Intense solar radiation has exposed a critical vulnerability in Airbus A320 family aircraft software, leading to the grounding of thousands of planes worldwide until fixes are applied, marking the largest recalls affecting the company in its 55-year history.

The issue affects the Elevator Aileron Computer (ELAC B) with software version L104, which calculates elevation and controls flight surfaces, causing potential data corruption at high altitudes during solar flares.

This prompted the European Union Aviation Safety Agency (EASA) to issue an Emergency Airworthiness Directive (EAD) on November 28, 2025, mandating repairs before passenger flights resume.

WHAT HAPPENED?

The problem surfaced during a JetBlue Airways A320 flight (B6-1230) from Cancun to Newark on October 30, when the plane experienced an uncommanded pitch-down at 35,000 feet, injuring at least 15 passengers and forcing an emergency landing in Tampa, Florida.

Airbus’s investigation linked the sudden altitude loss, brief but severe enough to exceed normal limits, to solar radiation corrupting ELAC data, though the autopilot corrected the trajectory.

This marked the only known incident, but analysis revealed broader risks across A320ceo and A320neo variants.

FLY-BY-WIRE VULNERABILITY

A320 family planes pioneered “fly-by-wire” technology, where cockpit controls send electronic signals processed by computers like the ELAC to adjust elevators and ailerons, eliminating mechanical linkages for efficiency and safety.

Solar flares, intense bursts of charged particles from the sun travelling at light speed, can penetrate aircraft electronics at cruising altitudes, flipping bits in memory and corrupting elevation calculations in vulnerable L104 software.

In the worst cases, uncorrected faults could trigger uncommanded elevator movements, risking structural damages.

FIXES AND GLOBAL IMPACT

Airlines must revert ELAC software to L103 or replace the hardware, a process taking about three hours per plane, before the next revenue flight; passenger-free “ferry flights” (up to three cycles) allow relocation to maintenance sites.

Roughly 6,000 aircraft, nearly half Airbus’s single-aisle fleet, are affected, impacting carriers like American Airlines, Delta, and IndiGo, with disruptions during peak holiday travel.

Airbus and EASA prioritise safety, apologising for delays while coordinating rapid implementation.

BROADER AVIATION RISKS

Solar activity peaks every 11 years, with the current cycle heightening radiation events that already disrupt high-altitude communications; this flaw underscores growing dependencies on radiation-hardened avionics amid climate-driven space weather monitoring needs.

Future mitigations may include shielded processors or real-time solar alerts, but immediate groundings prevent repeats.

Global regulators echo the urgency, ensuring no passenger flights until verified safe.

– Ends