While sections of European airspace are gradually opening some crucial core zones, particularly lower airspace over the UK and France, remain closed as a precaution against volcanic ash.
Eurocontrol's Central Flow Management Unit shows lower airspace in parts of Germany and Scandinavia are shut while other western European airspace sectors, notably in Belgium, Switzerland, are operating at 50% capacity at lower altitudes.
Airspace in a number of central and southern European states, including Austria, Bulgaria, Croatia, Romania, the Czech Republic, Serbia, Slovenia and Spain, has been declared open.
London's flight information region remains 'zero rated' below flight level 200 - meaning that the UK's capital airports will stay closed. Scottish airspace is open, however, and overflights in other parts of the UK are being permitted.
"Current forecasts indicate that the situation is changing through the day and diversion airfields may be a significant distance from the original destination," states a Eurocontrol update on the UK airspace situation.