Airbus has requested immediate modifications to thousands of aircraft after discovering that intense radiation from the sun could corrupt data crucial to flight controls.
About 6,000 planes are thought to be affected, about half the European aerospace giant's global fleet, but it is understood most will be able to undergo a simple software update.
The issue affects the A320 - its best selling aircraft - but also models from the same design fleet, including the A318, A319 and the A321.
Airbus said the problem was discovered following a recent "incident" in the US involving an A320 family aircraft and apologised for disruption to passengers.
The incident, which happened on 30 October, involved a JetBlue Airways A320 making an emergency landing in Florida, after a sudden drop in altitude. At least 15 people were reported to have been injured.
