Thousands of Airbus planes have been grounded after it was discovered that intense solar radiation could interfere with onboard flight control computers, leading to delays around the world. Around 6,000 A320 planes are thought to be affected, half the European firm's global fleet, but it is understood most will be able to fly again after undergoing a quick software update. The UK's aviation regulator said there would be 'some disruption and cancellations to flights,' though the impact at airports appears to be limited.

Airbus said it discovered the issue after an investigation into an incident in which a plane flying between the US and Mexico suddenly lost altitude in October. The JetBlue Airways flight made an emergency landing in Florida after at least 15 people were injured.

As well as the A320, the company's best-selling aircraft, the vulnerability also impacts the A318, A319 and the A321 models. It is understood that on around 5,100 Airbus planes, the issue can be addressed using a relatively simple software update which would typically take about three hours. However, the remaining 900 aircraft, which are older versions, will need to have onboard computers physically replaced, and will not be allowed to carry passengers again until the job has been completed. The length of time that takes will depend on the availability of replacement computers.

Airbus has acknowledged this will lead to 'operational disruption to passengers and customers' and has apologized. Aviation analyst Sally Gethin told BBC News the situation is 'very much out of the ordinary,' saying the disruption to passengers will depend on the 'different approaches' airlines take to upgrade their software.

In the UK, disruption at airports has been limited so far. London's Gatwick Airport reported 'some disruption,' while Heathrow has not experienced any cancellations. Manchester Airport said it did not anticipate significant problems. The extent of disruption varies between airlines: British Airways is understood not to be heavily impacted, while Wizz Air and Air India indicated that they were already undertaking updates.

Publicly available data suggested Air France was impacted more than any other airline, with 50 of its flights to and from its Paris hub canceled for Saturday morning. Easyjet stated it expects some disruption but reported starting and completing software updates on many aircraft, planning to return to full service.

In the US, the software issue emerged over the Thanksgiving holiday, one of the busiest travel periods of the year. American Airlines indicated that 340 of its planes were affected and expects some operational delays, but added that most updates would likely be completed soon. Delta Airlines believes the impact on its operations will be minimal. Meanwhile, in Australia, budget airline Jetstar canceled 90 flights as they confirmed around a third of their fleet was impacted.

The problem identified with A320 aircrafts relates to software that calculates a plane's elevation. Airbus found that at high altitudes, its data could be corrupted by intense radiation released from the sun. The European Union Aviation Safety Agency has issued an emergency directive for planes to be addressed before carrying passengers again.