Airbus grounded some 6,000 A320-family jets after a flight-control software fault

On 28 November 2025, Airbus ordered a precautionary grounding of the A320 family — roughly 6,000 jets worldwide — after a JetBlue A320 made an uncommanded descent in flight. It was the largest fleet action in Airbus's 55-year history, and airlines had to scramble to find aircraft to cover routes through the holiday weekend.

The manufacturer traced the fault to the ELAC flight-control computer software. Investigators found evidence that a software update designed to protect against in-flight loss of control had been corrupted by solar radiation — single-event upsets flipping bits in avionics memory — so the computers began commanding the aircraft to follow a flight path the pilots had not asked for.

Airbus said the affected jets needed a software fix before they could return to service, and it worked with airlines to roll the update out. The JetBlue aircraft landed safely, but the grounding rippled through global aviation, with carriers forced to cancel or re-time hundreds of flights and lease spare aircraft to cover demand.

The grounding of about 6,000 A320-family jets worldwide cost Airbus an estimated $1.2 billion in lost revenue and compensation.

A software update intended to protect against loss of control was corrupted by a single-event upset from solar radiation, flipping bits in flight-control memory.

The ELAC flight-control computers acted on the corrupted data and commanded an uncommanded descent, so a data error became a physical control input.

Because the fault was latent in the software base shared by the whole A320 family, Airbus had no local fix and grounded the entire fleet rather than risk a repeat.

Aviation safety software must be hardened against single-event upsets — solar radiation can flip bits in flight-control memory; a latent fault in a shared software base can ground a fleet at once.

Airbus worked with airlines to roll out a software fix so affected jets could return to service, while carriers covered the grounding by re-timing flights and leasing spare aircraft.