Radiation from space that led to more than 6,000 Airbus aircraft needing emergency computer updates could become a growing problem as ever more microchips run our lives.

"We need medical equipment," the pilot of a JetBlue passenger jet announced over the radio to air traffic control. His plane, an Airbus A320 commercial airliner had suddenly and unexpectedly dropped altitude during a flight from Cancun, in Mexico, to Newark, in New Jersey, US, on 30 October 2025. Three people appeared to have suffered "a laceration in the head", the pilot said. At least 15 people were later taken to hospital when the flight landed after being diverted to Florida.

A month later, this incident would lead to the mass grounding of more than 6,000 aircraft – one of the largest ever aviation industry recalls. It triggered widespread disruption and cancellations over the final weekend of November 2025, one of the busiest of the year for air travel following Thanksgiving in the US.

What caused all this? Tiny, high-energy particles from outer space, according to Airbus.

An initial investigation by the company revealed that the sudden drop in altitude was linked to a malfunction in one of the aircraft's computers that controls moving parts on the aircraft's wings. The malfunction seems to have been triggered by cosmic radiation bombarding the Earth on the day of the flight.

According to emergency airworthiness directives issued by both the European Union Aviation Safety Agency (EASA) and the US Federal Aviation Authority (FAA), such radiation-triggered computer errors could, in the worst-case scenario, lead to an "uncommanded" change in altitude so severe that it might exceed "the aircraft's structural capability". They stated that urgent updates to the on-board computers were required in dozens of variants of Airbus A320, A319 and A321 aircraft before they would be allowed to carry passengers.

All those planes required software updates and, in some 900 cases, new computer hardware, to better protect them against the threat of space radiation wreaking havoc with their electronics.

What Airbus says occurred on that JetBlue flight from Cancun to New Jersey was a phenomenon called a single-event upset, or bit flip. As the BBC has previously reported, these computer errors occur when high-speed subatomic particles from outer space, such as protons, smash into atoms in our planet's atmosphere. This can cause a cascade of particles to rain down through our atmosphere, like throwing marbles across a table. In rare cases, those fast-moving neutrons can strike computer electronics and disrupt tiny bits of data stored in the computer's memory, switching that bit – often represented as a 0 or 1 – from one state to another.

"That can cause your electronics to behave in ways you weren't expecting," says Matthew Owens, professor of space physics at the University of Reading in the UK. Satellites are particularly affected by this phenomenon, he says. "For space hardware we see this quite frequently."

This is because the neutron flux – a measure of neutron........

© BBC