Extreme space weather could expose airline passengers to high radiation levels and cause significant flight disruption, according to a new study by the University of Surrey.
The research, carried out by the Surrey Space Centre (SSC), found that this radiation could also affect onboard systems and flight crews.
Radiation levels can surge considerably at typical flight altitudes of between eight and 14 kilometres, the study found, while also triggering faults in aircraft electronics that could raise flight safety risks.
The study was published in the Journal of Space Weather and Space Climate.
Increasing frequency of high radiation events
Although the atmosphere shields against some radiation, passengers are still considerably more exposed to it on flights than at ground level. This exposure worsens during solar storms or events such as solar flares.
Solar storm events have surged in recent years, causing a corresponding spike in radiation.
In November 2025, a massive solar storm caused radiation to briefly jump to almost 10 times normal high-altitude flight conditions, according to calculations by the SSC.
Aircraft systems are also becoming increasingly vulnerable to these events, as high-energy particles from space can interfere with onboard electronics.
These interactions cause Single Event Upsets (SEUs), minor errors that can accumulate and eventually affect critical systems.
Last year, Airbus temporarily grounded 6,000 of its A320 planes after a vulnerability caused by intense solar radiation was found in a flight control computer.
The issue was discovered after a JetBlue flight from Cancún to Newark was forced to make an emergency landing in Florida in October 2025.
Beyond radiation exposure, such disruptions can also cause widespread operational challenges by increasing pilot workloads — in extreme scenarios, SEUs can surge from a few per hour to thousands.
The most severe risks are on polar flights such as London Heathrow to Vancouver International, where the effects can be felt much further south during severe geomagnetic storms, including over the UK.
“The recent Airbus A320 grounding linked to cosmic radiation shows that space weather is not a theoretical risk, it is already affecting aviation. As aircraft systems become more advanced and increasingly reliant on electronics, understanding and preparing for these events will be critical to maintaining flight safety,” said Dr Fan Lei, senior research fellow at the Surrey Space Centre and lead author of the study.
Crucial gap in current aviation safety
The study points to a critical gap in current aviation safety frameworks. Most frameworks today focus mainly on routine radiation exposure and do not adequately account for extreme space weather events.
Better integration of space weather data into flight planning, along with clearer guidance, is essential to keep air travel as safe and reliable as possible.
“At the moment, there is no consistent way for the aviation sector to assess and respond to extreme space weather risks. We’ve introduced a clearer, aviation-specific radiation scale to help support more informed decision-making in aviation, helping operators act quickly to protect passengers, crew and critical onboard systems,” said Professor Keith Ryden, leader of the Space Environment and Protection research team at the Surrey Space Centre and co-author of the study.
The scale is expected to provide clearer thresholds for when action such as increased monitoring, grounding flights or rerouting should be taken during particularly severe or disruptive space weather events.
“An atmospheric radiation scale has been needed for a long time, as current alerts based on low-energy proton events give at least 10 false alerts for every true alert,” said Professor Clive Dyer, visiting professor at the Surrey Space Centre and co-author of the study.
“The new scale is based on high-energy proton measurements in space and ground-level neutron monitors, as installed at Surrey, Lerwick and Camborne, and scales human dose and avionics upset rates from the study on the February 1956 event. In combination with our radiation modelling (MAIRE) and monitors (SAIRA) on aircraft, this should provide the basis for a proportionate response,” Dyer said.