operators.

The EASA action was followed by the FAA, which also issued an EAD requiring airlines the modify the software by 12.01 a.m. on Nov. 30 and before aircraft fly again. 545 aircraft registered in the U.S. are affected.

Through Nov. 29, the issue lead to relatively minor flight disruptions overall as many airlines tried to make the needed change during overnight stops on as many aircraft as possible, in spite of the large number of impacted aircraft.

The issue affects around 60% of the global A320 fleet, including first generation A320s and the newer A320neo variants as well as A319s and A321s in each case. Most ELACs can be fixed by reverting to a previous version of recently-updated software, Airbus said.

But about 1,000 of the oldest affected aircraft need a hardware change to accept the new software. These airframes will need the old hardware re-installed--a process that will take longer.

Airbus identified the issue during its probe into an Oct. 30 incident involving a JetBlue A320. The aircraft, en route to Newark from Cancun, suddenly lost altitude while in cruise.

An A320 "recently experienced an uncommanded and limited pitch down event," EASA's EAD said, without identifying the specific flight. "The autopilot remained engaged throughout the event, with a brief and limited loss of altitude, and the rest of the flight was uneventful. Preliminary technical assessment done by Airbus identified a malfunction of the affected ELAC as a possible contributing factor."

The aircraft had the newest ELAC software installed. Airbus determined reverting to the previous version eliminates the risk.

"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 manufacturer explained in a statement. "Airbus has worked proactively with the aviation authorities to request immediate precautionary action from operators via an Alert Operators Transmission (AOT) in order to implement the available software and/or hardware protection, and ensure the fleet is safe to fly," it added.

The exact combination of factors that may cause the unsafe condition remains unclear.

“The fix required on some A320 aircraft has been causing significant logistical challenges and delays since yesterday,” Airbus CEO Guillaume Faury wrote on LinkedIn Nov. 29. “I want to sincerely apologise to our airline customers and passengers who are impacted now. But we consider that nothing is more important than safety when people fly on one of our Airbus aircraft.”

Faury stressed that “our teams are working around the clock to support our operators and ensure these updates are deployed as swiftly as possible to get planes back in the sky and resume normal operations, with the safety assurance you expect from Airbus.”

American Airlines said in the morning of Nov. 29 that only four of 209 impacted aircraft had yet to receive the change. The airline expected “no further” operational disruption.

In Europe, EasyJet, the largest A320 operator, said that it had completed the software change on all of its operational aircraft and that it plans to operate a normal schedule on Nov. 29. Lufthansa Group, the second largest European customer, did not expect any cancellations. Hungarian low-cost airline Wizz Air confirmed it had completed the software change overnight.

In India, IndiGo had made the fixes on about 75% of the 200 affected aircraft on Nov. 28 and had no cancellations. Air India and Air India Express had to work on close to 140 aircraft and had completed changes on about one third of them as of late Nov. 28. Air India Express had to delay eight flights.

Avianca said that 70% of its fleet is affected by the software upgrades. “While we’ve already started implementing the required updates, we know this will inevitably cause significant changes to our operations over the next 10 days,” the airline stated. It closed ticket sales until Dec. 8.

Jetstar Airways in Australia and All Nippon Airways (ANA) cancelled around 90 flights each.

Solar radiation can spike because of space weather. It is typically associated with coronal mass ejections from the Sun. Strong solar storms can cause disruptions to systems such as power grids and navigation satellite systems, the National Oceanic and Atmospheric Administration says. The activity is cyclical and, NOAA notes, 2025 is a year of peak activity in the current solar weather cycle.

The global in-service A320 fleet totals about 9,900, excluding nearly 900 in storage, Aviation Week Fleet Discovery shows. The directive covers about 60% of the in-service fleet.